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MillerA

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  1. GSP Disco - Ouch for the piedmont..They appear not thrilled about advisory level snow. SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/... As of 230 PM EST Thursday: Guidance continues to indicate that a midlevel trough will sharpen over the Tennessee Valley Friday evening, even as a 120kt upper jet shifts over the Carolinas, amplifying into a split stream pattern aloft. This allows upper divergence to blossom off the NC coast overnight, and paired with deep-layer DPVA streaming into the Carolinas, this will result in rapid, potent cyclogenesis off the central Georgia coast. Both deterministic and ensemble guidance continues to favor the eastward, just-offshore track for the developing surface low, which suppresses a robust warm conveyor belt across the NC/SC Piedmont and inhibits development of a warm nose aloft, allowing for a rare rain-snow-only forecast for the NC Piedmont and SC Upstate. From perhaps 00Z Saturday onward, strengthening NW flow across the mountains will result in a widespread rain-snow mix beginning Friday evening, transitioning to all-snow by midnight. Lee troughing east of the mountains appear to result in the development of an additional circulation over the Piedmont, depicted in the HREF as a small-scale low pressure system which skirts just north of the NC-SC border. As a result, a changeover from rain to snow is expected across the NC Piedmont and at least the northernmost part of the SC Upstate, before profiles dry out leading up to daybreak Saturday. So, at this point, the NC Foothills/Piedmont and SC Upstate are forecast to see small accumulations, below advisory criteria; the NC mountains will see more appreciable snowfall. A Winter Weather Advisory has been issued for Buncombe and northern Jackson Counties, while an elevation-dependent Winter Weather Warning-Advisory has been issued for counties along the NC-TN border. After daybreak Saturday, the rapid intrusion of dry cP air on the backside of the departing system will sap profiles of their ability to produce precipitation, even as Z500 heights rebound. Gusty winds embedded in post frontal CAA are likely across the mountains and, more sporadically, the NC/SC Piedmont. Clear, dry conditions will maximize radiative cooling Saturday night, allowing temps to drop into the mid- to low-teens across most of the forecast area.
  2. Gsp discussion TERM /THROUGH TONIGHT/...As of 1045 AM EST: Upper divergence is ramping up, as indicatedby cooling cloud temps streaming into the area thanks to rightentrance region jet dynamics. This forcing is causing more snowto fall and seed the low-level moisture across the NC mountains(lots of reports of accumulating snow). So far, all the modelguidance seems to be struggling with this (consensus PoPs are lessthan 15%). So it`s really challenging to assess how much this willcontinue as we head thru the day. For now, think QPF will be verylight, and will handle with a Special Wx Statement (SPS). But anadvisory may be needed, if banding sets up (or the snow just staysmore persistent than expected). Outside the mountains, there`sa deeper dry layer preventing the seeder-feeder mechanism at themoment. However, both the NAM and GFS fcst soundings show overallmoistening profiles this aftn, and frontogenesis will ramp up towardsunset, as a strong shortwave approaches from the west. The bandingwill be parallel to the frontal zone (SW-NE orientation), butthe exact placement is still up for debate among the guidance. Itcould very well set up over the southern and central NC mountains,extending to the NW NC Piedmont. Then, things will shift SE, and thebest rates are still expected to be from Greenwood, SC to Cabarrus,NC and points E. This is where our current Winter Wx Advisory is,and that looks good. With the overall trends in the guidance sincethe 00z runs trending a little higher QPF this evening furtherwest into the Piedmont, we may need to expand the advisory. Butthere`s still not enough confidence, and will assess all the 12zguidance and the latest radar/satellite trends before making adecision. Will handle non-mountain snow/black ice concerns withan SPS as well for now.Otherwise, temps/dewpts/sky/wind all look good. It`s just thePoPs/QPF/SnowAmt we`re really concerned about.A strong short wave drops into the area tonight along with astrong upper jet streak. This induces cyclogenesis off the SEcoast. The surface low remains relatively far off shore. The H85low is also to our east. This keeps the low level flow weak and E toNE. There is quite a bit of low level moisture across the area butno significant moisture flux from either the Gulf or Atlantic. Thereis an increase in deep moisture late this afternoon and eveningthough. Given the strong forcing and decent moisture, have trendedtoward the higher precip chances seen in the guidance. That said,don`t have any likely PoP west of the I-77 corridor. Expect therewill be precip moving west to east across the area, but coverageand QPF will be limited. Forecast soundings and partial thicknessvalues suggest mainly snow for most of the area. Some sleet willbe possible at onset, with more of a rain/snow mix over NE GA,the western Upstate, and the warmer NC valleys to start. Precipchanges to all snow before ending after midnight.Highs today and lows tonight will be well below normal.
