February Mid/long Range Winter Discussion

[SnowNiner]

I'm cliff diving this event.  I was really hoping the set up shown earlier would stay where the high was locked in.  I just don't think it's going to hang in there.  Front end mixed bag changing to rain seems like the likely outcome IMO, trend is not our friend today. 

[Blue_Ridge_Escarpment]

I'm cliff diving this event. I was really hoping the set up shown earlier would stay where the high was locked in. I just don't think it's going to hang in there. Front end mixed bag changing to rain seems like the likely outcome IMO, trend is not our friend today.

For areas east of 77 it might not work. But WNC, WSC, and NEGA better be ready.

[franklin NCwx]

Could be, but it's not classic damming...i.e. the sfc high is working off the NE coast during the storm. As Cheez said, a whole lot to resolve with the overall wave and timing. The 'ace in the hole' here for wintry precip is the high and arctic airmass - I'm sure it's strength will evolve as we get closer as well - may not show as cold at go time

for some reason the para has been stronger with the high and therefore colder.

[pbrown85]

Correct me if I'm wrong but aren't we a little too far out to start writing off this storm? I've been lurking on the boards for a while and definitely don't understand the models as well most of you on here, but isn't there still time for the storm to trend in favor of a winter event?

[Blue_Ridge_Escarpment]

Correct me if I'm wrong but aren't we a little too far out to start writing off this storm? I've been lurking on the boards for a while and definitely don't understand the models as well most of you on here, but isn't there still time for the storm to trend in favor of a winter event?

Yes. Yes.

[Lookout]

Isn't it a model bias to underestimate the strength and cold of the wedge!

Two points...the initial airmass as the precip starts wold likely be very dry so there would be quite a bit of evap cooling. Even before that happens the euro has temps in the 20s when it starts. Second, given that low track and 850s that warm to only 4 or 5c at the peak, it would be very hard to picture cad areas warming above freezing..even though the parent high slides out during the storm. Of course discussing details like for a storm that far away is mostly a waste of time lol

[84 Hour NAM]

Might need a separate thread for the Friday night North Carolina possible event. 

[packfan98]

Might need a separate thread for the Friday night North Carolina possible event. 

Are any of the models showing anything besides the NAM?

[RubiksDestroyer]

 

Are any of the models showing anything besides the NAM?

 

Apparently the Euro hinted at something:

 

12z euro trying to throw back some light snow for the friday/sat event the  nam was hinting at. makes it just e of rdu.

 

[FallsLake]

As others have stated above, we're still 6 days out until the potential event. By the time we get to the storm the high could easily trend to the perfect position, or at least the CAD will show much stronger. The only important facts at this time are:

* There's a storm showing

* The general track of the storm is favorable

* There will be cold air in place

* Some models show wintery precip for sections of the SE

 

Trends we'll be looking for in the future model runs:

* High pressure placement

* Strength/type of CAD

* Track of storm

* Strength of storm

* QPF totals

[downeastnc]

Are any of the models showing anything besides the NAM?

 

Well the 12Z CMC did go from no snow accumulations to this, so a step in the right direction I guess.....these setups have produced for us before if the wave can get a decent enough SLP fired off ILM that tracks up and out......usually they are 1-3" events though that one in 2014 was 4-10" due to sound effect snow lol.

 

[Poimen]

The only saving grace, as I see it, is if the HP is much slower(seems unlikely), or if another unforeseen HP follows on its heels (which also seems unlikely). Otherwise most on this board can forget about any widespread winter event, as there really is no mechanism to keep the initial HP locked in.

[griteater]

GFS / CMC / UKMet / Euro for Monday at 7AM...

 

For a winter storm (cold + moisture combo), I'd say the CMC looks best, then Euro, then UKMet & GFS.  Note on the GFS and UKMet the northern stream troughing over the Great Lakes - leads to weaker and/or farther east surface high over the northeast

 

[FallsLake]

The only saving grace, as I see it, is if the HP is much slower(seems unlikely), or if another unforeseen HP follows on its heels (which also seems unlikely). Otherwise most on this board can forget about any widespread winter event, as there really is no mechanism to keep the initial HP locked in.

But man is the air going to be cold/dry before this event. Looking at the GFS it has dew points below zero for a good portion of the SE. It then jumps it up quickly to near 30 during the event but does keep it below freezing for at least RDU westward. Many of our best storm have had this type of cold in place before the storms occur. This goes with the point that the models have difficulty with CADs and in-situ CADs.

