Summer Shamal winds and dust begin to impact the Middle East

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 »

2015 Holiday Storm Retrospective

A powerful storm system tracked across the northern Great Plains this holiday season. Heavy snows and blizzard conditions were observed in the Dakotas, strong storms occurred in Kansas and Missouri, and an ice storm developed in areas between. Of significant note was a tornado report in Kansas that if confirmed would be the first tornado recorded on Christmas day in that state. In addition, wind gusts in excess of 70 mph were reportedIowa Environmental Mesonet Wind Speed Reports December 2016 in northwestern Iowa, causing structural damage in the area. These conditions are a stark reminder that like meteorologists, Mother Nature does not take the holidays off. Interestingly, a similar storm system impacted the southern plains last holiday season.

One year ago, a major storm system moved from Texas through the Great Lakes, capping off a year filled with extreme weather in Texas and beyond. Read More »

Santa’s global weather briefing from Wilkens Weather and Rockwell Collins

Christmas Eve is upon us and as we say in Texas, Santa is fixin’ to get his sleigh packed. But first, he is checking with Wilkens Weather, A Rockwell Collins Company, for the first leg of his journey around the world.  From the North Pole, his first stops will likely be in Uelen, Chukotka in far eastern Russia.  

From what Santa has entered into Rockwell Collins ARINCDirect Flight Manager, he will leave the North Pole on Friday, December 24, 1155UTC (11:55 PM in far eastern Russia).  

A low pressure center just east of Svalbard has a strong front extending just across the North Pole and across most of the Laptev Sea.  As Santa stays behind the front, he will encounter some light snow showers but will be able to take advantage of a strong northerly tailwind.  Once he is south of 78°N, winds are forecast to turn westerly, which will be ideal for his final approach into Uelen.

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South China Sea Monsoon Low

WWT Satellite Monsoon LowOver the past several days, an area of low pressure (Invest 91W) developed within the monsoon trough/ITCZ, generating bands of showers and thunderstorms across the southern South China Sea. As a result, fresh winds extended to the Borneo coast and Malay Peninsula over the weekend. Strong to near-gale force northerly winds also occurred along the northwest side of the low when it intensified this morning. Global models often underdo monsoon winds within these lows and these systems should always be monitored closely for tropical development. Read More »

Weather Forecasting in the Adriatic

WWT Adriatic Sea WaterspoutHigh terrain extending across Italy and central Europe yield a challenging environment for weather forecasting in the northern Adriatic Sea, especially during the winter months. The Alps, 120 miles wide with several peaks over 15,000 ft, block colder air to the north and often deflect it to the east over the Balkan States. The cooler air accumulates over the Balkan Peninsula, eventually reaching the height of the mountain passes. This induces a Bora, a local downslope wind effect that is common and at times violent during the cold season, usually from October through March. The Bora is one of two local winds that impact marine customers in this region. The other being Sirocco winds, a strong southeast wind, which often build over the course of a couple of days ahead of a Bora or impending low pressure system and is usually forecast with less uncertainty.Read More »