WEATHERAmerica Newsletter; Sunday, May 17, 2026; MEDIUM RANGE OUTLOOK

[Larry Cosgrove]

MEDIUM RANGE OUTLOOK

(Four To Ten Days From Now)

 

Polar Air Mass Quickly Moderates As It Approaches The Eastern Seaboard

METEOBLUE

WeatherBELL (4)

TrueWx.Com (4)

TwisterData.Com (4)

UQAM Meteocentre (4)

College Of DuPage Weather Laboratory

Besides being a prime severe weather month in the Midwest, May also carries with it the chance for MCS formation, mostly in the south central states. Most of the numerical model forecasts show at least two threats for gigantic thunderstorm groupings that would mostly target Texas, Louisiana and Arkansas. Potential exists for upwards of ten inches of rain in most of the Lone Star State, and by May 27 that barrage of convection could reach into the Ohio and Tennessee Valley. Note the weaker look of the polar air mass in late week. The heat ridge over Florida and the Bahamas will undergo retrogression and intensification in the longer term, so this may represent the last chance for excessive rainfall before summer drying gets underway after Memorial Day weekend. The hotter air mass across the West may in fact merge with its counterpart in the Southeast after this time frame, ending the possibility of a stronger cool intrusion until the fall.