burgertime Posted February 19, 2012 Share Posted February 19, 2012 With the GFS putting the low so far south does that enhance the cold more than the GFS is seeing? Link to comment Share on other sites More sharing options...
WeSuck Posted February 19, 2012 Share Posted February 19, 2012 We have some clowns for mets here in Hampton roads. They just posted this update. I legit have no clue what model they are looking at. There are going to be some confused people tomorrow... Let's keep this snow in the south mid atl. The guys up in dc are gonna start diving, lol SE VA Mets always play conservative and in these cases makes them look like fools. Hampton roads is a hard place to forecast in their defense though in view of the marine effect. Link to comment Share on other sites More sharing options...
beanskip Posted February 19, 2012 Share Posted February 19, 2012 0z UKie has surface low just NW of Savanah Ga. at 18 hours and just off Wilmington at 24 hours. Link to comment Share on other sites More sharing options...
rduwx Posted February 19, 2012 Share Posted February 19, 2012 Well, I think I would trust the NAM's soundings over the GFS although they do look awfully close. The precip totals look close too. Per the following the NAM shows 4"+ for RDU... I would be happy with half that. Thanks pb...What site are you using for soundings. I've used plymouth for years but I've had problems for certain hours w/ the gfs soundings today. Link to comment Share on other sites More sharing options...
packbacker Posted February 19, 2012 Share Posted February 19, 2012 Thanks pb...What site are you using for soundings. I've used plymouth for years but I've had problems for certain hours w/ the gfs soundings today. I use the following, only 6 hour increments for top down though...works good enough.... Edit: Note, there is sounds at the top for the NAM and surface parameters on the bottom for the NAM. http://www.wxcaster....models_text.htm Link to comment Share on other sites More sharing options...
MillerA Posted February 19, 2012 Share Posted February 19, 2012 these are the Hickory soundings for the 18z nam: 15 02/19 09Z 47 39 43 10 0.00 0.00 552 562 3.3 -14.8 1012 100 079OVC125 0.0 15.1 18 02/19 12Z 42 35 53 13 0.01 0.00 550 560 2.5 -16.7 1012 100 -RA 063OVC171 0.0 10.1 21 02/19 15Z 35 33 61 15 0.14 0.01 548 559 1.8 -16.4 1013 100 -RA 011OVC203 0.0 5.9 24 02/19 18Z 33 30 43 15 0.22 0.01 548 556 1.8 -16.9 1009 100 RA 013OVC189 0.0 1.6 27 02/19 21Z 33 30 37 14 0.16 0.00 543 550 -3.9 -20.0 1008 100 -PL 012OVC140 0.0 3.2 30 02/20 00Z 31 30 0 12 0.13 0.00 539 548 -7.0 -19.9 1011 100 SN 013OVC209 1.4 0.7 Link to comment Share on other sites More sharing options...
beanskip Posted February 19, 2012 Share Posted February 19, 2012 GFS never quite gets it there in Shelby -- rain all the way through the event (at least looking at 6 hour soundings). EDIT: Same for Rutherfordton, Lincolnton, CLT. Link to comment Share on other sites More sharing options...
tarheelwx Posted February 19, 2012 Share Posted February 19, 2012 Seems like RAH needs to move forward with a watch (or warning) for 64 north. Could be some really heavy stuffy in those areas as soon as it changes over. TW Link to comment Share on other sites More sharing options...
burkecountync Posted February 19, 2012 Share Posted February 19, 2012 Based on what I see on the models, the models are showing very little phasing between the northern system and the southern system. This can be a good and bad thing. The good thing is the system will stay further south; however, the bad thing is very little precipitation on the back side of the storm. Numerical models have trouble with phasing in general, so that should also be remembered. Lets wait and see what happens in general; however, the foothills of NC look to do really good. I think most spots along the I-40 corridor will do very well with this storm, ending the snow drought. We are still 12-18 hours from the event, and there will still be some changes in the forecast. No doubt thought, this is a weather forecasters worst nightmare of a storm. Link to comment Share on other sites More sharing options...
