It’s that time of year again when cold air from the mid-latitudes surges into the tropics. The effect in Africa is a strong east to northeast wind from the Chad basin to Mauritania and northern Gabon called the Harmattan.
Harmattan winds blow west to southwestward from the Sahara, with enough strength to carry desert sand and dust to the Atlantic Ocean. This occurs during the boreal winter as deep-layer troughs move across southern Europe and the Mediterranean, penetrating the Sahara. The preceding cold front often loses its identity over the desert due to intense surface heating and mixing. However, the warmed polar air continues moving southward into the Gulf of Guinea.
Harmattan winds become amplified as strong high pressure builds behind these troughs. If the high reaches the southern Sahara, Harmattan winds are likely to extend to the Atlantic coast. Saharan dust carried by the Harmattan reduces visibility to 2-4nm, covering areas offshore in a cloudy haze, and in severe cases reduce visibility to a few meters. These conditions often last for days and become paralyzing when visibility approaches zero, halting flights, increasing risk of flu and asthma, and delaying the wet season for farmers.
To improve planning during the Harmattan season, our meteorologists incorporate advanced, high-resolution dust data, specialized satellite imagery, and upstream surface observations to provide warning days in advance of potentially harmful events.
An abnormally strong low pressure system impacted the Mid-Atlantic States over the weekend. During the time of year when attention usually turns to the tropics, a winter-like Nor’easter lashed areas from D.C. to Atlantic City. The storm was spawned by a broad deep-layer trough diving into the northeastern United States from Ontario. An extended area of surface low pressure formed on Friday morning. This low stretched from Boston southwestward through West Virginia before becoming organized over Virginia during the afternoon hours. Above average sea-surface temperatures allowed ample moisture to push across the Delmarva Peninsula toward the nation’s capital. Widespread heavy rain showers developed Friday afternoon and evening, and flash flood warnings were issued from D.C. to Baltimore. Before the storm wound down on Saturday, over four inches of rain had fallen across Maryland’s most populous city, with areas to the east seeing almost six inches of rainfall.
Conditions were no better offshore, where Gale Warnings were issued from Morehead City, North Carolina to Cape Cod, Massachusetts. As the system was developing, model guidance indicated the potential for wind gusts near 70mph offshore, which is near hurricane force. Fortunately, these extreme winds did not materialize, but widespread sustained winds in excess of 35mph were noted from the Chesapeake Bay northeastward toward Rhode Island. This allowed seas to become quite rough, with significant heights pushing 12 feet just off the coast of Delaware Saturday evening.
The unseasonable strong storm finally subsided on Sunday while quickly moving east of the region. Although not tropical in nature, this weekend’s system was a reminder that the East Coast is entering the time of year where weather becomes the forefront of the mind, and this could be even more the case this August, as it looks to be particularly active in the tropics. Stay tuned!
The West Pacific Ocean became quite active last weekend, with four concurrent storms. This tropical activity was triggered by an active Madden-Julian Oscillation (MJO) phase coupled with the seasonal positioning of the monsoon trough. There have been seven named storms since July 1, the most recent being Typhoon Nesat.
Earlier this month, Tropical Storm Nanmadol formed northeast of the Philippines and within 48 hours made landfall along the west coast of the Japanese island of Kyushu. Wilkens Weather meteorologists closely monitored this storm for customers operating in the East China Sea and commenced storm advisories 42 hours in advance of the Joint Typhoon Warning Center (JTWC).
Marine Meteorologist Bryce Link explained his decision to initiate advisories at 09UTC on June 30th, “Deep thunderstorms were centered around a developing surface low and the system was in a fantastic environment”. Bryce pulled the trigger on this storm when operational models such as the GFS and ECMWF generally showed no signs of tropical development. ECMWF ensembles showed a stronger signal for tropical development, but the operational signaled nothing at the time the first WWT advisory was issued.
Sea surface temperatures (SSTs) have been on the rise since Nanmadol tracked across the East China Sea in early July. Early in the month SSTs were in the mid-80s across a small portion of the East China Sea, where Nanmadol tracked, and generally anywhere south and east of Taiwan. The graphic above (from July 24th) shows that SSTs are now in the upper 80s to 90°F (31-32°C) across much of the same region. These above average SSTs and favorable ocean heat content have created a conducive environment for tropical development. In fact, the last two tropical cyclones to form, Roke and Nesat, developed in this very warm area near the Philippines.
Currently, Typhoon Nesat is flaring convection northeast of Luzon. Further intensification is expected prior to landfall over Central Taiwan. Nesat formed along the monsoon trough, which is active from the Gulf of Thailand through the central Philippines as depicted in the 850mb wind graphic below. Tropical cyclones will not form in the area of enhanced westerly flow due to the presence of moderate to high vertical wind shear. Nesat was the second typhoon to develop in 2017.
