####018007837#### FXUS62 KRAH 190158 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 958 PM EDT Sun May 18 2025 .SYNOPSIS... High pressure will extend into the region from the north late tonight through Monday. The stalled front to our south will lift northward into North Carolina as a warm front Monday night into Tuesday. Low pressure tracking along the front will bring unsettled weather Tuesday through Wednesday. && .NEAR TERM /THROUGH TONIGHT/... As of 955 PM Sunday... As of 00Z, the quasi-stationary surface boundary remains draped across the area, within the surface trough. As the trough shifts ewd out of the region tonight, some drier air should begin to filter in from the north as high pressure pushes the boundary swd out of the area. Aloft, a weak upper level s/w should progress across the area early and continue ewd out of the area late tonight as the sub- tropical ridge amplifies and shifts ewd. Aside from some passing high clouds possible with the s/w, skies should be mostly clear tonight. Temperatures still expected to fall into the mid 50s north to mid 60s south. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... As of 255 PM Sunday... * Isolated storms possible SW late Mon aftn through Mon evening, but confidence is low. * Greater chance for showers and storms areawide late Tue afternoon through Tue night, with some possibly strong to severe. Mon/Mon night: Mon should start out with some sunshine, esp in the NE, but clouds will increase in the afternoon, with sct-bkn diurnal clouds developing by midday while thicker mid and high clouds spread in from SW to NE. The weak frontal zone dropping S through NC tonight is likely to follow in the footsteps of today's weak front and stall out over N SC before weakening and lifting back N by aftn. Aloft, as a mid level low drifts over and just off the Canadian Maritimes, a deep trough over the Front Range swings E into the Plains and becomes negatively tilted. Mid level ridging between these two systems will hold over the Ohio Valley into the Mid South and interior Southeast through Mon night, however the remnant MCV or dying MCS from tonight's anticipated powerful convection over KS/OK is expected to breach the flattening ridge and track ESE along the surface frontal zone through the Miss Valley and KY/TN Mon before moving SE through W NC and SC late aftn through Mon evening, a solution fairly well agreed upon by the latest HREF high res model suite members. Despite incoming decent lapse rates around 6.5-7.0 C/km just aloft, the afternoon mixing-out of surface dewpoints may result in only marginal SBCAPE. But HRRR forecast soundings over our S do show this resulting in a DCAPE over 900 J/kg, and with potentially plenty of moisture aloft in the mixed phase region along with long and roughly straight hodographs, we could see some strong surface gusts and large hail with this activity. Some models hold this convection to our S and SW, however, so for now, will carry a mention of isolated storms 21z-04z across the SW and see how things evolve tonight into early Mon to see if an increase in pops is needed. Models do suggest that this precip and resulting stable pool could facilitate the frontal zone pushing back to our SW as a backdoor cold front overnight, a reasonable response and one which would keep us mostly cloudy within stable air and areas of stratus over much of the CWA through daybreak Tue. After highs in the 80s, expect lows in the upper 50s N to mid 60s S. Tue/Tue night: The surface pattern over the E CONUS will remain complex, and our severe storm risk will depend in large part on the whims of the surface frontal zone. Most models indicate that the surface high to our N will weaken and push off the Mid Atlantic coast by late Tue, allowing the front to lift back NNE into W and S NC, although any lingering stable pool locked in over the NW Piedmont may retard this motion. The Plains low will lift gradually into IA and vicinity through Tue night as the trailing trough shifts E through the Ohio Valley and central/S Appalachians, while the surface frontal system matures and occludes, leaving a low over IL/IN with a second triple-point low somewhere to the ESE, potentially anywhere from KY to WV or WW VA/NC late Tue night. Overall, the chances for increasing PW and broad dynamic forcing for ascent do support a ramp-up to higher pops late Tue through Tue night, however our risk of severe storms (and placement of that risk temporally and spatially) will depend in large part on where the surface lows track, how long the stable low levels hold over the CWA Tue, how much heating we get, and how upstream convection evolves. For now, will show chance pops mainly across the W and S increasing to likely, highest across the NW and N closer to the triple-point low, with good chances in the SE. Expect highs in the mid-upper 70s N and back into the W Piedmont, with low-mid 80s SE and extreme S. Lows 59-68. -GIH && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 230 PM Sunday... The chance of scattered showers and storms remains on Wed ahead of a pre-frontal trough and cold front slated to move Wed night. A secondary low will track along the NC/VA border before exiting off the coast. The warm front from Tue will have lifted in VA by this time and the airmass is forecast to be much warmer under gusty southwest flow. Highs were raised to the mid 80s in the north and low 90s in the south. Coverage and severe threat of storms remains somewhat uncertain. The mid-level pattern shows a dry slot and capping inversion punching in during the day, which could limit overall coverage. The best chance appears east of US-1, especially along/east of I-95 where surface convergence may be maximized. Showers may be possible Thu as ensembles show a filament of vorticity moving through around the larger parent trough, but most areas should be dry. Otherwise, below average temperatures are forecast Thu through Sun under cooler northwest flow, with the most pleasant days Fri and Sat in the low to mid/upper 70s and dewpoints in the upper 30s to mid 40s. Lows are forecast to be in the mid 40s to low 50s Sat morning. While the weekend forecast is currently progged to be dry, there are some ensemble clusters that would indicate the trough pattern may break down sooner and favor some MCS potential late Sun or early next week. Given the model spread at this time frame, overall predictability on this is currently low. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... As of 725 PM Sunday... VFR conditions will hold across central NC terminals over the next 24 hours. There will be a few cirrus from time to time, but overall a mostly clear forecast. Looking beyond 00z Mon, VFR clouds will spread in from the west Monday night. Scattered to numerous showers and storms are possible Tue through Wed morning, lasting into Wed afternoon in the E, and a period of sub-VFR conditions with gusty/shifting winds is possible in and near any storms. There is also a chance of late-night/early- morning sub-VFR fog/clouds both Tue and Wed morning. And low level wind shear is possible Tue overnight into Wed morning, with gusty winds expected Wed afternoon/evening. VFR conditions should return for Thu-Fri. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...KC SHORT TERM...Hartfield LONG TERM...Kren AVIATION...Badgett/Hartfield