STORM2K

Right now, it doesn't appear that the Sunday/Monday storm will be as big as the event that exited off the NE coast today. The models are in some agreement that the low by day 3 will off the Carolina coast (probably once again near the thermaline of the Gulf Stream) with the 850mb low just inland from that ...

This low may take a similar track ... but right now, some speculation about the degree of "phasing" that will take place with the northern stream and southern stream energy ... Upon further discussion, and input from other knowledgable sources ... it appears there is some potential for a more substantial system than being depicted on the models ...

Again, the North Carolina Mountains will likely see all snow ... probably not as much as the 6-8" reported in a couple of counties. Right now, looks like Raleigh, NC will be on the imfamous rain line with snow just to the NW of there.

This system should not run up the coast, and probably will not have quite as much moisture to work with unless a more substantial system develops.
Right now, my thinking is either the PV (polar vortex) will either squash the SS s/w energy down and remain weak, or it will outrace the PV and not phase until it has raced out to sea on Monday ...

With that in mind ... Next Friday/Saturday definitely looks very interesting.
A potential for a SECL exists on this one ... but since this is 7-9 days out, I'll keep this brief.

The Day 7 ECMWF (500 mb Geopotential Heights)
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Southern Stream Energy in the SW will likely be ejected in the form of a surface low in Western Texas on Day 7. New energy may then develop in the Western GOM producing quite an overrunning event. A very strong surface high (1030+mb) in Eastern Canada expected to nose down very bitter arctic air - 850mb temperature below -30C in Northern NE. -

However, the degree of cold air penetrating down into the Southeastern regions is up for speculation right now ...

I will have more on the weekend possibilities in a couple of days.
I will hopefully have more on the Sunday/Monday event sometime tomorrow afternoon ...

Quick update on Sunday/Monday event - The ETA/GFS 06z run have slowed the development and speed of the surface reflection along the SBJ. I will not get into specifics but a degree of phasing of the northern and southern stream energy appears quite possible now, hence with this development, there is some potential for a bigger storm, not a SECL just yet but the 500mb trough goes neutral in 48 hrs, (BOTH ETA/GFS show this) - there is some degree of phasing at 60 hrs depicted by the GFS.

12z runs are going to be quite interesting.

12z Model Runs haven't shed any light in regards to agreement

The 12z GFS very aggressive in developing a decent size storm in 60 hrs
While the 12z ETA develops nothing, nada...Just some light snow showers over the MA and NE.

Henceforth, I am convinced that I need a couple more model runs before issuing anything more substantial at the time...except that the potential exists for a moderate quick moving system which could produce snows in the NC Mountains and parts of Central NC Northward.

However, this is from HPC ...for the next weekend event ...
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
138 PM EST SAT FEB 08 2003

VALID 12Z TUE FEB 11 2003 - 12Z SAT FEB 15 2003


PATTERN AND MODEL OVERVIEW...

MODELS AGAIN TDA CONT TO BE IN GOOD OVERALL AGREEMENT
KEEPING A PNA PATTERN OVER NOAM WITH AN INTENSE
POSITIVE/NEGATIVE ANOMALY COUPLET IN THE NERN PAC RIDGE
AND DOWNSTREAM ERN CANADIAN VORTEX. CURRENT PATTERN
CONTS THRU DAY 4 WED AFTER WHICH MODELS CONT TO
FORECAST A CHANGE AS SRN STREAM BECOMES MUCH MORE
ACTIVE DEVELOPING A SIG SRN STREAM SPLIT FLOW INCREASING
AFTER D+5 AND CONTG THRU D+11. OFFSHORE SRN CA CLOSED
LOW FORECAST BY MODELS TO COME INLAND LEADING THE
DEVELOPING SRN STREAM FLOW. GOOD MODEL AND ENSEMBLE
AGREEMENT WITH THIS SOLUTION. CAVEAT IS THAT USUALLY
THESE SYSTEMS COME IN SLOWER IN SPITE OF PROGRESSIVE
MODEL FORECASTS. NEWER 06Z AND 12Z GFS EVEN MORE
PROGRESSIVE. PREFER TO AT LEAST HOLD BACK ADVENT OF THE
SYSTEM TO TIMING OF 00Z GFS AND 00Z GFS ENSEMBLE MEAN.

SRN STREAM RETURN WILL BRING IN QUITE WET WEATHER
ACROSS SRN TIER OF STATES WHILE NRN PORTION WILL REMAIN
UNDER INFLUENCE OF COLD PNA PATTERN NRN PLAINS INTO THE
EAST. STRONG E-W ACTIVE BAROCLINIC BOUNDARY WILL BE
SETTING UP IN THIS FLOW REGIME.

