FXUS62 KRAH 190520 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 120 AM EDT Tue May 19 2026 .WHAT HAS CHANGED... * The backdoor front arrival on Thu has trended slower, thus highs have been nudged upward for Thu. && .KEY MESSAGES... As of 120 AM Tuesday... 1) Hot and mainly dry through Wednesday. 2) Rain chances will return Thu, with daily above-normal chances persisting into early next week. The highest rain coverage and amounts are still expected to be Thu afternoon through Thu night. && .DISCUSSION... As of 120 AM Tuesday... KEY MESSAGE 1... Hot and mainly dry through Wednesday. Confidence remains quite high that we'll see continued anomalously hot weather, near-record or record-breaking in some cases, as strong ridging near the surface through the mid levels persists. The latest HREF carries through with what the previous days' LREF indicated, with mid level heights over NC in the 99th percentile through tonight and just a slight reduction to 95th percentile for Wed. And 850 mb temps will sit above the 95th percentile for the date, as low level thicknesses hold around 20 m above normal with deep daily mixing. Highs will continue to be in the low-mid 90s across central NC both Tue and Wed. The deep mixing and resulting drop in afternoon dewpoints into the 50s is what will keep our max heat index values under 100F, however our daily Heat Risk will peak at level 2 of 4 (Moderate), with isolated patches of level 3 of 4 (High), suggesting heat that is unusually intense and which could lead to heat illnesses, especially for those most sensitive to heat. And given the generally light breeze with lots of sunshine each day, the WBGT index will be elevated as well. As such, in addition to frequent water breaks, spending time resting in the shade is encouraged, especially for those working or exercising outdoors. KEY MESSAGE 2... Rain chances will return Thu, with daily above- normal chances persisting into early next week. The highest rain coverage and amounts are still expected to be Thu afternoon through Thu night. A potent shortwave trough tracking through eastern Canada and New England Wed/Thu will take a cool high pressure area across the northern Great Lakes and St Lawrence Valley, pushing a backdoor front southward through the Mid Atlantic region. Models have been trending slower with the front's arrival, bringing it into our northern areas early-mid Thu afternoon before pushing the front just S of the CWA early-mid Thu evening. This slowing will allow for warmer prefrontal temps, particularly across the S where the cooler air will be last to arrive. Expect highs from the low-mid 80s near the VA border and Triad to around 90 in the Triangle and low 90s (and isolated mid 90s) in the far S. Given the slower frontal push, expect minimal pops prior to midday Thu, with just slight shower chances Wed evening in the far N. As the mid level ridge breaks down allowing for an increasing mid level southwest flow (although initially still fairly weak), minor perturbations aloft will track from Baja California across the S Plains into the S Appalachians. An increasing low level tap of moisture from both the Gulf and Atlantic will push PW levels above normal, and with increasing isentropic upglide along the southward- moving front, pops are likely to ramp up quickly Thu afternoon, continuing well into the night. Strengthening SW 850 mb flow will force increasing ascent along the front, which could lead to isolated heavy rain totals and propagating cells on the SW side of convection. The overall CAPE and deep layer bulk shear will be on the low end Thu, thus no severe weather is expected, and thunder may be limited to just isolated. By Fri, the surface high to our N will be shifting E off the Northeast coast but still extending down through central and W NC as a damming wedge. While the transitory nature of the parent high should curb the duration of this event, there should still be enough clouds and overrunning flow atop the low level CAA for high surface- based stability with limited insolation, favoring cooler temps, esp over the Piedmont where highs will be held in the low 70s, while SE areas of the CWA along and SE of the wedge front see highs in the mid 80s. As is always the case with even weak or brief wedge events, the greatest temp uncertainty will be either side of the wedge boundary, thus confidence in Fri highs remains low. The wedge should be vulnerable to dissolution by Sat, allow temps to rebound back above normal, although not to early-week heat levels. With a persistent long and wavy SW flow from N Mexico into the Carolinas combined with high low-level moisture flux from the Gulf and Atlantic through the weekend and into early next week, our rain chances are expected to remain above normal, focused on each afternoon and evening Fri through Mon. This would be a welcome respite from our ongoing drought conditions. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 700 PM Monday... Prevailing VFR conditions are expected through the 24 hr TAF period 00Z/19 May. Outlook: There is a chance of low stratus both Wednesday and Thursday mornings. Then scattered to numerous showers and a few thunderstorms are expected Thursday surrounding a backdoor cold frontal passage and breezy NE winds. Brief classical CAD will likely bring sub-VFR cigs to all terminals behind the fropa that will likely persist into Fri, especially in the typical CAD regime at INT/GSO and potentially RDU. There is a chance of showers/storms through the weekend with daily MVFR to nightly IFR conditions possible. && .CLIMATE... Record High Temperatures: May 19: KGSO: 96/1911 KRDU: 95/1962 KFAY: 96/2022 May 20: KGSO: 95/1917 KRDU: 96/2022 KFAY: 99/2022 May 21: KRDU: 96/1941 KFAY: 99/1941 Record High Minimum Temperatures: May 19: KGSO: 68/2018 KRDU: 70/2022 May 20: KGSO: 68/2022 KRDU: 69/2019 KFAY: 71/2022 May 21: KGSO: 67/2022 KRDU: 71/1898 KFAY: 71/2025 May 23: KFAY: 72/2011 May 24: KGSO: 69/2019 KRDU: 70/2011 KFAY: 72/2000 May 25: KRDU: 71/2019 KFAY: 71/2019 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Hartfield AVIATION...Badgett/AS CLIMATE...RAH