678 FXUS62 KRAH 061928 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 226 PM EST Sun Nov 6 2022 .SYNOPSIS... High pressure will extend across the region through Monday. A cold front will drop into the area from the northwest Monday night, and settle to our south early Tuesday, as strong low pressure develops off the Southeast coast. && .NEAR TERM /TODAY THROUGH TONIGHT/... As of 905 AM Sunday... Only very minor tweaks are needed to the forecast this morning. Patchy showers continue to stream northward across the Foothills and western Piedmont, within a stream of elevated PW around 1.5" and well ahead of the stalled front extending through central OH/KY/TN/MS. The 12z GSO sounding shows this well, with high RH above 350 mb (corresponding to the high cloud deck streaking across the region) and below 700 mb, responsible for the multi-layered lower clouds over the western CWA. This lower level moisture will persist over our W half today with a continued SE to S flow drawing in plentiful Atlantic moisture, although upstream, the CHS sounding is actually a bit drier than GSO below 700 mb, so we should still see some brighter spots and brief holes in the cloud cover. In the E, while the high clouds will shift E over the entire area, the low levels still appear likely to remain too dry for any appreciable precip from the Triangle E, so will restrict pops today to W of Hwy 1. Still appears that CAPE will be minimal, just a couple hundred J/kg at most with marginal amounts of moisture through the mixed phase region aloft, so have restricted any lightning to isolated this afternoon within the better shower coverage. Thicker and more abundant cloudiness NW will favor a lower diurnal range there, despite the warm start to the day areawide, while E sections with more insolation will be quite warm. Will keep highs from the mid 70s NW to mid 80s SE. See record temp info below. -GIH Earlier discussion from 249 AM: Broad southwesterly flow aloft remains in place across the region this morning, as an upper ridge maintains its position off the coast while a deep upper low makes its way into Canada. At the surface, a cold front continues its eastward trek through the TN Valley, albeit at a slowing pace as the parent low races northward into Canada. Meanwhile, central NC remains in the pre-frontal warm advection regime with southeasterly winds (with occasional gusts) persisting this morning. Temperatures have moved little since Saturday evening with many locations still in the mid to upper 60s as of 08Z. Showers moved across the western Piedmont earlier this morning and dissipated, but additional development is occurring just downwind of the mountains. Warm advection will continue through the day today and given the mild start to the day, temperatures this afternoon should once again have no problem rising into the lower 80s. Pre-frontal moisture transport will be maximized across the western Piedmont this afternoon with an axis of 200-500 J/KG of MLCAPE developing before 18Z. As such I've increased PoPs west of the Triangle and included a mention of thunderstorms this afternoon. Not anticipating a severe threat with anything that develops but some thunder is possible nonetheless. Meanwhile to the east the BL should remain too stable to support showers or thunderstorms and I kept the forecast dry. Any showers that develop today should dissipate by this evening, with cloud cover lingering into early Monday morning. As the front is not expected to move through until late Monday, overnight temperatures will remain mild once again with low/mid 60s forecast early Monday morning. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 249 AM Sunday... The cold front will finally make a push across the mountains on Monday and move through NC Monday night. The front will be displaced from any appreciable mid/upper level forcing and in all likelihood it will be a dry frontal passage, but some guidance is hinting at some enhanced pre-frontal moisture convergence Monday afternoon across the northern Coastal Plain and I've included some low PoPs (15-20 percent) in those areas. Monday will be the final warm day of this recent stretch with highs once again climbing into the low to mid 80s. However temperatures will drop rapidly behind the front, all the way into the upper 40s to mid 50s by daybreak Tuesday. && .LONG TERM /TUESDAY THROUGH SUNDAY/... As of 226 PM Sunday... Pattern aloft through the extended: An anomalous mid-level ridge will amplify across the eastern two thirds of the CONUS Tuesday through Thursday. An upper-trough