Despite convective and tropical cyclone activity in this region, the first typhoon of 2017 (Noru) developed at a higher latitude (near 28°N). Noru became a tropical depression over 1,000nm east-southeast of Yokosuka, Japan on July 20th. Early on, Noru tracked westward in response to two competing ridges to the south and northeast. Then, the cyclone’s movement slowed and the steering flow pulled Tropical Storm Noru and Tropical Storm Kulap around a central point. Noru became a typhoon on July 24th and the two cyclones “danced” cyclonically around each other the following day, a phenomenon known as the Fujiwhara Effect. The end result was Tropical Storm Kulap tracking across cooler waters and dissipating within 24 hours and Noru maintaining typhoon strength southeast of Japan. Wilkens Weather meteorologists forecast Typhoon Noru to persist over the Northwest Pacific Ocean into early August.
Author’s note: This blog was updated July 28th to reflect the latest tropical information.
Meteorologists worldwide are watching two cyclones in the Northwest Pacific begin their “dance” around each other. Tropical storm Kulap and typhoon Noru are beginning to endure a weather phenomena known as the Fujiwhara Effect.
The Fujiwhara Effect occurs when two cyclones rotate or “dance” around each other in a counter-clockwise direction (for the Northern Hemisphere). The two cyclones are actually rotating around a single point, or center, on an axis that connects the cyclone centers. Binary interaction of the cyclones can occur only if the cyclone centers are separated by a distance of roughly 1400km, or nearly 870 miles. The National Weather Service defines Fujiwhara Effect as the tendency of two nearby tropical cyclones to rotate cyclonically about each other.
The Fujiwhara effect is named after Dr. Sakhuhei Fujiwhara, who was the Chief of the Central Meteorological Bureau in Tokyo, Japan after the First World War. In 1921, he performed and studied the interaction and movements of water vortices. Dr. Fujiwhara concluded that if two water vortices spinning counter-clockwise came close enough to each other, each vortex would rotate around the other. In the atmosphere, if one vortex (tropical cyclone) is stronger than the other, eventually the smaller vortex (tropical cyclone) could get caught in the circulation of the larger one.
When the Fujiwhara Effect occurs, the intensity and track of a tropical cyclone can be greatly altered, creating a complicated and difficult forecast. In the Northwest Pacific, tropical storm Kulap will weaken and dissipate as it is engulfed by typhoon Noru over the next 24 hours.
According to Dong (1983), archived data from the National Hurricane Center portrayed the western Pacific Ocean to have a higher frequency of binary interaction than the Atlantic Ocean. During a 36 year period, 1946-1981, two spatially proximate storms averaged 1.5 annually over the western Pacific compared to .33 annually over the Atlantic. This is likely due to the Pacific having an overall higher tropical cyclone frequency compared to the Atlantic Ocean. Furthermore, Dong studied the Intertropical Convergence Zone (ITCZ) over the Pacific Ocean versus the Atlantic Ocean. He concluded the ITCZ is better defined in the Pacific basin, leading to higher tropical cyclone activity, compared to the Atlantic basin. A good majority of tropical cyclones in the Atlantic spawn from tropical waves that emerge off the West African coast.
Another example of a classic Fujiwhara Effect occured during the last week of September 1994 with tropical cyclone Pat and tropical storm Ruth.
One of the most anticipated seasonal weather changes during the northern hemisphere summer is the North American Monsoon. This monsoonal circulation produces significant rainfall over western Mexico and the Southwestern United States in response to summer heating over the higher terrain. While the monsoon brings beneficial rain, it can produce hazardous conditions over the desert. Monsoon thunderstorms may produce frequent lightning, hail, powerful flash floods, and blowing dust.
The onset of the monsoon is strongly influenced by the positioning of a 500mb area of high pressure. When this high is positioned over the Four Corners region, winds at this level turn more easterly over Arizona. Easterly flow allows inverted troughs to move west across the area, providing greater instability for thunderstorm development. Of greater significance is the resulting deep moisture advection from the Gulf of California. In July, mid-level winds over the Gulf of California are south to southeasterly, rounding seasonal high pressure that extends westward across the Gulf of Mexico during summer. Surface winds over the same region are southerly, transporting significant low-level moisture from both the eastern Pacific and Gulf of California. Lower wind speeds and weaker high and low pressure circulations are expected during summer as a result of less temperature variations. This often creates slow-moving monsoon thunderstorms, bringing an elevated risk of flash flooding.
Sunday, July 16th was the first very active day of the 2017 American monsoon season with nearly ideal conditions for hazardous weather over Arizona. With monsoon moisture on the rise, a Flash Flood Watch was issued for south central Arizona, including Phoenix. The forecast called for numerous thunderstorms over the higher terrain, propagating west to southwest across the lower elevations through the evening hours. NWS Storm Prediction Center issued a mesoscale discussion that afternoon detailing the threat of severe winds. Prime ingredients downstream included 20-25 knot easterly mid-level flow and sufficient instability as most unstable CAPE approached 2000 J/kg. Several severe thunderstorm warnings were issued by the National Weather Service forecast office in Phoenix that evening. At 6:16pm, a blowing dust advisory was issued for Northwestern Pinal County into southern Maricopa County until 8pm.
Severe thunderstorm warnings continued through the evening and early overnight hours. Flash Flood Warnings were issued for 30 minute rainfall totals exceeding 0.5 inch north and west of Scottsdale, according to the Flood Control District of Maricopa County (FCDMC). It is common for lower elevation areas and valleys to experience their heaviest rains at night.
