November 2013 pattern and discussion

[Wow]

Going to be a cold Sunday coming up.  Here's my sounding at 1 pm on 11/24, 12z GFS:

 

[Disc]

Going to be a cold Sunday coming up.  Here's my sounding at 1 pm on 11/24, 12z GFS:

 

 

I can read the traditional skew-t, but this is laid out nicely and easy to read. The more I see images from the model site here on AmWx, the more I'm drawn in to getting a subscription. Are you sure you aren't posting these strategically?   

[Wow]

I can read the traditional skew-t, but this is laid out nicely and easy to read. The more I see images from the model site here on AmWx, the more I'm drawn in to getting a subscription. Are you sure you aren't posting these strategically?   

 

Covert advertising, my friend.

 

Plus, who doesn't want full access to 2m temp maps that use the old school TWC colors?!  

 

[FallsLake]

Indices look a little better from yesterday. Not great looking but....:

AO goes negative but then jumps back solidly positive (but not as strongly as yesterday)

NAO goes negative and then looks to go slightly postive

PNA goes neutral and then looks to go slightly postive

**these are proximations from the many individual runs

[DopplerWx]

18z gfs has the double barrel low solution, nice track for the low, great low track but cold air isnt there.

[superjames1992]

Does the 18z GFS just look weird to anyone else?  It's hard for me to see that happening as modeled.  The SLP is moving like a snail.

 

Convective feedback? http://mag.ncep.noaa.gov/data/gfs/18/gfs_namer_156_850_temp_mslp_precip.gif

[burrel2]

FWIW,

 

18z DGEX drops about a 1/4 to 1/2 inch of freezing rain in the CAD area’s of GA/SC Monday evening.  Looks like some insitue CAD development along with a bunch of evaporational cooling thanks to the artic high pressure that drops down on Sunday.  

[Reb]

Does the 18z GFS just look weird to anyone else?  It's hard for me to see that happening as modeled.  The SLP is moving like a snail.

 

Convective feedback? http://mag.ncep.noaa.gov/data/gfs/18/gfs_namer_156_850_temp_mslp_precip.gif

Definitely an odd look. Moving on to 0z

[FallsLake]

Definitely an odd look. Moving on to 0z

Finally got a chance to look at the 18z GFS (five kids will drain the time).  Definitely odd but still has the players on the table. Really impressed with what it's showing in the LR; lots of cold with potential systems. Really amazed at the cold that we're getting when the indices (AO, NAO,PNA) are really not in our favor. You could say in the next couple of days they will temporarily be in our favor but that's really not enough time to warrant the cold shots we've been receiving. 

[griteater]

This is looking ahead, but for an ensemble mean at day 13, this is a pretty good signal for a -EPO pattern with the ridging centered up through Alaska, which would support cold air feeding into the U.S. east of the Rockies.  That type of ridging persists for days 10-16 (Nov 30-Dec 6) on the GFS Ensemble Mean.  There is a bit of NAO ridging that appears, but it doesn't look as stout during that same period.  It's likely a case where we'll see some cold air, but most would have to rely on excellent timing in order to see any notable wintry precip.

 

 

 

 

Here's the 8-14 day discussion from CPC:

 

