packbacker Posted February 21, 2013 Share Posted February 21, 2013 4km NAM, snowfall forecast... Link to comment Share on other sites More sharing options...
superjames1992 Posted February 21, 2013 Share Posted February 21, 2013 Wow, if the high-res NAM were to verify, things could be pretty serious here Friday morning. Accumulating snowfall and a fairly serious ice event (warning criteria for portions of the Triad). It seems to be on its own, though, and model-generated snowfall maps can be iffy. I want to be in Missouri right now, though! Link to comment Share on other sites More sharing options...
jburns Posted February 21, 2013 Share Posted February 21, 2013 Yeah, you really shouldn't talk about something that you obviously have no idea about. There's a lot more involved with geography then you apparently realize. There are things you don't realize as well. The intent of my post for one. Enough negativity. So when do you get your geography degree or do you already have it? Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 21, 2013 Share Posted February 21, 2013 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM CST THURSDAY......ICE STORM WARNING REMAINS IN EFFECT FROM 6 AM TO 3 PM CSTTHURSDAY...THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A WINTERWEATHER ADVISORY FOR SLEET AND FREEZING RAIN...WHICH IS IN EFFECTUNTIL 6 AM CST THURSDAY.* SLEET AND ICE ACCUMULATIONS...BETWEEN ONE QUARTER AND THREE QUARTERS OF AN INCH OF ICE AND UP TO ONE HALF INCH OF SLEET.* TIMING...FROM LATE WEDNESDAY EVENING THROUGH THURSDAY AFTERNOON.* IMPACTS...ICE ON ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES WILL CAUSE HAZARDOUS TRAVEL CONDITIONS. SCATTERED POWER OUTAGES ALONG WITH DOWN TREES AND POWER LINES ARE EXPECTED ON THURSDAY. Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 21, 2013 Share Posted February 21, 2013 21Z SREF delayed 1 - 2 hours. Link to comment Share on other sites More sharing options...
superjames1992 Posted February 21, 2013 Share Posted February 21, 2013 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM CST THURSDAY... ...ICE STORM WARNING REMAINS IN EFFECT FROM 6 AM TO 3 PM CST THURSDAY... THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A WINTER WEATHER ADVISORY FOR SLEET AND FREEZING RAIN...WHICH IS IN EFFECT UNTIL 6 AM CST THURSDAY. * SLEET AND ICE ACCUMULATIONS...BETWEEN ONE QUARTER AND THREE QUARTERS OF AN INCH OF ICE AND UP TO ONE HALF INCH OF SLEET. * TIMING...FROM LATE WEDNESDAY EVENING THROUGH THURSDAY AFTERNOON. * IMPACTS...ICE ON ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES WILL CAUSE HAZARDOUS TRAVEL CONDITIONS. SCATTERED POWER OUTAGES ALONG WITH DOWN TREES AND POWER LINES ARE EXPECTED ON THURSDAY. Yeah, I just saw that. Has that been expected? I didn't think northern Mississippi and the Memphis area would get in on the action, but I haven't been following that area very closely. Link to comment Share on other sites More sharing options...
NavarreDon Posted February 21, 2013 Share Posted February 21, 2013 Wow, if the high-res NAM were to verify, things could be pretty serious here Friday morning. Accumulating snowfall and a fairly serious ice event (warning criteria for portions of the Triad). It seems to be on its own, though, and model-generated snowfall maps can be iffy. I want to be in Missouri right now, though! I think the model is a tad over done but, my Mom is in Joplin.....gonna be pretty nasty with a mix of everything there. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 Hi-RES NAM out to lunch most likely. We have seen this multiple times this winter. (Snow depicted on the eastern side of the mountains is likely cold rain or mix.) In fact, so much, I have copied a mets quote on this. "The computer generated snowfall maps are based on some pre-set algorithms that are not really valid this event. Unfortunately the snowtopia for the ski areas will be greatly reduced by mixed precip. I was hoping earlier, but resistance is futile." I won't comment on the ice maps...but would think to use caution with those too not entirely sure. (In fact the map itself says ice accretion will be less than depicted due to drip loss.) Hi-RES NAM also showing a shadow for Surry County. Could be some adiabatic warming immediately in the lee of the mountains? Link to comment Share on other sites More sharing options...
