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Posted at 5:00 AM ET, 02/17/2008

Forecast: Cloudy and Wet, then Winter Wakes?

By Jason Samenow

Yes, rain is coming. But the good news about the rain forecast during the next 24 hours is that most of it will fall at night. With the exception of late this afternoon and early tomorrow morning, the daylight hours of the remainder of the holiday weekend will be dry and on the mild side (especially Monday). Much cooler air greets us Tuesday, when our attention will shift to the possible development of wintry weather Thursday and Friday.

TODAY

Rain developing towards dark. Near 50. It will be cloudy and cool for most of the day. It will only become mild very gradually, with temperatures not reaching 50 until the evening hours when strong southerly winds really start to kick in. A bit of rain may develop this afternoon, especially west of town. But most of the rain will fall overnight and may be heavy at times. Temperatures will continue their ascent during the overnight hours, reaching the mid 50s or so by morning.

Keep reading for the forecast for President's Day and the work week, including a chance of late-week wintry weather.

PRESIDENT'S DAY

Rain ends, becoming partly sunny and breezy. Mid 50s. Rain is likely in the morning, particularly east of town. By midday, a cold front will have cleared the area, with most places drying out courtesy of gusty winds from the northwest. Unseasonably mild 50s will start the day and persist into the afternoon since cooler air behind the front will probably wait until dark to make its presence felt.

A LOOK AHEAD

Tuesday and Wednesday will be partly sunny and cold, with highs in the low 40s, and lows in the low to mid 20s.

Wednesday night through Friday, shall we say, appear interesting... Periods of snow, other types of frozen precipitation and/or plain rain are possible.

SNOW LOVER'S CRYSTAL BALL

Next Chance of Accumulating Snow: Wednesday night through Friday
Probability: 30%
Potential Impact:

An area of cold high pressure -- critical for frozen precipitation in our region -- is currently forecast to be parked to our north. At the same time, waves of low pressure are forecast to develop along a stalled front to our south. These waves will produce areas of precipitation along and to the north of the front as they travel from west to east across the South, possibly resulting in periods of snow or ice in our region. Some important questions are:

1) How far north will the precipitation get and will it fall in large quantities? Or will the high pressure to the north suppress the precipitation to the south?
2) How strong will the cold air to the north be? Will it exist in sufficient quantities to provide all frozen precipitation, or will it be weaker than currently forecast, resulting in mostly plain rain?
3) How deep will the cold air be? Will the cold air only exist in shallow layer meaning ice or will the cold air exist at all necessary levels so snow falls?
4) Will we have multiple weak waves as shown in the forecast models now or one big wave?

These are just some of the key questions forecasters will wrestle with in predicting this possible late-week winter weather in the coming days. Stay tuned.

By Jason Samenow  | February 17, 2008; 5:00 AM ET
Categories:  Forecasts  
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Next: Where's the Snow? Ask a Badger

Comments

Any new insight on the mid week storm? What are the current models projecting? What needs to happen to get some snow etc.?

Thanks!

Posted by: Snowlover | February 17, 2008 8:13 AM | Report abuse

Man I need to start reading the entire forecast before I post my questions :)

Posted by: Snowlover | February 17, 2008 8:15 AM | Report abuse

Cad is limited, very little rain out of this system until tonight, most rain will be associated w/the cold front and that may or may not materialize in a significant manner. Best chance of sig. rain within a few hrs. either side of midnight.

The mid Atlantic still badly needs sig. rain. D.C. lucky yr. to date with 4.92", 105% of normal, Richmond 4.08" or 78% normal, Roanoke still way back at only 2.61" or only 52% normal. I come in at 3.38".

Late week system more uncertain than 24 hrs. previous. Models all over map. Latest GFS suppresses sig. moisture south. Wed. thru. Fri. looks cold,cloudy perhaps periods of mostly light snow or a mix. Some parts of the area possibly 1-3 inches.

Posted by: Augusta Jim | February 17, 2008 8:20 AM | Report abuse

I like the little 'at a glance' snow clouds. Does having two flakes represent more snow, like two rain-drops?

Posted by: Etta | February 17, 2008 8:45 AM | Report abuse

Hi Etta -- the snow (and rain) icons were designed such that the number of flakes (and drops) increases as the percent chance rises, with the idea that the higher percentages usually correspond to a higher confidence in there being more significant amounts of precipitation.

Posted by: Dan, Capital Weather Gang | February 17, 2008 9:13 AM | Report abuse

So...does multiple weak waves mean small events, likely some wet snow, some drizzle and one big wave means a storm-snow or rain, temperature dependent?

Posted by: missy | February 17, 2008 11:20 AM | Report abuse

Gotta say, I love those at a glance icons.

Posted by: Peter | February 17, 2008 11:33 AM | Report abuse

Missy-- You pretty much got it.

Posted by: Jason, Capital Weather Gang | February 17, 2008 11:53 AM | Report abuse

man it's crummy outside, drizzling already. I'm having a hard time believing temps will climb over 50 ...

Posted by: weathergrrl | February 17, 2008 12:10 PM | Report abuse

This winter has been a bust. Even the models didn't hold or grab a storm longer then 3 days. My two favorite times are hurricane season and winter. I love storms for their amazing power, not destruction. I certainly hope we get a late storm in March with the NAO trending negative. Its never too late. GFS models only show precip here when temps arewarm. Most of our cold shots have been dry besides some weak clippers. I have already accepted "the long wait" till next season for snow. I just hope we dont get any a similar pattern next winter Cold=Dry, Wet=Warm....

Posted by: StormChaser | February 17, 2008 1:20 PM | Report abuse

When you guys say "suppressed to the south"... how far south are we talking about? I live in the western suburbs of Richmond so just curious if that's far enough south to be in the precip, but far enough north to still be influenced by the cold air :-\...

KD

Posted by: kevin | February 17, 2008 2:06 PM | Report abuse

Even the guy who preaches rain is holding out SNOW hope:

00Z GLOBAL MODELS CONTINUE TO ADVERTISE A PROLONGED PERIOD OF WINTRY
PRECIPITATION BEGINING THU POSSIBLY LASTING INTO EARLY SAT. A FRONT
IS EXPECTED TO STALL ACROSS THE CAROLINAS ON THU WHILE SVRL WAVES OF
LOW PRES MOVE ALONG IT FOCUSING PRECIP NORTH OF IT. TRENDS IN THE
00Z ECMWF AND GEFS MEAN IS TO PUSH HIGH PRES FURTHER SOUTH PUTTING
CNTRL AND SRN VA MORE UNDER THE GUN INITIALLY FOR SOME FROZEN PRECIP
ON THU BUT AS COASTAL LOW FORMS ALONG FRONT AND WARM FRONT TRIES TO
LIFT NORTHWARD FRIDAY OR FRIDAY NIGHT THE ENTIRE REGION COULD BE
UNDER THE GUN FOR A POTENTIALLY SIG WINTER STORM.

Posted by: Greg | February 17, 2008 2:59 PM | Report abuse

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