Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/12/21

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1049 PM EDT Sun Apr 11 2021 .SYNOPSIS... High pressure remains over our region through Monday, leading to drier conditions. Another cold front will likely cross the area during the middle of the week, possibly bringing more rain to the area Wednesday. Drier and cooler air returns Thursday and continues into the weekend. && .NEAR TERM /THROUGH MONDAY/... As of 1045 PM: Quiet weather continued this evening under clear skies. The forecast is trending well with only minor tweaks to temp/dewpoints. Otherwise, we`re expecting mostly clear skies going into tonight. A stacked low pressure system over the OH Valley and Upper Great Lakes will continue to push ENE into the Lower Great Lakes into the mid- Atlantic through the forecast period. The attendant cold front associated with the occluded sfc low has now made a full fropa across the CFWA. 500mb RAP analysis shows the upper trough axis just west of the TN border and once the commences, the deep layer flow will shift from the SW to the NW. A weak CAA regime will be in store after this shift and allow for Min T`s to support values from the mid 40s to the low 50s, which is closer to normal for this time of the year. Deep mixing and downsloping westerlies will provide an uptick in Max T`s for Monday and gusty winds. Thicknesses are expected to recover and increase through the near-term, which provides additional support for Max T`s on Monday to reach into the 70s over the major mountain valley and low 80s over the foothills/piedmont. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... As of 130 PM Sun: A low-amplitude shortwave ridge will shift across the Southeast in the midweek period initially bringing above-normal aftn temps. Between this feature and a deep upper low over the Great Lakes, a quasi-stationary front will develop over the Tennessee/lower Ohio valleys by early Wednesday, moistening enough to produce some QPF on most of the deterministic output. As the low wobbles east, the front will be pushed in our direction as a cold front, warranting an uptick in PoPs late Wednesday. Midlevel lapse rates are not too shabby; deep mixing suggests relatively small instability overall, but enough for a thunder mention. Not excited about any severe wx threat attm given the relatively shallow convective layer and limited effective shear. Cold front expected to pass Wed night, with PoPs diminishing and a drier and slightly cooler airmass settling in Thursday. Based on fcst min temps in the mid 30s, can`t rule out some frost formation in the mountains Thu morning, though a light wind may act to minimize its extent to the more sheltered areas. RH may dip enough during peak heating Thursday aftn to be of some concern to fire wx interests. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 200 PM Sun: The upper low migrating across the northern tier of the CONUS looks to reach the Northeast urban corridor by Friday morning. Confluent flow on its upstream side will allow high pressure to continue building across the southern Appalachians thru early Saturday. We`ll remain under decent radiative cooling conditions Thu night; though blended guidance depicts min temps Friday morning as being on par with Thu morning, with front having pushed further past, think there is more potential for calming/decoupling and thus pushed mins down slightly. Thus, some frost/freeze concern that morning as well, and similarly low RHs are expected Fri aftn, despite max temps a category or two below normal. Model differences in the handling of the next upstream shortwave start to affect our forecast confidence at that point. Some remnant of the departed cold front will remain stalled across the Gulf of Mexico and Florida; it remains unclear exactly how the incoming shortwave will activate this boundary, but all the deterministic solutions show a warm sector developing up into our area in some fashion. Will maintain a chance PoP Friday night and Saturday. Cloud cover is expected to bring mins out of frosty range Sat morning, but also bring max temps a little further below normal. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... At KCLT and Elsewhere: VFR conditions will prevail through the period. As the diurnal cycle dwindles down, so have our wind gusts over most terminals. However, low end gusts could continue along and adjacent to the mountains tonight including KAVL and KHKY. Winds are expected to shift out of the W to NW over all TAF sites later this evening as the cold front and trough axis pushes east of the area. KAVL will have a more northerly component than westerly compared to all other TAF sites. Mostly clear skies will continue through the rest of the period at all terminals as wind gusts kick back into full gear by the lunchtime Monday and hold steady until sunset due to deep mixing in the PBL. Outlook: VFR conds will prevail early on this week. Rain chances and restrictions could make a return by the middle part of the week. Confidence Table... 02-08Z 08-14Z 14-20Z 20-00Z KCLT High 100% High 100% High 100% High 100% KGSP High 100% High 100% High 100% High 100% KAVL High 100% High 100% High 100% High 100% KHKY High 100% High 100% High 100% High 100% KGMU High 100% High 100% High 100% High 100% KAND High 100% High 100% High 100% High 100% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables are available at the following link: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...CAC/Munroe SHORT TERM...Wimberley LONG TERM...Wimberley AVIATION...CAC