862 FXUS62 KRAH 050828 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 428 AM EDT Thu Jun 5 2025 .SYNOPSIS... A developing area of low pressure along the GA/SC coast will track northward over eastern portions of the Carolinas through tonight, then shift off the southern Mid-Atlantic Coast on Friday. && .NEAR TERM /TONIGHT/... As of 350 AM Thursday... * Isolated to widely scattered instances of flash flooding possible * Conditional/low-end threat of a short-lived tornado Overview: A developing area of low pressure along the GA/SC coast will track northward over eastern portions of the Carolinas through tonight, then shift off the southern Mid-Atlantic Coast on Friday. Tropical moisture, featuring PWATs of 2-2.25"(99th percentile), will support increasing showers from the south between 09 to 15z. Rain may become heavy at times during the afternoon and early evening, with scattered thunderstorms also possible, especially across the Sandhills and southern/central coastal plain, and to a less extent across the central Piedmont and northern coastal plain counties. Heavy Rain/Flooding Threat: Temperatures will be tempered by widespread low cloud cover and rain, but increasing BL dewpoints into the upper 60s to lower 70s and modest heating will support the development of weak buoyancy of 500-1000 J/KG of MLCAPE during the afternoon. This instability will align with the arrival of a weak sfc circulation into the area. Combined with near record PWATs and enhanced low-level convergence along the sfc wave, locally enhanced rainfall totals are likely. HREF guidance suggests precip totals could reach 2-3"(neighborhood probabilities ~40%), with isolated pockets of 3-5" possible (neighborhood probs ~20-30%). These higher totals and flooding potential are most likely across the Sandhills and southern coastal plain counties, though such maxima can easily shift on mesoscale variability. Severe Threat: Despite generally weak deep layer flow, wind profiles will veer significantly in the 0-3km layer, supporting clockwise- curved hodographs and 150-250 m2/s2 effective helicity. This would favor the potential for rotating updrafts and mini supercells particularly from 12 to 18z, when low-level shear/helicity is maximized. By afternoon, the shear is forecast to weaken. Still a conditional threat exists for a brief, weak tornado, mainly across southeastern portions of the forecast area. Temperatures: Widespread clouds and rain will modulate high temps; 75-80. Lows 65-70. && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... As of 355 AM Thursday... The surface low centered over the Outer Banks on Friday morning will move NE into the Atlantic during the day Friday, taking the plume of deep moisture and associated cloud cover with it. Subsidence and N/NW flow on the backside of the low should prevail for a good part of the day especially in eastern parts of central NC, which will somewhat limit moisture and instability. Looking upstream, an MCS will be moving east across the TN Valley into the southern Appalachians during the afternoon and evening, but it looks to stay west of central NC until the overnight hours. Still, there should be plenty of sunshine and good surface heating on Friday, with high temperatures reaching the upper-80s to 90 in many spots (mid-80s across the far NE Piedmont and northern/central Coastal Plain). Latest guidance depicts potential for 1000-2000 J/kg of SBCAPE across the west, decreasing farther east. So while any convection should be isolated, it can`t be entirely ruled out, particularly in the NW Piedmont where the 00z HREF indicates there is the best chance for showers and storms. POPs there are in the 30-40% chance range, decreasing to slight elsewhere. The NW is also where the SPC has a marginal (level 1 of 5) risk for severe storms, with damaging winds being the main threat. However, think this threat will be very isolated given only 20-30 kts of bulk shear at most, and most of the cells should be pulse-like in nature. What is left of the MCS will move across central NC early Saturday, but given it will be in a weakened state and the unfavorable diurnal timing, expect any precipitation with it to be minimal. It should still bring extensive cloud cover, keeping low temperatures mild, in the mid-60s to lower- 70s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 425 AM Thursday... Broad troughing over the Southeast US with embedded disturbances and moderate to strong instability will bring a very unsettled period from this weekend into Wednesday. Shower and storm chances are above climo each day, maximized in the afternoons and evenings. Saturday looks to feature yet another MCS moving east across the TN Valley, but again the remnant MCV doesn`t look to move through central NC until late Saturday night. Even still, a belt of stronger westerlies looks to be in place, with mid-level flow on the order of 30-40 kts. Instability also looks to be better than Friday across the whole region, with 1000-2000 J/kg of CAPE amid rich low-level moisture (dew points in the upper-60s to lower-70s) and high temperatures reaching the upper-80s to lower-90s. So SPC has introduced a Day 3 marginal (level 1 of 5) risk for severe storms across the whole region, with a slight (level 2 of 5) risk clipping our southwestern zones. Damaging winds still look to be the main threat. POPs are also higher than Friday, mostly in the high chance range. Saturday`s heat indices could also reach the upper-90s to lower-100s across the far SE. POPs increase further on Sunday to likely everywhere as a low over the OH Valley and associated shortwave help push a cold front towards our region. Favorable instability and shear mean another threat of strong to severe storms is possible. This cold front looks to fizzle out on Monday, and with mid-level height rises behind the departing shortwave plus weaker flow aloft, Monday could feature a relative minimum in shower/storm coverage. POPs are only in the slight to low chance range. However, this reprieve looks to be short- lived, as a more potent shortwave over the Great Lakes helps push the broad mid/upper trough over the Deep South farther east with increasing SW flow aloft over the Mid-Atlantic. This will also drag a cold front into the Appalachians. So POPs are back in the likely range on Tuesday, and more severe weather is possible. The troughing finally starts to weaken and lift into the Northeast US on Wednesday as it gets replaced by ridging farther west. Still, with the cold front stalled either over or NW of our region, more showers and storms will be possible. Given these cold fronts look to either remain to our NW or fizzle out by the time they reach us, expect high temperatures to remain near to slightly above normal from Sunday through Wednesday, generally mid-to-upper-80s. Lows will be kept mild due to extensive moisture and cloud cover, generally mid- 60s to lower-70s. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... As of 220 AM Thursday... A developing area of low pressure along the GA/SC coast will track northward over eastern portions of the Carolinas through tonight, then shift off the southern Mid-Atlantic Coast on Friday. Tropical moisture lifting northward in association with this system will support increasing showers from the south between 09 to 15z. Rain may become heavy at times during the afternoon and early evening, with scattered thunderstorms also possible, especially at KFAY, and to a less extent at KRDU and KRWI. Flight restrictions are expected to deteriorate to IFR at most terminals, with some brief periods of LIFR possible. If the heavier rain/showers remain east of the KINT and KGSO, those sites could remain MVFR or even experience low-end VFR conditions. Between 00 to 03z Friday, bulk of rain and storms will shift east of the area, with only isolated showers possible across the eastern terminals. As the area of low pressure shifts towards the coast, drier air on the back side of the system will allow the sub-VFR ceilings at KINT and KGSO to improve to VFR. However, ceilings at KRDU, KFAY, and KRWI ceilings are expected to remain LIFR to IFR until after daybreak Friday. Outlook: Scattered showers/storms will be possible around the Triad terminals Fri afternoon/evening. A series of fronts moving into and stalling over the region will bring an unsettled period Sat through Wed for showers/storms each afternoon and potential for sub-VFR fog/stratus each morning. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...CBL/MWS NEAR TERM...CBL SHORT TERM...Danco LONG TERM...Danco AVIATION...CBL/Hartfield