According to NWS Phoenix, this activity brought temperatures down to 74°F, which was the first time the area had experienced 70° temperatures in nearly 30 days. It is typical of the monsoon to onset quickly, causing an abrupt change in weather conditions. Earlier this month, the Phoenix area was setting record high temperatures of 118-119°F.
Here are some strong wind reports from the storms this day:
Wilkens Weather’s annual spring outlook includes a forecast for the upcoming Atlantic hurricane season. This spring, our meteorologists predicted a near normal 2017 Atlantic hurricane season with 12 named storms, including five hurricanes.
One of the key parameters factored into each year’s tropical outlook is the long-range forecast of the El Niño – Southern Oscillation (ENSO). When our 2017 tropical outlook was initially released, long-range forecast models indicated a higher likelihood that an El Niño would develop than is currently being seen in recent climate models.
In late April, there was about a 50% likelihood that El Niño would develop over the tropical Pacific in the late summer months, extending into September. However, the most recent climate model issued by the International Research Institute for Climate and Society at Columbia University now projects a 35-45% likelihood of an El Niño phase developing over the next several months. With consideration to the updated ENSO forecast, Wilkens Weather has increased their 2017 Atlantic tropical outlook from 12 to 14 named storms, and 3 major hurricanes.
Since an El Niño phase in the central Pacific Ocean can produce a harsh environment for tropical development in the Atlantic basin, a reduced probability yields an increased chance of hurricanes in the North Atlantic. There is also consideration that the time frame for El Nino developing was before the peak of Atlantic hurricane season. Therefore, a lesser chance of El Nino would give a greater chance to more favorable atmospheric conditions for hurricanes during the peak season.
(Author’s Note: this forecast does not include Tropical Storm Arlene, which formed during the month of April before the official start of hurricane season. TS Arlene was only the second tropical storm on record during the satellite era to form during April in the Atlantic basin.)
The Madden Julian Oscillation (MJO) is an intraseasonal fluctuation that primarily initiates over the warm waters of the Indian Ocean and western Pacific. The MJO is comprised of regions with various atmospheric features such as deep convection and atmospheric wind anomalies that propagate eastward along the ITCZ. During a convective phase of the MJO, there is an enhanced region of tropical convection and moisture resulting in above-average rainfall. The opposite is true for a suppressed convective phase. As the MJO continues propagating eastward, the monsoon trough weakens and may shift southward. East of the MJO the easterlies are strengthened, and to the west, the easterlies are weakened. Therefore the passing of positive phase MJO can affect atmospheric wind shear, which could in turn affect tropical cyclone activity.
Phillip Klotzbach studied the relationship between the MJO and the development of tropical systems in the Atlantic Basin. In his 2010 study, Klotzbach found a direct relationship between the increase in vertical wind shear and relative humidity, and enhanced tropical cyclone activity and intensification. In the convectively enhanced phase of the MJO, upper-level easterly and low-level westerly wind anomalies act together to reduce vertical wind shear. One primary ingredient for tropical cyclone development is reduced vertical wind shear. Relative humidity throughout the atmosphere is also needed for tropical development. In Camargo’s study (2009), he found that mid-level relative humidity played the most important role, compared to low-level absolute vorticity, vertical wind shear, and potential intensity in tropical cyclogenesis by the MJO. Therefore, when an eastward moving MJO and a tropical wave meet, it is possible for the tropical wave to develop into a tropical cyclone due to the enhanced atmospheric moisture and reduced vertical wind shear created by the MJO. If a tropical cyclone already exists, its interaction with a MJO may cause the cyclone to intensify. Kingtse C. Mo discusses an increase in tropical cyclone activity over the Atlantic Basin when the convective phase of the MJO is located the Indian Ocean rather than the Pacific Ocean.
The image above represents a forecast for Outgoing Longwave Radiation (OLR) anomalies, a key detector for active MJO regions, issued by NOAA’s Climate Prediction Center (CPC). The CPC monitors and predicts climate variability and teleconnections for government, public, and private meteorological industries. Negative OLR values indicate enhanced convection or an active MJO phase (more cloud cover indicating more convective activity). Positive OLR values represent suppressed convection (less cloud cover).
The latest forecast from the ensemble mean GFS predicts an increase in OLR, possible MJO wave, across the Indian Ocean for the next two weeks. As Kingste C. Mo found in his study, there is likely an increase in tropical activity over the Atlantic Ocean when an MJO is present over the Indian Ocean.
Although Wilkens Weather is forecasting a very low chance for tropical development in the next five days, this will be a parameter worth watching this tropical season.
The second tropical storm of the 2017 Atlantic hurricane season, Bret, tracked unusually far south impacting the island of Trinidad. Bret is only the 6th tropical system to have tracked across Trinidad in the past 100 years. Coincidentally, the last tropical storm to make landfall over Trinidad in 1993 was named Bret.
