WEATHERAmerica Newsletter; Sunday; January 19, 2025; Two Small Storms Amidst The Bitter Cold Air Mass Over North America

[Larry Cosgrove]

Two Small Storms Amidst The Bitter Cold Air Mass Over North America

METEOBLUE

UQAM Meteocentre (4)

University Of Wisconsin Weather Server (3)

PivotalWeather.Com (3)

ECMWF

College Of DuPage Weather Laboratory (3)

The winter season so far has not featured the proverbial "big one", the type of storm that people remember through the years that made major news and had lasting impacts on daily and future life. Instead, we keep seeing the type of disturbance that may bring chances for measurable ice and snow on a mostly regional basis. For the near term, there are two such systems to look at.

A small shortwave moving through the Southeast may move offshore on Sunday night, enabling eastward motion of cold air over the Appalachian Mountains and points west of the Interstate 95 and 81 corridors above the Potomac River. Whereas the actual mountainous areas may see moderate to heavy snowfall (4 - 8", maybe more in New York and New England) it is a judgment call how much the urban areas end up with. Most of the heavier snow chances look to be above New York/Long Island through cities like Albany NY and perhaps Portland ME. The numbing cold behind the feature may be the bigger story for many.

Ice storms are a pain anywhere, but I am watching Texas and the Deep South for a particularly dangerous scenario beginning late Monday. The Arctic air mass will push all the way into Mexico and the open waters of the Gulf, then its frontal structure will stall as energy approaches from an impulse in the Colorado Rocky Mountains. This impulse will remain strong as it turns a corner through the Big Bend of the Rio Grande, and start forcing development of convection and stratiform precipitation across much of the Lone Star State below Interstate 20. With a pulse overrunning effect, areas of freezing drizzle will erupt across parts of South Texas and begin to spread eastward. Higher dewpoints will translate to more ground amounts; and then air aloft will be so cold as to overcome surface readings in the upper 30s (F) range. The event should unfold around 100 miles either side of the Interstate 10  corridor before recurving through the Carolinas by Wednesday night. The presence of freezing rain and sleet may keep accumulations down, but I am confident that on the north side of the described arc 1 to 3", and locally 3-6", of snow could occur. Best chances for those "lollipops" will be in E TX, C LA and W MS. It will be an interesting ride from San Antonio TX to Houston and New Orleans LA to say the least during a later Monday through Wednesday time frame. Be careful out there!