358 FXUS62 KRAH 231827 AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 225 PM EDT Sun Jun 23 2019 .SYNOPSIS... Weak high pressure centered over the mid Atlantic will dissipate and shift offshore tonight. A stationary front extending northwest to southeast across the Tennessee Valley into the southern Carolinas will lift northeast across the area tonight and Monday. A cold front will move east across the area Monday night into Tuesday. Weak high pressure will move into the region on Wednesday and Thursday. && .NEAR TERM /THROUGH TONIGHT/... As of 225 PM Sunday... Latest surface analysis shows a prominent stationary front extending from the western Great Lakes southeast across the TN Valley and then east across southern SC. A weak surface wave is located on the front across eastern SC. The air mass north of the front in central is characterized by dew points generally in the upper 50s to lower 60s. South of the front, dew points range in the upper 60s. Further aloft, a weak northwest flow is present as a weak short wave ridge at 500 hPa extends from the northeast Gulf of Mexico across the Deep South into the eastern TN Valley. The morning RAOB from Greensboro depicted a very stable airmass with a saturated layer between 850 and 700 hPa. The latest visible satellite image depicts a region of partly to mostly cloudy skies across central NC. The cloud deck has thinned a bit over the past few hours. The latest SPC mesoanalysis shows a stable air mass across the area with an arc of very limited instability stretching from the western Piedmont across the southern Piedmont into the Sandhills. The front should remain relatively stationary through this evening. The low stratus was driven by a layer of isentropic lift in the 300 to 305K surface. The axis of moisture will continue to shift east this afternoon and evening which will continue to allow the cloud cover to break up a bit. Precipitation chances this afternoon and evening will be confined to locations near a little northeast of the front with the best chance close to the front and the weak surface wave in the Sandhills and southern Coastal Plain. The stationary front begins lifting northeast overnight which allows the boundary layer to moisten and clouds to redevelop and thicken overnight. Precipitation chances are limited but a slight chance PoP is warranted across mainly the southern areas tonight with the front lifting into the area. Lows tonight will range in the mid 60s to around 70. -Blaes && .SHORT TERM /MONDAY AND MONDAY NIGHT/... As of 400 AM Sunday... Monday, a sharp upper ridge builds aloft over the Carolinas leading to an abrupt surge in thickness values, about 30m in most locations which yields an almost 10 degree increase in daytime highs over the area into the low to mid 90s. Southerly flow at the surface will also increase warm air advection over the area albeit minimal. The ridge will keep convection at bay for much of the day but later in the afternoon and towards early evening, attention will turn to the west where a frontal system begins to move over the Appalachians with a smaller convective complex out ahead of the front which moves through the Triad between 21-00z. As a result, the whole forecast area is in general thunder for Monday but much of the activity will not be until very late in the day. We lose the convective allowing models before the frontal passage on Monday night but large scale models are hinting at a drier frontal passage with both the ECMWF and NAM solutions coming in completely dry this round. The GFS has some convection at this time but it also decreases in coverage and intensity as it transverses the area from northwest to southeast. Lows will be steamy with temperatures only falling into the low to mid 70s for much of the area. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 400 AM Sunday... Mid level s/w ridging will build back into the area on Tuesday behind the exiting system. This will spell a return to generally dry weather for Tuesday and Tuesday night, though temps will be quite warm with decent amount of sun on Tuesday. Expect high temps Tuesday will be in the lower to mid 90s, with lows by Wednesday morning generally in the upper 60s to lower 70s. A weak mid level disturbance is forecast to approach and move across the area Wednesday afternoon/evening, which may be enough to trigger a few afternoon and evening showers and storms, with the best chance across the western Piedmont. Expect high temps on Wednesday will generally range from the mid to upper 80s NW to the lower 90s elsewhere. A weakness in the subtropical ridge and the mid/upper level ridge over the central U.S. will generally linger over central NC through the remainder of the medium range period, with main storm track staying to the north of the area. This will lead to mainly diurnal chances for showers and storms with highs generally in the upper 80s to lower 90s and lows in the upper 60s to lower 70s. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... As of 210 PM Sunday... 24 Hour TAF period: A fairly widespread region of mainly VFR SCT to BKN stratus and strato-cumulus clouds with bases generally around 3.5 to 5.5kft was present across central NC this afternoon. These clouds were driven by a layer of low-level moisture and a region of weak isentropic lift northeast of a stationary front near the NC/SC border. With time, the clouds will fracture a bit from west to east this afternoon and evening. A few showers may develop near the front, especially across the Sandhills, the Southern Coastal Plain, and the southern Piedmont with an isolated thunderstorm possible. A very limited threat of showers will persist into the overnight hours as the front lifts northeast but the limited coverage will not not warrant inclusion in the TAFs. Clouds will thicken overnight with mainly VFR ceilings expected, but a period of MVFR stratus is possible in the Piedmont and possibly IFR ceilings in the Sandhills and Coastal Plain. Clouds will become more scattered and bases will lift with mainly VFR conditions expected by mid to late morning on Monday. Light easterly winds this afternoon will become very light and southerly overnight and light south to southwesterly on Monday. Long term: An approaching cold front will trigger scattered showers and thunderstorms Monday afternoon and especially Monday night into early Tuesday. Mainly VFR conditions are expected during the remainder of the upcoming work week with a limited chance of mainly afternoon and evening showers and storms. -Blaes && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Blaes NEAR TERM...Blaes SHORT TERM...Ellis LONG TERM...BSD AVIATION...Ellis