00z Euro 2/15/2011

[NEG NAO]

about .25-.35

Advisory level amounts - should be interesting in their final update who HPC belives - my guess is a blend of the gfs = euro - snow changing to rain BUT the Euro has been consistant the last couple runs and the GFS has not - and the EURO is better at 7 days

[NJwinter23]

I just cannot come to grips how this could ever be a snowstorm this far south with that trough digging on the west coast, but we'll see.

[earthlight]

I just cannot come to grips how this could ever be a snowstorm this far south with that trough digging on the west coast, but we'll see.

Strongly agree. This run, the confluent flow is strong enough. That being said I don't think this pattern is conducive to such a development. We shall see, still a long ways to go.

[bmc10]

Strongly agree. This run, the confluent flow is strong enough. That being said I don't think this pattern is conducive to such a development. We shall see, still a long ways to go.

I stated earlier in a post how a snowier solution could evolve, although unlikely, not impossible.

[H2Otown_WX]

Strongly agree. This run, the confluent flow is strong enough. That being said I don't think this pattern is conducive to such a development. We shall see, still a long ways to go.

Last night's 00z GFS had a solid 50/50 low as well which forced it underneath us.

[NEG NAO]

HPC says LOW Confidence Forecast

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

208 PM EST TUE FEB 15 2011

VALID 12Z FRI FEB 18 2011 - 12Z TUE FEB 22 2011

D+7/D+8 MULTI-DAY MEAN CHARTS SHOW REASONABLY SIMILAR IDEAS TO

YDAY... WITH A MEAN TROF ALONG OR JUST INLAND FROM THE WEST COAST

AND MEAN RIDGE OVER THE GULF OF MEXICO/NRN CARIBBEAN. THE BEST

DEFINED CORES OF HGT ANOMALIES ARE A POSITIVE CENTER OVER THE NRN

PAC JUST S OF THE ALEUTIANS AROUND 160-175W LONGITUDE AND A

NEGATIVE CENTER OVER THE ATLC TO THE SE OF CANADIAN MARITIMES.

THE MOST AGREEABLE TELECONNECTION RELATIONSHIP IS TO FAVOR

MODESTLY ABOVE NORMAL HGTS OVER THE ERN CONUS. HOWEVER THERE ARE

DIFFS WITH DETAILS OF THE MEAN TROF NEAR THE WEST COAST. EXACT

POSN OF THE NRN PAC POSITIVE CENTER ALSO HAS SOME INFLUENCE ON THE

AXIS/ORIENTATION OF THE WRN TROF. IN ADDITION THESE

TELECONNECTIONS INDICATE AN AREA FROM THE LOWER MS VLY INTO THE

TN/LOWER OH VALLEY AS BEING MOST FAVORED FOR PCPN IN THE EXPECTED

MEAN PATTERN.

FOR THE MOST PART SIGNIFICANT MODEL/ENSEMBLE SPREAD AND RUN TO RUN

DIFFS AMONG INDIVIDUAL MODELS LEAD TO LOWER CONFIDENCE IN ANY

PARTICULAR DETAILS VERSUS 24 HRS AGO. ALREADY AS OF EARLY DAY 3

FRI THE 00Z ECMWF IS ON THE FAST SIDE OF THE SOLN SPREAD WITH THE

SYSTEM NEAR CA WHILE THE 00Z/06Z GFS AND 00Z GEFS MEAN ARE ON THE

SLOW SIDE OF THE SPREAD. GFS/GEFS MEAN/ECMWF/EC MEAN RUNS BRIEFLY

ACHIEVE A RELATIVE CONSENSUS WITH THE MID LVL TROF ENTERING THE

WEST ON DAY 5 SUN... WITH THE UKMET/CMC FASTER. HOWEVER AS OF

THIS TIME SOLNS ARE ALREADY DIVERGING NOTICEABLY OVER THE BERING

SEA/NRN PAC INTO THE NERN PAC... WHICH WILL ULTIMATELY IMPACT

EJECTION OF THE INITIAL WEST COAST TROF ACROSS THE CONUS DURING

SUN-TUE. WITH THE EVOLVING UPSTREAM FLOW BY DAYS 5-7 SUN-TUE THE

00Z ECMWF BECOMES RATHER EXTREME WITH ITS NERN PAC TROF

AMPLIFICATION WHILE THE 00Z GEFS MEAN BECOMES ONE OF THE FLATTER

SOLNS OVER THE NERN PAC INTO WRN NOAM. 00Z/06Z GFS RUNS BECOME

QUITE AMPLIFIED WITH THEIR WRN CONUS TROFS BY NEXT TUE IN CONTRAST

TO THE VERY LOW GEFS MEAN AMPLITUDE. THE 00Z ECMWF ENSEMBLE MEAN

DEVELOPS A LATE PERIOD WRN TROF MORE SIMILAR TO THE GFS RUNS BUT

WITH LESS SHARPNESS/DEPTH. FARTHER EWD THE TROFFING THAT THE 00Z

ECMWF DEVELOPS OVER THE NERN CONUS BY NEXT TUE DOES NOT COMPARE

WELL TO ENSEMBLE MEANS OR TELECONNECTION FAVORED FLOW.

