DaculaWeather Posted February 25, 2015 Share Posted February 25, 2015 Best AFD from Atlanta I think I've ever read. Trisha did an awesome job. http://www.daculaweather.com/4_afd_ffc.php Link to comment Share on other sites More sharing options...
toxictwister00 Posted February 25, 2015 Share Posted February 25, 2015 Best AFD from Atlanta I think I've ever read. Trisha did an awesome job. http://www.daculaweather.com/4_afd_ffc.php Agreed, FFC has really been on top of this system very well imo. She even mentioned the possibility of thundersnow in some areas. Link to comment Share on other sites More sharing options...
strongwxnc Posted February 25, 2015 Share Posted February 25, 2015 For upstate crowd, this map should put any concerns of a nice snow to bed. Nice little bullseye over Greenville! No doubt! Weirdest looking map I have seen with the pockets of 70% of more throughout! Stays true to what most maps have been showing. Gsp is also likening the north of I85 area in the upstate. Still wiggle room for where the banding will set up... Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
WxJordan Posted February 25, 2015 Share Posted February 25, 2015 Good Morning! I have updated my snow map and here is the latest call. Some areas could see locally heavier amounts where banding sets up. The biggest change was to lower western NC into a 3-6 category with higher amounts along the southern facing slopes of NC. Otherwise, the forecast is on track and looks good at the moment. Link to comment Share on other sites More sharing options...
RaleighWx Posted February 25, 2015 Share Posted February 25, 2015 Taken literally the 6z NAM and 6z RGEM do bring a period of sleet to RDU, although it is still mostly in the form of snow. NAM still likely overdone with QPF totals. Link to comment Share on other sites More sharing options...
TiltedStorm Posted February 25, 2015 Share Posted February 25, 2015 Is it just me or did the NAM slowed the system down a bit? Link to comment Share on other sites More sharing options...
GaWx Posted February 25, 2015 Share Posted February 25, 2015 Is it me or have last couple of GFS runs, especially 6Z, shown increasing CAD? I'm starting to wonder if sleet could possibly end up as a dominant ptype in/near much of ATL/AHN area. Any opinions? Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 25, 2015 Share Posted February 25, 2015 Is it me or have last couple of GFS runs, especially 6Z, shown increasing CAD? I'm starting to wonder if sleet could possibly end up as a dominant ptype in/near much of ATL/AHN area. Any opinions? Larry, was just looking at that. Even right now you see the pressure signature of a CAD Link to comment Share on other sites More sharing options...
burrel2 Posted February 25, 2015 Share Posted February 25, 2015 One thing is for sure... soil temperatures could not possibly be any better for this time of year. I know the soil temp arguement against accumulations is bogus, but soil temp does play a huge effect in how long the snow stays on the ground after it has fallen. Link to comment Share on other sites More sharing options...