SN_Lover Posted February 19, 2012 Share Posted February 19, 2012 Nice! I come back to see the models all trending favorably!! I really don't care for accumulation, although it would be nice to see the trees covered in slow before they are covered in leaves. Here is WRAL's model for the forecast of the snow. I don't know what models the are deriving this off. Link to comment Share on other sites More sharing options...
Poimen Posted February 19, 2012 Author Share Posted February 19, 2012 This is the 12 hour qpf totals from 21h to 33h on the GFS. Can't get much detail but it looks close to .50 qpf close to RDU at least. Am I to assume most of this falls in 3 hours? Link to comment Share on other sites More sharing options...
packbacker Posted February 19, 2012 Share Posted February 19, 2012 UKIE looks good to... Link to comment Share on other sites More sharing options...
Dunkman Posted February 19, 2012 Share Posted February 19, 2012 Seems like RAH needs to move forward with a watch (or warning) for 64 north. Could be some really heavy stuffy in those areas as soon as it changes over. TW I'd think they have to at least put out a WWA now that the GFS has come in with 5-6 in the Triad. edit: either I got my lines crossed or the UK looks nice and cold. Link to comment Share on other sites More sharing options...
BullCityWx Posted February 19, 2012 Share Posted February 19, 2012 these are the Hickory soundings for the 18z nam: 15 02/19 09Z 47 39 43 10 0.00 0.00 552 562 3.3 -14.8 1012 100 079OVC125 0.0 15.1 18 02/19 12Z 42 35 53 13 0.01 0.00 550 560 2.5 -16.7 1012 100 -RA 063OVC171 0.0 10.1 21 02/19 15Z 35 33 61 15 0.14 0.01 548 559 1.8 -16.4 1013 100 -RA 011OVC203 0.0 5.9 24 02/19 18Z 33 30 43 15 0.22 0.01 548 556 1.8 -16.9 1009 100 RA 013OVC189 0.0 1.6 27 02/19 21Z 33 30 37 14 0.16 0.00 543 550 -3.9 -20.0 1008 100 -PL 012OVC140 0.0 3.2 30 02/20 00Z 31 30 0 12 0.13 0.00 539 548 -7.0 -19.9 1011 100 SN 013OVC209 1.4 0.7 That's not a sounding, that's extracted data. Link to comment Share on other sites More sharing options...
Gastonwxman Posted February 19, 2012 Share Posted February 19, 2012 Okay now I have the correct NAM. The one I posted earlier was somehow the 12z even though it was in the 0z link: Link to comment Share on other sites More sharing options...
calculus1 Posted February 19, 2012 Share Posted February 19, 2012 GSP's latest thoughts. Still not going with an advisory for the I-40 corridor. .NEAR TERM /THROUGH SUNDAY/... AS OF 955 PM...LIGHT RAIN CONTINUES TO MAKE SLOW PROGRESS EAST/ NORTHEAST...AND CURRENTLY EXTENDS FROM THE NORTHEAST GEORGIA MOUNTAINS TO THE EASTERN SC PIEDMONT. JUDGING FROM UPSTREAM RADAR TRENDS...THE NAM SEEMS TO BE VERIFYING VERY WELL IN TERMS OF KEEPING OUR NORTHERN ZONE DRY THROUGH MOST OF THE NIGHT. POPS WERE LOWERED TO LIKELY IN THESE AREAS...BUT EVEN THIS MAY BE TOO HIGH. THE CURRENT PRECIP...FORCED BY LOW-TO-MID LEVEL FRONTOGENESIS IS EXPECTED TO SHIFT