Cold continues; snow hawks eye storm next week
Officially, despite sightings of flurries in many places around the Baltimore region Sunday, there was no snow at BWI-Marshall - not even a trace - on Dec. 5. So, for those counting the Dec. 5ths that have produced at least a trace of snow, we stand at six out of the last nine years. Of all the dates in December, it's still the record-holder.
Now the cold: Sunday's high of 39 degrees at BWI-Marshall marked the first time since last Feb. 26 that we've failed to reach 40 degrees. The unseasonably cold weather - the average high for this time of year at BWI is 49 degrees - is forecast to continue all week.
Blame a negative phase of the North Atlantic Oscillation - the key to snowfall in Maryland. That is contributing to a deep southerly loop in the northern jet stream, which is allowing arctic air to surge into the mid-Atlantic states. Foot's Forecast says low pressure over Maine is powering the NW winds that are crossing the Great Lakes and dumping lake-effect snows on the lee shores.
The folks in Sterling say we may see some snow showers in Baltimore overnight tonight, with a low of 27 degrees. Tuesday's high may be no better 35 degrees, with gusty winds that will make it feel much colder.
Our compatriots in far western Maryland have been seeing far more than flurries. There are Blizzard Warnings posted today for parts of West Virginia just south of Garrett and Allegany counties in Maryland. They're warning of 10 to 20 inches of snow from this afternoon into Tuesday, with winds of 20 to 25 mph gusting to 40 to 50 mph. Garrett and Allegany are under a Winter Storm Warning of their own.
Web cam photos from CHART and the WISP resort (photo) show the terrain draped in white. Some of the white stuff at WISP is manmade, but they're getting the natural variety, too. No skiers in evidence yet.
As the week unfolds, it will remain cold, with highs in the upper 30s to low 40s, and overnight lows in the 20s. At the far end of the 7-day forecast the NWS has inserted a chance of rain for Sunday. But there is considerable disagreement in the models about that storm, and the usual snow hawks have already begun to chatter about the possibility of a significant snowstorm for the mid-Atlantic early next week.
Once again it comes down to a debate over the storm track. A more westerly track up the Ohio Valley or the Appalachian chain would admit plenty of relatively warm air here, bringing us mostly rain. Edge the storm track farther east and we get a wintry mix. Send it out to sea and we keep the cold air in place and see the snow pile up.
What we need to remember, though, is that in a La Nina winter like this one, most of the storms can be expected to track to our west, bringing us more mixed precipitation and smaller accumulations compared with the big coastal storms more typical of an El Nino winter (like last year).
That said, there have been exceptions - big coastal storms in La Nina years. And even a few inches of snow and ice can be every bit as disruptive as an 18-incher, and maybe moreso as more people venture onto the roads, figuring they can tackle a few inches of snow and ice, no sweat.
Anyway, here's AccuWeather.com's take on the prospects for early next week.
Eric the Red, a professional forecaster form Baltimore and frequent contributor here, says we may see some light snow Friday, but:
"The bigger issue is Sunday into Monday. Models have been all over this for days. The idea is pretty straightforward... moisture-laden storm will approach from the west-southwest.
"But the models are all over the place on the track this thing takes... some have it going into the Ohio River Valley, which puts us on the warm, southeast side of the storm (mostly rain), while others take it right overhead (that's a mixed mess), and still others show a track closer to the coast (kaboom!).
"Two things here: (1) the models have been trending farther north and west with the track, and (2) this doesn't make much sense since a strong blocking high would typically cause the storm to track farther south and reform on the coast."
"So we have the models showing a less favorable track for snow, but this solution - for now - just doesn't make a whole lot of sense to me. Many days to sort this one out as well."
And finally, here's how Foot's Forecast sees it: "Forecaster Hunter Outten stated in a mid-November report that within a 60-day "Long Range Cycle" would be a significant event in the mid-December period. With the long duration period of cold weather to dominate much of the nation this week, the stars appear to be aligning for what could be the final significant coastal storm of the year to occur in the December 12-15 period."
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