Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 251931 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 330 PM EDT Tue Jul 25 2017 .SYNOPSIS... A cold front will drop south across North Carolina today and then stall across South Carolina on Wednesday. This front will lift back north on Thursday before a strong cold front approaches the region from the northwest on Friday. && .NEAR TERM /THROUGH TONIGHT/... As of 225 PM Tuesday... Latest surface analysis shows the cold front making good southward progress and stretching from near KPGV southwest to KGSB to near KGSP. Surface dew points have already fallen into the lower to mid 60s across the border counties with a dew point of 64 noted at Roxboro and Henderson, just to the east higher dew points in the lower 70s persist at KIXA and KASJ. Aloft, the upper-level trough axis has shifted toward the coast. Precipitable water values continue to fall and now range from 1.1" along the NC/VA border to around 1.6" across the south and southeast. A weak short wave will drop into the region from the northwest late tonight while a southwest-northeast elongated upper level jet axis extends across the Southeast. With decreased moisture, a weakly unstable air mass and limited forcing, precipitation chances will be limited this evening and tonight. The only organized area of convection near our CWA will likely be scattered storms across the coastal region near the surface front and another area of isolated convection across the higher elevation of the NC mountains. Given the higher dew points in the lower 70s lingering across the Coastal Plain and Sandhills and slightly better mid- level lapse rates, could see a shower pop up in the east or a shower in the higher elevations move into the western Piedmont. Will include slight chance pops tonight. Expect periods of cirrus tonight with the enhanced upper level jet. A layer lower stratus may develop late tonight in an arc from the Coastal Plain west and northwest across the Sandhills and into the Yadkin Valley. It will be cooler tonight with a some lows reaching the upper 60s across the northern Piedmont, especially near the VA border with most locations ranging from 67 to 74 degrees. The EC ensemble guidance for Henderson gives an operational and a mean low both of 67 with the warmest ensemble member giving a low of 69 and the coldest 63! -Blaes && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... As of 240 PM Tuesday... The cold front should be positioned south of central NC on Wednesday morning allowing high pressure to extend into the region from the north. The front will begin lifting north on later Wednesday as the surface flow veers to southeasterly and southerly. This will allow an increase in moisture roughly in the 925 to 850 hPa layer and promote an increase in cloud cover and perhaps a shower or storm, generally in an arc from the Coastal Plain west and northwest across the Sandhills and into the Yadkin early in the day that will expand northward during the afternoon and evening. Precipitation chances will be limited to the slight chance range across most of the area, so all in all it will be a much cooler and more tolerable day. Highs will range in the upper 80s to near 90 with lows in the 68 to 74 range. -Blaes && .LONG TERM /THURSDAY THROUGH TUESDAY/... As of 330 PM Tuesday... Mid level ridging amplifying over the central CONUS will induce corresponding deepening of east coast troffing and associated northwest flow. Cooler air will be edging south out of the upper midwest and slowly spreading east and southeast, with the associated cold front reaching the NC/VA border Thursday night. Thursday will be dry with potential for some showers in the western Piedmont late in the day. Highs will reach near 90 over the area with PoPs ramping up to 30-40% by Friday morning as the front creeps in, with at least 50% chances on tap for Friday into Friday night. Strongest convection is expected late Friday and through the overnight as convergence along the h85 trof will provide the best lift, with better shear profiles across the northern tier nearer the parent surface low and triple point. Highs Friday will be a shade cooler...mid 80s northwest to lower 90s east...mainly abetted by heavier cloud coverage and rain, as the cooler air doesn`t make its way into the area until Friday night. Some showers may linger into Saturday morning in the east, otherwise skies will be clearing with a noticeably cooler and drier airmass in place through the weekend. Highs Saturday through Monday will top out mostly in the mid 80s...3-5 degrees below normal, with morning lows in the mid to upper 60s. The front, meanwhile, will be stalled along the coast, with potential for development of a surface low along the front that could pull moisture back into at least the eastern sections of the state by midweek. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... As of 200 PM Monday... 24-Hour TAF period... Central NC is under the influence of high pressure to the north with a cold front stalled south of the area in SC and GS. This will result in VFR conditions across much of central NC through Wednesday afternoon with the exception of some morning MVFR stratus and fog across the south which may impact the KFAY terminal. An isolated shower or storm is possible across the Southern Coastal Plain, Sandhills and souther/Western Piedmont. But with limited and coverage and confidence, will omit from the TAF. Otherwise, expect periods of fair weather cumulus this afternoon and periods of BKN cirrus clouds. A layer lower stratus the VFR and MVFR range may develop in an arc from the Coastal Plain west and northwest across the Sandhills and into the Yadkin Valley late tonight and Wednesday morning. Light north to northeast winds at less than 10kts will continue through the period before veering to southeasterly on Wednesday afternoon. Looking ahead... The cold front to the south will lift north as a warm front on Thursday before a stronger cold front moves through the area on Friday and then stalls to our south over the weekend. Mainly VFR conditions expected through much of the period with scattered mainly afternoon and evening showers and thunderstorms and a chance of morning fog and stratus. The greatest chance of adverse aviation conditions in showers and storms will be Thursday night through Friday night ahead of the approaching cold front. -Blaes && .EQUIPMENT... The KRAX WSR-88D will be down for the Service Life Extension Upgrade (SLEP) beginning this morning and likely lasting through Thursday or Friday. The temperature & dew point sensor at site KFAY, located at the Fayetteville Regional Airport, is malfunctioning. NWS technicians have turned the sensor off and ordered parts to repair it. At this time, we expect the sensor to be returned to service early next week. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BLAES LONG TERM...RE AVIATION...BLAES EQUIPMENT...BLAES is the U.S. government's official web portal to all federal, state and local government web resources and services.