Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 240706 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 305 AM EDT SAT SEP 24 2016 .SYNOPSIS... Weak high pressure will hold over the area today. A backdoor cold front will approach from the north early tonight, and then move southward through the area late tonight through Sunday morning. A cooler air mass will push in from the north Sunday morning through Monday. The front will move back northward as a warm front late Monday, with brief high pressure following, before a cold front crosses the region west to east late Tuesday. && .NEAR TERM /today through tonight/...
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As of 305 AM Saturday... Today: Once the areas of shallow fog wear off an hour or two after daybreak, a fairly quiet and warm day is expected with plenty of sunshine. The latest surface analysis shows the remains of the weak trough just off the coast, with weak high pressure covering the rest of the region, although weak Piedmont trough development is anticipated this afternoon. Pronounced ridging is noted throughout the mid and upper levels centered just to our west, with a weak mid level flow from the NW or NNW over our area, and observed PW according to blended TPW imagery is low (1.0-1.4"). With deeply dry and stable air in residence and upstream, expect mostly sunny skies today. Thicknesses are expected to be 10-20 m above normal, favoring highs in the 86-90 range, highest west. Tonight: Warm conditions will hold through the evening, then the backdoor front currently stretching across central IN/central OH/ southern PA will push southward into NE NC overnight, propelled by cool dense high pressure to the north and flow around a strong vortex over SE Canada. Plenty of low stratus is currently found near and north of this front, and see no reason why this won`t hold as the front drops into NC. Models agree on light precip near the front with considerable low level moisture pooling taking place, and will hold onto low chance pops over the NE and far N CWA tonight, with low QPF overall given the shallow nature of the incoming moisture. Lows in the mid-upper 60s. -GIH
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&& .SHORT TERM / /...
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As of 320 PM Friday... To be updated shortly.
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&& .LONG TERM /SUNDAY THROUGH FRIDAY/... As of 245 PM Friday... The timing of the back-door cold front through the area on Sunday is still in question. The GFS and NAM are much quicker to blow the front south through the area late Saturday night/ear Sunday, while the ECMWF suggest the frontal boundary will tend to "hang up" or slow down across the forecast area on Sunday, which is very plausible given weak sfc pressure rises from the transitory parent high center retreating off the Northeast-Southern New England Coast. These models discrepancies are leading to lower than average forecaster confidence, making for a challenging temperature forecast on Sunday and likely setup a sharp temperature gradient across the area. For now will continue a "middle of the road approach" with highs ranging from mid 70s northeast to mid 80s southwest. Additionally, given the potential for the front invof the area, will continue isolated to slight chance chance pops. Mid/upper level ridge will build east over the area on Monday in advance of a closed low and upper trough progressing eastward into the Upper Great Lakes/Southern Canada. With the transitory parent high quickly moving off the Southern New England Coast, south- southeasterly return flow will quickly return to the area late Monday with rain chances generally restricted to upslope/differential heating over the higher terrain, while ridging aloft should keep the remainder of NC dry. SELY moisture advection and resultant weak isentropic upglide in advance of a cold front approaching from the west could produce showers across the area as early as Monday night/Tuesday morning with another round of showers and storms expected to accompany the frontal passage Tuesday afternoon/evening. Highs Monday and Tuesday slightly above normal with mild overnight lows in the 60s. In the wake of the cold front, high pressure will bring dry seasonable weather for the later half of the work week. Highs 75-80. Lows the 50s. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... As of 150 AM Saturday... IFR/LIFR conditions will hold over the NE CWA including RWI through daybreak, while at RDU/FAY, a trend to IFR conditions by 09z are less certain but still likely. VFR conditions are likely to hold over the western CWA including INT/GSO. Any sub-VFR conditions will trend to VFR by 14z this morning, mixed out by dry air aloft. Dry weather and very few clouds are expected areawide from mid morning through the evening. As a backdoor front moves in from the NNE, cigs will trend to IFR at RWI/RDU after 04z, with light/variable surface winds becoming light from the ENE or NE. Looking beyond 06z early Sun morning, sub-VFR cigs (likely IFR or LIFR) will spread over all of central NC late tonight as the backdoor front progresses toward the SSW through the area. Patchy light rain or drizzle is possible. These low cigs will trend slowly to MVFR during Sun, with a slight chance of light rain lingering, especially over the west and south at INT/GSO/FAY. The chance for light rain will increase in the west (INT/GSO) Sun night with IFR conditions, while MVFR conditions are expected elsewhere. A trend back to VFR conditions are expected Mon as the front starts to head back northward as a warm front. MVFR to IFR fog is expected late Mon night into early Tue morning. VFR conditions will dominate Tue into Wed, although passage of a cold front late Tue or Tue night will bring shifting winds from light/variably to N and NE. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Hartfield SHORT TERM... LONG TERM...CBL AVIATION...Hartfield is the U.S. government's official web portal to all federal, state and local government web resources and services.