Temp obs today and snow/winter storm potential

[WXBUFFJIM]

Good afternoon. The big story today is the clipper system, which is moving through the Great Lakes area. An arctic cold front trails this clipper with snow showers and squalls near State College, PA. Up to an inch is possible locally in heavier snow squalls in Pennsylvania. This arctic cold front is currently over a line from southwest PA up to north central Pennsylvania. Ahead of the front, temperatures are warming above freezing. It's 33 in Philadelphia, 37 in Baltimore, 44 in Washington DC, and a balmy 50 in Norfolk, Virginia. This warmth will be very short lived because much colder air will plow into these areas later tonight with dangerous wind chills as well. A wind chill advisory is in effect for eastern West Virginia and western Maryland as well.

Meanwhile behind the cold front, temperatures drop rapidly to 26 in Pittsburgh, mid teens in Erie, Pennsylvania, 12 in Detroit, Michigan, -6 in Ironwood, Michigan, and -11 in Iron Mountain, Michigan. The coldest spot I could find is Orr, Minnesota at -24 with a wind chill of -48. International Falls is -18 after a morning low of -24 this morning. Some dangerous cold. In addition, there is some lake effect on the Great Lakes today. A blizzard warning is in effect for the Keweenaw Peninsula. But there are lake effect snow warnings and advisories in effect for the upper peninsula of Michigan and for northern Lower Michigan. Some places across northern lower Michigan and the upper peninsula could see 6-12 inches of lake effect snow squalls today into tonight. That combined with strong winds could also create whuteout conditions at times.

Likewise near Buffalo and Erie, heavy snow squalls today. The lake effect favored areas of Erie and Ontario are under a lake effect snow warning as well. 6 inches plus of snow accumulation can be expected including in the Buffalo and Niagara Falls area where heavier snows are occurring even as we speak. The temperature is 18 in Niagara Falls. NY with 1/2 mile visibility in snow. Buffalo is seeing light snow and blowing snow and it's 19 in Buffalo as of 12 pm. Some areas could see near whiteout conditions in the lake effect favored zones of Lake Erie and Ontario.

Looking ahead to the weekend, it's looking quite interesting for the middle atlantic region as a potential winter storm could develop. The best chance of significant wintry precipitation will occur later Sunday into early Monday across the middle Atlantic region as a southern stream storm system approaches from the southern plains and heads into the Ohio Valley. A nice overrunning pattern will take shape across the middle atlantic. At the same time, cold air damming will likely keep temps at the surface below freezing down as far south as west central Virginia and potentially down into northwestern North Carolina. This could mean problems with not only significant snowfall such as the case for the I 95 corridor from DC to Philly, but also a significant ice/frez rain potential as well. The following are some of the computer models pinpointing and agreeing to this probable scenario and the timing of all this.

ETA 72 hours-84 hours

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_072s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_078s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084s.gif

GFS 72 hours-90 hours

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_072s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_078s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084s.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_090s.gif

Should these models verify, the timing would bring significant snow into Washington DC, Baltimore, and Philadelphia after noon on Sunday. With cold air damming down the spine of the Appalchians, areas south of DC into west central Virginia and northwest North Carolina could see a period of significant icing amounting several tenths of an inch potentially. But we must remember, if this cold air damming situation doesn't scour out much at all, ice accumulations could potentially be nearing damaging levels of 3/4 inch or more. Meanwhile the potential exists for a solid 4-8 inches of snow from DC up through Baltimore and Philadelphia. However a few places could see in excess of 8 inches of snow, especially in areas say along the Mason Dixon line into south central New Jersey. It's from noon Sunday until the rush hour Monday morning when the heaviest snow is expected in these areas and it could accumulate significantly potentially

This is a situation worth keeping an eye on throughout the next few days.

Jim

[yoda]

NICE JOB!!!

I like the anaylsis there WXBUFFJIM!!! Keep me updated!

[JCT777]

Great post, Jim. Looks good for a significant snow event Sunday/Monday!

[Dave C]

Agree Jim, local forecasters in Boston area seeing this and bringing snow south of Boston late Sun- Mon although minor amounts expected here (SE Mass) so far. Trend is your friend LOL

[Stephanie]

Your summaries are always very good Jim!