Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 240656 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 256 AM EDT SUN JUL 24 2016 .Synopsis... An area of high pressure aloft will extend across the region through Tuesday, bringing a period of hot and humid conditions to central NC. Chances for afternoon convection will increase by the later half of the work week. && .Near Term /Rest of tonight/... As of 1025 PM Saturday... Given the combination of post-sunset cooling BL temps and sinking/ drier air aloft advancing across our cwa from the north (as seen on the water vapor), this evening`s isolated storms have ended across our area. At this point, it appears that our cwa should remain dry the rest of tonight. However, it`s worth noting that the last few runs of the HRRR have been suggesting that an isolated sprinkle or two could drift into and across our far northeast zones (northern coastal plain) later overnight, left-over from the showers/tstms to our north across east-central VA as they drift southward. But given current coverage and latest radar trends, for now we`re fairly confident in leaving the forecast dry for the rest of the night. Lows in the low-mid 70s still appear to be on-track. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... As of 225 PM Saturday... This still looks like our hottest day, and convection chances appear to be very minimal. Models take the core of the upper ridge overhead Sun, with continued steady warming aloft evident on forecast soundings, cutting down considerably on the potential for destabilization despite surface temps peaking in the upper 90s. CAMs and models with parameterized convection favor virtually dry weather tomorrow, with only an isolated cell or two at most. Will keep an isolated thunder mention in the extreme west and extreme SE, with the potential for drifting terrain-induced cells and sea-breeze convection, respectively. Statistical guidance and model thicknesses support highs in the upper 90s, very close to earlier forecasts. With dewpoints remaining high but dipping a bit in the afternoon with mixing, heat index values are likely to reach 100-106, with the highest values along and east of the Highway 1 corridor. Will go forward with a heat advisory for these eastern sections. Even if some spots only reach close to 105 for an hour, given that we will have been atypically warm for a few days already, and with it being a Sunday and folks likely spending time outdoors, the risk for heat illnesses will be elevated. Any isolated convection is apt to dissipate quickly toward sunset, with fair and muggy conditions Sun night. Lows in the mid 70s. -GIH && .LONG TERM /WEDNESDAY THROUGH SATURDAY/...
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As of 250 AM Sunday... Medium range models continue to be in general agreement depicting a mid/upper level ridge located just to our southeast, extending into our region some to start the period, with a general trough to our north. At the surface a weak remnant cold front/surface trough is forecast to sink a bit further southward on Wednesday and help to focus scattered to numerous showers and storms across central NC, with locations across the north standing the best chance of seeing convection (closer to the actual boundary where better coverage is expected). Given this and central NC on the southern fringe of the better westerly mid level flow (maybe around 20-25 kts at 500 mb across the north) we may see some multi-cell clusters of storms. Given this and expected mlcape values of around 1500 J/KG or higher during the afternoon into the evening and expected frontal zone placement we may see a better chance for severe storms on Wednesday than past days (especially across the northern half of the area). Though hard to time disturbances/mcv`s from upstream convection can and will have and impact on the eventual convective chances and placement. High temps on Wednesday are again expected to be above normal despite increasing chances for storms. Expect high temps to range from the lower 90s north to the mid to even upper 90s south, with heat index values from around 100 north to around 103-105 degrees southeast. Lows Wednesday night are expected to generally be in the mid 70s. A general broad trough is expected to develop across our area and points northward as the mid level ridge is forecast to be suppressed a bit further south late week into the weekend. This should lead to scattered showers and storms each afternoon/evening, with more in the way of isolated showers and storms generally expected during the overnight/morning hours. However, with a lack of any airmass change we should still remain hot an humid through the period, with the possibility of heat advisories needed thanks to the number of days with heat index values of 100+ across the eastern/southeastern portions of the area. Highs are generally expected to be in the lower to mid 90s with lows in the mid 70s.
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&& .Aviation /06Z Sunday through Thursday/... As of 210 AM Sunday... High probability that VFR conditions will persist across central NC through Monday as an area of high pressure aloft strengthens overhead. There is a good probability that VFR conditions will persist through mid-week. Chances for afternoon-evening scattered convection will increase the later half of the work week, along with the possibility of early morning fog and low clouds. && .RAH WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon to 8 PM EDT Sunday for NCZ010-011- 025>028-040>043-075>078-084>086-088-089. && $$ SYNOPSIS...WSS NEAR TERM...rah SHORT TERM...Hartfield LONG TERM...BSD AVIATION...WSS is the U.S. government's official web portal to all federal, state and local government web resources and services.