strongwxnc Posted February 25, 2015 Share Posted February 25, 2015 Latest gsp forecast: Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
packfan98 Posted February 25, 2015 Share Posted February 25, 2015 Great read from NWS Raleigh: .SHORT TERM /TONIGHT THROUGH THURSDAY/...AS OF 550 AM WEDNESDAY...THERE HAS BEEN A CONTINUED SLIGHT NORTHWARD SHIFT IN GUIDANCE SINCEYESTERDAY...WHICH EQUATES TO A WETTER AND MARGINALLY WARMER SOLUTIONFOR CENTRAL NC...THOUGH THE OVERALL PATTERN REMAINS UNCHANGED WITHTHE DEAMPLIFICATION/ENE SHEARING OF A SHORTWAVE TROUGH FROM NEAR THERIO GRANDE THIS MORNING TO THE MIDDLE ATLANTIC COAST BY THU MORNING.THE ASSOCIATED FORCING FOR ASCENT ATOP A PAIR OF CLOSELY-SPACED ANDSTRONG FRONTAL ZONES DRAPED ACROSS THE NORTHERN GOM TO A SFC LOWABOUT MIDWAY BETWEEN CAPE HATTERAS AND BERMUDA...WILL RESULT IN THECONTINUED DEEPENING OF A SFC LOW OVER THE NW GOM THIS MORNING.GUIDANCE IS THEN FAIRLY TIGHTLY CLUSTERED WITH THE TRACK OF A MILLER"A" SFC LOW ACROSS THE NORTHERN FL PENINSULA THIS EVENING ANDROUGHLY ALONG THE GULF STREAM TO JUST EAST OF CAPE HATTERAS BY 12ZTHU.AS HAS BEEN NOTED IN PREVIOUS DISCUSSIONS...THE LACK OF A PARENTCOLD HIGH IS ADMITTEDLY SOMEWHAT CONCERNING. AN ARCTIC SFC HIGH AT1045 MB WILL BE CENTERED OVER SOUTHERN ALBERTA/SASKATCHEWAN AND WILLCONSEQUENTLY HAVE LITTLE INFLUENCE AT OUR LATITUDE DURING THE HEIGHTOF THE STORM TONIGHT. HOWEVER...A VERY FAVORABLE MILLER "A" CYCLONETRACK ALONG AND JUST OFFSHORE THE SE COAST...IN CONJUNCTION WITH APRECEDING ARCTIC HIGH THAT APPEARS TO BE JUST COLD ENOUGH DESPITEBEING IN A DRAMATICALLY WEAKENED STATE FROM A COUPLE OF DAYSAGO...BUT IS STILL CHARACTERIZED BY SFC TEMPERATURES AND DEWPOINTSMOSTLY IN THE TEENS TO 20S OVER NC THIS MORNING...WILL SUPPORT ASIGNIFICANT WINTER STORM **WITH A NARROW P-TYPE (SNOW/RAIN)TRANSITION ZONE AND DEEP NEAR FREEZING ISOTHERMAL PROFILESCHARACTERISTIC OF MILLER "A` SFC PATTERNS.** PRECIPITATIONRATES...OCCASIONALLY MODERATE TO HEAVY...WILL ONLY SERVE TO ENHANCETHE DEEP NEAR FREEZING ISOTHERMAL PROFILES RIGHT ALONG THE SNOW/COLDRAIN INTERFACE...OWING TO MELTING. A LITTLE MIX OF SLEET ANDFREEZING RAIN ARE HARD TO AVOID IN CENTRAL NC WINTER STORMS...AND INMILLER "A" STORMS INCLUDING THIS ONE...SUCH OCCURRENCE IS MOST LIKELYNEAR THE NARROW TRANSITION SNOW/RAIN ZONE. NO APPRECIABLE ICING ISANTICIPATED...HOWEVER...IN PART SINCE SURFACE TEMPERATURES AREEXPECTED TO HOLD NEARLY STEADY IN THE 29 TO 33 DEGREE RANGE OVER THEWARNING AREA...AND 32 TO 34 DEGREES OVER THE ADVISORY AREA WHERESUCH ICING OCCURRENCE WOULD BE MOST PROBABLE.DESPITE SOME MINIMAL OVERALL RISE IN THICKNESS VALUES VERSUS THESLIGHTLY COLDER AND DRIER SOLUTIONS OF YESTERDAY...PROJECTED PARTIALTHICKNESS VALUES OVER MOST OF THE PIEDMONT AND NORTHERN COASTALPLAIN REMAIN SQUARELY IN THE RANGE TYPICAL OF SIGNIFICANT SNOWSTORMSIN CENTRAL NC. WITH A SLIGHTLY MILDER SOLUTION COMES A SLIGHTLYWETTER ONE...LED BY A BLEND OF THE VERY SIMILAR 00Z ECMWF ANDGFS...SO QPF HAS BEEN RAISED TO AROUND ONE HALF INCH OVER THE NWPIEDMONT TO AS MUCH AS ONE INCH OVER THE