Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 250055 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 855 PM EDT WED AUG 24 2016 .SYNOPSIS...High pressure will extend across the region through the rest of the week, with slowly rising temperatures and humidity. && .NEAR TERM /THROUGH TONIGHT/...
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As of 855 PM Wednesday... High pressure continues to dominate the pattern and keep conditions dry overnight although some low level moisture could lead to some patchy fog or low stratus overnight, particularly in the KRWI area. Although CAM models had been bullish on a few showers overnight, the latest runs have backed off of this trend. Low temperatures mainly in the mid 60s.
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&& .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... As of 245 PM Wednesday... The high pressure system will gradually strengthen with the core eventually settling over our area by early Friday. Continued warming/modification of the air mass will translate to warmer temps, both afternoon and overnight. Low level thicknesses Thursday afternoon projected to be a solid 15m warmer than this afternoon. Based on past afternoons, this warming suggest max temps Thu near 90 nw Piedmont to the lower 90s elsewhere. Overnight temps Thu night should be a degree or two within 70. While patchy cloudiness still expected Thursday and Thursday night, lack of sufficient moisture through the column and overall sinking motion will deter convective development across most of central NC through Thursday night. A caveat to this is the tail end of minor s/w crossing the northern Mid-Atlantic late Thu/Thu night will clip the far northern sections of central NC. Available instability suggest isolated convection possible though whether enough lift and moisture aloft will be present is questionable. For now will paint a 10-14 PoP across sections of the northern Piedmont late Thu-Thu evening and see how subsequent model runs evolve this potential. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 240 PM Wednesday... Fri-Sun: Quite warm to start this period, followed by moderating temps, and very low precip chances throughout. Strong mid level ridging will remain the dominant weather feature heading into the weekend, with its center drifting slowly from the western Carolinas early Fri ENE to over eastern VA/NE NC by Sun, all the while maintaining dry and stable mid-upper levels over our area. A surface cold front approaching from the NW Fri will drop into and through NC over the weekend, causing a dip in thicknesses from much above normal Fri/Sat to near or just slightly above normal starting Sun. With a weakening low level wind field and no opportunity for moisture influx at any level, any convection ahead of or with the front will be feeble and very isolated, likely limited to a few cells drifting slowly off the higher terrain (extreme NW CWA) and along an inland-drifting sea breeze (far SE CWA) late in the day Fri, with perhaps a bit better (but still low) coverage Sat afternoon over the southwest CWA near weak upglide and low level mass convergence near the Piedmont trough. The front settles to our south Sun with a high pressure ridge centered off New England nosing narrowly to the SW through central NC, supporting a drop in max temps from the mid 90s Fri/Sat to around 90 or the lower 90s beginning Sun. Mon-Wed: Starting Mon, the mid level ridge weakens and flattens yet continues to extend W-E across the region. Low level flow from the east or ENE may be sufficiently strong and onshore-directed to boost low level moisture profiles and increase diurnal sea-breeze convection chances in the SE CWA on Mon, although the limited deep moisture should keep coverage low. Models still vary quite a bit with the tropical wave now over the northern Leeward Islands which may be driven toward the WNW by the mid level ridge and may affect a portion of FL and/or the Gulf Coast by early to mid week. Model solutions continue to range widely, with the GFS remaining weak with an erratic motion and the so-far-strongest ECMWF solution showing a slowing trend with the 12z/24 run, which all results in reduced confidence in any details this far out. At the very least, the increasing easterly low-mid level component should draw increasing amounts of Atlantic moisture into the eastern Carolinas, and we should see an increase in daily showers and a few storms mainly east as we head into midweek. We will, of course, continue to monitor the tropical wave, although by all accounts it will not be a direct factor in our weather through at least Wed. With thicknesses holding a bit above normal, temps are expected to peak around 90 to the lower 90s Mon-Wed, with lows mostly in the lower 70s. -GIH && .AVIATION /00Z THURSDAY THROUGH MONDAY/... As of 755 PM Wednesday... 24 Hour TAF Period: There is a high probability that VFR conditions will generally persist across central NC through the 24 hour TAF period. The one exception will be pockets of MVFR to LIFR visibility between 07Z-12Z Thursday, mainly across the eastern TAF sites (KRWI/KFAY/KRDU). This possibility appears highest at KRWI, where LIFR conditions will be possible. Otherwise, an area of high pressure will maintain generally dry weather with light and variable winds (small chance at KINT/KGSO of a shower Thursday afternoon). Outlook: This area of high pressure is expected to maintain its influence over our region through early next week. This suggest an extended period of VFR conditions, aside from patchy early morning MVFR/IFR fog or low clouds and increase small chances of showers/storms each day. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Ellis SHORT TERM...WSS LONG TERM...Hartfield AVIATION...BD/WSS is the U.S. government's official web portal to all federal, state and local government web resources and services.