DAYS 6 AND 7 FRI/SAT UNCERTAINTY PLAINS THRU THE EAST
DEVELOPS THIS PERIOD. WHILE MID LEVELS VERY SIMILAR ECMWF
BRINGS SWD MORE HIGH PRESSURE AND KEEPS FRONTAL
BOUNDARY SWD ERN U.S. WHILE 00Z AND ESPECIALLY 06Z GFS
TAKE A SFC WAVE MORE NWD THRU THE MID ATLC REGION.
PREFER A MORE SUPPRESSED ECMWF/ GFS ENSEMBLE MEAN
SOLUTION FOR THESE LAST TWO FORECAST DAYS WITH A
STATIONARY BOUNDARY AND IDEA OF 12Z GFS OF SERIES OF
IMPULSES ALONG THE E-W STATIONARY FRONT..

12Z GFS FOLLOWS TREND OF 06Z BUT WITH A SUPPRESSED FRONT
FARTHER SWD CLOSER TO 00Z GFS THAN 06Z RUN BUT DECIDEDLY
CLOSER TO 00Z GFS ENSEMBLES AND ECMWF. IT HOWEVER IS
CLOSER TO 06Z GFS MOVING PCPN FASTER EWD FROM THE
SOUTHWEST INTO THE EAST.

HPC WILL FOLLOW GFS ENSEMBLE MEAN SOLUTION WHICH IS
CLOSEST TO 00Z OP GFS RUN BUT WITH A FARTHER SWD FRONTAL
BOUNDARY ERN THIRD CONUS LEANING TOWARD ECMWF AND GFS
ENSEMBLES AS IT BRINGS SEWD MORE HIGH PRESSURE.

REGIONAL HIGHLIGHTS...

...AK...
MORE OF THE SAME...NRN STREAM PNA PATTERN CONTS WITH
ONSHORE FLOW AND EMBEDDED ENERGY COMING OVER NERN
PAC RIDGE WITH SYSTEMS CONTG TO AFFECT SRN COAST AND
SERN PANHANDLE.

...WRN US...
ALL MODELS ON BOARD WITH SWRN U.S. PCPN EVENT AS
OFFSHORE CLOSED LOW MOVES INLAND. ALWAYS A DANGER HERE
AS MODELS ARE OFTEN TOO FAST. HVIER QPF TARGET IS AZ
WHERE OP GFS IS QUITE HVY PUMPING OUT NR 4 INCHES LIQUID.
THIS SEEMS EXCESSIVE AND CUT BACK CONSIDERABLY BY HPC.
PROGRESSIVE SRN STREAM PATTERN OFFRS THREAT OF NEXT
OFFSHORE SYSTEM BRINGING IN MDT HVY RAIN AGAIN INTO
CENTRAL AND SRN CA DAY 8 SUN.

...CNTRL AND ERN US..
COLD PATTERN REMAINS IN STORE FOR FIRST SEVERAL DAYS.
INCOMING SRN STREAM SHORTWAVE ENERGY WILL BRING IN A
WIDESPREAD AREA OF PCPN THRU THE SRN AND CNTRL PLAINS
MAINLY AS RAIN BUT FRZN PCPN ACROSS NRN EDGES. PROBLEMS
BEGIN HERE FROM PLAINS TO EAST AS TO PCPN TYPE LATE IN THE
WEEK AND NEXT WEEKEND. GENERALLY E-W STATIONARY
BOUNDARY WILL SET UP FROM NC WWD THRU TN INTO AR. SERIES
OF WAVES WILL MOVE EWD ALONG THE FRONT UNTIL MAIN
SYSTEM MOVES OFFSHORE DAY 8. COLD HIGH IN THE NRN STREAM
WILL MOVE FROM LAKES REGION TO OVER NW ENG.
GOOD GULF INFLOW IMPLIED BY MODELS WILL KEEP FRONTAL
BOUNDARY AREA AND SWD QUITE WET WITH MDT/LCLY HVY
RAINFALL FROM OK/AR EWD THRU LOWER MS VALLEY INTO TN
VALLEY. NWD MORE FROZEN WINTERY PCPN THREAT INCREASES
ACROSS OH VALLEY INTO WV/VA/MD/DE...POSSIBLY SWD DEEPER
INTO VA AND NC WITH HIGHER SRN CONUS HTS BUT WITH LARGE
ARCTIC HIGH TO THE N WHICH MAY ALLOW LOW LEVEL COLD AIR
TO PENETRATE FARTHER SWD. DAY 6-7 TOO FAR AWAY FOR
DETAILS. POTENTIAL FOR A PROLONGED VERY SIG WINTER WX
EVENT FRI-SUN.
ROSENSTEIN

GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov

Ok ... as it stands right now, the next system to affect the Southeastern region looks to be a rain event, unless you are in Central and Western NC.
Western NC Mountain Regions: will probably stay all snow ... 1"-3" possible. Central NC - little accumulation to 1" before warmer air changes the snow/sleet to a mix or just plain rain. Raleigh, NC - may get a mix to start but will likely change to plain rain, or just stay all rain.

This does not look to be a heavy event for the Carolinas.

Some conjecture with the strength of the system in regards to the Robust GFS's depiction of a moderate coastal for the MA and NE regions. However, again, the other models are leaning a little more towards a stronger solution, but the GFS stands alone in regards to the strength of this system.

Now down to business .... next weekend's storm ....

A lot of uncertainty into the degree of cold air will entrain down into the Carolinas right now...however, a significant overrunning scenario with a strong high progged at about 1034 mb to park itself over Eastern Canada pulling down some bitterly cold arctic air down the East side of the Appalachians. This overrunning event could be quite prolonged - maybe as long as 48 hrs ... Virginia at this time that this discussion is being typed, looks to possibly be in ground zero for a significant icestorm ... and North Central NC could very well join in ...

From experience with CAD events, the models aren't picking up the degree of the strength and in general always underestimate shallow arctic air at the surface ... so with said ... The Carolinas, and Virginia should check periodically for changes and discussions from their local NWS, and/or news media outlet for further developments ...

This will be the last statement issued on the Sunday night/Monday event unless conditions warrant.

The next full discussion for next weekend's event will be issued sometime around 8:00 pm EST ...

NC mountains - possible significant snows in the range of 3"-6" as Winter Storm Warnings have been issued. Winter Weather Advisories for Western NC, Foothills, and NW Piedmont counties for 1-2" of snow.

Next weekend - Monday (15-17th)

Tonight's ECMWF run only strengths my belief for next weekend...A significant arctic high forecast to be 1035 mb sets up shop in an ideal locale for significant CAD and an overrunning event. This actually appears to be 2 low pressure systems.
HPC final discussion from earlier also feels the upcoming weekend event will be suppressed further southward as well, which still may include portions of NC in the favored cold air damming (wedge) scenario.
The GFS has problems with the placement of the high at day 7 and also develops a too far north low in Kansas in this timeframe ... something looks awry here. A second low towards Sunday night develops in the GOM, and may be setting up a Miller low scenario .... with cold air damming, likely a Miller B out past 7 days ....

Bottom line is a potential significant icestorm/winter storm will be quite likely somewhere in Virginia, or maybe a little further south into North Carolina. Depending on the degree of the CAD, and if it's stronger than GFS/EC are showing (which I'm quite positive since the models do not pick up CAD's very well and underestimate even in short range) ... it's quite possible for something for upper part of South Carolina to watch for as well.

HPC preliminary discussion for the potential on next weekend event.

...ERN CLUSTER...
SINCE GOING WITH A MORE SUPPRESSED SOLN...LWRD TEMPS ON
DAYS 6/7 OVER THE CLUSTER...ESP E OF THE MTNS WHERE
DAMMING IS LIKELY. KEEPING POPS AT MOS GIVEN IT VARIES
LITTLE FROM THE ENS M OR 6Z GFS FORECAST. POTENTIAL FOR
ICE ON DAY 6 IN DAMMED REGION OF MD...VA... AND NC. STILL
CONSIDERABLE UNCERTAINTY IN THE FORECAST.

Again, for North Carolina, as I have been harping on for over 2 days now, a heads up as the potential ice event still looks like a good possibility.

was really a non-event. No accumulation down at the Jersey shore or up by my house. It looks like the storm was too far off shore and it was above freezing all day, so the snow that did fall didn't have a chance to stick.

There were a lot of complications with this morning's storm ... dynamics were all screwed up ... at least with the developing storm was gathering itself ...