EAST OF THE AREA...SOMETIME BETWEEN 09Z AND 12Z. THERE WILL BE A BIT OF A LULL BEFORE THE MORE SIGNIFICANT DEFORMATION ZONE PRECIP ARRIVES DURING MID-TO-LATE MORNING. OTHERWISE...THE COLD AIR ASSOCIATED WITH CANADIAN HIGH PRESSURE ACROSS THE MIDWEST IS BEGINNING TO SPILL INTO NORTHERN VIRGINIA AT THIS TIME. BACKDOOR FRONT SHOULD ARRIVE TO THE NORTHERN ZONES BY 12Z...BRINGING MUCH COOLER AIR TO THE REGION. SUNDAY...THERE ISNT A WHOLE LOT TO ADD FOR SUNDAY AT THIS TIME. THE MODELS GENERALLY AGREE THAT THE HIGHEST DEFORMATION ZONE QPF WILL OCCUR ACROSS WESTERN AND NORTHERN PORTIONS OF THE CWFA. BY EARLY AFTERNOON...MOST AREAS OF THE NORTHERN MOUNTAINS SHOULD BE NEAR FREEZING. MODEL SOUNDINGS DEPICT A BIT OF A WARM NOSE LINGERING IN WANING LOW/MID LEVEL WARM ADVECTION. THEREFORE...THERE PROBABLY WILL BE A TRANSITORY PERIOD OF FZRA/SLEET BEFORE THE TRANSITION TO SNOW. THIS WILL ALSO BE POSSIBLE FURTHER SOUTH ALONG THE EASTERN ESCARPMENT AS TEMPS FALL THEN LOCK IN AROUND FREEZING IN THE STRONG EASTERLY FLOW. SNOW SHOULD BE THE PREDOMINANT PRECIP TYPE IN THE CURRENT WARNING AREA...AND IT APPEARS THAT 4-6 INCHES ARE EASILY ATTAINABLE IN THIS AREA. FURTHER SOUTH...LIGHT ACCUMULATIONS OF A MIXED BAG ARE EXPECTED ALONG THE EASTERN ESCARPMENT. MEANWHILE... THE INTERIOR VALLEYS (INCLUDING ASHEVILLE/HENDERSONVILLE/ WAYNESVILLE) WILL LIKELY SEE AROUND AN INCH OR LESS AS PRECIP CHANGES TO SNOW BEFORE ENDING. ANOTHER AREA OF CONCERN WILL BE THE I-40 CORRIDOR IN THE PIEDMONT...AS SUFFICIENT COLD AIR SHOULD BE IN PLACE TO ALLOW FOR ACCUMULATING SNOWFALL BY THE TIME PRECIP ENDS LATE TOMORROW AFTERNOON/EVENING. PER COORDINATION WITH NEIGHBORING OFFICES...AN ADVISORY WILL NOT BE ISSUED FOR THESE AREAS ATTM...BUT MEASURABLE SNOWFALL DOES APPEAR LIKELY BEFORE PRECIP ENDS. THE FINAL AREA TO WATCH WILL BE THE HIGHER ELEVATIONS OF THE CENTRAL NC MTNS...ESPECIALLY ALONG THE TENN BORDER. THE CONCERN HERE IS THAT AS THE HEAVIER DEFORMATION ZONE PRECIP MOVES OVER THIS AREA...SNOW LEVELS WILL QUICKLY PLUMMET AND A GOOD CHUNK OF TOMORROWS PRECIP COULD END UP FALLING AS SNOW ABOVE 3000 FEET OR SO. THIS IS ENOUGH OF A CONCERN THAT A WINTER STORM WATCH WILL BE ISSUED FOR THE HIGHER ELEVATIONS OF HAYWOOD AND MADISON COUNTIES. Link to comment Share on other sites More sharing options...
packbacker Posted February 19, 2012 Share Posted February 19, 2012 This is the 12 hour qpf totals from 21h to 33h on the GFS. Can't get much detail but it looks close to .50 qpf close to RDU at least. Am I to assume most of this falls in 3 hours? On the 0z GFS RDU has roughly 0.5" of precip that falls from 18z to 0z, virtually nothing after 0z, I would bet we switch to something frozen by 21z, similar to NAM, so we are looking 0.2" of something frozen per the GFS. The NAM has another 0.2" of precip after 0z. The NAM is notorious for overdoing precip but the Euro seems to be the best. Link to comment Share on other sites More sharing options...
