Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 240211 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1003 PM EDT Mon May 23 2016 .SYNOPSIS...An upper level low will pull away from central NC tonight and Tuesday. A strong upper level ridge will build over the Southeast through the remainder of the week. && .NEAR TERM /through tonight/... As of 955 PM Monday... Showers have largely dissipated across the region this evening with the loss of heating. However, another disturbance rotating around the offshore mid/upper level low is helping to support a few lingering showers across the southern half of VA. This disturbance should rotate across portions of our area... while the center of the mid/upper low slowly begins to wobble north and eastward and away from the area tonight. Thus, we could possibly see a shower or two affect northern/northeastern portions of central NC before the activity dissipates with further nocturnal stabilization and/or the disturbance rotating through the area late this evening/early Tuesday morning. The main forecast problems of the night though appear to be how much cloud cover we will have and the resulting effects on the low temp forecast, along with the possibility of some fog. Skies are currently clear/mostly clear across a large portion of central NC, which has allowed temps to drop quite nicely with light and variable to calm surface winds. However, we will at least see some increase in cloud cover across the northern/northeastern half of the CWA, before clearing across most if not all of the area by late tonight/before daybreak Tuesday. Thus, with recent rains, light and variable to calm winds, and clearing skies think we may see at least see some patchy fog. Low temps are generally expected to be in the lower to mid 50s, with perhaps a few of the coldest sites dipping into the upper 40s. && .SHORT TERM /Tuesday and Tuesday Night/... As of 325 PM Monday... Upper level ridge over the Mississippi Valley will begin to expand northeast into the southeast U.S. Tuesday, in the wake of the departing low. Rising heights/associated subsidence will suppress cloud growth depth, resulting in scattered flat cumulus in the afternoon. Late May sun will aid to warm temps to near or above 80 for the first time since May 14th for many locations. High pressure at the surface and aloft will continue to strengthen over our region Tuesday night. Under clear skies and a light or calm wind regime, min temps by early Wednesday will average in the upper 50s to around 60. && .LONG TERM /Wednesday through Monday/... As of 305 PM Monday... Wed-Fri: Warm and mainly dry. The mid level pattern will feature longwave troughing over the western CONUS with ridging in the east, albeit with a weakness aloft which will extend from a weak low over the central Bahamas northwestward across SW NC. At the surface, Bermuda-centered high pressure will ridge narrowly westward across the Southeast, yielding a light low level flow with minimal moisture influx. The above normal heights aloft and resulting subsidence, along with the absence of lift mechanisms and the lack of a good moisture source, will help suppress deep convection over central NC. While the aforementioned weakness in heights aloft to our SW may lead to scattered afternoon storms over the higher terrain, the steering flow pattern does not favor movement of any such convection into our area. Thickness will be well above normal, supporting highs each day in the mid 80s to around 90 (Thu appears likely to be the warmest of these days) with lows in the lower to mid 60s. Sat-Mon: Lots of uncertainty in the details, although guidance continues to favor temps staying slight above normal through the upcoming holiday weekend, but with an increasing chance of showers/storms by Sun/Mon. The western end of the surface ridge axis will pivot northward (following the strengthening of the Atlantic mid level ridge extending into the mid Atlantic region), and this will allow a long-fetch southeasterly flow to stream increasing amounts of moisture into the Southeast. Meanwhile, the Bahamas mid level low begins to drift to the NW into the height weakness toward the Southeast states, and model solutions are converging toward some similarity at the surface, showing either an inverted trough or low tracking northwesterly toward the Southeast coast. It is far too early to say whether or not this feature might have tropical or subtropical characteristics, but regardless, we are still likely to see an increase in clouds and precip chances as mid level heights fall and moisture increases and deepens through the low levels. Thicknesses support temps slightly above normal, tempered by the increase in clouds. -GIH && .AVIATION /00Z Tuesday through Saturday/... As of 800 PM Monday... 24 hour TAF period: VFR conditions across the area this evening as rain showers have tapered off and dewpoints are starting to dive into the lower 50s across the area. Therefore have high confidence of VFR conditions maintaining through the TAF period. Winds will be light and variable tonight and then obtain more of a westerly direction on Tuesday at 5-10 kts. A few clouds in the 3-5 kft range will prevail on Tuesday but overall mostly clear skies expected. Long term: VFR conditions should prevail through much of the extended until Thursday night into Friday when rain becomes more of a threat in the NW Piedmont. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...22 NEAR TERM...BSD SHORT TERM...WSS LONG TERM...Hartfield AVIATION...Ellis is the U.S. government's official web portal to all federal, state and local government web resources and services.