Storm track, rain/snow line uncertain for Mon/Tues
The chances we'll see some sort of snow, rain or mixed slop from late Monday into Tuesday crept upward a bit overnight as the National Weather Service bumped its forecast of the precipitation chances from 30 percent to 40 percent.
But uncertainties about the storm's track this far in advance leave unanswered those questions about which type of precipitation we should expect, or how much.
It's hard to say which outcome would be best for our winter-weary region. Rain would add weight to what remains on our rooftops, just as more snow would. It would also accelerate the melting and runoff, and could threaten wet basements and urban and river flooding.
And a wintry mix of rain and snow - perhaps the mostly likely outcome - would add an extra dash of misery all of us can do without.
The good news is that, for now, the sun is out, temperatures have reached the 40s and there is a lot of melting going on. Perhaps we can get rid of enough of this mess before Monday to minimize the impact of whatever falls next week.
In any event, it seems like a good time to dig some runoff channels through the snow pack if a fast melt would threaten flooding in poor drainage areas (like my back yard), and to open those storm drains and downspouts.
So what are those in our stable of forecasters saying this morning? Here's a bit of the forecast discussion from NWS Sterling:
"THE 00Z EURO [MODEL RUN] FEATURES A WEAKER BLOCKING LOW OFF THE CANADIAN
MARITIMES WHICH ALLOWS THE [STORM] SYSTEM TO TRACK NORTHEAST UP THE
APPALACHIANS...KEEPING THE [FORECAST AREA] IN THE WARM SECTOR WITH MOSTLY RAIN.
"A STRONGER BLOCKING LOW IN THE 00Z GFS [ANOTHER MODEL RUN] DIRECTS THE STORM ACROSS THE
[FORECAST AREA] IN A COLDER/SNOWIER SOLUTION. TIMING IS IN BETTER AGREEMENT IN
00Z GUIDANCE THAN PREVIOUS RUNS...BUMPED [PRECIPITATION PROBABILITIES] UP TO HIGHER CHANCES MONDAY/MONDAY NIGHT /WITH GEFS MEMBERS STILL SHOWING A WIDE RANGE OF
"WENT WITH A ROUGH AVERAGE OF THE TWO FOR
PRECIPITATION-TYPE...RAIN/SNOW SOUTHEAST AND SNOW NORTHWEST. PRECIP TYPE DEPENDS
ON THE LOW TRACK IN THIS CASE...SO WILL HAVE TO WAIT FOR BETTER [MODEL] AGREEMENT."
"...[Y]ou guessed it, the swath of heavy snow may roll into the central Appalachians and the mid-Atlantic Sunday night and Monday. While a wedge of warm air will try to work northward along the Atlantic Seaboard with this storm, odds favor mostly snow verses mostly rain at this time of the year, due to the cold ocean, cold ground, etc.
"While this does "not" appear to be a storm that produces 2 to 3 feet of snow, it will add more weight to the existing snow on the ground and on roofs, be it water or more snow. We will say the path of this storm is uncertain at this point, and the storm's exact track will determine if rain, snow, or nothing falls in your area. If the storm does track north of your snow-clogged area, concerns of flooding will be raised due to snowmelt."
Mr. Foot's forecast team has issued a "Level 1 Alert," warning of "potentially moderate to significant" snow and wintry precipitation Sunday night through Monday night.
Eric the Red, a professional meteorologist from Baltimore, throws up his hands at recent model runs that were "aaalll over the place ... Some are annoying, some are novelties, and of course there's always Armageddon."
The worst case he cites is the Canadian model:
"It takes a low from the southern Plains into northern Kentucky ... then another low explodes (ka-boom) in eastern North Carolina. The Canadian [model] then drifts the low in Delaware, where it stalls. I'm not makin' this up."
"At this very early juncture, I think the MD/DC/VA region is under the gun for another significant winter storm. Major? Hopefully tomorrow's data will clear that up."
(SUN PHOTOS/Top: Karl Merton Ferron/Bottom: Algerina Perna)