Since 1856, 43 storms have passed within 100nm of the island, but only two of these storms were major hurricanes. Typically, Trinidad is too close to the equator to experience strong tropical systems. According to WWT Meteorological Specialist, Marshall Wickman, “most systems at that latitude don’t get the Coriolis force needed for significant intensification”. Therefore, the bulk of the stronger storms and hurricanes tend to track to the north of Trinidad and Tobago.
Major Hurricane Ivan in 2004 and Flora in 1963 tracked too close for comfort. Both storms packed winds of 105 knots when within 60nm of the northern coast of the island.
For an area surrounded by water and unaccustomed to experiencing these storms, even a weak tropical storm can be frightening.
“Trinidad experienced torrential rainfall and heavy winds for approximately three hours, especially in southern Trinidad. It was very scary and as I looked through the windows at my home, I prayed all through this period asking for protection”.
When we checked-in with our Trinidad customers after Bret, it was heartwarming to hear that essential staff working on offshore and onshore facilities were safe. The main threats with this storm were heavy rainfall and flash flooding.
Flooding is major threat during any tropical cyclone and is not directly related to storm intensity. To learn how to stay safe during flood events, visit the National Weather Service’s flood resource page.
Since the official start of the Atlantic hurricane season, June 1, two tropical storms have formed and impacted land areas. In June, the area with the greatest risk of tropical development is the Gulf of Mexico, Bay of Campeche and western Caribbean.
Contradicting climatology, Tropical Storm Bret formed 108nm East of Trinidad on June 19th. This area is typically unfavorable in June due to the amount of dry air and wind shear in the region. Bret was the earliest storm to form this far south in the Atlantic since official records began in 1851.
Bret originated as a rather unimpressive African wave, which progressed westward across the Atlantic in a marginally favorable tropical environment. A weak tropical wave to its west moistened the atmosphere over the eastern Caribbean, assisting in making conditions more favorable for Bret to develop. Here is a look at the moisture content over the tropical Atlantic in the days leading up to Bret’s formation:
While Bret was causing alarm in Trinidad in northern South America, Tropical Storm Cindy began to develop over the northern Gulf of Mexico. Cindy originated as an area of disturbed weather over the western Caribbean and Central America, and became Invest 93L East of the Yucatan Peninsula on June 17th.
This broad, disorganized low became difficult to track over the next five days. The ECMWF model maintained a forecast for landfall over Mexico or southern Texas. On the other hand, the GFS model favored a landfall near the Florida Panhandle. The discrepancy between the global model tracks continued through landfall on June 22. Higher resolution, regional forecast models eventually offered a more accurate middle-ground solution near the upper-Texas coast.
Weak steering flow in the region contributed to the poor model performances. Another complexity was the close proximity to an upper level low over the northwest Gulf of Mexico. This feature provided high wind shear, resulting in a disorganized and asymmetrical storm. As a result, Cindy appeared to be subtropical rather than purely tropical through its duration. Southwesterly upper level winds from the trough pulled dry air into Cindy, restricting deep convection to the East side of the storm. Cindy’s battle with dry air on June 20th is seen in the brown coloring in the NOAA water vapor animation below.
High pressure from the western U.S. eventually built eastward over Texas, forcing Cindy to move northward. Air Force Reserve reconnaissance aircraft and a nearby ship confirmed a maximum intensity of 50kts the evening of June 20. Despite being a weak tropical storm, Cindy produced a large area of gale force winds and storm force gusts across the northern Gulf of Mexico. Cindy weakened to 40kts before making landfall near Sabine Pass, Texas on June 22nd.
Both storms were short-lived with the primary threats of heavy rainfall and flash flooding. The Trinidad & Tobago Meteorological Service forecast 2-6 inches of rain for Trinidad and Tobago, Grenada and its Dependencies during the passage of Bret. NASA’s Integrated Multi-satelliE Retrievals for GPM (IMERG) data estimated rainfall totals over the eastern Gulf of Mexico and southeastern U.S. for the duration of Cindy. Notably, rainfall in excess of 10 inches occurred well east of Cindy’s center over the northeastern Gulf of Mexico and along the Gulf coast from southeastern Louisiana to the western Florida Panhandle.
The peak of the Atlantic hurricane season is still to come, so it’s important to remain vigilant for any approaching tropical storm. Whether you are concerned with a tropical storm tracking toward the eastern Caribbean, or a major hurricane developing in the Gulf of Mexico, our meteorologists are available 24/7 to keep you ahead of the storm.
Contact us to learn more about our online and mobile interactive tracking tools.
While the majority of our weather reports are produced at WWT Headquarters in Houston, TX, we also have meteorologists based in the UK. We understand the importance of having local representatives in your region for maintaining client relationships as well as providing direct client consultation. WWT Sales Manager, Steve Krcek, enjoys traveling around the world to meet with new and existing clients:
“Every customer has a different expectation and requirement. The same can be said for the region.”
Weather across the pond was active this week, with rounds of heavy precipitation and strong thunderstorms as a vigorous upper level low parked over western Europe. Fortunately, Dan and Steve dodged the heavy rain traveling from Rotterdam to Aberdeen to Paris. Despite overcast skies and some soggy afternoons, client visits remained optimistic while discussing market trends, upcoming projects and our latest products and services.