SOUTHERN COASTAL PLAIN.PARTIAL THICKNESS VALUES HEAVILY WEIGHTED TOWARD THE FAVORED 00ZECMWF AND GFS...FAVORS MOSTLY SNOW OVER THE PIEDMONT AND NORTHERNCOASTAL PLAIN...WITH A MIX OF SNOW AND A COLD RAIN (OR FREEZING RAINWITH LITTLE ACCRUAL WHERE SFC TEMPERATURES OSCILLATE ABOUT THEFREEZING MARK) OVER THE ADVISORY AREA.SNOW RATIOS BETWEEN 00-06Z THU OF 10-14:1 PER WPC WWD SLR GUIDANCEAND SUPPORTED BY THERMAL PROFILES THAT RANGE FROM DEEP NEAR FREEZINGISOTHERMAL IN THER NARROW TRANSITION ZONE TO WELL BELOW FREEZING...EXCEPT RIGHT AT THE SURFACE...ALONG AND NORTH OF THE I-40/I-85CORRIDOR...ARE EXPECTED TO DECREASE PARTICULARLY NEAR NARROWTRANSITION ZONE TO CLOSER TO 8-10:1 PER WHAT IS TYPICAL OF EVENTSCHARACTERIZED BY PARTIAL THICKNESS VALUES IN THE ~1285/~1535 METERRANGE. SLIGHTLY LOWER RATIOS...CLOSER TO 4-6:1 WITHIN THE SNOW/RAINTRANSITION ZONE - OR ROUGHLY ALONG THE BOUNDARY OF WINTER STORMWARNING AND WINTER WEATHER ADVISORY - WHERE THE MIXING WITH A COLDRAIN WILL RESULT IN A MORE SLUSHY ACCUMULATION VERSUS POINTSNORTHWARD.BASED ON THESE RATIOS...AND THE QPF NOTED ABOVE...WIDESPREADSNOWFALL ACCUMULATIONS OF 3 TO 6 INCHES ARE LIKELY OVER THE WARNINGAREA...WITH A STRIPE OF 6 TO 8 INCHES ROUGHLY INVOF OR JUST NORTH OFTHE US HIGHWAY 64 CORRIDOR...WITH LOCALLY HIGHER AMOUNTS FROM THETRIANGLE TO ROANOKE RAPIDS AND ROCKY MOUNT. MEANWHILE...LESSERTOTALS OF 1 TO 3 INCHES ARE EXPECTED OVER THE ADVISORY AREA...WHEREAGAIN...PARTIAL THICKNESS AND SFC TEMPERATURE VALUES MARGINALLYABOVE FREEZING WILL SUPPORT A MIXING WITH OR CHANGEOVER TO A COLDRAIN BETWEEN MIDNIGHT AND 5 AM. EVEN THERE...HOWEVER...THE NORTHERNPORTIONS OF THE ADVISORY COUNTIES MAY EXCEED WARNING CRITERIA OF 3INCHES. Link to comment Share on other sites More sharing options...
nchighcountrywx Posted February 25, 2015 Share Posted February 25, 2015 Latest Hires NAM Actual Snow on Ground Accounting for Surface Melting(Documented to see if the Hires NAM is actually calling the surface correctly. It will be interesting to see what the HRRR shows for actual snow on ground as model runs come in todayIt will come down to the ability for the total column to be brought down below freezing as both surface temps and dew points will be in the mid 30s or higher going into the event.Image courtesy of WeatherbellWithout melting :HRRR surface temps and dew points 8:00pm The HRRR is also pushing afternoon temperatures this afternoon up to the upper 40s to 50 degrees in many areas Link to comment Share on other sites More sharing options...
burrel2 Posted February 25, 2015 Share Posted February 25, 2015 The RAP and HRR are starting to key in on the frontogenically forced band out in front of the main show. It looks like they really want to strengthen it and dump on the northern upstate/Southern NC mountains by as early as 4 oclock this afternoon. It wouldn't surprise me one bit as the southern mountains always seem to find a way to get in on the heavy precip before anyone else, regardless of trajectory.... Link to comment Share on other sites More sharing options...
