Wednesday, February 2, 2011

Winter Storm Update & End-of-Week System Preview

The far-reaching, historic storm system that blasted the nation's heartland yesterday is aiming for the Great Lakes and New England today, with continued heavy snow and whiteout conditions at times from strong winds. Here are some of the biggest snowfall totals from this storm system so far:

You can view more snowfall totals at the Hydrometeorological Prediction Center. In the warm side of the storm, wind damage was common through the southern U.S. yesterday. You can view some of the storm reports at the Storm Prediction Center.

As of Wednesday morning, Blizzard Warnings (in red on the map) continue for parts of the Upper Midwest, with Winter Storm Warnings for most of New England:

This potent low pressure system will continue to track northeast, dumping its highest snowfall amounts just to the north of the low's center. This is the forecast snowfall from 7 a.m. Wednesday through Saturday evening:

Of course, that snow total you see in Chicago of 4.5" is what will fall on top of what already fell yesterday and overnight with blizzard conditions. Here's a breakdown of the rest of this system's life through Thursday:

Scattered rain showers will continue in central Virginia through about 10 a.m., and temperatures will soar through this afternoon as the low pressure pulls in much warmer air from the south into the Commonwealth. High temperatures will reach the 60s and low 70s!

Expect a warm and windy afternoon with winds shifting to the west as the low moves to our north and northeast. Most of central Virginia will have sustained winds in the 20-30 mph range with some higher gusts around 35 mph today, but the strongest winds in response to the low pressure system will occur in western Virginia. There is a Wind Advisory in effect from 11 a.m. through tonight for the counties highlighted in tan on the map below.

High profile vehicles traveling along I-81 today will certainly have a rough drive with these strong crosswinds.

After high temperatures this afternoon peak in the upper 60s and low 70s, the strong cold front associated with this low pressure storm system will sweep through the region after 7 p.m. Much colder air will move into central Virginia tonight, returning us to seasonable temperatures for the duration of the week.

Our next storm system will approach us from the south at the end of this week. It will not be nearly as strong as today's monster storm, but it will pull moisture from the south northward into Virginia on Friday. First, we'll notice the increase in cloud-cover from the south during the day.

Rain should begin moving into the Commonwealth late Friday evening, so most of Friday will be dry.

Rain will continue to be likely into Saturday.

At this time, it appears that the precipitation mode will be rain only for central Virginia. Here is the GFS model forecast sounding (vertical view of the atmosphere from the ground up...the right line is air temperature, the left line is dew point temperature) for Saturday morning, which clearly indicates rain (the right-slanted blue 0 degree Celsius line is the freezing line):

Even the forecast sounding by Saturday night at 7 p.m. still has surface temperatures above freezing and the rain ending:

If colder air on the backside of the system can arrive quickly enough Saturday afternoon, we may see a brief changeover to light snow, but that scenario does not appear likely right now.