Krcek highlights the conversations on the trip, specifically detailing the difference between model-driven and meteorologist-produced forecasts: “It was interesting to explain our forecast methodology clearly to the end users. A large majority of the people we spoke with understand weather forecasting as a model output, not a science that uses models as a guidance tool. So, discussing the science behind the models was quite interesting and engaging for most.”
For more information about our forecast products and services or to schedule a meeting with our meteorologists, send us your information below.
Summer is officially underway in the northern hemisphere beginning today, June 20th. Quite the range of weather conditions are forecast across the United States today. In the East, a cold front moves offshore New England and stalls across the Carolinas. Showers and storms remain a threat near the stalled boundary from the Carolinas to the Gulf coast, while comfortable 50 degree dewpoints filter in behind the front in the Northeast. Cloudiness and rain chances will keep high temperatures near to below average across this region for the start of summer.
Residents along the Gulf Coast are watching a tropical storm brewing over the north central Gulf of Mexico. Louisiana residents are beginning to feel the effects from the outer rainbands of the storm. Flash Flood Watches are in effect from Southeast Louisiana to the eastern Florida Panhandle. Tropical Storm Warnings are in effect for portions of the Louisiana and Texas coastlines.
Across the Great Plains, temperatures are near average with mostly sunny skies to start the season. While this afternoon will be warm, in the upper 80s to low 90s, outdoor temperatures will feel more comfortable than they did over Father’s Day weekend. If you live in Central Oklahoma, like me, you may recall dewpoint temperatures climbing to 75 degrees Saturday morning, and persisting near 73 degrees through mid-afternoon. Dewpoint temperatures are a measure of moisture in the atmosphere, so higher dewpoints correlate to higher moisture content and humidity. Although the actual high temperature was only 92 degrees, when you factor in the moisture and humidity, the maximum heat index was 104 degrees.
What does this mean? Heat Index calculations use air temperature and dew point temperature to determine an “apparent” temperature, which is how your body feels when you are experiencing summer heat. The National Weather Service (NWS) Heat Index calculations are for shady areas, so it’s important to know that direct exposure to sunlight can increase the “apparent temperatures” by 10 to 15 degrees. High heat index values, generally over 100 degrees, are given an heightened awareness of hazardous outdoor conditions. Local NWS offices issue special heat advisories and excessive heat warnings for moderate to extreme heat indexes, when the risk of heat-related illnesses is highest. A day with a high heat index feels uncomfortable and sometimes oppressive. Sweat is slow to evaporate and the body struggles to cool down. Direct exposure to the sun only exaggerates this.
But, it’s not just the feel-like temperatures that are uncomfortable and dangerous. In the desert southwest, temperatures are normally in the 100s in June with very low dewpoints. The start of the 2017 summer will be no different with above average, and potentially record-breaking heat, forecast across much of the Southwest.
Heat advisories and excessive heat warnings are in effect for Arizona and portions of California and Nevada through Friday. Hot summer days in the desert can feel like you are walking into an oven! Outdoor structures, such as playgrounds, are often unusable. A recent test in Tuscon, Arizona found that a children’s slide in the sun can reach 150 degrees, which is more than hot enough to cause a second-degree burn.
Take precautions and stay safe during the 2017 summer season!
Chances continue to increase for a tropical low to develop in the Caribbean for Father’s Day weekend. The time-frame for any tropical formation is Sunday-Tuesday.
So the big question on everyone’s minds, will we have a tropical storm in the Gulf of Mexico?
The answer is much more complicated than a simple “yes” or “no”. Storminess is beginning to increase across the northwestern Caribbean, however a disturbance has not been detected yet and Wilkens Weather is not expecting tropical development over the next 24 hours. Several factors are analyzed when forecasting tropical weather including sea surface temperatures (SST), vertical wind shear, and tropical atmospheric moisture. The sea surface temperatures in the southern Gulf are around 28°C, indicating favorable conditions for development. Atmospheric moisture, explained in a previous blog here, surges into the southern Gulf this weekend providing ideal conditions for tropical development. The third and final key ingredient meteorologists are monitoring is vertical wind shear. Light winds are vital to sustain and strengthen the structure of tropical systems.Read More »
It’s critical that offshore operators are aware of tropical hazards well in advance of tropical storm development.
Two years ago we were monitoring an area of disturbed weather near the Yucatan Peninsula. At the time, forecast models indicated that a trough of low pressure would move offshore the Yucatan within the next 24 hours and form a closed circulation as it tracked northwest toward the Texas coastal bend. Hurricane Carlos, off the southern coast of Mexico, was feeding in abundant tropical moisture from the Pacific, aiding thunderstorm development. Over the next few days, upper-level winds over the Gulf weakened, enhancing convection and improving the low-level circulation. Within 36 hours a tropical storm was designated over the northern Gulf of Mexico. About 15 hours later, Tropical StormBill made landfall over Matagorda Island, Texas with maximum sustained winds near 60 mph.Read More »
With hurricane season officially underway today in the Atlantic basin, all eyes are on thunderstorms streaming northward across the Gulf of Mexico. This convection is associated with Tropical Storm Beatriz off the coast of Mexico in the East Pacific. Although Beatriz is not a direct threat to the Gulf, tropical moisture from this storm will continue to provide deep convection across the southern Gulf. This moisture will interact with an existing surface trough over the Bay of Campeche providing the potential for low pressure to develop over the weekend, but there are limiting factors for tropical development.