  3. I am now down to 1 to 2 inches, lol. Newton, nc
  4. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...As of 240 pm EST Wednesday: The forecast for the weekend remains ina state of flux. Readers are advised to continue to manage theirexpectations. On the one hand, confidence continues to increasethat we will have a winter storm that will probably impact theentire forecast area beginning Saturday night and continuingthrough most of Sunday. Precip probs are now into the categoricalfor that time period. On the other hand, details about precip-typedistribution are very murky in both space and time, and that ishaving a negative impact on confidence. The latest problem isthe operational GFS solution, which has trended toward moving the850 mb low well west of the mtn chain, allowing for strong warmadvection that would establish a warm nose in most places eastof the mtns. The result would be a steady changeover/mix to sleetand freezing rain, if the operational GFS is correct. It is worthnoting the 12Z GEFS is still holding onto snow as the most likelyp-type at GSP, but there is enough of an increase in sleet/freezingrain outcomes that places like CLT have an almost equal chance ofthe primary p-type being any one of the four. Meanwhile, the ECMWFkeeps its 850mb low moving overhead/southeast of the mtn chain. Theoperational ECMWF would allow for a long enough period of time forsnow to fall east of the mtns before a weaker warm nose pokes upfrom the south to changeover along/S of I-85. Worth considering isthat in most situations, the warm nose wins across the area south ofI-85. Still way too early to consider amounts of individual p-types,but the trend in the QPF has gone up substantially, which willin turn flow down into the precip accums. The forecast guidanceblend used to create the new fcst will sometimes show a lag thatdoes not quickly jump to any new trend, so for the time being,the fcst will look more like the cooler ECMWF/Canadian ensemblesinstead of the more icy GFS. High temps will not get out of themid-30s. Eventually, as the system passes, a change back towardlight snow should happen late Sunday. Model guidance shows a strongsignal toward a NW Flow Snow event along the TN border Sunday nightthat would continue through Monday and might not taper off untilTuesday morning. Temps will remain about 10 degrees below normalthrough Tuesday, with a warming trend into Wednesday. Anotherweaker system may approach from the west Wednesday afternoon,but this was downplayed for the time being.
  5. Gsp noaa weather office has out their afternoon discussion, and have updated local forecast. Enjoy.
  6. Same here in newton. Not doing anything at all. A dusting at best.
  7. Gsp short term. Not putting catawba and iredell into the warnings yet. As of 1015 am: Water vapor imagery shows upper low centered near Ark-La-Miss junction. Associated cirrus shield will continue spilling over the downstream ridge into the forecast area throughout the afternoon, resulting in generally mostly cloudy/partly sunny conditions. Filtered insolation will likely result in max temps around 5 degrees below normal across much of the area this afternoon. Model consensus carries the surface low south of the I-20 corridor late today through Friday morning, with the core of the upper low moving near the southern border of TN and NC during this time frame. This will place most of the CWA just on the cool side of the warm front. Most of the area will start off well above freezing in the early evening; moisture will quickly deepen as the sfc/upper low encroach on the area before midnight, bringing in precip chances from the SW. The strongest dynamic forcing will precede the upper low into the area, peaking in the predawn hours Friday, with the better moisture lagging the forcing somewhat. The best frontogenetic forcing will occur nearer the warm front. Precip type still looks quite tricky, mainly east of the mtns, and perhaps across the mountain valleys of southwest NC. There will be a lot of midlevel dry air to overcome early in the event, and the WAA gives us a weak warm nose as well (though not as strong as we often see with these sorts of systems). The higher mountains likely will see snow through most of the event, but lower elevations and areas further south will see some period of sleet, or perhaps even freezing rain where the warm nose (along with evaporative cooling diminishing it at least locally) is present. Confidence is sufficient such that all zones in the Watch were converted to a Warning earlier this morning with the exception of Catawba, Iredell, and Davie Counties in NC. This area will take longer to see accumulation reach any criteria, and with the potential for accumulations to go one way or the other, we have held off on upgrading there. These areas almost certainly will need an Advisory or Warning depending on where their final forecast total ends up. With the upper low crossing the area during the day Friday, even as winds turn more downslope and moisture becomes more shallow, there will remain support for significant precip as the deformation zone scrapes the NC Piedmont. Temperatures will be held nearly steady in the 30s where the precip is ongoing, and many areas will continue to see snow during the day, possibly mixing with rain. Strong lapse rates under the low may allow enhanced precip rates and snow will be more likely during those periods. The event will transition to northwest flow late Friday across the NC/TN border area as PoPs continue to drop off east of there.
  8. 38 and a light rain is moving in. Newton, NC. Rain cooled us down 2 degrees.
  9. Charlotte spectrum news futurecast at 1pm tomorrow.
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