Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EST Mon Dec 05 2022 Valid 12Z Mon Dec 05 2022 - 12Z Wed Dec 07 2022 ...Heavy rain and the risk for scattered flash flooding developing over the Tennessee Valley... ...Snow across the central Rockies, parts of the northern Rockies, and extending east into the northern Plains... ...Showers will expand northeast toward New England on Tuesday ahead of a cold front as rain becomes more focused near the trailing portion of the front across the southern Plains... A cold front associated with a reinforcing surge of cold air from Canada is forecast to move rapidly south through the northern and central Plains today. Meanwhile, a plume of moisture associated with the subtropical jet stream continues to trigger scattered precipitation across the southern Rockies. This jet stream will help develop a wave of low pressure along a frontal zone across the southern Plains as warm and moist air from the Gulf of Mexico begins to push northward. Rain is beginning to develop across the interior Deep South ahead of a warm front. The jet stream interacting with the warm front in conjunction with the cold front arriving from the north will help focus a round of heavy rain by later today from the interior Deep South up into the Tennessee Valley. The heavy rain axis is forecast to lift slowly northward into Kentucky by early on Wednesday ahead of the warm front and the wave of the low pressure. In the mean time, rain chances are expected to increase across the southern Plains by Tuesday night into early Wednesday near a stalled front. Farther to the northeast, showers will expand northeast toward New England on Tuesday ahead of the cold front. An area of enhanced rainfall is possible Tuesday night into Wednesday morning from the northern Mid-Atlantic to southern New England. A low pressure system just off the West Coast is slowly weakening. Precipitation over northern California is forecast to slowly taper off today. Farther inland, snow is expected to continue across the central Rockies, parts of the northern Rockies, and extending east into the northern Plains near the arctic boundary. Temperatures will remain below normal while winds will also be a bit blustery along the front of the Rockies. Meanwhile, bitterly cold air will spread south from Canada into the northern Plains and upper Midwest. Highs near the Canadian border will be in the single digits with wind chills running below zero. Kong/Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php