Regardless of tropical development, one key tropical ingredient is present: atmospheric moisture. The higher the moisture content in the atmosphere, the greater chance for deep, persistent convection which furthermore enhances development within tropical systems. Meteorologists analyze a parameter known as PWAT, Precipitable Water, to gauge atmospheric moisture content. NOAA defines PWAT as the “measure of the depth of liquid water at the surface that would result after precipitating all of the water vapor in a vertical column over a given location”. Imagine having a column of water vapor, from Earth’s surface to the top of the atmosphere, and squeezing that column of air until all the water fell out (very similar to wringing out a sponge). The resulting measure of water, calculated in inches, is a good indicator of how much rainfall a region could see.
As we transition to summer, our meteorologists prepare to forecast longer duration Shamal events. Shamal winds are strong winds that blow from the north to northwest over the arid Middle East. In winter, Shamals are associated with the passage of cold fronts. Cold fronts still influence the region’s weather through May, but by summer the region warms significantly and fronts become less frequent. Shamals from fall through spring are typically short-lived, lasting one to two days. By June, nearly stationary thermal lows along the monsoon trough over Northwest India, Pakistan and Southeast Iran interact with high pressure over the eastern Mediterranean and Saudi Arabia to produce more persistent northwesterly winds over the Arabian/Persian Gulf. Winds strengthen between these seasonal highs and lows as the low pressure areas intensify during summer months. Rao et al. (2003) found that gale force winds and rough seas offshore Qatar are more common in June than May and July.
Shamal winds are strongest during the afternoon when hot surface air rises, creating turbulent eddies that mix winds higher in the atmosphere to the surface. High temperatures, strong winds and the seasonal lack of precipitation all contribute to the formation of blowing dust during these events. Sand and dust may be carried hundreds of kilometers across the Gulf states in dust storms, producing areas of near zero visibility. Read More »
As we head into the Northern Hemisphere summer, the Southwest Monsoon is making its return to the North Indian Ocean. Once the southwesterly winds become persistent and strong, this will signal the end of the spring transition period, and the region will be entirely influenced by the Southwest Monsoon. On average, the Southwest Monsoon spans from June through September. The monsoon flow creates a convergence of moisture, promoting cloud growth and convection across the region. According to NOAA’s Climate Prediction Center, western and central India receive more than 90% of their total annual precipitation during these months.
Low pressure systems that track across the northern Bay of Bengal, Arabian Sea, and the mainland produce the majority of India’s rainfall, which is the driving force of the Indian economy. Farmers count on monsoonal rains to fill aquifers, lakes, and surrounding rivers for efficient crop growth and production. In years with insufficient rain, the nation is forced to depend on imports from other countries, creating a loss for domestic producers. Conversely, years with above-average rainfall can destroy crops and cause a poor harvest.Read More »
What an appropriate week to discuss weather forecasting with the people who rely on it the most. Heavy rain, strong winds and flash flooding with the cold front that moved through southwestern Louisiana on Monday, caused me to postpone one meeting with a client near the Gulf coast. “Your weather report says we are expecting up to four inches of rain today,” David said to me on the phone. “If we get that much, you’ll be stuck in town for a day or two; we better reschedule.”Read More »
The first post in this series detailed an exhilarating and dangerous chase under cover of night in northwestern Iowa. As a storm chaser, the drawback to a night chase is the near impossibility of acquiring photos and videos of the storms. On the afternoon of May 18th, 2013, darkness was not an issue as a violent tornado tracked across the open country of southwestern Kansas.
I had just graduated from Iowa State University the week before. My thoughts at the time were not on severe weather, but that would quickly change as long range forecast models indicated a multiple day severe weather threat across the Southern Plains. Recent grads and I made the decision to embark on one last chase in Oklahoma and Kansas before moving into the “real world.”
We are thrilled to announce two meteorologists have recently joined our forecast team! With severe weather season in full swing in the northern hemisphere and the Atlantic tropical season just around the corner, it is critical that we have additional eyes on customer sites around the globe. Alec and Samantha are well-rounded meteorologists with zest for dynamic weather. Here’s more about them:Read More »
Tropical cyclones have significant impacts on marine operations worldwide. Prior to experiencing tropical cyclone threats, offshore facilities must secure equipment, shut-in wells, and evacuate personnel. Operations can remain shut down for extended periods in the event that an offshore platform or rig is damaged or destroyed. Damaged pipelines along the seafloor are a common cause of interruptions to oil and gas supply.
To prevent structural damage and spills, control costs, and ensure the safety of personnel, accurate weather forecasts and advanced notification of tropical hazards are paramount. Even a weak tropical cyclone can produce hazardous weather conditions and put coastal and offshore operators at risk. Be sure to determine your exposure to the risks associated with tropical cyclones before the start of this Atlantic hurricane season.
