Freezing rain, warmup prelude polar air intrusion

As crazy as it may currently sound, temperatures in the 40’s and 50’s are not far away. The teens and 20’s which settled into the area behind the significant snowstorm on Friday have essentially dominated the weekend, but an increasingly strong southerly flow will eventually push out the cold air in favor of warmer air surging northward. The cold air will be slow to scour out at the surface, however, which could create the potential for freezing rain across the interior.  Below, a forecast sounding from Northeast NJ shows the very cold air trapped at the surface — but warm air aloft. This kills the development of snowflakes, so precipitation falls as rain, but the rain can refreeze at the surface once it falls as temperatures remain a few degrees below the freezing mark of 32 F. By later Sunday into Sunday night, forecast models are in good agreement that precipitation will have changed to all rain across the forecast area.

The warmup will come to a crescendo on Monday morning and early afternoon, just ahead of an approaching cold front. A large and powerful system forming over the Central United States (more on that below) will drive extremely cold air into the Central and Eastern United states by Tuesday. But along and ahead of the front, increasing low level moisture and rising temperatures will be the cause for showers and temperatures into the 40’s to near 50 early on Monday. Behind the front, the coldest air in recent memory will begin surging into the area.

A forecast sounding from the NAM model in Northeast NJ on Sunday. Notice the cold air (below freezing) trapped near the surface while warm air dominates aloft.

A forecast sounding from the NAM model in Northeast NJ on Sunday. Notice the cold air (below freezing) trapped near the surface while warm air dominates aloft.

Read more