[jburns]

Might need a separate thread for the Friday night North Carolina possible event. 

 

We need to be careful.  The "Island of Misfit Threads" is threatening to sink under the weight.  

[Upstate Tiger]

Yep, a lot of factors to consider but we have a storm and artic air. We'll see where it goes from here. My bet is WOW will need to be starting a thread Thursday after the 1200 runs.

As others have stated above, we're still 6 days out until the potential event. By the time we get to the storm the high could easily trend to the perfect position, or at least the CAD will show much stronger. The only important facts at this time are:

* There's a storm showing

* The general track of the storm is favorable

* There will be cold air in place

* Some models show wintery precip for sections of the SE

 

Trends we'll be looking for in the future model runs:

* High pressure placement

* Strength/type of CAD

* Track of storm

* Strength of storm

* QPF totals

[burrel2]

The only saving grace, as I see it, is if the HP is much slower(seems unlikely), or if another unforeseen HP follows on its heels (which also seems unlikely). Otherwise most on this board can forget about any widespread winter event, as there really is no mechanism to keep the initial HP locked in.

not everybody lives in eastern north Carolina. Gfs, cmc, and euro all drop 3 to 6 inches of snow across the upstate Monday with surface temps in the 20's.

[franklin NCwx]

not everybody lives in eastern north Carolina. Gfs, cmc, and euro all drop 3 to 6 inches of snow across the upstate Monday with surface temps in the 20's.

I think you guys might score with this one as the storm doesn't really amp up until it's easy of you. That should help with the waa. Its also fairly dynamic with a low running up 95.

[Tony Sisk]

not everybody lives in eastern north Carolina. Gfs, cmc, and euro all drop 3 to 6 inches of snow across the upstate Monday with surface temps in the 20's.

I love the sound of that!

Weather Models have been as predictable as political polling this season. Should be a fun few days of flip flopping!!

 

I do agree with others....no way the cold air erodes as quickly as some of the models are suggesting. I realize El Nino is strong, but there is gobs of cold air trapping on the east side of the mountains.

[Brick Tamland]

Euro ensembles look better.

[franklin NCwx]

Euro control is a slightly colder version of the op. Its a better run for North ga mtns, nw SC, and the foothills.

[Upstate Tiger]

KGSP has been consistent mentioning Sunday night Monday storm. They're pretty conservative as are most NWS offices. So that tells me this bears watching closely...

UNCERTAINTY INCREASES IN THE FORECAST SUNDAY NIGHT INTO MONDAY AS AN

UPSTREAM TROUGH AMPLIFIES ACROSS THE MIDWEST...BUT WITH MODEL

DIFFERENCES SHOWING UP AS THE BASE OF TROUGH REACHES THE SOUTHEAST.

WARM FRONTAL MOISTURE MAY BRUSH THE SOUTHERN APPALACHIANS AHEAD OF

THIS SYSTEM LATE SUNDAY...BUT THE BEST MOISTURE AND FORCING AHEAD OF

A REINFORCING COLD FRONT WILL BE LATER SUNDAY NIGHT THROUGH MONDAY

NIGHT. THE GFS/GEFS FEATURE A MORE PROGRESSIVE TROUGH PASSAGE INTO

TUESDAY WHILE THE ECMWF REAMPLIFIES THE WAVE WEST OF THE

APPALACHIANS. THIS PERMITS ANOTHER ROUND OF SOUTHEAST MOISTURE TO

DEVELOP. THERMAL PROFILES SUGGEST AN ONSET AS SNOW THROUGH GIVEN THE

COLD AND DRY ANTECEDENT AIR SUNDAY NIGHT INTO MONDAY. SOME

CHANGEOVER TO RAIN ACROSS SE SECTIONS WILL BE POSSIBLE MONDAY

AFTERNOON BEFORE A RETURN TO SNOW PROFILES INTO TUESDAY WITH ANY

LINGERING OR REDEVELOPING PRECIPITATION. UNCERTAINTY REMAINS TOO

HIGH ON TIMING AND QPF...HOWEVER...FOR ANY HWO MENTION AT PRESENT.

[franklin NCwx]

Ensembles mean is similar to previous runs with the h5 track. There are many many good hits on the ensembles for wnc and tennessee. There are a few for far north ga and nw SC.

