Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 260700 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 300 AM EDT TUE JUL 26 2016 .Synopsis... Strong high pressure aloft will extend across the region through Wednesday, bringing a period of hot and humid conditions to central NC. The chances for afternoon storms will increase toward the end of the work week. && .NEAR TERM /THROUGH TONIGHT/... As of 1010 PM Monday... We still have heat indices in the 90-95 range at mid-evening from RDU and FAY eastward through the Coastal Plain. Heat advisories go back into effect Tuesday, but it should be noted that the same precautions to beat the heat should be highlighted, even at night. This is because of the unusually high dew points (mid to upper 70s). Otherwise... isolated storms are far removed from central and eastern NC this evening with mid/upper ridging overhead. A slim 10 percent chance of a shower/brief storm will linger from near the Yadkin River westward through the Mountains overnight. Essentially no POP needed in the rest of the region with lack of a trigger. Mostly clear, warm and humid overnight. Lows in the mid 70s, except 70-75 NW-N Piedmont. && .SHORT TERM /Tuesday and Tuesday night/... As of 325 PM Monday... Shortwave energy over the central part of the country will push eastward into the OH valley toward the mid-Atlantic/Northeast through Tue night. While the primary bound of mid level westerlies will stay well to our north, this wave will help push both the surface frontal zone and the slightly deeper moisture (as noted on water vapor imagery) to the SSE toward NC, not quite reaching the NC/VA border but making enough southward progress to bring a scattered showers and storms to northern NC. Mid level lapse rates should be a bit better than today, in the 5.7-6.0 C/km range, although deep layer shear will remain minuscule as the mid-upper level ridge axis will continue to extend across the region. Model forecast CAPE values are expected to remain muted with the continued warmth aloft, particularly across the southern two-thirds of NC, closest to the ridge axis. Will bring in late-day low chance pops across the northern sections of the CWA Tue into early Tue evening, before coverage drops off through the evening with loss of heating. See little reason to depart from persistence regarding temps, with thicknesses remaining well above normal, topped by anomalously high temps and heights through the column, and high surface dewpoints holding at or above the low-mid 70s for a good portion of the day. Will retain highs in the mid-upper 90s, as statistical guidance supports, with lows again in the mid 70s. These temps again equate to heat indices near or above 105 over the south and east, so will go with another heat advisory for Tue for the same areas. These successive days of hot temps and high humidity without much recovery at night will exacerbate the risk of heat illnesses heading into mid week. -GIH && .LONG TERM /Thursday through Monday/...
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As of 300 AM Tuesday... Persistent upper level high over the Southeast U.S. will maintain hot conditions over central NC Thursday and Friday. Heating of the moist and moderately unstable air mass will support the development of isolated-scattered late afternoon-evening convection, mainly north of highway 64 where subtle height falls and presence of surface trough will occur. Low level thicknesses Thu still support max temps in the mid/upper 90s, and with sfc dewpoints in the low/mid 70s, potential for the continuation of heat advisory very possible. Thicknesses Fri lower 15-18m as the upper high begins to weaken, though this may be too aggressive as history suggest that the thicknesses may only lower 5-8m. Thus expect highs Friday back into the mid/upper 90s. Potential for more appreciable change in the weather pattern expected by Saturday-Monday as center of upper ridge shifts southward. This will allow weak upper disturbances to skirt across our area, especially across the north. This should lead to an uptick in the coverage of afternoon-evening convection. In addition, with more clouds/convection, should see max temps lower a few degrees with max temps generally in the 90-95 degree range. Presence of the surface trough and available moisture and instability will support additional convective development early next week.
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&& .AVIATION /06Z TUESDAY THROUGH SATURDAY/... As of 150 AM Tuesday... 24-hr TAF Period: VFR conditions are generally expected to continue outside of some patchy morning sub-VFR fog/stratus (best chance at KRWI) and isolated to widely scattered showers and storms late this afternoon into the early evening (again best chance at KRWI). Otherwise, a mid/upper level area of high pressure over the region will help steer the main track of convection to the north and west of central NC, yielding VFR conditions with south to southwesterly winds at around 6 to 10 KTS. Looking ahead: VFR conditions will generally prevail through mid- week as an upper level ridge remains in place over the southern CONUS. Diurnal convection will become increasingly possible as the ridge weakens /week progresses/, with chances near climatology by late week into the weekend. && .RAH WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon today to 8 PM EDT this evening for NCZ007>011-024>028-040>043-074>078-083>086-088-089. && $$ SYNOPSIS...WSS NEAR TERM...Badgett SHORT TERM...Hartfield LONG TERM...WSS AVIATION...BSD/Vincent is the U.S. government's official web portal to all federal, state and local government web resources and services.