Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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014 FXUS62 KRAH 250013 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 813 PM EDT SAT SEP 24 2016 .SYNOPSIS... A cold front will move south through the area late tonight and early Sunday. The front will move back northward as a warm front Monday and Tuesday. && .NEAR TERM /THROUGH TONIGHT/... As of 130 PM Saturday... With the cold front still located over northern VA, observational data and the latest models strongly suggest that it will be well into the overnight before the it makes it into our region. A prefrontal trough was located over the foothills of VA and NC with dew points mixing out into the 50s and lower 60s into our NW Piedmont Triad region. East of the trough, lingering low level moisture in the east provided dew points ranging in the mid 60s to lower 70s. Highs this afternoon in the upper 80s to lower 90s will be slow to cool in the pre-frontal environment this evening. CAMS indicate a very low end chance of a shower with the front between 1100 PM and 300 AM in the NE zones, but the chance appears to be less than 15 percent. Otherwise, a clear and warm evening will give way to a low overcast that will spread/develop into the region from the NE later tonight and early Sunday. Cool advection will not begin until late, thus lows will be warm in the mid 60s NE, to near 70 in the south and west. && .SHORT TERM /SUNDAY and SUNDAY NIGHT/... As of 130 PM Saturday... A quick turn from summer to fall expected Sunday with some hybrid CAD expected into the Piedmont region Sunday and Sunday night. Sunday will bring much more fall-like conditions led by the cooling NE flow and cloud cover. The cooling conditions will be pushed down the eastern seaboard by surface high pressure (1025 MB) centered over SE Canada. The high pressure ridge is forecast to extend southward into NC/SC into Sunday night before the ridge axis moves east. Models still bring low stratus deep into our region with even a chance of light drizzle in the NW Piedmont by early Sunday afternoon. It appears that little if any QPF can be expected as the moist upglide is expected to be too shallow for anything more that a trace to 0.01 or 0.02 in the northwest zones, with nothing more than a sprinkle expected elsewhere. Highs will be much cooler with overcast skies in much of the region. Highs Sunday will be coolest in the north-central Piedmont where readings may hold in the 60s. Elsewhere, highs will range into the 70s across the south and west. The overcast may break into variably cloudy skies in the SE, otherwise extensive cloudiness is expected through the day into Sunday night. Lows Sunday night in the upper 50s to mid 60s. && .LONG TERM /MONDAY THROUGH SATURDAY/... As of 310 PM Saturday... Monday through Tuesday night: Surface high pressure is expected to shift eastward and off the Northeast U.S. coast on Monday, with any hybrid CAD eroding from SE to NW with possibly some lingering light precip (mainly west where the damming should linger the longest). High temps are expected to generally range from the mid to upper 70s north/northwest to the lower 80s south. A mid/upper level low will slowly wobble east and southward across the Great Lakes region early next week, allowing an associated cold front to to approach the area on Monday night into early Tuesday, then slowly cross the area on Tuesday into Tuesday evening as the cold front begins to become more parallel to the mid level flow (helping to slow its progress). With regard to any severe threat instability looks to be weak, however, deep layer shear is expected to be respectable. Thus, we could see a some storms even some weakly organization convection, but the severe potential will remain quite low. Highs Tuesday are generally expected to be in the upper 70s to lower 80s, with lows Tuesday morning in the mid to upper 60s and lows Wednesday morning ranging from the mid to upper 50s nw to the lower to mid 60s se. Wednesday through Saturday: the mid to upper level flow pattern is in question mid to late next week, with regard to what happens to aforementioned deep mid/upper low over the Great Lakes early next week. The latest GFS continue to show the feature becoming a deep trough and moving through the area Wednesday/Wednesday night, helping to push the front (which is expected to linger across coastal portions of NC on Wednesday) offshore and away from the area. Meanwhile, this is the second run in a row of the ECMWF showing the mid/upper low sinking southward towards our area mid week, and lingering the low as it becomes cut off from the westerlies. The 00Z ECMWF ensemble members didn`t show much support for the scenario, so will keep the forecast dry from Wednesday evening onward (but will need to watch this). Otherwise, surface high pressure is expected to build/extend into the area through the period, with highs and lows expected to be near to slightly below normal. && .AVIATION /00Z SUNDAY THROUGH WEDNESDAY/... As of 812 PM Saturday... A cold front nearing the VA border will continue to drop south through the state overnight. Behind the front, likely IFR stratus will develop as low level flow behind the front becomes northeasterly. KRWI and KRDU are likely to be impacted first, around 06z, spreading to other sites between 07-09z. A brief period of fog is possible at KFAY with moisture pooling ahead of the front before the stratus moves in. MVFR conditions will persist into the afternoon on Sunday. Conditions will begin to trend to VFR Sunday night into early Monday. Showers and associated sub-VFR cigs are possible Monday and Tuesday as a cold front approaches and moves through the region. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Badgett LONG TERM...BSD AVIATION...30 is the U.S. government's official web portal to all federal, state and local government web resources and services.