661 FXUS62 KRAH 031757 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 157 PM EDT Wed Aug 3 2022 .SYNOPSIS... A surface trough will move east across central NC this morning, then weaken and dissipate over the eastern Carolinas later this afternoon through tonight. Persistent high pressure will otherwise extend across the western Atlantic and Southeast through early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 1130 AM Wednesday... A mid-level ridge is currently located off the East Coast, with another ridge centered over the Desert Southwest. Current surface analysis shows a weak trough currently extending SSW down the northern Mid-Atlantic coast into eastern NC. This will continue to move west and merge with the seabreeze, and convergence along this boundary will result in potential for a few showers and storms over the southern Coastal Plain and Sandhills from mid-afternoon into the early evening. There will be PW values of 1.75-2" and MLCAPE of 1000- 2000 J/kg in the far SE, but coverage continues to look fairly isolated given weak mid-level lapse rates and weak forcing. Also not expecting a severe threat given the lack of shear. The CAMS show potential for showers and storms late this afternoon and early evening across the southern Piedmont from a pair of vortmaxes that will be across eastern GA and SC. Given the best forcing will be to our west across the mountains, coverage again looks fairly isolated and the 12z CAMS have trended drier. Across the northern Piedmont and northern Coastal Plain, the more westerly flow aloft is helping keep PW values only in the 1.2-1.4 inch range, with a layer of very dry air near 500 mb showing up on the 12z GSO sounding. Thus continue to keep any precipitation chances out of those areas today. Did bring forecast dew points today down a hair in the latest update, given the latest observations and statistical guidance showing widespread mixing out into the mid-to-upper-60s this afternoon. This will also help high temperatures rise into the mid- to-upper-90s in most places, or about 5-10 degrees above normal. The lower dew points will help keep heat indices below Heat Advisory criteria, though they could still reach the lower-100s across the south. Any convection should diminish tonight with loss of daytime heating. Lows will be in the upper-60s to mid-70s. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... As of 349 AM Wednesday... Hot and increasingly more humid conditions are expected Thursday as a low level SSW flow returns. There is a chance of mainly afternoon and evening thunderstorms in the western Piedmont where the moisture will be higher, with lesser (20 percent) chances to the east. Highs should range in the lower to mid 90s with heat indices generally 100 to 104, except near 100 in the NW. Isolated evening thunderstorms will give way to mainly fair skies Thursday night with lows in the lower to mid 70s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 345 AM Wednesday... It still appears that the higher chance of mainly afternoon and evening thunderstorms will be on Friday and Saturday. This occurs as a weak front to the north stalls just to our north late Friday into Saturday before washing out. The broad SSW low level flow will transport plenty of moisture into the region with PW on the order of 1.7 to 2 inches. The higher POP is still expected to be in our western and northern Piedmont each afternoon and early evening. We may have to raise POP into the likely category either day. The rest of the region will have 30-40 POP. QPF both days should average 0.25 to 0.50 in the west, with around 0.25 in the east. Localized 1+ inch totals are expected, especially closer to the front in the NW Piedmont. Highs will "cool" just a bit into the upper 80s NW-N, ranging into the lower to mid 90s SE. Lows will be in the upper 60s to mid 70s. Sunday and Monday, the Bermuda high is forecast to build back over the SE allowing for some suppression of convection chances. This will allow highs to rise back into the lower to mid 90s. Convection chances return on Tuesday as another weak front should make a run into the mid-Atlantic states from the north. Temperatures will remain hot. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... As of 155 PM Wednesday... 24-hour TAF period: VFR conditions are generally expected across central NC through the TAF period. Radar shows scattered showers and storms beginning to develop along a sea breeze boundary across SC and far SE NC. A few of these could make it into the Sandhills and southern Coastal Plain, including FAY, from now into the early evening. Brief gusty winds and reduced visibilities are possible with any storms, but they should be isolated and quickly diminish after 00z. Elsewhere just scattered fair weather cumulus is expected today. As the low-level flow turns more moist/southerly, some sub- VFR ceilings/visibilities from fog/low stratus can't be entirely ruled out late tonight and early tomorrow morning across the Sandhills and Coastal Plain (including FAY and RWI). However, the RAP is the only model currently showing this, with even the usually bullish NAM keeping the low levels too dry. Thus confidence in this occurring is low. Light and variable winds today will switch to S/SW around 5-10 kts tomorrow. Looking beyond 18Z Thursday: Areas of stratus and fog will be possible through eastern NC, including as far west as FAY and RWI, each morning through the weekend. Weakly-forced, pop-up showers/storms will also be possible throughout central NC each afternoon-early evening, particularly around INT/GSO. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...Danco SHORT TERM...Badgett LONG TERM...Badgett AVIATION...Danco