Review of June Tropical Cyclone Activity in the Atlantic

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.

Origins and Tracks of June Tropical Cyclones

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:

noaa-goes-wv-animated-june15-16

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.

WV Cindy Tues

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.

NASA IMERG Data Cindy 2017
Cindy Estimated Total Rainfall from NASA

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.

Tropical Low Brewing in the Caribbean Father’s Day Weekend

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?

ir
Infrared Satellite of the northwestern Caribbean valid for 17:00Z.

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 »

Tropical development in the Gulf this weekend?

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.

PWAT Animated Loop
Simulation of PWAT values for the Gulf of Mexico valid June 2-4, 2017.

Read More »

Celebrating 40 Years: Memories & Successes

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.

Read More »

Celebrating 40 Years: The Wilkens Story

WWT Early Years
Meteorologists Richard Wilkens and Tim Maystrick preparing weather reports

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 »

Remembering 2005’s Major Hurricane Rita in the Gulf of Mexico

Hurricane Rita made landfall in extreme southwestern Louisiana on September 24th, 2005 with an intensity of 100 knots (Category 3). About 48 hours earlier, Rita was a Category 5 hurricane with a minimum pressure of 895mb, the fourth-lowest central pressure on record in the Atlantic basin. Although Rita’s history was overshadowed by Katrina, which made landfall just a few weeks earlier, the storm provided a unique challenge for both forecasters and public officials.

NASA Rita Terra satellite_20050918
NASA satellite image of Tropical Depression Eighteen over the Bahamas on Sept. 18, 2005

Rita originated as a weak tropical wave off the western coast of Africa on September 7th. The Saharan Air Layer, commonly known as Saharan Dust, and high levels of wind shear prevented the wave from producing thunderstorm activity as it moved across the tropical Atlantic. Conditions became more favorable for development later in the month as the wave reached the Bahamas. A tropical depression formed on September 17th and the system was designated as Tropical Storm Rita the following afternoon.

Rita continued to strengthen as it tracked across the Florida Straits, reaching Category 2 status by the time it reached the Gulf of Mexico on the 20th. Over the next 18 hours, the storm underwent rapid intensification over the Loop Current, becoming a Category 5 storm with an intensity of 145 knots. Rita continued to intensify and recorded an incredible 70mb drop in central pressure in a 24-hour period. At maximum intensity on September 22nd, Rita’s central pressure was estimated to be 895mb with winds near 155 knots (178 mph).

NASA Aqua satellite_20050923
NASA satellite image showing Hurricane Rita approaching the Gulf coast on Sept. 23, 2005

Thankfully for the residents of the Gulf Coast, Rita did not maintain its unprecedented strength as it pushed ashore. After moving past the Loop Current the system gradually weakened to a Category 3 before making landfall near Sabine Pass as a major hurricane. Hurricane force winds spread over 150 miles from the center while tropical storm force winds stretched as far north as the Louisiana/Arkansas border. Peak storm surge of nearly 17 feet occurred on the eastern side of Rita, causing severe flooding in several parishes in southwestern Louisiana. Heavy rainfall worsened this situation, with most of southwestern Louisiana receiving 7-10 inches, with some areas receiving over 15.

Rita continued to progress northeastward after being absorbed by a front across the central United States. That accelerated movement prevented a significant flood event in the Ohio River valley, with most rainfall totals being limited to around 2-3 inches as the remnant low raced toward the Great Lakes.

Although meteorological impacts to extreme southeastern Texas and southwestern Louisiana were unforgettable, only seven direct deaths occurred as a result of Rita in the United States. Most citizens in the southwestern Louisiana coastal areas evacuated before the worst impacts arrived, likely significantly reducing the death toll in that area.

The majority of the storm’s causalities occurred during the evacuation iWWT Hurricane Rita Wind Speed Analysisn Texas, where poor planning and heightened fears, resulting from Katrina, resulted in mass gridlock around Houston. Over 100 Texans perished due to accidents, fires, and health related issues during the evacuation. Much work has since been done to streamline the evacuation process from the Houston area, including the streamlining of the contraflow process on major highways exiting the city.