MON 0Z NOGAPS: intense SE US Arctic outbreak plunges FRI

[LarryWx]

If the newest NOGAPS run (the MON 1/26 0Z run) is anywhere near correct, the coldest air of the winter by far will be plunging into the southeast US on Friday. The prior run was already quite cold for Friday for the SE. This latest run is even quite a bit colder than that run. This intense cold for the SE is in direct conflict with the ECMWF and the GFS. So, confidence in this solution has to be fairly low for at least the time being.

Here is the link to the brutal cold looking 132 hour 500 mb map:

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 00&tau=132

Notice the 528 500 mb HEIGHT (not thickness) line pointing almost straight southward ~2000 miles and making a beeline from Baffin Island, Canada to northeast GA! This map has "historical cold wave" written all over it for a lot of the SE.

Here is the 132 hour 850 mb map:

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 50&tau=132

Note the ~-20C air making it into extreme NE GA!

But then again, this is only a model that is somewhat of an outlier. So, I am taking it with a grain of salt right now. However, we're only talking ~5 days away here, not 14 or 10 or even 7 days away. So there may be something to this.

[WEATHER53]

Better detail than I had but about 3 days ago I posted on WWBB that Fri-Sun would be bitter cold in DC area, NWS and TWC highs of 40's at that time were not in the realm, now we finally have snow cover after some impressive daytime highs 20-27 in full sunshine with bare ground, you can take off 5-7 degrees with the snow pack in full sunshine and if we got some cloud cover, might not get above 15.
That 850 would be a 7am temp of 5-10 at DCA and sharp almost V shape plunge has classic signature of cold air plunging kicking off spin in gulf, we are getting 6-8" in DCA right now with no real low, equally cold temps as now with some gulf tiger would put these lat two winters into the back to back record books.

[LarryWx]

Better detail than I had but about 3 days ago I posted on WWBB that Fri-Sun would be bitter cold in DC area, NWS and TWC highs of 40's at that time were not in the realm, now we finally have snow cover after some impressive daytime highs 20-27 in full sunshine with bare ground, you can take off 5-7 degrees with the snow pack in full sunshine and if we got some cloud cover, might not get above 15.

Hey 53,
Long time no see. Good to see you posting. Your (and KA's) insight is always interesting since it seems kind of unique.

[WEATHER53]

Wanted to revive this as a lot of back and forth about what is next. When the "V" shaped plunging of cold air reaches down toward the gulf, it is historically an excellent catalyst for kicking off some spin that moves northeast and up the coast.

[PTrackerLA]

Shreveport NWS Discussion hints at very cold air possible.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
ISSUED BY NWS FT WORTH TX
300 PM CST TUE JAN 27 2004

.SHORT TERM...
ANOTHER VERY COLD NIGHT IN STORE FOR THE ARKLATEX REGION TO THE MS
RIVER...AS HIGH PRESSURE EASES SLOWLY EWD ACROSS THE CWA. NEAR CALM
WINDS AND CLEAR SKIES SHOULD RESULT IN MAXIMUM RADIATIVE COOLING
POTENTIAL AND COMBINED WITH VERY DRY AIRMASS (DEW PTS BETWEEN 5-15
DEG F)...TEMPS SHOULD DROP INTO THE UPPER TEENS/LWR 20S NORTHEAST
...LWR-MID 20S SOUTHWEST...WHERE SOME RETURN FLOW OF 5-10 KTS IS
EXPECTED TO OCCUR AFTER MIDNIGHT. FEEL OVERNIGHT LOWS SHOULD STAY
JUST OUT OF HARD FREEZE CRITERIA AND WILL FOREGO ANY SUCH ISSUANCE
FOR NOW PER COORDINATION WITH OTHER OFFICES. EVEN WITH GRADUAL
INCREASE IN RETURN FLOW WED AND AMPLE INSOLATION WED...FEEL THAT
AIRMASS WON'T MODIFY QUITE THAT QUICKLY...ESPECIALLY THIS TIME OF
YEAR. WILL LEAN WITH COOLER MAV NUMBERS FOR HIGHS WED.