DUE TO THE LACK OF CONFIDENCE WITH INDIVIDUAL MODEL SOLNS... THE

DAYS 3-7 FRI-TUE UPDATED PRELIM FCST STARTS WITH A

BLEND/COMPROMISE OF THE 00Z GEFS/ECMWF ENSEMBLE MEANS WHICH IS

WEIGHTED MORE TO THE ECMWF MEAN FROM LATE DAY 5 ONWARD DUE TO THE

GEFS MEAN POSSIBLY BECOMING TOO FLAT WITH WRN NOAM FLOW BY EARLY

NEXT WEEK. THE INITIAL BLEND IS ADJUSTED TO ADD DETAIL ESPECIALLY

TO CNTRL-ERN CONUS LOW PRESSURE MID-LATE PERIOD. FURTHER LOWERING

CONFIDENCE IN THE FCST IS THE FACT THAT BY THE LATTER HALF OF THE

PERIOD THE MODELS/ENSEMBLE MEANS HAVE LESS QPF FOCUS ON THE LOWER

MS-TN VALLEY REGION THAN SEEMS TO BE RECOMMENDED BY

TELECONNECTIONS. IT REMAINS TO BE SEEN WHETHER GUIDANCE COULD BE

UNDERDONE WITH WARM SECTOR RNFL AS THERE IS SOME DEGREE OF GULF

INFLOW... OR MASS FIELDS MAY ULTIMATELY ADJUST TO FAVOR MORE RNFL

WHERE FAVORED BY TELECONNECTIONS.

12Z UPDATE... DETAILS ALONG THE WEST COAST AS OF EARLY DAY 3 FRI

REMAIN UNRESOLVED AFTER ARRIVAL OF 12Z SOLNS SO AN INTERMEDIATE

SOLN REMAINS PREFERRED HERE. FASTER TREND OF THE 06Z/12Z GEFS

MEANS WITH THE CNTRL-ERN CONUS LOW PRESSURE ASSOC WITH THE

EJECTING WEST COAST TROF... ALONG WITH SOLNS PRESENTED BY 12Z

MODELS ASIDE FROM THE SLOW/DEEP CMC... FAVOR ADJUSTING THE FINAL

FCST SOMEWHAT FASTER/STRONGER THAN THE UPDATED PRELIM ISSUANCE.

AS A RESULT SOME 06Z GEFS MEAN AND SMALL PROPORTION OF OPERATIONAL

GUIDANCE WAS INCLUDED TO BRING TIMING SOMEWHAT AWAY FROM THE

SLOWER EDGE OF GUIDANCE. THE 12Z ECMWF SUPPORTS THIS ADJUSTMENT

IN PRINCIPLE... THOUGH BY DAY 7 TUE IT IS ON THE SRN SIDE OF THE

SOLN SPREAD. THE FINAL MANUAL FCST REPRESENTS A COMPROMISE

LATITUDE. FARTHER WWD THE 12Z ECMWF/GFS ARE BOTH FAIRLY EXTREME

WITH THEIR WEST COAST SOLNS BY DAY 7 TUE BUT AT LEAST THE 12Z

ECMWF HAS TRENDED SIGNIFICANTLY TOWARD BEST GUIDANCE CLUSTERING

WITH UPSTREAM NERN PAC FLOW AT THAT TIME.

THE WRN STATES SHOULD SEE PERSISTENTLY BELOW NORMAL DAYTIME TEMPS

WITH PERIODS OF UNSETTLED WEATHER DURING THE PERIOD. AREAS ALONG

THE WEST COAST AND FAVORED TERRAIN FROM THE GRTBASIN/SOUTHWEST

INTO THE CNTRL ROCKIES SHOULD HAVE THE HIGHEST PCPN TOTALS FOR THE

FULL FCST PERIOD. THE CNTRL-ERN CONUS WILL SEE A DECENT

TEMPERATURE GRADIENT FROM N TO S... WITH VARIABLE TO BELOW NORMAL

TEMPS NRN AREAS AND ABOVE NORMAL OVER THE SOUTH. MUCH OF THE EAST

WILL SEE WELL ABOVE NORMAL HIGHS ON FRI WITH SOME LOCATIONS E OF

THE APLCHNS POSSIBLY REACHING TO WITHIN A FEW DEGS OF RECORD

LEVELS. INITIAL FRONT CROSSING THE EAST WILL BE ACCOMPANIED BY

MOSTLY LGT RNFL. THEN AN EXPANDING AREA OF PCPN OF VARYING

INTENSITY SHOULD AFFECT AREAS FROM THE PLAINS EWD SUN ONWARD...