Wilkens Weather provides a suite of online and mobile tracking tools to warn our customers of these risks. To be confident that you’re prepared this hurricane season, trust in the tropical expertise and tools provided by WWT: Read More »
In 1977, WWT began with a few meteorologists striving to provide offshore forecasts for the oil and gas industry. Within 40 years, WWT has grown from what once was a four-man team, to a trusted global metocean business providing forecasts and hindcasts for every major oil basin.
In addition to our daily operations, WWT has supported unique forecasts for:
The U.S.’s first offshore wind farm near Rhode Island
Tall ship races throughout several regions of Europe
Weather analysis for the area where the Costa Concordia tipped over offshore Italy
Weather analysis for Tycoon, that ran aground near Christmas Island
For 36 years, Wilkens Weather Technologies has exhibited at the annual Offshore Technology Conference (OTC), showcasing its products and services with professionals of the global oil and gas industry. Although oil prices have rallied in recent weeks, the demand for more cost-effective solutions continues. WWT is mindful of the challenges the industry is facing and continues to revamp its marine and tropical forecasting products to stay ahead of client demands.
At this event, WWT meteorologists align with other energy professionals to explore growth opportunities, strengthen partnerships, and foster new business relationships. WWT program manager, Ryan Fulton, shares his insight on this valuable networking experience:Read More »
In the early days of WWT, meteorologists arrived at 4am to work on the morning weather forecast for the Gulf of Mexico. These reports were typed up and printed, so the person on fax duty could send them out one by one. Typically it would take forecasters four hours to complete the regional gulf report forecast and distribution. Other daily tasks included hand-analyzing surface charts and producing temperature, wind, and sea-state forecasts for coastal sites and international marine customers.
Over time, as business grew, so did the demand for immediate, operational weather information. In the early 2000s, WWT introduced customized client web pages, a tool that would provide customers easy access to weather information for their region and site-specific locations worldwide. In the late 2000s, with enhanced forecast models at our fingertips, there became a demand for long-range forecasts and historical analyses.
Our story began in 1977 with Richard Wilkens’ idea to start a weather forecast company to service the oil and natural gas industry. At the time, there was a high concentration of oil companies operating in the Gulf of Mexico. Over the years, petroleum exploration expanded, prompting Wilkens Weather to expand their services globally.
Meteorologist Marshall Wickman recalls one of WWT’s early business transactions, “[Richard] agreed to do one free sample forecast in the Strait of Magellan where data was sparse and told them, if it busts remember how much it cost you. If it is right remember where you got it from.” Apparently they liked what they received as it led to 20 years of continuous forecast service.
When we started, our technology consisted of fax machines that sent 8×11 inch pages at six minutes a page. Most weather reports were a few pages and included a hand-drawn, 3-panel surface map (depicting fronts, precipitation, and high and low pressure areas). Today, we have a wealth of online and mobile interactive tools that can provide quick and easy access to all critical weather information. Read More »
Today, Wilkens Weather Technologies, a subsidiary of Rockwell Collins, celebrates 40 years as a reliable, customer-centric metocean forecast company. April 12, 1977 marks the founding of WWT by Richard Wilkens, whose vision was to tailor weather information to the oil and natural gas industry. For decades, highly-trained meteorologists have provided accurate weather support, allowing our customers to make timely decisions and ensure the safety of their personnel.
During the next few weeks, we will share memories and successes from the last 40 years. We begin with the foundation of WWT – the meteorologists responsible for preparing weather reports and monitoring global assets 24/7.
Here is what you may not know about our team:Read More »
Most meteorologists recall a moment in their childhood that fostered their obsession with weather. My moment was in second grade, when a severe thunderstorm hit my hometown while school was in session. I vividly remember classmates being frightened, while I sat in the school’s basement thinking the situation was pretty sweet, to use with the parlance of a second grader. After that day, I was hooked on severe weather, and although that specific event did not spawn a tornado, I remain fascinated by them to this day.
Many years later while attending Iowa State University in Ames, Iowa, I had opportunities to travel across the Midwest during spring and summer, in search of the elusive and dangerous tornado. There are three specific storm chases I will be detailing this spring, the first of which occurred on April 9th, 2011.Read More »
Thirty five years ago a ruthless nor’easter swept across the Northern Atlantic Ocean catapulting a wave of disastrous events leading to the demise of an “unsinkable” oil rig.
Located nearly 300km off the Newfoundland coast in the Hibernia Oil Field in 1982, the Ocean Ranger was the largest semi-submersible offshore drilling rig in the world at the time. The platform sat atop eight columns fixed upon two pontoons beneath the surface of the water. Stability of the platform, and overall safety of crew and operations, was achieved by the placement of water and fuel in ballast tanks inside the pontoons. According to a NASA Study from the NASA Safety Center, only two men aboard the Ocean Ranger performed the huge task of maintaining the appropriate equilibrium of the platform. The two men operated in the Ballast Control Room, rotating on 12 hour shifts.
