Evening winter WX update, a dangerous one at LEAST!!

[WXBUFFJIM]

Good evening everyone. There is alot to discuss tonight given the dangers nationwide from #1 heavy snow, #2 blowing snow due to strong wind, and #3 very dangerous and life threatening wind chills. All of those will be covered in this evenings update.

First starting with storm #1 across the midwest, which has dropped some significant snow amounts already and there's still several more hours to go for Chicago, Des Moines, and the Quad Cities area. Detroit will also likely share into some of this wintry weather as well in the form of snow. All of the cities and communities mentioned will have winter storm and heavy snow warnings remain effect through this evening.

Some of the latest amounts show 7-8 inches already on the ground in portions of Keokuk County with a half foot likely already on the ground in the Quad Cities area. The problem is more snow is expected and will last for several more hours as frontogenesis forcing and a pretty strong deformation zone enhances the lift, and thus the higher snow totals. Also noticing on satellite imaginary a classic comma head feature over Iowa this evening. This is a good indicator of a well developed winter storm. It's usually within these comma head features just north and west of the surface low pressure system where snowfall rates are maximized and could be in the 1-2 inch per hour range for a few more hours yet. This is important if you live say across eastern Iowa and into northwestern Illinois. Some places from say Clinton to Washington, and Davenport, and Moline could end up with 1 foot of snow before this is all said and done with. That will most likely be the heaviest snow swath in this storm and worth watching carefully over the next few hours or so. However there are other areas to look at also.

Further west in Des Moines, winter storm warning continues with snow ongoing at this hour. However snow will likely diminish in Des Moines in the next 3 hours or so. But not before a general 4-8 inch snowfall. Most areas around Des Moines will likely see a half a foot of snow on average with this thing.

Meanwhile in the windy city, snow has been heavy today at O Hare and across all of Chicago. With 1/4 mile visibility, you have to figure snowfall rates have ben 1-2 inches per hour at times in Chicago given that visibility observation from O Hare over the past few hours. Snowfall totals in Chicago will likely be in the 5-9 inch range, which is pretty respectiful considering Chicago has been in a lull as far as snowstorms are concerned. However wind gusts in the 20-30 mph range is #1 blowing the snow around and #2 causing low wind chills. Same can be said in Detroit where snow is expected tonight. 4-6 inches of snow looks like a respectiful amount from Detroit north and west. So we got a three fold problem with this winter storm in the midwest and great lakes region. #1 Heavy snow potential, #2 blowing snow due to wind, and #3 dangrous wind chills.

Speaking of wind chills, we got a huge weather story unfolding across big sky country and the northern plains today through tonight and a good deal of the upcoming week. Cold arctic air combined with wind, and snowpack will result in the most dangerous wind chills in quite sometime for the Big Sky Country, the Dakotas, and Minnesota also. This arctic plunge will just dive south and eastward into areas where heavy snow fell today. As a result, wind chills could approach advisory criteria for Minnepolis, Des Moines, and the Quad Cities Monday night into Tuesday.

What's causing this arctic plunge is a combination of this winter storm over the midwest and developing high pressure over Saskatchewan diving southeastward through the northern rockies at this time. Some places had dangerously low temperatures and wind chills this morning because of this cold arctic high. Regina in Saskatchewan dived to -26 with a -50 wind chill this morning while Havre, Montana dropped to -31 with a wind chill of -52. This is the kind of temperature and wind chill we're talking about tonight for the Dakotas, eastern Montana, and northern Minnesota overnight tonight. As a result, a wind chill warning is in effect for Minot and Williston, ND tonight and Rapid City, SD as well. Low temps in these areas tonight will drop to -25 to -35 overnight with wind chill values between -40 and -60 overnight. Some of these dangerous and deadly wind chill and temperature readings will dive south and east with time and cover new real estate Monday through Wednesday. Minnepolis, Des Moines, and the Quad Cities could see sub zero lows easily Monday and Tuesday night. Wind chill values Monday night could range from -10 to -30. It's nearing wind chill advisory criteria and we must keep an eye on that. The Chicago area is forecast to drop to near zero tomorrow night with wind chills in the negative teens.

Meanwhile on a brighter note, it as a nice day back east from DC southward into Richmond and Norfolk, VA. Norfolk hit 78 degrees today on the tidewater. Just an absolutely gorgeous day. However don't get used to that warmth. After a high near 70 tomorrow around midday in the tidewater area and eastern North Carolina, temps plunge into the upper 40s to low 50s by evening aided by a stiff northwest wind at 20-35 mph. By midweek, lows will be in the 20s in the tidewater area and in North Carolinas Piedmont while highs struggle to get above freezing in Virginia Beach and might not hit 40 for Raleigh and Elizabeth City, North Carolina. Further north up the coast, expect midweek lows in the teens for DC, Baltimore, and Philly with single digits possible north and west of those cities. High temps midweek will only be in the upper 20s to near 30 in DC and Baltimore, low 20s in Philly, and upper teens to lo 20s in the Poconos and Laurel Highlands. Some brutually cold stuff even without the snow cover in through here midweek.

If that wasn't enough, we have a winter storm watch for Seattle and Portland for Monday and Tuesday. Some of the snow totals at sea level could be similar to the widespread very heavy snow of after Christmas 1996. By Tuesday, the snow is expected to change to rain in Seattle and Portland while heavy snow continues in the cascades. A high avalanche danger is probable for the washington and oregon cascades as this heavy snow and wind combo results in natural avalache dangers. Keep an eye on this!! More on this and the midwest winter storm/arctic plunge coming up later tonite.

Jim

[wx247]

Thanks for the very comprehensive update Jim!

[rainstorm]

THANKS

[weatherlover427]

Very impressive update Jim. I like it a lot.

[JCT777]

Nice update, Jim. Thanks!

[Lowpressure]

Nice update.