WITH THE RAIN/SNOW TRANSITION ZONE MOST LIKELY TO SET UP ACROSS

N-CNTRL AREAS.

RAUSCH

[earthlight]

HPC says LOW Confidence Forecast

Very shocking at this range..surprised to see them going out on such a limb.

[NEG NAO]

Very shocking at this range..surprised to see them going out on such a limb.

Just taking their new graphics at face value looks like north of a line from AC - Pitt at least starts as snow - question is - will a secondary form off of south jersey to keep the cold air locked in north of 40....

http://www.hpc.ncep.noaa.gov/medr/5dayfcst_wbg.gif

[Quincy]

ECMWF looks good

[rossi]

What does the rest of Euro look like?

Does it stay cold or do we go into spring?

Rossi

[uofmiami]

What does the rest of Euro look like?

Does it stay cold or do we go into spring?

Rossi

Looks warm after Day 8:

[TomieV]

What happened to Tombo?

[bmc10]

Although the EURO supports a snow event, overall it looks ugly down the road. The blocking is transient and the SE ridge flexes its muscles. Another interior cutting storm with no blocking would result in another warm period for the eastern US.

[A-L-E-X]

I just cannot come to grips how this could ever be a snowstorm this far south with that trough digging on the west coast, but we'll see.

Omega block? Trough west coast, ridge in the middle, another trough on the east coast. That would do it.

[A-L-E-X]

Hey JM I see you reading this thread-- take a look at the NESIS maps for Jan 26-27 (Cat 1), they have us under 4-10 inches of snow for that storm.... I think we got that much in one hour lol.

[pazzo83]

What happened to Tombo?

tom's a philly guy

[TomieV]

Thanks Pazzo

[EasternLI]

Hey cool, I haven't been paying attention for a little while but it looks like there's something to be interested in. Happy return of winter everyone (hopefully).

[CooL]

Looks like the 00z gfs took a step towards the euro. Low is weaker and further south and therefore colder, still need some work but its something to watch atleast. All hope is not lost

[bmc10]

Going to be interesting to see what this run of the euro produces. Already at 120hrs the confluence is much more pronounced with a strong 1036mb area of HP and a strong block. The polar vortex is situated just to the north and the pattern is flat/progressive. Wonder how this will affect the storm, will it be squashed? Or will energy eject?

[bmc10]

WOW at 132hrs the euro goes wild! Huge block, large area of hp, and strong confluence with much colder temps over the entire eastern US with surface and 850's down to northern NC. Storm developing over the plains and ejecting into the cold dome of HP...looks like an overrunning setup!

[uofmiami]

EC DAY 6:

[bmc10]

At 150hrs continues progression eastward passing south of Illinois. Plenty of cold to support snow as this moves east, question is will there be any moisture?

[bmc10]

It fizzles out, light snow for the area.

[uofmiami]

EC DAY 7:

[Wxoutlooksblog]

It fizzles out, light snow for the area.

Light snow? Hmm. If this solution were correct, there's incredible blocking, lots of cold air, 500mb low in position to wrap this all up the coast slowly...light snow? I don't think so.

WX/PT

[jconsor]

Something to watch that no one is mentioning - the ECMWF indicates the potential for snow squalls late Sun afternoon and night, as the arctic front crashes through and a weak wave develops south of Long Island. RH values are better over New England and upstate NY than the immediate NYC area, however.

The Canadian hints at this as well.

Does the 0z ECMWF show any measurable QPF on Sun/Mon?

[jconsor]

I would say the opposite - I'm not sure I can come to grips how this can be a significant snowstorm this far *north* given the trough digging on the west coast, the strong confluence, and the polar vortex dropping into southern Quebec/northern New England ahead of the storm.

I'm more concerned this system will minor out and the sfc low will be squashed south over VA/NC than I am about a Lakes cutter with mainly rain and freezing rain.

I just cannot come to grips how this could ever be a snowstorm this far south with that trough digging on the west coast, but we'll see.

[bmc10]

Light snow? Hmm. If this solution were correct, there's incredible blocking, lots of cold air, 500mb low in position to wrap this all up the coast slowly...light snow? I don't think so.

WX/PT

Yea but the EURO depicts a progressive zonal flow, and so that does not happen. Things have, can, and will continue to change.

[SnowGoose69]

I would say the opposite - I'm not sure I can come to grips how this can be a significant snowstorm this far *north* given the trough digging on the west coast, the strong confluence, and the polar vortex dropping into southern Quebec/northern New England ahead of the storm.

I'm more concerned this system will minor out and the sfc low will be squashed south over VA/NC than I am about a Lakes cutter with mainly rain and freezing rain.

I could see it going both ways...many of these systems in the pattern back in December were sqaushed but we had a severely -NAO then...this time I would tend to lean towards it going north though seeing the Canadian and Euro want to be south of the GFS is remarkable...thats a rarity on a SW flow type system.