Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 180657 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 255 AM EDT Sun Jun 18 2017 .SYNOPSIS... A warm, moist, and unsettled air mass will remain in place today through Monday. A cold front will move slowly into the area from the northwest Monday night through Tuesday. && .NEAR TERM /Today through tonight/...
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As of 255 AM Sunday... Coverage of convection should be a bit lower today than in previous days, thanks to drying aloft of sufficient magnitude to result in reduced PW across the area. The cold front currently spanning the Midwest, from the Great Lakes down to the southern Plains, will continue to ease slowly to the ESE today. Its approach combined with the presence of the strong Atlantic ridge will lead to a tightening MSLP gradient and a southerly breeze over NC today, a contrast to the stagnant air and light winds of recent days. The vast majority of the area saw ground-moistening rain yesterday, and as a result we`re already seeing low stratus across the area. These clouds should persist through the early to mid morning, followed by lifting and dispersion, allowing for partly to mostly sunny skies today. The GFS shows slightly higher deep layer shear (15-20 kts) than in the last few days, and MUCAPE is projected to rise to 1000-2000 J/kg this afternoon, mainly over the Coastal Plain. But the lower water content today (PW down to 125-135% of normal) and an apparent lack of a focus for convection should limit coverage. Thus, will stick with just scattered showers/storms this afternoon. This is in line with the sparse coverage seen on convection allowing models including the HRRR and NAM Nest. An isolated strong storm or two is still possible, but the continued weak mid level flow and lack of dynamic contribution to lift will greatly curb this risk. Highs today 88-92, with thicknesses above normal and several meters higher than yesterday. Any showers/storms should dissipate soon after nightfall with a loss of heating and subsequent stabilization. Redevelopment of shallow late-night stratus is likely overnight. Lows in the lower 70s. -GIH
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&& .SHORT TERM /Sunday through Sunday night/... As of 135 PM Saturday... With drier air expected to move in aloft and lower PW values across the area, Sunday should see less convective coverage than previous afternoons. That being said the environment will still be unstable enough to support scattered showers and thunderstorms across the CWA especially later in the day as the seabreeze front moves in from the southeast. Back to the northwest a frontal system will move closer to the area but its influence should stay far enough west to not have any impact on our CWA. SPC maintains an outlook of general thunder through Day 2 and little severe weather is expected outside of an isolated downburst. Temperatures are expected to be warmer with better insolation across the area and should top out in the upper 80s to lower 90s. Lows once again in the lower 70s. && .LONG TERM /MONDAY THROUGH SATURDAY/... As of 200 PM EDT Saturday... A trough will move across the Mid-Atlantic and Northeast regions Monday through Wednesday. Southerly flow ahead of the trough axis will draw abundant tropical moisture northward across the eastern half of North Carolina, which should help set the stage for scattered showers and tstms Monday afternoon into early Monday night. A cold front associated with the trough will make its way into the mountains Monday night and into central North Carolina on Tuesday before moving east of the area by late Wednesday. Best chance for severe thunderstorms on Monday will be in the Triad region mainly north and west of Greensboro closer to the cold front with widespread convection possible Tuesday in central North Carolina. Big uncertainty in Thursday through Saturday forecast as there is a possibility of a tropical system developing in the Gulf of Mexico. As of now, it looks like Thursday will be fair with little if any chance for rain with a return to afternoon and evening convection Friday and Saturday. However, it`s a low confidence forecast as there are large differences in model solutions for the latter part of the week. && .AVIATION /06Z Sunday through Thursday/... As of 135 AM Sunday... Dry weather is expected through daybreak. But nearly all of central NC having seen at least at least some measurable rainfall in the last 24 hours, leading to a moist ground. Current VFR conditions are likely to drop to IFR as patches of stratus based below 1,000 ft AGL develop. This stratus is expected to affect TAF sites mainly between 08z and 13z, and is apt to vary between scattered and broken. Any cloud bases should rise to MVFR 13z-15z, and to VFR 15z-17z, with VFR conditions expected to dominate after 17z through the end of the TAF valid period. Scattered showers and storms are expected to develop after 17z, however these should be much more sparse than in previous days, given the presence of drier air aloft. Brief sub-VFR conditions and erratic gusty winds are possible in and near any such storms. The chance of a shower or storm will diminish by evening, with dry weather from mid evening into the night. Winds will be very light through mid morning, then increasing from the south at 5-15 kts with sporadic gusts. Looking beyond 06z early Mon morning, there will be another chance for sub-VFR stratus as we approach daybreak Mon. As a cold front approaches from the NW, chances will increase for sub-VFR conditions in and near scattered to numerous showers and storms Mon afternoon through Tuesday, and perhaps beyond. Uncertainty increases as we head through mid week (Wed/Thu), as the front may stall out over or just NW of the area, keeping us in a wet pattern with a greater chance of adverse aviation conditions as Gulf moisture streams NE over the Carolinas. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Hartfield SHORT TERM...Ellis LONG TERM...Franklin AVIATION...Hartfield is the U.S. government's official web portal to all federal, state and local government web resources and services.