WEATHERAmerica Newsletter, Saturday, August 2, 2025; SHORT RANGE OUTLOOK

[Larry Cosgrove]

SHORT RANGE OUTLOOK

(Through The Next 72 Hours)

 

Cool Enough For You? Most Of Central, Eastern USA Under A Polar Air Mass

METEOBLUE

PivotalWeather.Com (3)

ECMWF

While not lasting very long, polar air from Canada has made a successful entrance into the lower 48 states, reaching as far south as Interstate 10. The leading edge of the cPk air mass will stall, since the heat rodge cores in the Sonoran and Bermudan positions are quite strong and should start to expand by the middle of the new week. A weakness at 500MB from Minnesota to Louisiana should enable moisture transport, so two impulses digging out of the trough and upper low in the Gulf of Alaska will trigger MCS or even derecho formations in the northern High Plains on into the Great Lakes from Sunday through Thursday. The monsoon will be disrupted in the Southwest, as the subtropical high will be positioned in a way to shut off higher dewpoints from the Pacific Ocean and Caribbean Sea. Some of the mP air will reach into the Pacific Northwest but advance little beyond that region, at least in the near term.

Heat Slowly Rebuilds Across The Southwest, Texas And Great Plains; Thunderstorms Increase In Canada And The Deep South

METEOBLUE

UQAM Meteocentre (3)

TwisterData.Com (3)

University Of Wisconsin (3)

College Of DuPage Weather Laboratory

The first in a series of five disturbances associated with the giant Aleutian Islands + Gulf of Alaska Low will hit the Pacific Northwest on Sunday and Monday. I expect higher chances for intense thunderstorms with severe weather and flooding rain, especially in Alberta, Saskatchewan and Montana. A breakaway mesolow in the weakness  developing in the Great Plains will set off thunderstorms as far south as the Texas Panhandle on August 3, and possibly into the lower Interstate 35 corridor of OK/TX Monday. The remnant diffuse frontal structure could also set up multiple convective risks in Dixie and Florida. Do not be surprised if the convective circulation off of the South Carolina coast attains depression or named storm status, although any system there is likely not to be well-organized, and likely to linger before moving out to sea.