SLY FLOW WILL INCREASE BY WED NIGHT AS PRESSURES FALL ALONG SRN
ROCKIES AHEAD OF ARCTIC COLD FRONT NOW DRIVING THROUGH WY/SD (VERY
COLD AIR) AND SRN STREAM DISTURBANCE CURRENTLY DIVING RAPIDLY SEWD
ACROSS CA/NV. PER CURRENT TEMPS BEHIND COLD FRONT AND SNOW PACK AS
FAR SOUTH AS NRN OK/AR...WE'RE CONCERNED THAT MODELS AREN'T HANDLING
THE SPEED/OR TIMING OF THIS SHALLOW...YET BITTERLY COLD AIRMASS.
HEIGHT FALLS EXPECTED AHEAD OF SRN STREAM SHORTWAVE ARRIVING THURS
NIGHT...WE'RE VERY CONCERNED THAT SOME OF THIS ARCTIC AIR COULD
SNEAK SWD INTO AT LEAST INTO NRN/WRN SECTIONS OF THE CWA AND
UNDERNEATH THE CONFLUENT FLOW ABOVE. THEN OVERSPREAD THE ENTIRE CWA
BY 12Z FRIDAY. WILL PLAY IT CONSERVATIVE THIS FAR OUT...BUT LOWER
TEMPS OVER W/NW ZONES AT LEAST A COUPLE OF CATEGORIES THURS AND
LOWER TEMPS MOST OF CWA FOR THURS NIGHT. IF TRENDS NEXT 24 HRS
CONTINUE...TEMPS WILL NEED TO BE LOWERED MUCH MORE SO THAT WE'LL
INDICATE ON THIS PACKAGE. THIS WILL BE INTERESTING TO WATCH. &&

.LONG TERM...
COLD FRONT EXITS EAST OF THE MS RIVER BY 12Z FRIDAY. TEMPTED TO
REMOVE LOW RAIN CHANCES BY 06Z FRIDAY/AFTER...AS SUBSIDENCE AND NWLY
FLOW ALOFT ENSUE. MEX GUIDANCE FOR FRIDAY AND EVEN SATURDAY LOOKS
TOO WARM...AND WILL LOWER MAXES DOWN ON BOTH DAYS. OTHERWISE...MUCH
UNCERTAINTY THIS UPCOMING WEEKEND AND BEYOND...AS MODELS DIVERGE
QUITE SIGNIFICANTLY AND ARE WELL OUT OF PHASE THIS TIME FRAME. MAY
TWEAK A FEW TEMPS...BUT LEAVE FCST THIS FAR OUT ALONE UNTIL BETTER
MODEL AGREEMENT CAN OCCUR.

[SacrydDreamz]

12z GFS Ensembles and 00z EURO (from what I hear) support a potential SECS for the lower Mid-Atlantic into NC. Looks quite chilly afterwards! The Southeast has been left out of the cold thus far this winter.. it's about time you guys got yours.

BCB is FINALLY below normal for the month.. impressive considering the first five days were +12, +13, +21, +28, and +15. Also had a +10 on the 12th and a +9 the following day. Here ya go.. http://www.erh.noaa.gov/rnk/climate/f6/ ... KSBURG.txt

[Stormsfury]

12z GFS Ensembles and 00z EURO (from what I hear) support a potential SECS for the lower Mid-Atlantic into NC. Looks quite chilly afterwards! The Southeast has been left out of the cold thus far this winter.. it's about time you guys got yours.

BCB is FINALLY below normal for the month.. impressive considering the first five days were +12, +13, +21, +28, and +15. Also had a +10 on the 12th and a +9 the following day. Here ya go.. http://www.erh.noaa.gov/rnk/climate/f6/ ... KSBURG.txt

It's been COLD believe me in Lower South Carolina, but it's been VERY DRY .. yesterday's icestorm (and heavy rainstorm, with some ZR in Lower SC was the heaviest precip event so far this year, with 1.3" of rain, and a trace of ice ...)

SF

[PTrackerLA]

SF do you think the arctic blast will move all the way down to the gulf coast? And with this weather system coming in Friday is there any chance for frozen precip? Y'all have been seeing all the action lately, time to let the deep south have some excitement.

[sertorius]

The forecast here in North east Kansas has changed drastically-we went from forecasted highs tomorrow and Thursday 40-45 down to the teens!! The models just didn't pick up on this arctic (the GFS had us 50 on Thursday) front untill now-they had it, lost it and now broght it back-the other thing, is that now there is snow and ice all the way to Wichita Kansas so this cold air won't modify alot if it indeed does come-it has already passed through the Dakotas and we are now getting high clouds as it approaches!!

