Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 290732 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 332 AM EDT Thu Jun 29 2017 .SYNOPSIS... High pressure will continue to shift offshore today. A warm front will track from the Gulf Coast northeastward into North Carolina on Friday, bringing a return to warm and humid weather for the upcoming weekend. && .NEAR TERM /Today and Tonight/... As of 911 PM EDT Wednesday... A modified ~1023mb cP surface high will move off the DELMARVA coast this evening with attendant sfc ridge axis extending east into the area overnight. Mostly clear skies, light winds and antecedent dry air in place (BL dewpoints in the mid 50s and PWATS between 0.5- 0.6")will result in good radiational cooling conditions overnight. So expect another night of below normal low temps, ranging from the mid/upper 50s to lower 60s, coolest in the typical rural/low-lying areas. && .SHORT TERM /Thursday and Thursday night/... As of 135 PM EDT Wednesday... A relatively dry airmass associated with modified Canadian high pressure extending westward (from the Atlantic) into the Carolinas will persist on Thu, albeit with a gradual increase in moisture from the S/SW during the aft/eve as the surface high moves further offshore, the ridge weakens, and a light return flow commences. Upper level moisture will also increase on Thu as a deamplifying upper level low progresses NE from the TX/LA Gulf coast into the Deep South. With the above in mind, expect dry conditions and increasing cloud cover on Thu with highs in the mid to upper 80s, warmest E/SE. The deamplifying upper level low is progged to make little progress Thu night, progressing NE into northern AL/northwest GA. Strengthening southerly return flow /moisture advection/ is expected to result in the development of stratus from S/SW to N/NE overnight. As a result, expect much warmer lows than observed in previous days, in the mid to upper 60s, except in the far NE Coastal Plain where lower 60s cannot be ruled out. Will introduce a slight chance of showers after midnight in the far S/SW, though the best potential for showers should remain upstream in upstate SC, southwest NC and northern GA where richer low-level moisture will be juxtaposed with DPVA attendant the upper level low. -Vincent && .LONG TERM /SATURDAY THROUGH WEDNESDAY/...
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As of 330 AM EDT Thursday... The weekend will start with a weak upper level trough moving through the Great Lakes and a surface low over Ontario with an attendant cold front pushing towards the Appalachians. This will be slow to arrive however and Saturday will be characterized by southerly flow with pre-frontal moisture supplying diurnal showers before the front pushes through on Sunday morning. Despite winds trying to go northerly on Sunday morning they will quickly switch back to southerly as the lee trough develops over central NC. This leaves little airmass change and highs still in the upper 80s to low 90s. By Monday the ridge axis moves through and begins to weaken brining more westerly upper level flow. Monday looks like a drier day as high pressure tries to move in from the north but diurnal showers and storms are still possible, especially in the far southeastern counties. Highs will still be in the lower 90s. Tuesday looks like more of the same as zonal flow aloft combine with a lee surface trough that give us a chance for afternoon thunder but severe weather is not expected. Confidence is low for Wednesdays forecast as a lot will depend upon the development of a surface low either to our northwest (GFS solution) or pretty much right over central NC. The latter would bring a much wetter forecast for Wednesday but it is still too early to hash out those details. Either way it will be hot with highs in the mid 90s and heat indices beginning to approach 100 degrees.
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&& .AVIATION /06Z Thursday through Monday/... As of 145 AM Thursday... High confidence in VFR conditions today through tonight. The center of high pressure will continue to move out over the Atlantic while extending back westward across NC into tonight, bringing light surface flow mainly from the S or SSW. Any cigs will be based above 20,000 ft AGL through 06z Fri, with just scattered afternoon cumulus based around 5,000 ft AGL expected. Looking beyond 06z Fri, there is a chance for late-night sub-VFR conditions late tonight/Fri morning, however models aren`t in good agreement on this, as there is also a chance that mid and high clouds will thicken and lower as they spread over the area from the SW, which would limit radiational cooling and thus limit stratus and fog development early Fri morning. As a warm front moves into the area from the SW on Fri, the chances for showers/storms will return Fri afternoon. Sub-VFR conditions, mostly thick low stratus, are likely Fri night, starting in the evening and persisting through Fri night and into Sat morning. Scattered showers/storms will remain possible through the upcoming weekend, mainly in the afternoon through early evening. Sub-VFR stratus is again possible early Sun morning, but with a lower coverage and duration as compared to Fri night/Sat morning. Shower/storm chances will be lower on Mon, although a chance remains along/east of I-95. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...CBL SHORT TERM...Vincent LONG TERM...Ellis AVIATION...Hartfield is the U.S. government's official web portal to all federal, state and local government web resources and services.