[84 Hour NAM]

not everybody lives in eastern north Carolina. Gfs, cmc, and euro all drop 3 to 6 inches of snow across the upstate Monday with surface temps in the 20's.

 

You're right, not everyone is that fortunate.

[Poimen]

not everybody lives in eastern north Carolina. Gfs, cmc, and euro all drop 3 to 6 inches of snow across the upstate Monday with surface temps in the 20's.

Hence the word "most"

[toxictwister00]

FFC is growing confidence in a winter storm next week.

 

SUNDAY AND MONDAY...CONFIDENCE IS INCREASING THAT A WINTRY EVENT
WILL UNFOLD ACROSS THE SOUTHEASTERN STATES DURING THIS TIMEFRAME.
THE BASIS IS THE STRONG ARCTIC SURFACE RIDGE WHICH SLIDES INTO THE
OHIO VALLEY WHICH ALL OF THE EXTENDED MODELS AND EVEN THE
ENSEMBLE MEMBERS ARE PROGGING. BOTH THE GFS...ECMWF AND THEIR
MEMBERS ARE PROGGING A STRONG CAD EVENT SETTING UP LATE SUNDAY
INTO MONDAY AS STRONG SHORT WAVE DIVES SOUTHEAST ON THE BACKSIDE
OF THE LONG WAVE TROF AND TAPPING A BIT OF GULF MOISTURE. THE
BIGGEST QUESTION AND LOWEST CONFIDENCE EXISTS IN DETERMINING ANY
PRECIPITATION TYPE AT THIS POINT WHICH COULD RANGE EVERYTHING FROM
AN ALL VERY COLD RAIN TO FREEZING RAIN TO SNOW AND SLEET...WHICH
ALL DEPENDS ON THE TIMING...DEPTH OF THE COLD AIR...AND THE WARM
NOSE. NONETHELESS. FOR NOW...LEFT EVERYTHING IN THE FORECAST AS A
RAIN OR SNOW. KEEP IN MIND THAT IT LIKELY WILL CHANGE AND IS SOMETHING
TO WATCH AS THE EVENT DRAWS NEARER.

 

Full Discussion below

http://forecast.weather.gov/product.php?site=FFC&issuedby=FFC&product=AFD&format=CI&version=1&glossary=1

 

This is the Forecast for Valentines Day night/President's Day for Atlanta right now...

Sunday NightA 30 percent chance of snow. Mostly cloudy, with a low around 27.
Washington's BirthdayA chance of rain and snow. Cloudy, with a high near 36. Chance of precipitation is 50%.

[griteater]

Euro ensembles look better.

Ens mean looks very similar to previous run.  Only thing I noticed was that it was a touch colder at the sfc on Monday morning with the precip moving in, with slightly more damming signature then...but it warms from there

[PackGrad05]

the GFS bufkit gives RDU .25" of fzra sandwiched between some bursts of snow....

[PackGrad05]

RAH not convinced yet...but leaves open possibility for NW piedmont (which is what they mean by climatologically favored)
.THIS PRESENTS
THE POSSIBILITY OF A SHORT-LIVED COLD AIR DAMMING EVENT LATE MONDAY
INTO PERHAPS EARLY TUESDAY WHICH WOULD LIKELY FEATURE SOME P-TYPE
TRANSITION CONCERNS ACROSS THE CLIMATOLOGICALLY FAVORED PIEDMONT.
THERE IS STILL A LOT OF UNCERTAINTY AS TO JUST HOW THIS WILL PLAY
OUT DUE TO THE PROGRESSIVE NATURE OF THE FEATURES...FOR EXAMPLE THE
LATEST ECMWF SHOWS A STRONG COASTAL LOW DEVELOPING WHICH WOULD SCOUR
THE COLD AIR QUICKLY...BUT ALSO PROLONG THE EVENT AND INCREASE THE
AMOUNT OF RAIN WE MIGHT EXPECT INTO TUESDAY. AT THIS POINT WILL
INTRODUCE TUESDAY WITH CHANCE POPS EARLY AND HIGHS REACHING THE
MID TO UPPER 40S.

[burrel2]

Hence the word "most"

Don't mean to get in a debate with you, but this threat looks good for west Tennessee, north Georgia, upstate sc, and western nc including the foothills and most of north central nc.

That encompasses more than half of this board