will then approach late this week drawing anomalous moisture associated with an offshore low northward into the southeast this weekend. Troughing will then persist across the eastern US into early next week. Tuesday through Wednesday: Canadian high pressure will shift over New England on Tuesday extending increasingly nerly flow down into central NC. Models continue to suggest good mixing with a strong sfc pressure gradient both Tuesday and Wednesday. As such, expect gusty nerly winds at times both days, especially across the Sandhills and Coastal Plain. Increasing CAA Tuesday and Wednesday will return temperatures to near to just below normal in the lower to mid 60s during the day and mid to upper 40s at night. Otherwise, Tuesday and Wednesday will remain dry under the increasingly robust mid-level ridge. Thursday through Monday: Latest run to run model guidance has come somewhat into better agreement with respect to the evolution of an area of low pressure expected to deepen off eastern Florida later this week. The GFS/GEFS and ECMWF/EPS both simulate the low retrograding westward across Florida into the eastern Gulf Thursday, before getting pulled northward into the Carolinas by the aforementioned upper trough Friday through late Saturday. While there are still timing differences to be sorted out over the next few days, the latest consensus is beginning to pinpoint Friday into Saturday with the highest chances for rain across our area (PWATs rise to above 2 inches or ~350% of normal Friday morning through early Saturday morning). As such, trended the POPs higher in this temporal period, with a general tapering off from west to east as the low pulls north of the area later Saturday. We will continue to monitor and make further adjustments to timing, rain chances, QPF, and potential impacts as we get closer to the event and confidence increases. A pattern change is expected behind the departing low, as a strong cold front will push through ushering in dry weather but below normal highs in the lower to mid 50s and overnight lows in the lower to mid 30s Sunday and Monday. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... As of 100 PM Sunday... Warm moist air will flow over central NC through Mon morning, esp in our west sections, before a cold front drops in from the NW starting late morning Mon. The most adverse aviation weather today/tonight will occur in the west (INT/GSO), although late-night fog remains a threat in the eastern terminals tonight into Mon morning. INT/GSO: Occasional showers and perhaps a storm will continue at INT, with slightly less coverage near GSO, through the afternoon until early evening, with vsbys briefly going MVFR in rain. Current MVFR cigs will lift this afternoon, becoming VFR for a short time after 21z before becoming IFR/LIFR with fog and low cigs a good bet after 05z. Slow improvement to VFR is expected between 14z and 17z. Surface winds from the S and SSW will be mostly 10 kts or less, with a few gusts to 15 mph possible this afternoon especially near showers/storms. Winds become light/variable this evening, then light from the N and NNE after 16z Mon. RDU/FAY/RWI, mostly VFR conditions should continue through this evening, with little to no rain chance. But MVFR to IFR cigs/vsbys are expected after 06z as fog and stratus develops. Slow improvement to VFR will occur between 13z and 15z Mon. Surface winds will be from the S and SE 8-12 kts through early evening before becoming light and variable, lasting through midday Mon. Looking beyond 18z Mon, a mostly dry cold front passage Mon afternoon will bring a NW-to-SE shift of winds to be from the NE, and perhaps some gusts late in the day as colder air pours into the area from the N. These brisk winds from the NE with occasional gusts will continue from late Mon night through Fri, within a tight pressure gradient between cool high pressure to the north and a developing low pressure system off the Southeast coast. As this NE flow pulls Atlantic moisture into the area, periods of MVFR cigs are possible Wed into Fri, mainly in the SE, with rain chances increasing Thu night/Fri. LLWS can't be ruled out each night Mon night through at least Wed night. -GIH && .CLIMATE... Record Max and High Minimum temperatures through Mon, November 7: GSO RDU FAY 11/6: 80 (1975)/65 (1938) 83 (2003)/65 (2015) 85 (1961)/71 (2003) 11/7: 78 (1938)/61 (1938) 80 (2008)/61 (2003) 81 (1975)/65 (2003) && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Hartfield/Leins SHORT TERM...Leins LONG TERM...Luchetti AVIATION...Hartfield CLIMATE...MWS