Friday, January 25, 2013

Mid-Atlantic Snow & Southeast Ice: Checkmate?

3:00 PM EST 1/25/13 (Winter Stormcast Team) Light snow has begun across portions of Maryland and southern PA, with moderate snow in portions of the Hereford zone in Baltimore County and York County, PA. Accumulations of an inch have been reported in western Maryland, with a dusting thus far further east. 

Forecaster Greg Jackson of our Three Rivers team in Pittsburgh reported snow arrived earlier than expected and coated the ground quickly. As noted by Forecaster Joey Krastel in the Maryland Team, dry air across the I-95 corridor into Southeast PA was a formidable barrier to the snow getting underway until recently.

In the Southeast, earlier expectations of a significant ice event across North Georgia and Metro Atlanta have subsided, the region reporting light rain and sleet mixed, according to Forecaster Jason Isaacs of the Georgia Team.

Latest  intellicast radar shows that while snow may be falling at upper levels
very low surface humidity will negate much of this initial precipitation, known as "Virga"* 

Follow this link for more on the importance of accurate forecasting and detecting of Virga.

As of last report, readers in Maryland and Pennsylvania have not observed any significant traffic issues - with occasional light snow expected as we head into the evening rush for most areas. We cannot rule out that brief burst of moderate to heavy snow may occur, producing temporary reductions in visibility. For this reason, we urge all commuters to allow extra time, even if roads "seem fine." 

Earlier report and accumulation forecast map follows:

11:30 AM EST 1/25/13 | Winter Stormcast Director Zachary Fasnacht & Mid-Atlantic Team. Visit the following Facebook links for reports from our Southeast Team on the ice situation from South Carolina to Metro Atlanta. 


OVERVIEW: A swath of light snow is currently moving into the western Mid-Atlantic, reported in much of eastern Ohio, western Pennsylvania, in Pittsburgh and western Maryland. While this system will not drop a significant snowfall, several inches of snow are likely throughout the region by midnight tonight. 

Although some schools in the southeast, MD and PA have closed or are closing early, the storm will be a relatively low impact event. The primary effects should be felt during the evening commute. Please review the current NWS Advisories, Watches & Warnings from the NOAA Eastern Regional Headquarters as shown below right.

TIMING: Precipitation is moving in from the Midwest right now and should be approaching western portions of the mid-Atlantic around noon Friday. The snow will push east through the day Friday, reaching all areas of the mid-Atlantic by sundown. Expect snowfall to end shortly after midnight Friday night.

PRECIPITATION TYPE: All snow. The cold air from earlier in the week is staying around, so all precipitation is expected to be in the form of snow. Heavy snow of ½”-1” per hour is possible in the mountains and ridges of western Pennsylvania and West Virginia.

IMPACTS: Light snow totals are expected
The main impact of this system will be Friday evening rush hour. Temperatures will be in the teens and twenties across the region, so if any snow melts with the sun or cars driving over it, it could refreeze during the evening and overnight. The snow should be very fluffy and so it will be easy to clean up from this system.
  • Generally 1-3” across the mid-Atlantic region. 
  • 4-6” are possible across the ridges and mountains of western Pennsylvania and West Virginia. 
  • 3-5" are possible in coastal areas of southern Maryland and Virginia, as well as southern Delaware if the storm strengthens quickly enough when it arrives at the coast. 

10TH ANNIVERSARY CAMPAIGN! A special team history note. Saturday January 26 will mark the beginning of our team's run up to our 10th year of operations. Once again, as we mark the anniversary of our founding, that another storm graces the headlines! It was January 26, 2004 at the height of a Mid-Atlantic snow and ice storm that our founder, Mr. Foot took the recommendation of his 10th grade students from Dundalk High School. The students said, "Just put it on the internet. That way, people will stop coming into class and ask us about it. They can get the weather online from people they trust."

Later today, we'll have more on our history and how you can help support our plans to expand strategic delivery of our services to readers and clients alike heading our 10th year celebration.


ravensbbr said...

little bit falling now in NE CC...starting to get per GFS, dry slot intruding from west...water vapor loop shows most moisture to the south so far...

Amy said...

Just started in Pasadena. Decent sized flakes.

BioPat said...

It has been snowing for about an hour in Catonsville. Nothing exciting yet, but a nice snowfall today would be great.

HoCoKTchr said...

It started about 12:00 in Frederick...but not too heavy until 2:00. Streets and sidewalks all covered now! :) Glad the schools closed early so more folks could be off the roads!

Enjoy the white stuff! Faith in the flakes!

Julee said...

Started snowing at about 12:15 in Hereford. All kidlets safely on buses by that time. Good call BCPS!!!!!
Snowing beautifully now in Pikesville. Thanks, Nature!!

Unknown said...

Excited about the forecast models in Feb. it seems the southern branch will start to get involved farther north which means we could be in for some fun :-)

ravensbbr said...

Works for me, Mike, hope it pans out as such.

BioPat said...

Works for me as well.
We had a similar winter, 78 or 79. We had quite a bit of below average temps in January with very little snow - then February hit with a blizzard President's Weekend. I'm betting on a similar winter.

ravensbbr said...

I remember that one, Pat, '79 as a four year old, the drifts were over my head...