8-14 DAY OUTLOOK FOR NOV 28 - DEC 04, 2013   THE FORECAST PATTERN FOR THE WEEK-2 PERIOD IS VERY SIMILAR TO THAT FOR THE 6-10  PERIOD AND IS MORE HIGHLY AMPLIFIED THAN YESTERDAY'S FORECAST. ENSEMBLE SPREAD  AND RUN-TO-RUN VARIABILITY HAS IMPROVED A BIT SINCE YESTERDAY. THE OFFICIAL  500-HPA HEIGHT MANUAL BLEND REVEALS A STRONGER RIDGE ALONG THE WEST COAST  COMPARED TO YESTERDAY'S FORECAST, WITH THE ECMWF ENSEMBLE COMING BACK IN LINE  WITH THE OTHER GUIDANCE. WITHOUT ANY LONGSTANDING BLOCKING DOWNSTREAM IN THE  NORTH ATLANTIC, THE PATTERN CONTINUES TO LOOK FAIRLY PROGRESSIVE. THAT SAID,  TELECONNECTIONS UPON THE LARGEST HEIGHT ANOMALY CENTER FORECAST SOUTHWEST OF  THE BERING STRAIT SUGGEST CONTINUED ANOMALOUS MID-LEVEL FLOW INTO WESTERN  CANADA, WHICH WILL LIKELY CAUSE POST-FRONTAL AIR MASSES TO BE QUITE COLD.  ELEVATED ODDS FOR BELOW-NORMAL TEMPERATURES ACROSS THE SOUTHEASTERN HALF OF THE  CONUS ARE LARGELY DRIVEN BY A COLD AIR MASS MOVING SOUTHEASTWARD IN THE WAKE OF  WHATEVER STORM MOVES OFF THE EAST COAST EARLY IN THE PERIOD. UNCERTAINTY IS  HIGH TOWARD THE END OF THE PERIOD ACROSS MUCH OF THE CONUS, WITH THE ECMWF  ENSEMBLE MEAN SUGGESTING THE DEVELOPMENT OF A SUPPRESSED ZONAL FLOW ACROSS THE  CONUS WITH A FULL-LATITUDE TROUGH EXTENDING SOUTHWARD FROM THE ARCTIC CIRCLE  TOWARD THE GREAT LAKES DURING DAYS 12-14.  GUIDANCE FOR THE PERIOD BEYOND WEEK-2 HAS BEEN VERY INCONSISTENT OF LATE, WITH  THE ONLY REASONABLE SIGNAL BEING SOME CONTINUATION OF THE QUASI-BLOCKING  PATTERN OVER THE NORTH PACIFIC. TO BE SURE, THIS PATTERN IS ONE OF THE MORE  PERSISTENT PATTERNS OF INTERNAL VARIABILITY IN THE EXTRATROPICS DURING WINTER.  THE LARGEST UNANSWERED QUESTION OF PERIOD LEADING UP THE CHRISTMAS SEASON IS  WHETHER ANY PERSISTENT HEIGHT RISES WILL OCCUR ACROSS PARTS OF THE NORTHWESTERN  ATLANTIC AND GREENLAND, SOMETHING THAT HAS NOT HAPPENED THUS FAR THIS COLD  SEASON. ADDITIONALLY, THE MJO REMAINS FAIRLY INCOHERENT, AND ANY REORGANIZATION  OF THAT IMPORTANT TROPICAL PHENOMENON WILL LIKELY HAVE RAMIFICATIONS FOR NORTH  AMERICAN HYDROCLIMATE LATER IN DECEMBER.

[Shawn]

Covert advertising, my friend.

 

Plus, who doesn't want full access to 2m temp maps that use the old school TWC colors?!  

 

Off topic I know.. but when you guys get the Euro data; if there is anyway to basically do the text version of all the levels like accuwx has on their service; that'd be amazing.  You know the part that comes out really fast before even the maps?

[griteater]

Off topic I know.. but when you guys get the Euro data; if there is anyway to basically do the text version of all the levels like accuwx has on their service; that'd be amazing.  You know the part that comes out really fast before even the maps?

I'm with you Shawn on the accuwx Euro text.  I wish wow and allan would eventually just build out the best features from each of these services and go ahead and bury them.  As it is right now, each service has there own little cool feature that the other doesn't have, so it kind of sucks as a buyer.

[Shawn]

I'm with you Shawn on the accuwx Euro text.  I wish wow and allan would eventually just build out the best features from each of these services and go ahead and bury them.  As it is right now, each service has there own little cool feature that the other doesn't have, so it kind of sucks as a buyer.

 

I think Allan may be using GemPAK currently?  Which is pretty darn capable of anything he wants really.  The only competition he may have is the "pretty" maps put out by WxBell.  With the right settings, resolution changes, and all that kind of good stuff... that could be done too.

 

Plume diagrams would be immesnely popular.. currently I use a free site to see the gefs plumes.. and although it's good enough for mby; its not for everyone's and the graphics could definitely see a tune up.  Somehow getting the CMC/GGEM plumes would be something I dont think anyone else has.