griteater Posted February 21, 2013 Share Posted February 21, 2013 The euro ensembles are down right frigid from day 7 to 15. The cold is centered in the southeast just like the gefs show. The nao is in the tank too which is a very strong signal from 51 members. I see winter just keaps rolling on even tho the cries of bring on spring have been heard since dec. Does anyone have a temp departure map for feb?I think my area will have a below nornal month. http://imageshack.us/photo/my-images/713/monthtdeptus.png/'> Link to comment Share on other sites More sharing options...
calculus1 Posted February 21, 2013 Share Posted February 21, 2013 Hi-RES NAM out to lunch most likely. We have seen this multiple times this winter. (Snow depicted on the eastern side of the mountains is likely cold rain or mix.) I think it did really well with last Saturday's storm. The Hi-Res NAM had a nice depiction of the secondary snow development in the lee of the mountains. It demonstrated the development in Caldwell and Burke counties in the lee of the Apps and showed the progression to Charlotte and on to the beach in the simulated radar. Now, I still doubt we'll see any snowfall from this particular system on Friday morning, but I would hesitate to be so quick to throw this model under the bus. I think the Hi-Res NAM is one of the best models we have to work with inside of 60 hours. Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 21, 2013 Share Posted February 21, 2013 Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 I think it did really well with last Saturday's storm. The Hi-Res NAM had a nice depiction of the secondary snow development in the lee of the mountains. It demonstrated the development in Caldwell and Burke counties in the lee of the Apps and showed the progression to Charlotte and on to the beach in the simulated radar. Now, I still doubt we'll see any snowfall from this particular system on Friday morning, but I would hesitate to be so quick to throw this model under the bus. I think the Hi-Res NAM is one of the best models we have to work with inside of 60 hours. It is one of the best models we have to work with inside of 60 hours I agree. This time though surely looks like the NAM is picking up on freezing rain, mix or cold rain and counting it as snow. I guess what I am trying to explain is some of the snow development in the mountains is false this time way more-so than the last event...its highlighting the eastern sections...(eastern Watauga County vs. western Watauga County etc.) When it does this I know the NAM can not handle it. Last Saturday event did not show this...it was a much more widespread mountain event with little ice accretion on the maps. Link to comment Share on other sites More sharing options...
NCSNOW Posted February 21, 2013 Share Posted February 21, 2013 Check out ptype hr 36 i beleive on latest SREF. I can't paste off the iPad but it shows a large portion of NC in mix. Lite qpf probably Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 For those asking if northern Mississippi was expected to get ice...HPC had/has them at a 0% chance. A far cry from the 70-80% chance in the NC mountains. If we take equal to or greater than .25 as warning criteria...HPC has the northern mountains of NC near a 40% chance. 1-5% chance across the NC/VA border counties and northern foothills. Link to comment Share on other sites More sharing options...
CaryWx Posted February 21, 2013 Share Posted February 21, 2013 RAH has really been trending in the CWA for more snow and a longer duration of the overall inclement mix/ice event. Noticed this over the last 48hrs or so. Link to comment Share on other sites More sharing options...
Busick Posted February 21, 2013 Share Posted February 21, 2013 I know this is a nonevent for anyone south of Hwy 64, but shouldn't we do a separate thread since the potential is there for some advisory level icing somewhere in NC???? Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 I know I am getting ahead of myself...but lets look at the current dew points...which ran lower than expected today based on earlier AFD from Greenville. 7 Boone 7 Winston Salem 9 Asheville 10 North Wilkesboro 14 Charlotte 21 Raleigh 39 Waycross, GA The llvls will start out dry Thursday evening...so the onset of precipitation may result in some snow/sleet mix...mainly in the NC mountains and foothills. Taking the top-down approach with a NAM/GFS blend to get precipitation type...have precipitation changing to rain/freezing rain in the 06z-09z time frame...then all rain by noon Friday. Models in decent agreement on generally 0.25" NE to 0.75" of quantitative precipitation forecast in the SW by middle morning Friday. With some of the this likely falling as a wintry mix...I do not get the 0.25" of ice accumulate needed for a Winter Storm Watch in any part of the County warning forecast area at this time. The one piece of guidance that gives ME pause is the 09z sref plume diagrams...which show a mean ice accumulate at ktnb of 0.5" on Friday. However...when comparing the sref mean quantitative precipitation forecast with the other models...it is a wet outlier. The thinking as of now is for a high-end advisory level event for the NC Blue Ridge vicinity generally north of I-40. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 I know this is a nonevent for anyone south of Hwy 64, but shouldn't we do a separate thread since the potential is there for some advisory level icing somewhere in NC???? Que new thread once the winter weather products are issued...should be tonight following 0z suit I would think. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 Raleigh This weather system will initiate an area of precipitation over mainly our western Piedmont counties between 10 PM and 4 am. Best lift occurs in the favored dendrite growth region. While sub-cloud layer quite dry initially...ice crystals falling through this layer will melt...cooling the atmosphere just above the surface. This evaporative cooling will lead to a mix batch of precipitation with wintry precipitation (snow/sleet mix) probable where precipitation rates are highest. Where light precipitation intensity occurs...expect mainly rain mixed with wintry precipitation since surface temperatures will be in the upper 30s. Link to comment Share on other sites More sharing options...
