Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 300043 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 743 PM EST Tue Nov 29 2016 .SYNOPSIS...
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A cold front will cross the area late Wednesday through early Thursday. Behind the front, high pressure will build into the region over the remainder of the week.
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&& .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 345 PM Tuesday... The band of showers that has been moving across central NC this morning and afternoon has reached the Interstate 95 corridor and should exit central NC this evening. In its wake, precipitation chances decrease significantly for tonight as forcing for ascent is rather limited despite a fairly moist boundary layer. The result will be mainly dry conditions overnight with just some isolated showers scattered about. Model BUFR soundings are consistent in redeveloping widespread overcast across central NC during the evening. Some guidance including the NCAR ensemble suggests that fog (perhaps even dense despite 10m winds of around 10kts) could be an issue across the western Piedmont, especially after midnight while other guidance such as the SREF suggests a much more reduced threat. While the moisture profile is supportive, it appears that there should be a sufficient pressure gradient to keep sustained winds at least in the 5 to 10 kt range which should mitigate the potential for widespread fog. With the sustained southerly flow along with a moist airmass and cloud cover, temperatures should be mild tonight. Lows should range in the 58 to 64 range, -Blaes && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 300 PM Tuesday... A series of shortwave perturbations will help amplify the longwave trough over the Midwest and enhance the line of pre-frontal convection over western NC on Wednesday. Given the slow progression of the convection as the parent upper low re-develops over the eastern Great Lakes/southeast Canada, Wednesday could remain dry for much of central NC. Strong southerly flow will continue to usher warm moist air into the area (highs in the low to mid 70s), however the persistent mid-level dry air will remain in place until the convection moves in. The majority of the rain is expected to occur after 7 PM and will be quick hitting, moving from the NW (Triad) to the SE (NC coast) by early Thursday morning. Rainfall totals will likely be highest in the NW and lowest in the southeast ranging from quarter of an inch to an inch. The cold front will also progress eastward through Central NC overnight. As a result of the current fropa timing, lows should bottom out in the mid 40s to upper 50s given that the winds will remain in the 5-10 mph range. The low-mid level flow will be rather strong ahead of the front and could result in fairly strong wind gusts, however instability, even during peak heating, is low and decreases prior to the arrival of the convective line. Central NC is in a marginal risk for Wednesday, however if thunderstorms are able to become strong/severe, the main threat would be isolated damaging wind, though the confidence is low at this time. && .LONG TERM /THURSDAY THROUGH TUESDAY/... As of 315 PM Tuesday... Expect a return to more seasonable temperatures behind the cold front, though highs Thursday may still be in the mid 60s across the southeast, as surface high pressure builds into and over the region. Highs will be mainly in the low to mid 50s through the weekend and lows in the low to mid 30s should prevail into early next week. Though westerly winds may remain a bit breezy on Thursday, the pressure gradient should slacken as the high builds in from the west. The result will be a trend toward clear skies and light winds through Friday Night. The big forecast problem continues to be how the next weather system evolves. The models are coming into slightly better agreement, trending toward each other. Generally, an upper level low cuts off over the southwest U.S on Saturday. It gets absorbed into the next trough as it amplifies over the Rockies. The resultant shortwave energy will help precip develop over the Midwest as it impinges on the upper level ridge. Though the amplitude, speed, and timing of this system are still highly uncertain, expect precipitation chances to increase Sunday into early next week, though for now it appears the surface high may hold over the region through the weekend. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
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As of 740 PM Tuesday... 24 Hour TAF Period: A moist southerly low level flow will continue tonight into Wednesday in advance of a cold front. Patchy MVFR cigs this evening will fill in and lower tonight with low end MVFR/IFR cigs expected by early Wednesday morning areawide, with possibly some LIFR cigs and reduced visbys around daybreak. Cigs are expected to slowly lift on Wednesday, with winds increasing out of the south/southwest. By mid Wednesday afternoon expect generally VFR conditions at KRDU/KFAY/KRWI with wind gusts of up to 30 to 35 mph possible. Further west, a band of showers associated with the approaching cold front will move into KINT/KGSO on Wednesday afternoon, with winds gusts of up to 30 to 35 mph as well and cigs possibly lingering in the high end MVFR range or low end VFR. Outlook: The cold front will approach the area late Wednesday triggering an additional band of convection during the late afternoon and evening with showers and perhaps a thunderstorm resulting in some restrictions. High pressure with fair weather is expected for thursday into Saturday. A storm system will approach the region for Sunday with a period of adverse aviation conditions.
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&& .CLIMATE... Record high minimums for 11/29 RDU 62 1934 FAY 66 1990 GSO 57 1957 Record highs for 11/30 RDU 77 2006 FAY 80 1927 GSO 74 1991 Record high minimums for 11/30 RDU 62 1934 FAY 62 2001 GSO 62 1934 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...KDS NEAR TERM...BLAES SHORT TERM...KCP LONG TERM...KCP AVIATION...BSD/BLAES CLIMATE...RAH is the U.S. government's official web portal to all federal, state and local government web resources and services.