[Anonymous]

Any Arctic airmass that comes on down the pike here in the EUS will find all the snowpack that will indeed keep it from ever modifying!!!

Now we will have extremely cold air that I will take jebwalks in with utmost gusto!!!!!!!!!



-JEB!!!!!!!!!!!!!!!!!!!!!!! JUST BRING IT, GREENLAND BLOCK!!!!!!!!!!!!!!!!!!!!

[WEATHER53]

Two more clippers coming to reinforce the cold air, snow cover takes 5-7 degrees off projected values and most projections are too high anyway, Thursday barely breaks the streak of consectuvie days nto above freezing at DCA, now 6, but Fri-Sun will have highs in the 20's.

[WEATHER53]

Going to be interesting to see how it pans out, LWX issued statment referencing their need to dramatically reduce temperature outlooks.

[CaptinCrunch]

NATIONAL WEATHER SERVICE FORT WORTH TX
355 AM CST

ARCTIC AIR CONTINUES TO MEANDER SLOWLY SOUTHWARD THIS MORNING...AND IS
CURRENTLY NEAR AN OKC TO AMA LINE. INCREASING WARM AIR ADVECTION
PATTERN AHEAD OF APPROACHING SHORT WAVE WILL CONTINUE TO CAUSE
PROBLEMS FOR THE ARCTIC AIRMASS...WHICH HAS LOST MUCH OF ITS
PUNCH...AS SEEN BY THE PRESSURE FALLS IN OKLAHOMA AND KANSAS.
EXPECT A VERY SLOW PROGRESSION SOUTHWARD THROUGH THE DAY...AS MIXING
ALONG THE LEADING EDGE CONTINUES. WARM AIR ADVECTION OVER NORTH
TEXAS TODAY WILL BRING CLOUDY SKIES...SOME INCREASING LOW LEVEL
MOISTURE...AND TEMPERATURES IN THE 50S TO LOWER 60S. APPROACHING
SHORT WAVE MAY KICK OFF A FEW SPRINKLES OR SHOWERS THIS AFTERNOON
AND EVENING...MAINLY IN THE SOUTHEAST. BY TONIGHT...SOME OF THE
MODIFIED ARCTIC AIR WILL MOVE INTO NORTH TEXAS...AS THE SHORT WAVE
MOVES SOUTHEAST. ALTHOUGH...TEMPS WILL COOL INTO THE 20S TO LOWER
30S...THE FULL BRUNT OF THE ARCTIC AIR SHOULD REMAIN NORTH OF THE
REGION.

[Anonymous]

Going to be interesting to see how it pans out, LWX issued statment referencing their need to dramatically reduce temperature outlooks.

I am so thankful for our snowpack with its high albedo that constrains our high temps and promotes free-fall of our overnight lows that I want to cry genuine tears of joy It's been a long time since we have actually had snowpack AND arctic air at the same time here in N VA!!




-ICE MAN JEB, and darn proud of it!!!!!

[WEATHER53]

Keeping this oldie but goodie going. Cold air, especially enhanced by snowpack, has been underestimated both in intensity and duration and pricipally duration. I do not see any sign as far out as 2/7-2/10 for any real mild up, after that is harder to say. Yesterday was just about like same day last week, one day mild up only this time instead of upper 40's we had near 40 due to snowpack, then back to the -10 and colder departures from normal. Sat will have highs 27-30 in DC area, sunday 30-33, Monday 32-35. See more emphasis now being placed on early week rather than late week event, cold air looking better for early week I think but early week does not seem to get far enough south to get gulf moisture involved and seems to count on western low redeveloping off coast which often screws DC area although secondary placement seems more along nc/sc coatal border rather than Va coastal area which definitely helps DC area. Either way, DC/mid atlantic has a very legitiamte snow threat next week, I still do not see a moster as this has not been the year of the monster, but a lot of nice 4-6", may see 8" DCA/BWI/IAD next week.

[thstorm87]

do you really think we have a shot an decent snow here in philly next week? Because I am having doubts after hearing what jb has to say.

[WEATHER53]

do you really think we have a shot an decent snow here in philly next week? Because I am having doubts after hearing what jb has to say.

I am not sure what JB did say, heard something to effect that he expected first tow weeks of Feb would not be as cold as Jan which is kind of like saying first two weeks of Sept will not be as hot as August-it just goes to figure climatologically to be so. I think with both events next week DC and Phillie will be in about the same boat, not big differentiaion these times.