metalicwx366 Posted February 21, 2013 Share Posted February 21, 2013 Lol should we expect the opposite like all the other times it has shown cold. Link to comment Share on other sites More sharing options...
Marion_NC_WX Posted February 21, 2013 Share Posted February 21, 2013 The event late tomorrow night and early Friday continues to nudge slightly colder. For the first run I can think of the GFS brings the surface to freezing at KMRN at 12z Friday. -2 runs all the up to 900mb and the freezing line is between 850-900mb. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 Slightly colder...0z GFS Instant Weather Maps showing snow to freezing rain to cold rain even into the Piedmont. Link to comment Share on other sites More sharing options...
Marion_NC_WX Posted February 21, 2013 Share Posted February 21, 2013 If I was a betting man, I would wager towards GSP putting up advisories for Eastern McDowell, Greater Burke, Greater Caldwell in the morning. Maybe Winter Storm Watches for McDowell Mtns, Burke/Caldwell Mtns and Yancey, Mitchell, Avery. Issuing watches allow's them to go either pull the trigger on a warning or just match up with the lower elevation areas. Just looked at HKY, wouldn't take a whole lot to even put them in business. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 Raysweather right on que beginning to show some love for the foothills...lowered Wilkes 5 degrees from yesterday and put in sleet/freezing rain. Also mentions possible freezing rain early next week for the foothills. Link to comment Share on other sites More sharing options...
Busick Posted February 21, 2013 Share Posted February 21, 2013 I think a lot of this is going to be about timing and how much Radiative cooling can take place before the clouds roll in Thursday night-Friday morning. Link to comment Share on other sites More sharing options...
tarheelwx Posted February 21, 2013 Share Posted February 21, 2013 Slightly colder...0z GFS Instant Weather Maps showing snow to freezing rain to cold rain even into the Piedmont. Would appear to be over .25 freezing/frozen by 7am Friday. Another thing I find interesting is how cold it will be when the main precip comes in later Friday night/Saturday. Since models usually underplay cad, is there any chance that there would be zr to deal with friday night/saturday? TW Link to comment Share on other sites More sharing options...
DCMetroWinston Posted February 21, 2013 Share Posted February 21, 2013 It is interesting that RAH is more bullish on frozen precip chance in Piedmont than most. They are usually very reserved. Link to comment Share on other sites More sharing options...
tarheelwx Posted February 21, 2013 Share Posted February 21, 2013 It is interesting that RAH is more bullish on frozen precip chance in Piedmont than most. They are usually very reserved. Agree. If they take the 00z gfs precip of over .25, wouldn't that be warning criteria - if snow 2-3" or if zr .25? TW Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 Would appear to be over .25 freezing/frozen by 7am Friday. Another thing I find interesting is how cold it will be when the main precip comes in later Friday night/Saturday. Since models usually underplay cad, is there any chance that there would be zr to deal with friday night/saturday? TW Think Blacksburg mentioned it but likely further north into VA. Widespread 1-2 inches of cold rain for many at least. May be way to drippy and slightly warmer for ice then but who knows. Heavier totals in SC/GA too. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 21, 2013 Share Posted February 21, 2013 Agree. If they take the 00z gfs precip of over .25, wouldn't that be warning criteria - if snow 2-3" or if zr .25? TW Probably a better chance of sleet/snow mixing in causing no warning criteria for ice or snow altogether. Mixing does that. Maybe a advisory event for the northern Piedmont if things trend colder/wetter. Link to comment Share on other sites More sharing options...
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