Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 010605 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 105 AM EST Thu Dec 01 2016 .SYNOPSIS...
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A cold front will cross the area early this morning. High pressure will then build over the Eastern U.S. from the west through the upcoming weekend. An approaching upper level disturbance and increasing moist flow from the Atlantic and Gulf will bring increasing rain chances beginning Sunday night.
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&& .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 943 PM Wednesday... Nocturnal cooling and resultant increasing BL CIN quickly wiped out the weak instability across Central NC and thus resulted in a rapid weakening of the primary convection band that`s currently advancing east into eastern NC. This band will exit the area in the next couple of hours. However, rain chances are entirely over just yet, with Hi-Res WRF models showing a secondary and narrow line of convection accompanying the cold frontal passage through the area between 03 to 12z. Temperatures will fall behind the front with lows by daybreak ranging from around 50 in the Triad to around 60 in the Coastal Plain where the front will just have cleared the area. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... As of 230 PM Wednesday... The synoptic cold front will have moved to the coast by 12Z tomorrow morning, with perhaps some early morning clouds giving way to sunny skies and cold air advection throughout the day. Models indicate low level thicknesses during mid afternoon about 50 meters down from Wednesday afternoon...which translates to 10-15 degrees cooler. As such, highs will edge above normal one final day...reaching around 60 northwest ranging to upper 60s in the southeast. Seasonable high pressure over the central plains will build eastward and the pressure gradient will relax Thursday night. Under clear skies with the cool dry airmass in place, mins will tumble into the 30s over the area, with some locations in the north and west potentially falling slightly below freezing near sunrise. Near zonal flow aloft and reinforcement of the surface high with modestly cooler air from the northern plains will maintain the status quo with mostly sunny skies Friday and increasing high cloudiness Saturday. Highs will be in the mid to upper 50s Friday cooling to the low and mid 50s Saturday. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 252 PM Wednesday... In the Sunday time frame...moisture advection out of the Gulf will stream east along a frontal zone setting up across the Gulf States. With a cool dry airmass in place, we should see a thickening cloudiness Saturday night with light rain breaking out due to isentropic lift in the west by mid day Sunday, and will maintain ongoing chance PoPs in the west during the morning spreading over the east during the afternoon. Highs will be subsequently suppressed by clouds and evaporative cooling, ranging from mid 40s in the northwest to lower 50s in the southeast. The forecast from Sunday night onward remains low confidence pending consensus as to the progression of a cutoff low over northern Mexico which will be lifting ENE across the plains early next week. Initially, the high pressure over the area is reinforced by the arrival of a second surge of cool dry air from a transitory surface high oriented more classically from New England south down the east coast, which would suppress moisture southward on Monday. This would set the stage for another isentropically induced rain regime on Tuesday/Wednesday as the moisture associated with the aforementioned cutoff low and associated surface reflection ride up the cooler denser air. Will keep PoPs on the low chance side for now, with highs in the 50s Monday through Wednesday as we wait to see how the scenario plays out. && .AVIATION /06Z THURSDAY THROUGH MONDAY/...
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As of 105 AM Thursday... Widespread MVFR cigs have given way to VFR at INT/GSO as the cold front approached from the west. Similar improvement is expected at RDU/RWI/FAY between 08z and 11z, with VFR conditions areawide by 12z, as the cold front sweeps through the area and high pressure begins to build in from the west. Current surface winds from the SW at 10-15 kts gusting occasionally to 20-25 kts will veer to westerly then northwesterly later this morning with diminishing speeds to around 10 kts and infrequent gusts to 15 kts, lasting into the afternoon as VFR conditions persist. Winds will diminish further after 22z late today, with VFR conditions holding through tonight. Looking beyond 06z early Fri morning, VFR conditions will hold well into the weekend as the ridge of high pressure builds into the area. High clouds will spread in from the WSW on Sunday, and these clouds will thicken with lowering bases to MVFR then IFR Sunday night as an upper level disturbance approaches from the WSW, in conjunction with increasing low level moisture from the Atlantic and Gulf. MVFR to IFR cigs/vsbys will persist through Monday with light rain developing. -GIH
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&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...CBL SHORT TERM...MLM LONG TERM...MLM AVIATION...Hartfield is the U.S. government's official web portal to all federal, state and local government web resources and services.