The forecast thread for snow in Dulles - I called for 2"-4" aggressively just solely on radar trends, and not the RUC/ETA/GFS models due to poor performance in Oklahoma, Arkansas, and Tennessee. However, by the time the 850mb low got into NC, the moisture was transferring to the new developing surface low in evidence of the thunderstorms that developed in Florida overnight. So the dynamically driven 300mb jet, and 850mb WAA-VKNT were greatest in North Carolina, the moisture was on the wane. I should have seen this coming, and went with the original thinking of 1"-3" in DC (Dulles) and more like 1"-2".
Pfffhh.... it was even worse!!!!. DULLES ONLY GOT A TRACE ....

CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
436 PM EST MON FEB 10 2003

...................................

...THE WASHINGTON DULLES CLIMATE SUMMARY FOR FEBRUARY 10 2003...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1962 TO 2003

WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
..................................................................
TEMPERATURE (F)
TODAY
MAXIMUM 35 359 PM 63 1990 44 -9 48
2001
MINIMUM 29 326 AM -10 1979 23 6 30
AVERAGE 32 34 -2 39

PRECIPITATION (IN)
TODAY 0.05 0.65 1970 0.10 -0.05 0.08
MONTH TO DATE 0.84 0.95 -0.11 0.28
SINCE DEC 1 7.14 7.07 0.07 3.06
SINCE JAN 1 3.53 4.00 -0.47 1.50

SNOWFALL (IN)
TODAY T 0.5 1986 0.2 -0.2 0.0
MONTH TO DATE 6.1 2.6 3.5 T
SINCE DEC 1 19.4 12.9 6.5 2.6
SINCE JUL 1 19.4 13.8 5.6 2.6
SNOW DEPTH 2

DEGREE DAYS
HEATING
TODAY 33 31 2 26
MONTH TO DATE 327 322 5 273
SINCE DEC 1 2426 2231 195 1795
SINCE JUL 1 3408 3208 200 2598

COOLING
TODAY 0 0 0 0
MONTH TO DATE 0 0 0 0
SINCE DEC 1 0 0 0 0
SINCE JAN 1 0 0 0 0
..................................................................

WIND (MPH)
HIGHEST WIND SPEED 14 HIGHEST WIND DIRECTION SW (210)
HIGHEST GUST SPEED 15 HIGHEST GUST DIRECTION S (200)
AVERAGE WIND SPEED 3.7

SKY COVER
POSSIBLE SUNSHINE MM
AVERAGE SKY COVER 1.0

WEATHER CONDITIONS
THE FOLLOWING WEATHER WAS RECORDED TODAY.
SNOW
LIGHT SNOW
FOG
FOG W/VISIBILITY <= 1/4 MILE

RELATIVE HUMIDITY (PERCENT)
HIGHEST 100 800 AM
LOWEST 69 100 AM
AVERAGE 85
..........................................................

THE WASHINGTON DULLES CLIMATE NORMALS FOR TOMORROW
NORMAL RECORD YEAR
MAXIMUM TEMPERATURE (F) 44 67 1999
MINIMUM TEMPERATURE (F) 23 -7 1979

SUNRISE AND SUNSET
FEBRUARY 10 2003......SUNRISE 707 AM EST SUNSET 541 PM EST
FEBRUARY 11 2003......SUNRISE 706 AM EST SUNSET 542 PM EST

- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.

For Virginia, Maryland, and North Carolina ...

The GFS is trending in that direction, but still underestimating the potential for significant icing. A strong 1035-1040mb to set up in almost the ideal locale to set the stage for a significant wedge down the east side of the Appalachians. The models tend to underestimate CAD events.

Interestingly enough, the Day 7 ECMWF develops a closed 500mb low over Arkansas.

Overview ...

For the Gulf Coast States and Southeast ....

Training showers/thunderstorms across the lower Gulf and Southeast are quite possible in the MR ... both GFS and ECMWF support a 1-2 punch...a very moisture laden SBJ and the upper low in the SW could be the "big dog".

GFS 60 hr Precip - 60-120 hrs out
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_120m.gif

GFS 60 hr Precip - 126-180 hrs out
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_180m.gif

00z ETA update .... record lows are quite possible in Maine.... -30 to -40 C 850mb temps in 72hrs!....

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_072m.gif

Potential this weekend for a significant ice storm set up for Northeastern GA, NW South Carolina, And Western NC ... but the potetial for CAD may even be more than progged and/or realized ...

HPC prelim discussion this morning indicated this ...

