From the 60s to ice in 8 hours Monday?

Enjoy those partly sunny skies and the temperatures near 70° today because some of the wildest weather we have seen in a long time arrives tomorrow. Temperatures tomorrow will start in the 60s late morning to around noon but will fall below freezing by dinner time with possible wintry weather.  The real question is who wins the race. The cold air or moisture? The cold air and moisture will be in a race with the moisture leaving at about the same time the cold air arrives. Right now I think it will be close enough that the shallow cold air could cause a brief wintry mix by evening before the moisture leaves.

Mega Backdoor Cold front Monday:

This is a wedge front on steroids tomorrow or what we call a “backdoor” cold front. Meaning it moves in from the north and east as opposed to the west or northwest. Check this thing out below!

Check out the temperature change possible during the day Monday.  Just a crazy drop from near 60° at noon to about 28° by 7pm.

With such a drastic drop a few things come into play.

1. Possible strong storms along the back door front. Though that seems unlikely but I wouldn’t rule it out.
2. Then the chance of wintry weather as the cold air undercuts the moisture and warm air just above the surface. This means a chance for freezing rain or sleet before the moisture leaves maybe even with thunder.

Wintry Weather Chances Monday:

Both the GFS, NAM and even the ECMWF show a very slight chance of the cold front bringing in a brief wintry mix Monday evening. The set-up is clearly an ice or sleet set-up. The amounts will be light and with a warm ground I do not expect any road or travel issues, at least initially. It’s going to be more of a shock to the system than anything else.

The GFS shows sleet and ice for a few hours around 5-7pm Monday evening. The ECMWF shows the light amounts as well. Remember the ECMWF or EURO model snowfall maps always show all frozen precipitation as snow, even though it can be sleet or freezing rain.

What are the chances?

The SREF or short-range ensembles show the chances are low but still high enough to mention in my forecast for Monday evening.

What are the impacts?

The impacts to roads will likely come later Monday night as temperatures fall below freezing. We are talking a flash freeze as we get the drastic drop and everything freezes up.  What ever falls earlier, be it rain before the cold front or sleet and ice after the front.  If they are wet than roads could become slick late as the heart of the cold air moves in Monday night into Tuesday morning.

Another Winter Hit Thursday into Friday?

If Monday isn’t crazy enough for you stay tuned we could see another chance of ice late this week. So much for March acting like Spring. This week at least will feel more like Winter than the 1st week of Meteorological Spring.  Remember these are early looks and ECMWF isn’t snow. It’s “ALL” frozen precipitation as if it were snow, which means this is likely ice. Stay tuned!