MillerA Posted February 19, 2012 Share Posted February 19, 2012 gsp discussion: as of 955 PM...light rain continues to make slow progress east/ northeast...and currently extends from the northeast Georgia mountains to the eastern SC Piedmont. Judging from upstream radar trends...the NAM seems to be verifying very well in terms of keeping our northern zone dry through most of the night. Probability of precipitation were lowered to likely in these areas...but even this may be too high. The current precipitation...forced by low-to-mid level frontogenesis is expected to shift east of the area...sometime between 09z and 12z. There will be a bit of a lull before the more significant deformation zone precipitation arrives during middle-to-late morning. Otherwise...the cold air associated with Canadian high pressure across the Midwest is beginning to spill into northern Virginia at this time. Backdoor front should arrive to the northern zones by 12z...bringing much cooler air to the region. Sunday...there isnt a whole lot to add for Sunday at this time. The models generally agree that the highest deformation zone quantitative precipitation forecast will occur across western and northern portions of the County warning forecast area. By early afternoon...most areas of the northern mountains should be near freezing. Model soundings depict a bit of a warm nose lingering in waning low/middle level warm advection. Therefore...there probably will be a transitory period of freezing rain/sleet before the transition to snow. This will also be possible further south along the eastern Escarpment as temperatures fall then lock in around freezing in the strong easterly flow. Snow should be the predominant precipitation type in the current warning area...and it appears that 4-6 inches are easily attainable in this area. Further south...light accumulations of a mixed bag are expected along the eastern Escarpment. Meanwhile... the interior valleys (including Asheville/Hendersonville/ waynesville) will likely see around an inch or less as precipitation changes to snow before ending. Another area of concern will be the I-40 corridor in the Piedmont...as sufficient cold air should be in place to allow for accumulating snowfall by the time precipitation ends late tomorrow afternoon/evening. Per coordination with neighboring offices...an advisory will not be issued for these areas at this time...but measurable snowfall does appear likely before precipitation ends. The final area to watch will be the higher elevations of the central NC mountains...especially along the tenn border. The concern here is that as the heavier deformation zone precipitation moves over this area...snow levels will quickly plummet and a good chunk of tomorrows precipitation could end up falling as snow above 3000 feet or so. This is enough of a concern that a Winter Storm Watch will be issued for the higher elevations of Haywood and Madison counties. Link to comment Share on other sites More sharing options...
tarheelwx Posted February 19, 2012 Share Posted February 19, 2012 Not seeing as much sleet and zr showing up as earlier runs. TW Link to comment Share on other sites More sharing options...
rduwx Posted February 19, 2012 Share Posted February 19, 2012 Not seeing as much sleet and zr showing up as earlier runs. TW Yeah, w/ the slp not being as strong and further south there is not as much of a warm nose. Link to comment Share on other sites More sharing options...
Carvers Gap Posted February 19, 2012 Share Posted February 19, 2012 UKIE looks good to... RGEM basically holds serve, though just a tad south. The NAM, GFS, and RUC are way south of previous runs. The Ukie doesn't look as far south w/ its precip shield nor does the 21z SREF. Radar looks north. Ukie looks like a good compromise. Going to be really interesting to see the Euro. Link to comment Share on other sites More sharing options...
packbacker Posted February 19, 2012 Share Posted February 19, 2012 RGEM basically holds serve, though just a tad south. The NAM, GFS, and RUC are way south of previous runs. The Ukie doesn't look as far south w/ its precip shield nor does the 21z SREF. Radar looks north. Ukie looks like a good compromise. Going to be really interesting to see the Euro. Agreed, the Euro has had the best handle on this storm, it's had it's variations but for the most part has been solid, with it being the best about forecasting precip I would push all my chips in with what the Euro shows tonight. I imagine if it shows for 4"+ for the triad WSW's are going to be thrown up shortly thereafter. I think RDU will see some snow, probably 1-2", should be nice to look at. Link to comment Share on other sites More sharing options...
packbacker Posted February 19, 2012 Share Posted February 19, 2012 RGEM basically holds serve, though just a tad south. The NAM, GFS, and RUC are way south of previous runs. The Ukie doesn't look as far south w/ its precip shield nor does the 21z SREF. Radar looks north. Ukie looks like a good compromise. Going to be really interesting to see the Euro. Also, just to compare the 12z UK with the 0z UK, it shifted south some, thus colder, definitely nice to see... 0z UK at hour 24 12z UK at hour 36 Link to comment Share on other sites More sharing options...
