Sunday-Monday Mid-Atlantic Event

[jacindc]

Goodness gracious, where IS everybody? Possible wintry mix in the mid-Atlantic on Saturday, then a second storm winding up Sunday-Monday, and there's not a soul in here? Is everyone still too busy with Epsilon? It's WINTER, people!

Here's the new discussion from LWX about Sat-Tues:

.LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...

MODELS ARE IN RELATIVELY CLOSE AGREEMENT WITH RESPECT TO THE
PATH/POSITION OF THE PAIR OF LOW PRESSURE SYSTEMS THAT WILL CROSS
THE REGION THIS WEEKEND. THE FIRST LOW...EXPECTED ON SATURDAY
NIGHT...IS WARMER AND WEAKER THAN THE SECOND. THIS FIRST SYSTEM WILL
CROSS DIRECTLY OVER THE FORECAST AREA ON SATURDAY NIGHT. THE WARM
FRONT IS EXPECTED TO HELP THE CHANGE OVER OF PRECIPITATION AS IT
MOVES NORTH. THIS FRONT WILL HAVE LITTLE IMPACT HOWEVER ON THE FAR
NORTHERN AND WESTERN TIERS. BUFKIT SOUNDINGS INDICATE A COMPLETE
MIXTURE OF PRECIP WITH THIS FIRST SYSTEM...BEGINNING WITH
SNOW...THEN MIXING...THEN CHANGING OVER TO ALL RAIN. ICING MAY BE A
PROBLEM...AS TEMPERATURES ARE EXPECTED TO HOVER THE FREEZING MARK.
WILL LEAVE THIS FOR FUTURE SHIFTS TO FINE TUNE.

THE SECOND SYSTEM IS MORE IMPRESSIVE. THIS IS APPROACHING FROM THE
SOUTHEAST AND PASSING OVER THE CAROLINAS...MAKING IT A MUCH MORE
FAVORABLE WINTER WEATHER SCENARIO FOR THE REGION. A STRONG COLD POOL
WILL NOT HAVE TOO MUCH TIME TO SETTLE IN PLACE...BUT 850
TEMPERATURES WILL STILL BE BELOW ZERO. EXPECTING SNOW BY SUNDAY
EVENING ACROSS MOST AREAS...EXCEPT A MIX ACROSS THE SOUTHEAST. A
SECONDARY BAND OF SNOW IS POSSIBLE BEHIND THE SYSTEM WITH STRONG
UPSLOPE DEVELOPING...SO CONTINUED POPS FOR TUESDAY.

HIGH PRESSURE WILL BUILD IN BY TUESDAY NIGHT...USHERING MORE COLD
AIR INTO THE REGION. STUCK CLOSELY TO HPC GUIDANCE FOR WEDNESDAY
THROUGH FRIDAY. LONG RANGE GFS INDICATES YET ANOTHER LOW APPROACHING
THE REGION BY THURSDAY NIGHT AND FRIDAY. FOR NOW...WILL LEAVE OUT
MENTION OF PRECIPITATION AT THIS TIME.

&&

[Tip]

Both the Euro and the NAM are showing the Monday storm out to sea. Nothing much north of DC. The 3rd short wave at about 168hrs on the Euro is even further suppressed to the south and may result in a southern snowstorm - NC south.

[Lowpressure]

Down here there is some short term interest, but the winter possibility seems best next Thursday-Friday with the Low coming out of the gulf and appearing to stay supressed as mentioned in the post above. We will be cold enough by late next week even in this region.

[WindRunner]

LWX was really playing up the storm this morning, and still are. Still labeling it as a significant event, with snow Sun night through Tues morn.

Link to my forecast:
FORECAST

[Lowpressure]

LWX planning to issue advisories for central VA to lower MD. Areas like Charlottesville and Fredericksburg may get 2-5 inches from the second (Monday) system. Windrunner, I would imagine Warrenton would be in the advisory area, they were not that clear. Looks like Warrenton to Quantico southward would be a good guess. Prince William will be iffy.