[FLweather]

Alot colder in the southern plains so far compare to 12z on the gfs.

[deltadog03]

Looks like a very nice rain event for many, expect the mtns.  Either way, the pattern is trying to evolve into a better pattern.  

[mackerel_sky]

This looks like a Texas special! Where all are good events come from! 00z FTW

[DopplerWx]

colder thru 126, lp further south a tad off western la.

[DopplerWx]

through 156 just not cold enough, plenty of precip but the 1005mb low is over southern ga.  0c line well above the nc/va state line.  the lp is a single low this time though unlike 18z and a tad slower.

[griteater]

wow, old school gulf low with copious moisture, just no cold air

[DopplerWx]

wow, old school gulf low with copious moisture, just no cold air

yep, at 168 a 1001mb low right off myrtle beach, man oh man if we had the cold air.

[Disc]

Hmm. Interesting. Mountains of NC and VA see snow?

 

[NCCatawba]

[Marion_NC_WX]

Big difference in our southern stream feature...

 

 

18z run @ 180...

 

 

 

 

0z @ 174...

 

 

 

 

 

 

Much stronger and slower look with our southern stream...was closed off 2 contours at 168 and 171,,,this could have significant implications on the North Carolina mountains if this is the start of a trend for a stronger southern stream. That possibly creating its own cold pool combined with the incoming arctic high...and some in WNC could be in business.

[Disc]

Definitely a CAD signature on the 0z GFS. Don't recall seeing that on previous runs.. GFS is starting to pique my interest.

[superjames1992]

Definitely a CAD signature on the 0z GFS. Don't recall seeing that on previous runs.. GFS is starting to pique my interest.

 

The surface freezing line works its way all the way down to the NC/VA border at hr 180, in fact, as precip is still falling rather heavily.

[NCCatawba]

GFS drops 10.5" in south-west VA. 6-12" northern NC mountains.1-3" from Charlotte north-west into the mountains. 0" Piedmont Triad.

[FLweather]

I really dont know whats up with the models. Ive seen worse setups then this deliver snow but I don't understand given the longwave pattern being depicted. The long wave pattern would support a SE snowstorm imo. Deep trough from Canada to SE with a robust s/w at the end. There is a ridge as well one would logicially think the s/w energy would dive s/e into the s/w into the southern stream. Considering too the distance and amount of bagginess being shown on the main models. 

[dsaur]

I had some rain a while ago.  Nice big leaf pattering drops, not fog drizzle like I've been having when something precip like this way comes.  Sounded like sleet out there, and I take that as a good sign   A good old fashioned gulf storm is just what we need down here, and where there is one the will come others.  Bodes well for the winter if we can get some gulf involvement to set into a pattern.  49 and rain, like now,  isn't so far off from the promised land if come cold air comes down, or a cad sets up with deep enough cold.  It's not so far off, but like a snow storm I won't bite until is much closer, lol, though I need some good rain very badly, I've learned not to expect it.   That said, a low coming up into a cad always has my attention though the map doesn't show a cold enough high right now, it's still a ways out, and there is cold air in the vicinity.  Ice in early Dec. wouldn't be all that unusual.  I'd like to see a reinforcing shot show up in the next few days, and that low stay on the map, of course, lol. T

[franklin NCwx]

I really dont know whats up with the models. Ive seen worse setups then this deliver snow but I don't understand given the longwave pattern being depicted. The long wave pattern would support a SE snowstorm imo. Deep trough from Canada to SE with a robust s/w at the end. There is a ridge as well one would logicially think the s/w energy would dive s/e into the s/w into the southern stream. Considering too the distance and amount of bagginess being shown on the main models.

its not the models, its.a.few things.really. 1 its November, climo is against any major snowstorm. 2 without any blocking the northern branch is.too progressive and.sweeps eastward instead.of being forced to slow down and dig south.

[mackerel_sky]

It's dead in here! Did Dr. No live up to the name, and take any chance of frozen precip away?