WEATHERAmerica Newsletter, Saturday, Kune 7, 2025; SHORT RANGE OUTLOOK

[Larry Cosgrove]

SHORT RANGE OUTLOOK

(Through The Next 72 Hours)

 

Probably An MCS (Or Derecho) In The South Central States As Cool Air Tries To Move Eastward....

METEOBLUE

University Of Wisconsin Weather Server (3)

TwisterData.Com (3)

WeatherBell.Com (3)

College Of DuPage Weather Laboratory

With a slow-moving upper trough and frontal structure over the southern and eastern tiers of the lower 48 states, there will be a huge incentive for thunderstorm formation along and into the edge of the tropical/unstable air mass. Either an MCS or derecho will form in the lower High Plains on Sunday, then progress either in a linear or clustered fashion eastward into the Mid-South and Ohio Valley into Monday. The interaction of a strong storm aloft in the Great Plains should give a boost to convective development, so much so that the Mid-Atlantic and New England could be targeted by torrential rain, hail and tornado threats as the system exits the USA on Tuesday. 

There is some potential for another MCS build-up over Texas and Louisiana On Tuesday afternoon into Wednesday, since it is unlikely that the IcP/mTw boundary will get below the Interstate 10 corridor. But note that the cooler regime will modify greatly over the Great Plains and Midwest; it is entirely possible that the incentive for repeated, and intense, convection will disappear as we move later into the week.

....While Waiting On The Mexican Heat Ridge And Bermuda High

METEOBLUE

PivotalWeather.Com (3)

ECMWF

Although there may be a day or two where the modified polar air mass reaches the Gulf and Atlantic shorelines, the near term mostly presages the entrance of hot and humid weather from the West into Texas and along the Eastern Seaboard. This is the time of year, especially using La Nina climatology, where cold fronts seldom reach below the Interstate 20 and 95 corridors. The hotter cTw air mass over the Desert and Intermountain Regions will build strongly into the Great Plains, and eventually the Eastern Seaboard during the middle of the new week. Once established, the cTw+mTw regime will likely continue in full force through much of September. The only likely dents in the hotter air will be from tropical cyclone formation, which should initiate in the Atlantic Basin this month.