[Dave C]

The Mon nite-Tues storm is becoming less likely for New England. Only 1 model going for a hit as of this morning. If models don't trend north during today then will probably be a brush job for Southern New England. Our NWS is gradually backing off this storm but waiting to see any change in models before completely backing off. They are generally going with 1-3 inches for the weaker Sun. event with change to rain on Cape Cod.
http://www.erh.noaa.gov/box/products/BOSAFDBOX

[krysof]

This storm will be a I-95 issue and long island issue probably. Those areas may receive 6+ inches.

[WindRunner]

LWX planning to issue advisories for central VA to lower MD. Areas like Charlottesville and Fredericksburg may get 2-5 inches from the second (Monday) system. Windrunner, I would imagine Warrenton would be in the advisory area, they were not that clear. Looks like Warrenton to Quantico southward would be a good guess. Prince William will be iffy.

Yeah, we're always on the edge of things out here, either the edge of the mountain snows, the edge of the coastal storms that dump on the eastern half, and the edge of these little Carolina storms that brush to the south. Usually we're pretty close to the freeze line as well, but that doesn't appear to be an issue this time. It's gonna be close, but I wouldn't be surprised to see a slight northern shift of that area LWX is defining there, it seems awfully far south to me. However, I might have a little bit of bias in saying that.

BTW, Fauquier County just got bumped up into the area to recieve freezing rain tonight. Fun on the roads for sure.

[Mike2002]

So what do you guys think Central Virginia could get out of this. More specifically Richmond and the surrounding areas. Enough to make the roads slippery in the morning?

[EFrancis]

I would certainly say so.

[WindRunner]

Richmond area, they probably won't be slippery tomorrow morning, but most likely Monday morning they will.

[Lowpressure]

Monday seems to be the time for Richmond -which is normally void of snow- to get in on some action. Richmond is strange in regards to snow. I lived in Fredericksburg for 2 1/2 years and was amazed at how Richmond was right on the edge.

[Tri-State_1925]

The Mon nite-Tues storm is becoming less likely for New England. Only 1 model going for a hit as of this morning. If models don't trend north during today then will probably be a brush job for Southern New England. Our NWS is gradually backing off this storm but waiting to see any change in models before completely backing off. They are generally going with 1-3 inches for the weaker Sun. event with change to rain on Cape Cod.
http://www.erh.noaa.gov/box/products/BOSAFDBOX

Yeah, they were downplaying it on TV too this morning, but you should check out this afternoon's update...

.LONG TERM (MONDAY THROUGH SATURDAY)...
CONFIDENCE IS GROWING IN A SIGNIFICANT WINTER STORM FOR MUCH OF SNE
LATE MON NGT INTO TUE. SFC LOW ACRS SE US ON MON WILL LIFT NE AS IT
INTERACTS WITH UPPER TROF MOVING EWD ACRS PLAINS AND TN VLY. THE
QUESTION IS HOW CLOSE WILL THIS STORM GET TO SNE AND RESULTING
IMPACT.

MODELS ARE TRENDING TOWARD A SOLUTION TAKING COASTAL STORM NEAR OR
JUST OUTSIDE THE BENCHMARK. 12Z GFS TRENDED FURTHER WEST AND DEEPER
AND IS SIMILAR TO MAJORITY OF ENSEMBLE MEMBERS WITH LOW NEAR
BENCHMARK BY 18Z TUE. ECMWF AND EVEN NAM ALSO TRENDED FURTHER W AND
UKMET/GGEM TRACKS LOW CLOSE TO BENCHMARK BUT ARE SLOWER THAN GFS.
GIVEN PROGRESSIVE UPPER TROF FASTER GFS SOLUTION PREFERRED AND WILL
BE FOLLOWED FOR THIS FORECAST.

