CAD_Wedge_NC Posted January 12, 2019 Share Posted January 12, 2019 Just now, calculus1 said: This panel shows the furthest reach of the freezing precipitation types of the most recent Euro run: It is already wrong .... we have been getting sleet and flurries on and off this morning. Upper levels are colder than what that map is showing. Maybe the model expects major warming before the bulk of the precip moves in. Link to comment Share on other sites More sharing options...
calculus1 Posted January 12, 2019 Share Posted January 12, 2019 1 minute ago, CAD_Wedge_NC said: It is already wrong .... we have been getting sleet and flurries on and off this morning. Upper levels are colder than what that map is showing. Maybe the model expects major warming before the bulk of the precip moves in. Yeah, I wasn't looking at panels for this afternoon's novelty flakes and pellets. I was looking at the panels once the bulk of the precipitation arrives. Link to comment Share on other sites More sharing options...
Solak Posted January 12, 2019 Share Posted January 12, 2019 RAH: .NEAR TERM /THROUGH TONIGHT/... As of 310 PM Saturday... What has changed: The chance of substantial snow in the forecast area continues to decrease, while the ice accumulation predictions remain largely the same, albeit with some spatial tweaks. Forsyth and NW Person county should see the greatest totals of wintry accumulation, near a quarter inch of icing and under 1 inch of snow/sleet, and Davidson county has been added to the warning, with expectations of significant icing over its NW sections (although S sections will see little accrual). Surface temps may not get as cool as earlier expected, particularly over the SE Piedmont and Sandhills, and if this trend continues, we could see less icing in portions of the existing advisory area. No changes to this area at this time, however, as we monitor short term trends. We're still looking at a sheared mid level trough axis stretching across the area with a Miller B pattern at the surface, consisting of a primary surface low moving into the Mid South and weakening, while a secondary low forms over coastal NC. A steady feed of low level cold dry air at the surface, from the high centered over Ontario, should help maintain near- or sub-freezing surface temps over the NW Piedmont through the night, although reduced advection resulting from a somewhat weak pressure pattern will eventually result in surface wet bulbs rising above freezing across the S and E toward daybreak. Little has changed with regards to overall expectations. Areas from Durham to the N and W will see the main impacts of this storm, the most severe of which will be in the far NW Piedmont. The cold dry air is in place at the surface, and apart from lower stratus over our SE (due to moist upglide at 280-285K), the lowest 5-8k ft remains rather dry, especially over our NE sections. This has limited the ability of precip to reach the ground, despite numerous pockets of returns on MRMS. The heavier precip is still poised to spread into our NW sections after 6 pm, picking up in intensity and spreading E through the evening and overnight as forcing for ascent (including mid level DPVA within the incoming shear axis aloft and strengthening upper divergence associated with dual jets) strengthens and deepens overnight. Categorical pops will spread into W sections before midnight then expand over all of central NC overnight. The bulk of the accumulation of wintry precip is expected to occur between 05z and 10z, when the windows of strongest lift and sufficiently cold low and mid levels are likely to coincide. Precip will start out as snow and sleet with a little freezing rain this evening over the W Piedmont, with minimal snow/sleet accumulations (under one inch). A switch to mostly freezing rain is expected after midnight as rates increase. As we approach daybreak, the arrival of the 850 mb warm nose and some low level warming will result in a changeover to mostly rain across the S and NE Piedmont, leaving predominantly freezing rain over the far NW. Link to comment Share on other sites More sharing options...
BIG FROSTY Posted January 12, 2019 Share Posted January 12, 2019 Little more mention of snow in the latest forecast, at least may have some mix in? .WINTER STORM WARNING IN EFFECT UNTIL 7 PM EST SUNDAY... .TONIGHT...Snow with possible sleet, rain and freezing rain this evening, then sleet, a chance of freezing rain and snow after midnight. Precipitation may be heavy at times after midnight. Snow and sleet accumulation of 1 to 3 inches. Ice accumulation of up to one quarter of an inch. Near steady temperature in the lower 30s. Light and variable winds. Chance of precipitation near 100 percent. .SUNDAY...Rain likely. Freezing rain with sleet likely in the morning, then sleet likely or a chance of snow or freezing rain in the afternoon. Little or no additional snow and sleet accumulation. Ice accumulation around a trace. Near steady temperature in the lower 30s. Light and variable winds. Chance of precipitation 80 percent. .SUNDAY NIGHT...Cloudy with patchy freezing drizzle. A chance of snow or rain or sleet or a slight chance of freezing rain in the evening, then a slight chance of light snow after midnight. Little or no snow and sleet accumulation. Near steady temperature in the lower 30s. Light and variable winds. Chance of precipitation 50 percent. .MONDAY...A slight chance of light snow in the morning. Cloudy with patchy freezing drizzle. Highs in the upper 30s. Light and variable winds. Chance of precipitation 20 percent. Link to comment Share on other sites More sharing options...
QC_Halo Posted January 12, 2019 Share Posted January 12, 2019 Can someone tell me why Charlotte is under WWA? Is that a ‘just in case’? the forecast doesn’t have us below freezing for the next 48hrs. Link to comment Share on other sites More sharing options...