IN THE EAST...THE ECMWF IS IN PRETTY GOOD AGREEMENT WITH
THE GFS WITH THE UPPER TROF DIGGING INTO THE S-CNTRL
PLAINS AND LOWER MS VALLEY THAT WILL BE HAVING AN IMPACT
ALONG THE ERN SEABOARD SATURDAY AND SUNDAY. WENT WITH
THE IDEA OF A FRONTAL WAVE MOVING INTO THE TN VALLEY WITH
SECONDARY LOW FORMATION OFF THE VA/NC COAST. GFS
INDICATES A SIGNIFICANT COLD AIR DAMMING EVENT SETTING UP FOR THE WEEKEND WITH THE POTENTIAL FOR WIDESPREAD SNOW AND ICE OVER MUCH OF THE SOUTHEAST AND MID-ATLANTIC BEFORE THE ENTIRE SYSTEM MOVES OFF THE COAST.

CHANGES TO MOS FOR THE CLUSTERS...

..EAST..
BIGGEST CHANGE TO 00Z MOS WAS EAST OF THE APPALACHIANS
WHERE HPC TEMPS ARE MORE THAN 10 DEGREES COLDER IN SOME LOCATIONS. FOR SOME REASON MOS TEMPS EAST OF THE MTNS ARE NOT REFLECTING THE MODEL LOW LEVEL PROGS WHICH SHOW A PRONOUNCED COLD AIR DAMMING EVENT FOR THE WEEKEND.

Even Charleston, SC AFD discusses something very interesting about monitoring weekend interests .... (back door cold frontal passage).

Bottom line is this .... South Carolina, Northeastern Georgia, and North Carolina needs to be very vigilant for changing trends as the potential for a SIGNIFICANT CAD EVENT AND ICESTORM exists.....full discussion later in a new thread.

I wish this was a snow issue once again and not another ice one OH well thanks for the indepth coverage Stormsfury ;);););););)

That's what I'm here for, JQ ... when Charleston mentions this ...

FINAL CONCERN IS THE WEEKEND...WITH CURRENT HPC FCST...GFS GUIDANCE
AND LAST COUPLE OF NOGAPS FCSTS SHOWING A BACKDOOR FRONT AND
ASSOCIATED WEDGE FOR SUN. AFTER COORDINATION WITH ILM WITH WILL GO
WITH THIS THINKING...BUT KEEP FRONT N OF GA WATERS AT THIS TIME.
LATER FCSTS WILL BE HIGHLY DEPENDENT UPON THE FRONTAL PUSH S...AND
THOSE WITH WEEKEND INTERESTS SHOULD STAY TUNED.

Hmmm, I take notice ... especially very conservative Charleston (95% of the time, the conservativeness is right on the money. The other 5% percent we end up with fresh snow cover without a mention until too late!...Hmmm, see January 26th, 2000 - 3" of snow, 2" in Charleston when nada in the forecast - only a few flurries in the AFD that afternoon...whoops!)

I'm waiting on the new EURO run tonight, but practically speaking, the models are overall trending further south with solutions and with copious amounts of ST moisture ... and CAD down the east side of the Appalachians ... it's a serious threat.

Overall view ... coordination with the associated NWS offices, well, actually bad choice of words here ... some are picking up on this, some aren't ...

To put this plain and simple ... the NOGAPS may have good handling in regards to a backdoor cold front east of the Appalachians. The EC has a 1038 mb high over Eastern Ontario Canada, an almost ideal locale for a cold air damming event ...

Irregardless ... very heavy precip either in the form of rain or ice will occur with very robust totals coming from 2 events ... the second, being a closed 500 mb low developing in MS (as depicted by the EC tonight) ... moving east across the Southeast - (which develops a surface low off the SC coast on Day 7) - this would be a classic setup for coastal snows along the Carolina Coast - however, the EC also depicts warmer 850mb temps - in fact all the way up to NY state.

HPC final discussion highlights the threat for NW SC, NE GA, and Western NC ...

Just a reminder - CAD events aren't generally picked up well on the models, but sometimes are - however, the temperature schemes at the surface are usually done quite horribly and temperatures are usually 10 degrees lower and sometimes more than depicted at the surface ...

The GFS 60 pcpn has a ton of liquid QPF, and according to one knowledgable source on another board pointed out that quite possibly using the MR QPF output from GFS could quite possibly be UNDERDONE since it is a known bias for underdoing QPF's in the Southeast at this range.

GFS 60 hour QPF outlook


In summary - if even 1/2 of the QPF is ice in the locales mentioned - Dec. 5 (as Downeast NC put it) would make Dec. 5 look like a sunny day.

I'm not trying to scare anyone or play the "hype game" but this has serious potential (and actually the first situation I've actually hyped all winter long) ...

