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Posted at 12:20 PM ET, 02/ 8/2011

No more than flurries likely Thursday

By Wes Junker

The models are increasingly bearish about the possibility of snow Wednesday night and Thursday.

This morning's NAM model did bring a flurries to a dusting into the area so the threat of seeing a few flakes is not yet dead though on life support. No Short Range Ensemble Forecast member predicts the 0.05 inch liquid equivalent line (a half inch of snow) to advance north of Williamsburg, attesting to how little potential there is for more than a dusting from the system.

gfs-021011.jpg
GFS model simulating very light precipitation having fallen in the six hours prior to 1 a.m. Thursday, mainly southeast of the District.

Last night's GFS and European model crushed the southern jet stream (along which the storm will travel) and had no snow anywhere near us. This morning's GFS does bring the light snow a little closer and has edged toward the NAM so the threat of flurries or a dusting limps along.

A moderating trend still looks likely next week with more warmer than normal days than colder than normal ones. How long this warmer pattern will last is however up in the air. The Global Ensemble Forecast System members are split about whether the North Atlantic Oscillation will stay positive (the warm phase for us) or will flip to negative (cold) later this month. A flip toward a negative NAO usually brings cooler than normal weather to the East.

By Wes Junker  | February 8, 2011; 12:20 PM ET
Categories:  Latest, Winter Storms  
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Next: Rate our cold winter so far

Comments

Thanks for the write-up, Wes.

Sort of off-topic question, but one that's been bugging me for a while. The NAO clearly plays such a prominent role in winter temperatures. But what about during the summer? If we're entering into a trend where the NAO tends to be negative, shouldn't that make the summers here cooler as well? Or does the negative NAO = cool northeast not apply during the summer months?

Posted by: jms12 | February 8, 2011 12:37 PM | Report abuse

jms12, The jet stream shifts well to the north in summer so the impact of the nao is different. A negative NAO actually correlates to warmer than normal temps across the south and colder than normal temperatures across the northeast. That's almost the reverse of the typical correlation in winter. We're close to the transition but are weakly correlated to having above normal temps when the NAO is negative during summer and colder than normal when the nao is negative in winter.

Posted by: wjunker | February 8, 2011 12:52 PM | Report abuse

Wes - thanks for that concise and clear answer.

Posted by: jms12 | February 8, 2011 1:06 PM | Report abuse

Latest Euro model suggests we may get some flurries Wed night.

Posted by: Jason-CapitalWeatherGang | February 8, 2011 1:15 PM | Report abuse

Wes-

Thanks for the brief NAO crash course. I never knew that about its summer effect. Very interesting. As the saying goes, "you learn something new every day".

Thanks again for the insight.

Posted by: ThinkSpring | February 8, 2011 1:28 PM | Report abuse

quite a few GEFS members give us a dusting to an inch though I hate using them in the short range as the low resolution tends to spread the precipitation out so amounts can be misleading when the gradient is tight.

Posted by: wjunker | February 8, 2011 1:33 PM | Report abuse

This pretty much sums up winter in DC this year, other than our one storm.

http://www.weather.com/weather/wxdetail/22307?dayNum=1

http://www.weather.com/weather/wxdetail/22307?dayNum=2

Posted by: TBAlexandria | February 8, 2011 2:16 PM | Report abuse

the 15Z SREF memebers have trended north threatening dc with flurries to a dusting. 20 percent of the members now have 0.05 reaching DC compared to none earlier getting north of Williamsburg. The low still is really suppressed so the precipitation looks to be associated with the 500h vorticity (spin center) passing by. If you like flurries or a dusting the probabilities seem to be edging back up a little.

Posted by: wjunker | February 8, 2011 2:54 PM | Report abuse

Flurries only, please!

A dusting would just cause unnecessary problems with the morning commute.

I'm assuming this would fall during the overnight hours?

Seems like the lighter events always occur overnight or near the morning rush.

Posted by: ThinkSpring | February 8, 2011 3:14 PM | Report abuse

do i smell a feb surprise storm?

wes' statement, "20 percent of the members now have 0.05 reaching DC compared to none earlier getting north of Williamsburg" is the kind of thing we will look back on friday morning, from the safety of our snowed-in houses, and say that's when the trend began to shift. by friday am, we'll be thinking of stupid names for this storm!

snap! what?! **awakes from reverie**

Posted by: walter-in-fallschurch | February 8, 2011 3:15 PM | Report abuse

its funny that Wes's latest update here came at 2:56pm then 10 minutes later the NWS updated their page and took away the 20% chance of snow wed night. They mention nothing about snow wed or thurs and actually added scattered snow flurries to todays forecast. I dont understand whats happening, CWG and HM form accu mention snow chances increase while NWS show the chances dissappeared :/

Posted by: KRUZ | February 8, 2011 3:37 PM | Report abuse

Around what time would the dusting happen? Would it stick right away due to temps outside? We sand and salt parking lots, sidewalks,just wondering if this will be needed. As always, thanks for the response.

Posted by: dannythe357 | February 8, 2011 3:43 PM | Report abuse

@dannythe357

If it happens, would expect mostly overnight Wednesday. Although, we get above freezing Wednesday during the day, it would probably stick given cold temps tonight and tomorrow night. At this point, not sure there would be enough to coat the roads, but worth keeping an eye on.

Posted by: Jason-CapitalWeatherGang | February 8, 2011 4:09 PM | Report abuse

The 00Z nam has trended back towards the south and now has a complete miss. Right now I don't see much more than flurries or a dusting and doubt it would be enough to coat the roads even if it snows which still looks like is the less likely outcome. If I had to bet, I'd go with a miss or flurries. In reality nothing much has changed since I wrote the blog.

Posted by: wjunker | February 8, 2011 9:27 PM | Report abuse

The comments to this entry are closed.

 
 
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