COASTAL LOW FCST TO UNDERGO RAPID DEEPENING LATE MON NGT INTO TUE AS
IT COMES UNDER INFULENCE OF COUPLED JET STRUCTURE. BUT SYSTEM WILL
BE A QUICK MOVER IN PROGRESSIVE FLOW SO IT SHOULD BE MOSTLY DONE BY
LATE TUE. LOW TRACK IS EXPECTED TO BE FAR ENOUGH S TO DRAW COLDER
AIR SWD TO ALLOW FOR ALL SNOW EVENT FOR MOST OF SNE. SOUNDINGS AND
PARTIAL THICKNESS PROFILE SUPPORT THIS. HOWEVER...LOW LEVEL ELY
FLOW OFF WARMER OCEAN WILL LIKELY WARM BL ENOUGH FOR MIX OR EVEN CHG
TO RAIN FOR OUTER CAPE AND ISLANDS BY TUE MORNING BEFORE CHANGING
BACK TO SNOW TUE AFTN AS LOW LEVEL WINDS BACK MORE TO N.

EXPECT SNOW TO OVERSPREAD FA FROM S TO N AFTER MIDNIGHT WITH
HEAVIEST SNOW NEAR 12-18Z PERIOD. VERY STRONG MID LEVEL FGEN
COMBINED WITH STEEP MID LEVEL LAPSE RATES SUPPORTS BURST OF HEAVY
SNOW TUE MORNING...ESPECIALLY ALONG I-95 CORRIDOR. GOOD MESOSCALE
CSI BANDING SIGNAL WITH -EPV ABOVE STRONG FGEN SIGNATURE AND MAX
LIFT INTERSECTING FAVORED THERMAL ZONE FOR OPTIMUM SNOW GROWTH. IF
THIS ALL PLAYS OUT THE WAY IT IS CURRENTLY MODELED SNOWFALL RATES OF
2"/HR PSBL. NO WATCHES YET AS THIS IS STILL DAY 3 SO WILL UPDATE
SPS.

OPERATIONAL GFS SHOWING QPF 0.5"-1" FROM I-95 EWD WITH MAX ON CAPE
COD. IT IS INTERESTING TO NOTE THAT ABOUT HALF OF ENSEMBLE MEMBERS
ACTUALLY SHOW 1"+ SE OF I-95. PRELIM THINKING IS FOR 5-10" SNOWFALL
NEAR I-95 CORRIDOR...LESS ON CAPE AS WELL AS NW MA/SRN NH. GIVEN
POTENTIAL FOR HIGHER QPF PER ENSEMBLES AND STRONG BANDING SIGNAL
THIS STORM HAS THE POTENTIAL TO BRING A FOOT OF SNOW BUT DURATION
WILL BE A LIMITING FACTOR. WE NEED TO SEE NEXT FEW MODEL RUNS
CONTINUE HITTING THIS STORM BEFORE WE BECOME MORE CONFIDENT OF A
FOOT OF SNOW.

[fasteddy77]

With respect to this storm, how does the Northern DC suburbs look?? Northern Central Maryland

[sphinx]

The NAM has "dropped its guns" and is no longer suppressing the Mon/Tue storm.

So ... it looks pretty good for the northern D.C. suburbs.

A "significant snow is likely". Don't you just hate when the forecasters say that! The NAM typically overdoes precip amounts but thicknesses should be low. Seriously, 4" or more looks very likely. 8" or slightly more a possibility.

[DS]

I think we're already seeing a very clear trend for this winter season- a rather strong bias to suppress storms too far south. Although, given a negative NAO, this is not too surprising.

[fasteddy77]

Thanks sphinx!

That was good to hear!! I'm originally from western PA, so any snow is great news!!

I'll cross my fingers for 4-8 inches!!

[Lowpressure]

Thanks sphinx!

That was good to hear!! I'm originally from western PA, so any snow is great news!!

I'll cross my fingers for 4-8 inches!!

Experience from living in D.C. has shown me that Fredrick gets colder and usually more snow than D.C. It stays out of the Ocean influence. I worked soem on FT Detrick last year and it would snow hard there and dwindle as I drove down 270 towards Metro. This is not your event , you may see some sbow, but this is a Charlotteville-Fredericksburg-Tappahannock event.

[angelwing]

Woke up to about an inch or 2 inches of wet snow on the ground here. It's stopped for now, but wondering how much Philly will get with the next one?

[Dave C]

Moderate to heavy bands moving through our area. Should end quickly this afternoon as back-edge is currently moving into western Conn. We have 1.5 inches now and could approach 4 before all is said and done. Next up.... Tuesday event, hopefuuly the models will converge on a solution today!