GaWx Posted February 25, 2015 Share Posted February 25, 2015 Steve, Look at the 6Z GFS progged 925's vs 850's for MGE, PDK, and AHN. They're generally colder and at -1 C most of the time while 850's are as warm as +1 C. So, 4K feet above ground 34 F while it is 30 F at 2K feet above ground?? That seems sleety if those levels were to be accurate. In the past, I've noticed 850's in the +1C to +2.5C range while there is decent wedging has resulted in sleet as the main precip type. Regardless, 2M temp's, which are a little warmer on this GFS run, are almost certainly quite a bit too warm and would likely be closer to 28-30 F. Opinions Steve or others? Link to comment Share on other sites More sharing options...
Wild Weather Monger Posted February 25, 2015 Share Posted February 25, 2015 Steve, Look at the 6Z GFS progged 925's vs 850's for MGE, PDK, and AHN. They're generally colder and at -1 C most of the time while 850's are as warm as +1 C. So, 4K feet above ground 34 F while it is 30 F at 2K feet above ground?? That seems sleety if those levels were to be accurate. In the past, I've noticed 850's in the +1C to +2.5C range while there is decent wedging has resulted in sleet as the main precip type. Regardless, 2M temp's, which are a little warmer on this GFS run, are almost certainly quite a bit too warm and would likely be closer to 28-30 F. Opinions Steve or others? Yeah, I was just looking at the nearby soundings as well. As much as I dislike sleet, it beats plain old rain any day. Of course I'm praying that 850's are modeled a little too warm. I'm sure the surface is in CAD areas, and likely 925's too. I did find it interesting in the FCC AM disco that they have concern with down sloping in the NE Ga CAD areas. Been trying to figure out what they are seeing there??? Seems the opposite ie CAD holds to me. Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 25, 2015 Share Posted February 25, 2015 I would prefer a wet heavy snow. I'm on the edge here so I expect that, at least part of the time. Link to comment Share on other sites More sharing options...
oconeexman Posted February 25, 2015 Share Posted February 25, 2015 Latest gsp forecast: Sent from my iPhone Now that looks good right there! This is the map I've been waiting to see. Glad to see them start raising totals for here. Basically 4.5-8" for the corner...that's a start! Link to comment Share on other sites More sharing options...
franklin NCwx Posted February 25, 2015 Share Posted February 25, 2015 The RAP and HRR are starting to key in on the frontogenically forced band out in front of the main show. It looks like they really want to strengthen it and dump on the northern upstate/Southern NC mountains by as early as 4 oclock this afternoon. It wouldn't surprise me one bit as the southern mountains always seem to find a way to get in on the heavy precip before anyone else, regardless of trajectory.... that comes with enhanced orographic lift with the sudden increase in elevation. The same way the up slope works along the Tennessee border it's the same way here. It's also the reason we average so much rain. Warm gulf air is wrung out over the high souther peaks. Link to comment Share on other sites More sharing options...
Tacoma Posted February 25, 2015 Share Posted February 25, 2015 schools in Buncombe county will be scampering to get kids home. some buses are out there until 5:30 or a little later. Link to comment Share on other sites More sharing options...
Cold Rain Posted February 25, 2015 Share Posted February 25, 2015 Looks like the northwest trends continue. Apparently all of the concerns about this being overamped in the modeling were overamped. From northern Wake to Roanoke Rapids looks to be the sweet spot. Looks like southern Wake goes over to mix or rain. Link to comment Share on other sites More sharing options...
packfan98 Posted February 25, 2015 Share Posted February 25, 2015 Matthew East video: https://www.youtube.com/watch?v=V5j_4PxeNy4&feature=youtu.be snow map: Link to comment Share on other sites More sharing options...
packbacker Posted February 25, 2015 Share Posted February 25, 2015 Looks like the northwest trends continue. Apparently all of the concerns about this being overamped in the modeling were overamped. From northern Wake to Roanoke Rapids looks to be the sweet spot. Looks like southern Wake goes over to mix or rain. You are not going to rain, it may 30 miles SE of you but we will see. We will mix, we always do with big events. 4-6" with some sleet will be a big event. I think just NE of us is all snow, SuperJames gets 6"+ and CLT looks to be around that too. Also, we only mix as the coastal approaches ILM, before that a lot of the precip has fallen. Link to comment Share on other sites More sharing options...