Local weather forecast still going with rain this weekend. The only change since Monday has been a drop in the forecasted highs from low 50's to upper and mid 40's. Lows are in the mid 30's.

It's still going to be a good time to curl up next to the fireplace and read a book...just wish I had a fireplace

Big changes to the initial event and the secondary event.

The first event for Friday/Friday night - looks to be all rain right now, except in NW SC, Western NC as these areas should start out as a mix.
However, these areas change to rain ...

Saturday - a back door cold front moves south through NC and then SC later ... continued overrunning and dropping temperatures could play havoc with p-types later in the period ...

Sunday-Monday - problems in regards to the secondary low development.
But with the potential of CAD and favorable positioning of the second low, even the Coastal Carolinas may have something to watch Monday.

More details later.

This looks to be a historic ice storm for NC and VA.


4 X worst than the DEC storm.

wrkh99 ....

I couldn't have said that any better ... I just got home, and as expected, the southward trend is on ... before it's all said and done, parts of South Carolina may get in this as well ...

Preliminary HPC discussion this morning.

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
819 AM EST THU FEB 13 2003

VALID 12Z MON FEB 17 2003 - 12Z THU FEB 20 2003

PRELIMINARY ADJUSTMENTS TO THE 00 UTC GFS

LATEST 06Z GFS CONTINUES CONSISTENT THRU WED DAY 6 WITH
ITS 00Z COUNTERPART OVER THE CONUS...EXCEPT FOR TIMING
DIFFERENCES TUE DAY 5 ALONG THE NRN CA/WA/OR COAST.
THERE ARE ALSO 00Z VERSUS 06Z GFS TIMING DIFFERENCES THU
DAY 7 CONCERNING ANOTHER SYS ENTERING THE W COAST...AND
WITH A FRONT APPROACHING THE ATLANTIC COAST STATES. FOR
TUE DAY 5 AND THU DAY 7...WE ARE COMPROMISING THE
SHORTWAVE TIMING OF THE 00Z/06Z GFS WITH THE ABOVE
MENTIONED SYS.

EVEN THOUGH WE ACCEPTED THE 00Z/06Z GFS WITH THE MESSY
SCENARIO ALONG THE SE AND MID-ATLANTIC COAST SUN-
MON...THE CANADIAN...UKMET....AND NOGAPS MODELS SUGGEST
MORE VIGOROUS COASTAL DEVELOPMENT BY SUN EVE THAN THE
GFS. THESE SMALLER SCALE DETAILS...INCLUDING THE RA/SN LINE
AND QPF AMOUNTS...WILL BE REFINED FURTHER AS WE MOVE INTO
THE SHORT RANGE FORECAST WITH THIS MAJOR WINTER STORM.

CHANGES TO MOS FOR THE CLUSTERS...

...EASTERN...

NO MAJOR CHANGES TO THE 00Z GFS MASS FIELDS. ADJUSTMENTS
TO MOS REFLECT COLD AIR DAMMING E OF THE APLCNS AND
PROLONGED PCPN.

CENTRAL...

NO SIGNIFICANT CHANGES TO 00Z GFS MASS FIELDS. SEE
GRAPHICS.

...WEST...

OUR COMPROMISE ON THE TIMING OF THE 00Z/06Z GFS
SHORTWAVE REACHING THE NRN CA/WA/OR COAST TUE DAY 5
AFFECTS POPS SURPRISINGLY LITTLE. SEE GRAPHICS.

FLOOD

GRAPHICS AVAILABLE AT http://www.hpc.ncep.noaa.gov

ETA PRECIP TYPE 84hr LOOP
http://www.rap.ucar.edu/weather/model/d ... typ&loop=1

GFS PRECIP TYPE 180hr LOOP
http://www.rap.ucar.edu/weather/model/d ... typ&loop=1

The ETA shows the best of the cold air damming solution - actually has the best signature that I've ever seen on a surface map ... look for the trend to continue more southward, for this is what I feel could happen.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_072m.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_072m.gif

VA, NC, and SC need to monitor the situation very closely ...

Along Coastal South Carolina - temperature disparities could range from the 60's to just a little farther inland into the 30's ... a very classic looking CAD representation.

Case history of a Classic CAD event,
http://www4.ncsu.edu/~nwsfo/storage/tra ... clint.html

VA, NC, and SC need to monitor the situation very closely ...

A job well done guys. Keep the info coming

The 18z ETA and GFS are COLDER!!...