SN_Lover Posted January 12, 2019 Share Posted January 12, 2019 Over-performer incoming! Models under doing the CAD. Link to comment Share on other sites More sharing options...
tarheelwx Posted January 12, 2019 Share Posted January 12, 2019 Here in the Triad, I just don't see this being a big deal unless something happens to bring in some colder air. Current wetbulb is 31 which is enough to cause a lot of tree damage. But, I think we'll creep up to stay around 32 for the most part, and I think rates will be high enough that we won't get efficient freezing. I love a good ice storm and thought this one had potential to be pretty major. But, it seems temps are a couple of degrees above optimum level. We'll see. 34.9 here in Colfax. Need about a 3 degree drop to get some decent glazing on trees, cars, etc. TW Link to comment Share on other sites More sharing options...
griteater Posted January 12, 2019 Share Posted January 12, 2019 38 minutes ago, QC_Halo said: Can someone tell me why Charlotte is under WWA? Is that a ‘just in case’? the forecast doesn’t have us below freezing for the next 48hrs. They are probably just playing it safe. Canadian RDPS drops temps to 31 in overnight precip. NAM and 3KM NAM keep temps just above freezing...but they would go with an advisory for even minimal icing Link to comment Share on other sites More sharing options...
Isopycnic Posted January 13, 2019 Share Posted January 13, 2019 Link to comment Share on other sites More sharing options...
beanskip Posted January 13, 2019 Share Posted January 13, 2019 HRRR busting on temps by 2-3F — latest runs have southern NC Piedmont/Upstate 36-37 at 1z — current temp in Shelby/Rutherford 34 Link to comment Share on other sites More sharing options...
griteater Posted January 13, 2019 Share Posted January 13, 2019 1 hour ago, beanskip said: HRRR busting on temps by 2-3F — latest runs have southern NC Piedmont/Upstate 36-37 at 1z — current temp in Shelby/Rutherford 34 Lincolnton has light rain at 33 deg / 30 dewpoint Link to comment Share on other sites More sharing options...
calculus1 Posted January 13, 2019 Share Posted January 13, 2019 Inching ever nearer... 32.2/30 = 31.3 WB Link to comment Share on other sites More sharing options...
CADEffect Posted January 13, 2019 Share Posted January 13, 2019 How’s the triad areas doing guys. Do we have a obs thread?. Link to comment Share on other sites More sharing options...
calculus1 Posted January 13, 2019 Share Posted January 13, 2019 NWS GSP Expected Ice Accumulation continues to rise... Link to comment Share on other sites More sharing options...
beanskip Posted January 13, 2019 Share Posted January 13, 2019 0z RGEM keeps ALL of Spartanburg County below freezing all the way though 13z Sunday. Link to comment Share on other sites More sharing options...
NEGa Posted January 13, 2019 Share Posted January 13, 2019 It’s 31 with freezing rain here. About .10 inch on trees, deck etc. driveway just wet Link to comment Share on other sites More sharing options...
calculus1 Posted January 13, 2019 Share Posted January 13, 2019 Wow! The overnight forecast just upped the ante on totals IMBY: Tonight Freezing rain. Patchy fog. Low around 30. North northeast wind around 7 mph. Chance of precipitation is 100%. Total nighttime ice accumulation of 0.3 to 0.5 of an inch possible. Sunday Rain or freezing rain before 9am, then a chance of rain. Patchy fog. High near 38. Northeast wind around 6 mph. Chance of precipitation is 80%. New ice accumulation of less than a 0.1 of an inch possible. Link to comment Share on other sites More sharing options...
calculus1 Posted January 13, 2019 Share Posted January 13, 2019 NWS GSP evening update: Quote .NEAR TERM /THROUGH SUNDAY/... As of 955 pm EST: The latest LAPS and Obs analyses of surface wet bulb temperatures show values of 30 to 31 degrees across the vast majority of the Warning area this evening, lending confidence to the idea that freezing surface temperatures will persist in these mountain/foothill/NW piedmont areas and permit significant ice accumulations as the heavier QPF rates moves through the region overnight. Farther south into the Advisory area, sfc wet bulbs are running around 32 degrees, except 33 degrees in the lower piedmont. The mesoscale models still feature some modest cooler of surface temps overnight, so will keep the Advisory in place despite any icing likely being more patchy in nature southeast of the I-85 corridor. Regional composite radar shows plenty of heavier rates still upstream of the area as upper-level jet divergence, deeper-layer DPVA, continued isentropic lift, and steeper mid-level lapse rates look to cross the region overnight. Established cold air damming will maintain, or cool, surface temperatures slightly - with the coldest values likely centered around 09Z before we see any very slight warming around the edge of the wedge layer through the later morning hours. The window for accumulating sleet across the northern Blue Ridge area is dwindling, and icing from freezing rain is expected to be the major concern overnight. Although forcing will weaken as the 850 mb flow turns westerly on Sunday, channeled vorticity will keep some mentionable PoPs going through the day, with perhaps additional light ice/sleet accumulations possible across the far northern tier. It`s likely that the Warnings/Advisories will be able to be cancelled early, at some point, from south to north on Sunday. Link to comment Share on other sites More sharing options...
Dunkman Posted January 13, 2019 Share Posted January 13, 2019 From now on I think we can just immediately toss any model run that shows a storm drying out. That's no longer possible in the southeast. Link to comment Share on other sites More sharing options...
CAD_Wedge_NC Posted January 13, 2019 Share Posted January 13, 2019 8 minutes ago, Dunkman said: From now on I think we can just immediately toss any model run that shows a storm drying out. That's no longer possible in the southeast. You are right. Precip just wants to over-perform, at least while we are in this El-Nino winter. This storm was a good example of that. Link to comment Share on other sites More sharing options...
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