FallsLake Posted February 25, 2015 Share Posted February 25, 2015 Looks like the northwest trends continue. Apparently all of the concerns about this being overamped in the modeling were overamped. From northern Wake to Roanoke Rapids looks to be the sweet spot. Looks like southern Wake goes over to mix or rain. I don't know man. Going off RAH's discussion you could do well. It looks like the transition line will setup right along the warning/advisor county lines. That gives you all of Johnson and Harnett County as a buffer. Looking at the 6z GFS you would be right on the line but high rates can over-come slightly above 850 temps. **as Pack said yesterday toe the line... Link to comment Share on other sites More sharing options...
burrel2 Posted February 25, 2015 Share Posted February 25, 2015 Some 1 inch liquid lollipops showing up in NE GA and the western upstate at the end of the RAP's range(and more left to come).... definitely looks as wet or wetter than the NAM... Link to comment Share on other sites More sharing options...
GaWx Posted February 25, 2015 Share Posted February 25, 2015 There's still so much cold air all over SE US. 6Z GFS 2M's look too warm. Hard for me to believe that wintry precip won't dominate ATL -AHN though I do wonder if sleet sneaks in as at least part of it in some CAD areas like ATL-AHN. I do remember the great 2/1979 sleetstorm. It was predicted to be mainly snow. I'm not predicting sleet but am wondering about the possibility. Any opinions? Link to comment Share on other sites More sharing options...
Regan Posted February 25, 2015 Share Posted February 25, 2015 You are not going to rain, it may 30 miles SE of you but we will see. We will mix, we always do with big events. 4-6" with some sleet will be a big event. I think just NE of us is all snow, SuperJames gets 6"+ and CLT looks to be around that too. Also, we only mix as the coastal approaches ILM, before that a lot of the precip has fallen. Yes, if I was reading it correct NWS said the advisory counties could see cold rain mixing. They weren't referring to the warning area (Wake). But the said the the northern part of the advisory "counties" could exceed 3. I could be wrong. Link to comment Share on other sites More sharing options...
PackGrad05 Posted February 25, 2015 Share Posted February 25, 2015 I think I may see a good mix of rain. I'm near Fuquay, right near the southern edge of Wake... Northern Wake could be quite different than me. Link to comment Share on other sites More sharing options...
packbacker Posted February 25, 2015 Share Posted February 25, 2015 I don't know man. Going off RAH's discussion you could do well. It looks like the transition line will setup right along the warning/advisor county lines. That gives you all of Johnson and Harnett County as a buffer. Looking at the 6z GFS you would be right on the line but high rates can over-come slightly above 850 temps. **as Pack said yesterday toe the line... I want to be 10-20 miles NW of the rain/snow line, playing with fire but it's go big time. Link to comment Share on other sites More sharing options...
packbacker Posted February 25, 2015 Share Posted February 25, 2015 Yes, if I was reading it correct NWS said the advisory counties could see cold rain mixing. They weren't referring to the warning area (Wake). But the said the the northern part of the advisory "counties" could exceed 3. I could be wrong. I think we mix with sleet, not rain, we almost always do with big events. Link to comment Share on other sites More sharing options...
Cold Rain Posted February 25, 2015 Share Posted February 25, 2015 Thanks guys. Either way, yesterday was awesome and it's been and continues to be fun tracking this one. Hopefully BL temps don't get too out of control today. I was hoping for some low clouds and/or fog to start the day. But we have beautiful sunny skies instead. Link to comment Share on other sites More sharing options...
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