WEATHERAmerica Newsletter, Saturday, March 1, 2025; MEDIUM RANGE OUTLOOK

[Larry Cosgrove]

And Another Storm, With A Further South Track Scenario!

UQAM Meteocentre (4)

TrueWx.Com (4)

College Of DuPage Weather Laboratory (2)

This is a progressive pattern with multiple, mostly amplified disturbances that start in the northern Pacific Basin. Model guidance has been consistent on the prospect for two more important storms affecting the lower 48 states in the 6-10 day range. The next in the series likely will be of the Colorado/Trinidad "B" variety, taking a more southern route than its larger, more powerful predecessor. A question that arises: could this impulse be suppressed in terms of size and intensity? In other words, as a full-blown cyclone as opposed to being a frontal wave? This is a valid supposition, and it means the difference between presenting a sizable severe weather outbreak over parts of Texas and the Dixie states vs. smaller areas of stratiform rain and sleet/snow from the Red River Valley (OK/TX) into Appalachia and perhaps the Northeast. I lean toward a more defined, convective feature which would imply severe weather threats followed by a brief cold spell across the eastern half of the nation.

Setting Up A Cold Western U.S./Canada Vs. Warm Central, East Alignment?

ECMWF (4)

PivotalWeather.Com (4)

In the 500MB longwave pattern that is developing in a weaker La Nina (which, later this spring will ease into negative/neutral character) episode, it is typical for the Sonoran and Bermudan heat ridges to build northward. What results is colder air trapped over the Pacific Northwest as well as alonmg and above the Canadian border. Sometimes New England will be involved in a cPk domain. Analog forecasts agree with projections from most numerical model forms on a cold West Coast/Canada vs. warm Central/East USA temperature array, with the area between the Great Plains/Texas and Mississippi Valley prone to severe weather and very heavy rain. The next storm series is shown to be of the Colorado/Limon (longwave) cyclone type, generating very strong winds with cold air and heavy snow not making any eastward progress from the Front Range/High Plains/Black Hills. Projected strike time will likely be March 10 - 11. Meanwhile, be sure to watch if soil moisture levels lessen from the Rio Grande watershed into the Corn Belt and Mid-Atlantic. That would probably mean an especially hot MJJAS time frame (summer season).