SN_Lover Posted February 19, 2012 Share Posted February 19, 2012 One thing that is starting to worry me is the dew point. it's in the lower 40's right now. I know from observations historically for my location(40min N of Charlotte), when that happens, It takes a long time for the dew point to go down. Getting nervous about that. Link to comment Share on other sites More sharing options...
Cold Rain Posted February 19, 2012 Share Posted February 19, 2012 For those in the Triangle area, I think we're going to want to see the trailing vort come south, maybe track along the NC/SC boarder,...not necessarily the main system coming south, although that would allow for a colder profile. Our snow is going to come from the trailing energy. But if I'm not thinking about that right, feel free to correct me. Link to comment Share on other sites More sharing options...
Carvers Gap Posted February 19, 2012 Share Posted February 19, 2012 Also, just to compare the 12z UK with the 0z UK, it shifted south some, thus colder, definitely nice to see... Just a touch southeast. Thanks for the comparison. What's crazy here in NE TN, is that originally the dreaded warm nose was going to cause problems. Now, we are on the western extent of the northwest quadrant! I think the Euro will be south - but not as much as the NAM. Pure guessing on my part. Link to comment Share on other sites More sharing options...
BullCityWx Posted February 19, 2012 Share Posted February 19, 2012 Link to comment Share on other sites More sharing options...
dsaur Posted February 19, 2012 Share Posted February 19, 2012 Let's bank it! If this trend continues, we might be looking at Charlotte or Columbia as the sweet spot. This time last night, I believe that the NC/VA border up to Roanoke was the big winner. 24 hours has produced a huge shift. Now we're talking A little more and I get to play. I'm sure racking up on the rain, so some snow would be icing, lol. T Link to comment Share on other sites More sharing options...
NCSNOW Posted February 19, 2012 Share Posted February 19, 2012 Well when I awake in the a.m. and want my overnight Euro news, I won't come here first but instead click NWS. If I see WWA or WSW, then I'll know the Euro is still toting the water with latest trends. I'm sure it will start the coordination between Blacksburg/RAH and Greenville puting out advisories. Can'tkick the can down the road any longer. HAVE ALSO BEEN CONSIDERING THE POSSIBILITY OF EXTENDING THE WINTER WEATHER ADVISORY FURTHER SOUTH INTO OUR NORTH CAROLINA COUNTIES FOR SUNDAY EVENING AFTER COORDINATING WITH SOME OF OUR SURROUNDING OFFICES. BELIEVE IT WILL BE COLD ENOUGH FOR SNOW LATE SUNDAY EVENING...BUT AT THIS POINT...NOT SURE IF WE WOULD REACH ADVISORY CRITERIA FOR ACCUMULATIONS. WILL PASS MY CONCERNS TO THE MIDNIGHT SHIFT AND...AFTER REVIEWING A NEW BATCH OF MODEL DATA...WILL LET THEM MAKE THE CALL. Link to comment Share on other sites More sharing options...
griteater Posted February 19, 2012 Share Posted February 19, 2012 For those in the Triangle area, I think we're going to want to see the trailing vort come south, maybe track along the NC/SC boarder,...not necessarily the main system coming south, although that would allow for a colder profile. Our snow is going to come from the trailing energy. But if I'm not thinking about that right, feel free to correct me. I'd say that is spot on Cold R. Sfc low will have little say in the deformation band precip. You want that trailing vort max to be as far south and as strong as you can get it for both colder and more lift / precip. You also want the 850mb and 700mb lows trending south Link to comment Share on other sites More sharing options...
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