Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 181843 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 243 PM EDT Wed Apr 18 2018 .SYNOPSIS... A dry cold front will move east through the area late tonight through late Thursday morning. Cool high pressure will build into the Carolinas Thursday night through Saturday. && .NEAR TERM /THROUGH TONIGHT/...
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As of 243 PM Wednesday... Tonight: Sfc cold front will cross the mountains aoa midnight and will push east into the NC Piedmont during the predawn hours. Moisture is very limited with the front. So aside from a brief period of some broken high base stratocumulus immediately along/ahead of the front, dry conditions will prevail. A steady 10 to 15 kt breeze will support mild temperatures overnight. Lows generally in the lower to mid 60s. The exception will be across the far NW zones where the late onset of CAA behind the cold front could allow temperatures to fall into the mid/upper 50s right around daybreak.
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&& .SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
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As of 245 PM Wednesday... Sfc cold front will exit the coastal plain counties by mid-late morning. Soundings remain very unimpressive wrt sufficient moistening and essentially no instability given strong inversion aloft. Thus, thus will keep forecast dry. Otherwise, drier cooler air will advect into the area by the afternoon and will continue overnight, with blustery W-NWLY winds gusting between 25 to 30 kts by mid to late morning and continuing into the afternoon. Initially, the cold air advection may be offset by low-level westerly downslope flow, but by the afternoon a more nly direction could allow temperatures to fall slightly. Highs ranging from 60 NW to lower/mid 70s SE. Continued CAA Thursday night will result in the first of two chilly nights to come. Lows overnight in the 35 to 40 range. A steady 5 to 7 kt range should preclude widespread frost development. However it`s possible that patchy frost could develop in sheltered areas, especially across the NW Piedmont where the pressure gradient relaxes towards daybreak.
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&& .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 230 PM Wednesday... An upper level ridge and surface high pressure over the Midwest will keep conditions cool and dry for the end of the week and into the weekend. Temperatures for Friday and Saturday will generally be in the 60s with lows in the 40s. On Friday night a few of the VA border counties might drop into the mid to upper 30s, so it is possible that a frost advisory may be needed but will continue to monitor temperatures as latest guidance was slightly warmer than prior forecasts. Clouds will begin to increase Sunday as high pressure sets up offshore in a hybrid or in-situ damming scenario. This wont happen until late in the day however, which will allow temperatures to rise into the upper 60s to near 70 degrees Sunday afternoon. For early next week, strong hybrid cold air damming sets up on Monday and isentropic lift increases over the area. In addition, a low pressure system will try to move into the area from the southwest, however, strong high pressure may keep it further south than the GFS solution suggests. The EC solution does keep it well to the south. A blend of the two ramps up precipitation chances on Monday, especially across the western Piedmont. Whether the precipitation is from the isentropic lift or the approaching low remains to be seen but regardless, expect rain chances to increase early next week and an unsettled pattern will prevail through Wednesday. Highs will be in the 60s with lows in the upper 40s across the Piedmont to low 50s in the southeast. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... As of 130 PM Wednesday... In advance of a dry cold front that will cross the region late tonight through Thursday morning, gusty SWLY winds of 20 to 25 kts are expected to develop late this afternoon and evening. While sfc winds will remain between 10 to 15 kts overnight, a strong 50 to 55 kt low level jet crossing east through the area will support a period of LLWS this evening and into the overnight hours. In the wake of the cold front moving east of the area during the mid to late morning hours, gusty conditions are expected again on Thursday, with WNW winds gusting 25 to 30 kts, strongest at KFAY and KRWI. Dry VFR conditions are expected to persist into the weekend. The next threat for sub VFR ceilings may occur as early as Sunday night, but may hold off until late Monday or Monday night. && .FIRE WEATHER...
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Coordination with neighboring NWS offices and the North Carolina Forestry Service has led to the issuance of Increase Fire Danger statement today across sections of western and central NC, and across the bulk of the state for Thursday. Across central NC, the most critical fire weather parameters today will be across sections of the southern Piedmont into the Sandhills as lower dewpoints and warm afternoon temperatures will yield late afternoon humidity values in the 25-30 percent range. This will occur at about the same time the strongest wind gusts will occur (19Z-22Z) with gusts 22-25kts. On Thursday, minimum humidity values in the afternoon will bottom out between 25 to 35 percent areawide with gusty westerly-nw sfc winds of 25 to 30 kts developing in the wake of the exiting cold front from mid morning into the afternoon hours. Based on what fire activity occurs today, and if model dewpoint guidance comes in lower, cannot rule out the possibility of a short-fused Red Flag Warning for parts of central NC on Thursday.
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&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...CBL NEAR TERM...CBL SHORT TERM...CBL LONG TERM...ELLIS AVIATION...CBL FIRE WEATHER...WSS

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