... Strong cold front tonight with cold temps and some snow. Record cold temps possible Tuesday night. Dry for the second half of the work week.
NEAR TERM /UNTIL 11 PM THIS EVENING/... As of 723 PM Monday...
Will update the forecast to raise temperatures this evening in advance of the cold front based on current observations.
As of 545 PM Monday...
Updated the forecast to slow down the arrival of the showers early this evening based on latest meso models and radar.
As of 245 PM Monday...
Surface low pressure that developed over the Ohio Valley this morning had suppressed advancement of the cold front, but is now beginning to pick up steam and pushing northeast out of the area. Timing of the frontal passage appears to have been delayed by a few hours compared to the overnight forecast, so adjusted accordingly with this package. The delayed departure of the low did impact temperatures as well today, allowing for more efficient warm air advection to ensue and afternoon temperatures to rise a few degrees above previous expectations. This slight increase in temps will play a role in the overnight forecast, as plunging temperatures may now also be delayed a tad behind the frontal passage. The main story holds true, however, that precipitation approaching along and just ahead of the cold front will start off as rain and then transition over to snow around midnight.
Snow showers will persist into the morning hours Tuesday, draping 1-2 inches across the lowlands before the remainder of the event lines up along the mountains. Hi-res model guidance is becoming more on board with isolated lake-effect snow crossing into Central Appalachia during the day Tuesday, so tailored the forecast to have slight chance of POPs for areas outside of the mountains a few hours longer than previous forecast. Areas along the mountains will achieve higher snow accumulations, as the 850mb thermal trough remains overhead and the 500mb upper trof swings into the eastern portions of the country. With all of this in mind, the most updated snow total map shows 1-2 inches in the lowlands and 2-4 inches of snow in the higher elevations. Blustery winds behind the frontal passage may also lead to blowing snow up in the mountains through the remainder of the near term period. With this being the first winter event for the majority of the forecast area, have maintain the Winter Weather Advisory beginning late tonight through Tuesday evening.
SHORT TERM /11 PM THIS EVENING THROUGH THURSDAY NIGHT/... As of 255 PM Monday...
Upslope snow showers will be ongoing at the start of the short term period in the northern mountains, but will gradually taper off into Wednesday morning as surface high pressure in the mid-Mississippi Valley builds in from the west. In addition, record low temperatures will be possible Wednesday morning throughout the region, especially if clouds can clear out pretty quickly with high pressure building in. Regardless, it will be very cold with widespread low/mid teens across the lowlands and temps around zero in the mountains. While winds will gradually ease overnight into Wednesday morning, winds will still remain strong enough in the mountains to support a wind chill advisory through Wednesday morning as wind chill values reach 10 to 15 below.
Surface high pressure quickly shifts off to the northeast on Wednesday afternoon and light return flow in the low levels allows temperatures to moderate slightly. However, highs on Wednesday are only expected to reach the mid 30s throughout the area, which is about 20-25 degrees below normal for mid-November.
Cloud cover will be on the increase Wednesday night through Thursday in advance of a shortwave trough and associated cold front that will be moving across the Great Lakes region. However, have not introduced any PoPs in the forecast on Thursday as moisture availability appears to be very limited. Thus, a dry frontal passage is expected Thursday afternoon and evening with clouds decreasing Thursday night as high pressure in the central US builds into the area. This will set the stage for mainly sunny day Friday but highs will remain below normal with temperatures reaching the mid/upper 40s in the afternoon.
LONG TERM /FRIDAY THROUGH MONDAY/... As of 255 PM Monday...
Surface high pressure builds into the Great Lakes region Friday night into Saturday and brings quiet weather across the area for the upcoming weekend. Temperatures to begin the weekend are expected to be around 10 degrees below normal on Saturday, but temperatures will gradually increase later in the weekend and the start of the new work week as the flow becomes southwesterly ahead of an upper level trough. Precipitation chances may slightly increase by the end of the long term period as the upper trough gets closer to the area, but with timing and placement differences in the trough axis, have decided to leave a consensus blend of PoPs in for now.