First Major Winter Storm Heading for the Washington Region

*Much of the Washington Area outside of southern Maryland will likely receive their first accumulating snowfall of the season*

Probability (%) of Greater than One Inch of Snow (courtesy: NOAA/HPC)

Snow will begin falling between sunrise and the noon hour on Sunday.  Snow may hold off until the afternoon hours across northern Maryland.

Preliminary data indicates that 2 to 4″ of snow is possible with locally higher totals north and west of downtown Washington by Sunday evening.

GEM (Global Ensemble Model) potential snowfall accumulation
GEM (Global Ensemble Model) Potential Snowfall Accumulation (Sunday through Tuesday)

 *A High Impact Ice Storm will affect a large portion of the Washington Region Sunday Afternoon through Monday Morning*

*Be Prepared for the Potential of Ice Accumulations (from Freezing Rain) of One-Tenth to One-Quarter of an Inch (or more), especially along and west of the Interstate 95 Corridor*

Proba
Probability (%) of One-Tenth Inch (or more) of Ice Accumulation from Freezing Rain through 7PM Sunday (Image Courtesy: NOAA/HPC)
prb_24hicez_ge.25_2013120600f072
Probability (%) of One-Quarter Inch (or more) of Ice Accumulation from Freezing Rain through 7PM Sunday (Image Courtesy: NOAA/HPC)

Snow will change over to sleet and freezing rain from southeast to northwest across the DC Region on Sunday. According to the latest data, it is possible that northern Maryland may hold onto snow through the early evening hours before changing to sleet and freezing rain.

If Freezing Rain remains as the predominant precipitation type across the Region through sunrise on Monday, we are going to have one heck of a mess on our hands with widespread closings.

Freezing rain will likely change over to rain on Monday as temperatures creep up into the middle 30s.  Exactly when this changeover occurs is by no means edged in stone. Models are notoriously terrible at timing when the cold air trapped at the lower levels gets scoured out. 

Bottom Line: This could be a very prolonged freezing rain event in the favored, colder, sheltered valleys. Yes, some of us may be under *Ice Storm Warnings* on Sunday, especially from the Interstate 95 corridor… points west.

*Lastly, it is looking like a third wave of low pressure may ride along the stalled arctic front on Monday night into Tuesday producing a period of more snow across the Washington Region before things dry out Tuesday afternoon*

*Winter Storm Watches will likely be issued by the National Weather Service on Friday afternoon/evening as they are usually issued 36 hours before a storm impacts the area*
As always, I try to keep you ahead of any weather that threatens the Washington Area.
Friday would be a good time to head to the grocery store and stock up on the rock salt.

 

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