990 FXUS62 KRAH 270749 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 350 AM EDT Thu Jun 27 2019 .SYNOPSIS... High pressure will extend across the cntl Appalachians through Friday, while a trough will strengthen in their lee each afternoon. A backdoor cold front will settle into the srn middle Atlantic states Sunday night. && .NEAR TERM /THROUGH TONIGHT/... As of 1020 PM Wednesday... Some high clouds, thick in places, linger across central NC this evening and could remain over the area through much of tonight. As such, despite high pressure in place and a dry forecast with light winds expected tonight, lows may not dip much lower than mid to upper 60s. Forecast soundings from both the NAM and GFS indicate the high clouds sticking around through the overnight, with a few mid clouds (6-8 kft) developing before daybreak. Have kept forecast lows limited to the 67-71 degree range, though they could dip a bit lower if/where the clouds scatter out more than expected. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... As of 335 PM Wednesday... To the east of a mid to upr-lvl low forecast to develop over the mid- South by early Thu, a shear axis will extend from the srn Appalachians to the srn middle Atlantic coast through Thu night. Continued periods of high level ceilings, though mostly thin enough for the sun/moon to shine through, will result. Aside from persistent ridging centered along the srn and cntl Appalachians, a lee trough and a more prominent/wwd-retreating sea breeze (than Wed) will be the dominant features at the surface; and those may focus an isolated to widely scattered shower or storm Thu afternoon-evening, with the relative highest (slight) chance over the cntl-srn Coastal Plain and Sandhills - related to the sea breeze. It will otherwise be hot, with air mass modification and warming characterized a 5-10 meter increase in forecast low level thickness values over those of Wed -into the upr 80s across the nrn piedmont to mid 90s in the Sandhills- followed by near average lows in the upr 60s to around 70 degrees. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 350 AM Thursday... Hot, humid, and low end POPs will be the key phrases throughout the long-term portion of the forecast. Sub-tropical ridging will build westward with time over the weekend with a steadily strengthening area of Bermuda high pressure remaining firmly in place at the surface. This will help to limit POPs throughout much of next week, with little in the way of upper-level atmospheric change/influence likely across central NC. The one exception will be a rapidly digging upper-level trough to our northeast Sunday night and Monday, which will help to usher in a backdoor cold front pre-dawn Monday. With timing of said boundary progged to pass through well after peak heating, have kept POPs low, with only a dewpoint drop and brief wind shift evident in the sensible weather pattern at the surface. Southwesterly flow re-establishes on Tuesday with the upper-level subsidence inching further east off the Atlantic Coast. This will result in t he return of low-end diurnal favored POPs to the forecast late in the work-week. With 850mb temps generally in the 18 to 22 degree Celsius range across our area, and little in the way of airmass change anticipated, have trended toward a persistence type temperature forecasts. Highs should remain slightly above normal throughout the period, topping out in the 89 - 95 degree range across central NC, limited only locally by intermittent high clouds and the formation of a fair-weather cumulus deck each afternoon. Overnight lows will dip into the upper-60s to low-70s. With temperature and humidity values remaining high, will need to monitor heat indices during this forecast period, as a few areas could top out near 100 degrees Saturday and Sunday afternoons. Some relief will be evident behind the front, with max HI values falling into the low to mid 90s beginning Monday afternoon thanks to the drop in dewpoints. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... As of 215 AM Thursday... An area of high pressure will be the main weather factor across central NC through the end of the week. Thus, there is a high likelihood that VFR parameters will persist across central NC through Friday. Sfc winds will be variable through the period, remaining below 10kts. Outlook: Mainly VFR through the period with brief MVFR/IFR conditions with possible early morning fog and/or low stratus. The arrival of a backdoor cold front late in the weekend should allow for an increase in coverage of showers and storms by Sunday afternoon At this time, it appears that afternoon-early evening convection will be limited in coverage. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...KC SHORT TERM...MWS LONG TERM...JJM AVIATION...CBL