Located only 30 feet above the surface, the Ballast Control Room contained an electric control panel embedded with lighted push button switches configuring valves, pumps, and tanks. These valves were used to pump ballast forward, backward, onboard or overboard from the tanks to account for any “list” (tilt) from various cargo loads or changing sea states. As small as a five degree list would hamper drilling production. In order to assess current sea conditions, there were four circular glass portlights (windows) constructed in the control room. These portlights would eventually lead to the disaster of the Ocean Ranger.Read More »
This week, Aaron Studwell, Manager of Weather Operations, is attending the 97th Annual Meeting of the American Meteorological Society (AMS) in Seattle, WA. During the first two days, Studwell, along with Joel Siegel from the ARINC office in Annapolis, MD represented Rockwell Collins at the AMS Career Fair. Over these sessions, Studwell and Siegel met about 125 students, discussed careers in marine and aviation meteorology at Rockwell Collins, what we look for in prospective employees – a passion for weather and forecasting and willingness to learn.
The 2016 West Pacific tropical season was near normal with 24 named storms, according to the Joint Typhoon Warning Center (JTWC). A total of 13 storms reached typhoon status and 6 became super typhoons. This fell short of the annual average of 16.5 storms reaching at least typhoon status.
Typhoon Nepartak became the first named storm of the year on July 3, breaking a 199-day streak of no named storms across the basin.This tied the 1997-1998 interval for the longest number of days to pass without a named storm. Nepartak was classified as a super typhoon on July 6 and maintained one-minute sustained winds of 152kts (175mph) for 18 hours while tracking northwest toward Taiwan.The storm weakened to 130kts (150mph) before making landfall over Taiwan on July 8 (Taiwan local time). Continued weakening occurred as Nepartak tracked across mountainous terrain, and the storm made its final landfall over China on July 9 as a tropical storm.
Other significant storms to impact Taiwan in 2016:
Super Typhoon Meranti made a nearly direct hit to Taiwan on September 14. The extended time over water promoted further intensification and a peak intensity of 165kts (190mph) over the Luzon Strait.
Typhoon Megi intensified over the Philippine Sea and made landfall over northeastern Taiwan on Tuesday, September 27 with maximum sustained winds near 115kts (132mph).
The northern South China Sea was also an active area in 2016. Marine assets offshore Hong Kong took direct hits from two typhoons, Nida and Haima, and Typhoon Sarika passed just to their south. Here are a few details on these storms:
Typhoon Nida developed east of the Philippines and reached typhoon status north of Luzon. Nida intensified to 80kts (92mph) before making landfall east of Hong Kong in Dapeng Peninsula on August 2. Storm photos can be found here.
Typhoon Sarika began as a tropical wave southeast of the Philippines. Sarika reached its peak intensity of 115kts (132mph) before making its first landfall in Luzon. The cyclone moved quickly across the Philippines and the South China Sea, and made a second landfall across Hainan Island. The storm continued to weaken as it made its third and final landfall near the Vietnam/China border.
Super Typhoon Haima caused mass destruction across the Philippines just days after Sarika. Photos and video footage from the devastating storm can be viewed here. Haima ranked as the third strongest typhoon of the season with maximum sustained winds of 145 kts (167mph). The storm weakened to 122kts (140mph) before making landfall over Luzon on October 19.
While around half of 2016 West Pacific typhoons followed a general East to West track, the other half were able to find a weakness in the steering ridge and curve northward. Mainland Japan would be directly impacted by four of these typhoons (Nepartak, Mindulle, Lionrock, and Malakas); however, the majority of these weakened significantly before making landfall. Typhoon Lionrock was the most unique system of the season given its length of life and erratic track.
Of the main cyclones to impact the mid-latitudes, Typhoon Chaba tracked the closest to offshore interests in the Korea Strait and Sea of Japan. Chaba reached super typhoon intensity upon entering the East China Sea on October 3 and then gradually weakened as it moved south of Busan, South Korea. Chaba moved across northern Japan as an extratropical cyclone.
Just as the season’s first named storm became a super typhoon, the season’s final named storm also became a super typhoon. Nock-ten developed near Yap Island on December 21st. Nock-ten would become the strongest tropical cyclone ever recorded worldwide on Christmas Day. Nock-ten made landfall across the Philippines on the evening of Christmas Day before emerging across the South China Sea the next day. Nock-ten dissipated in the Northeast Monsoon on December 28th, bringing an end to the 2016 West Pacific tropical season.
WWT tracked all of these storms for stationary assets and marine transits across the West Pacific and Southeast Asia.
About Wilkens Weather Tropical Weather Guidance
Wilkens Weather provides a variety of tropical products to monitor potential development, forecast tracks, and anticipated intensities of tropical systems in this region. Tropical service options include tropical cyclone formation alerts (TCFAs) and tropical cyclone bulletins. Once tropical cyclone bulletins commence, clients are provided a wealth of resources to review the storm data and potential impacts on their site-specific locations. The interactive tropical tools on our website and Mobile App provide clients with the flexibility to focus on the needs of their operation.
Site-specific storm bulletins with alert areas are also available and may be customized to the needs of a current project or operation.