Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/23/22

National Weather Service Raleigh NC
1158 PM EDT Tue Mar 22 2022 .SYNOPSIS... High pressure will continue to shift offshore through tonight. A strong storm system will bring widespread showers and potentially severe thunderstorms to the region on Wednesday, followed by a cold front on Thursday. && .NEAR TERM /TONIGHT/... As of 935 PM Tuesday... High pressure was located off in the western Atlantic as strong low pressure tracks NE through the Midwest this evening. The trailing cold front and associated severe weather extended south through the TN and MS Valley regions. Mid and high cloudiness continued to increase across western NC, with mostly high clouds over central and eastern NC. Low level flow and moisture continue to increase from the south. Cloud bases will lower and thicken in the west overnight. This will keep temperatures rather warm with lows in the mid 50s to near 60. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... As of 400 PM Tuesday... ...Risk of isolated strong to severe storms and locally heavy rainfall remains for Wed/Wed night... Wed/Wed night: Large upper level low centered over the mid/upper region of the Mississippi Valley dominates much of the CONUS with a weakening ridge over the Mid-Atlantic will all continue to move east over the next few days. At the surface, an associated surface low centered over MO/IL with an extended occluded front into KY branching off a warm front over southern NC and a cold front down along AL and into the Gulf of Mexico. The warm front is expect to lift northward early Wednesday giving way to the strong cold front approaching the region. Showers are expected to begin pre-sunrise in the NW Piedmont and continue to spread southeast during the morning commute. With limited CAPE in the morning hours, expect only showers and isolated thunderstorms before noon. As instability increases in the early afternoon, especially in the southern portion of the Sandhills region, even only with a few hundred J/kg, the threat for severe thunderstorms increases. The primary threat as these storms come from the south and east, are damaging wind gusts, but cannot rule out the potential for an isolated tornado or two either. Some training, or lingering, storms and stronger convective bands are possible and with slow moving storms along with above daily record PWs up to 1.9 inches (the normal is around half and inch) locally heavy rainfall is also possible, which may cause river rises and flooding in some areas. The threat for severe storms will slowly diminish as the instability axis shifts east. In the overnight hours there continues to be chance of showers and isolated storms but the severe threat is expected to be over shortly after midnight. Thurs/Thurs night: Chance of showers and isolated storms will continue through the day Thursday with a a chance of another round of thunderstorms along the Coastal Plain Thursday afternoon/ early evening. The severe threat is greatly diminished by this point as the CAPE has moved offshore. The weak cold front will make its way across the area Thursday with chance of showers continuing through the day Thursday with a chance of another round of thunderstorms along the Coastal Plain Thursday afternoon/ early evening. The showers are expected to begin to clear out of the NW Piedmont beginning early Thursday evening and progressing eastward and completely clearing the region by Friday morning. Between Wednesday and Thursday rainfall amounts are expected to be near 0.75 inch in the NW up to 2 inches in the SE Coastal Plain. Temperatures will be in the low 70s north to the upper 70s in the south on Wednesday, with slightly cooler temps on Thursday. Lows on Wednesday night will be in the 60s and after the cold front moves through lows will be in the mid/upper 40s on Thursday night. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 330 PM Tuesday... In the upper-levels, flow on Friday will remain northwesterly behind the exiting trough, then a shortwave will dig from the Midwest on Friday to the Mid-Atlantic on Saturday. A large ridge across the West will slowly push east early next week, with northwesterly flow lingering across our region through the period. At the surface, an Appalachian lee trough will develop across the region on Friday, then a cold front will move from the OH Valley southeast across the area on Saturday. An Appalachian lee trough then redevelops Sunday and Monday afternoons, with surface high pressure building across the Southeast on Tuesday. Dry weather is expected on Friday behind the exiting system, then isolated showers may develop on Saturday with the passage of the next cold front. However, a lack of sufficient forcing and moisture will likely limit shower coverage to more of the Mid-Atlantic. Dry weather will then prevail early next week, with NW flow aloft. Cold air advection will keep highs around 5-10 degrees below normal through Monday, then surface flow shifts southerly on Tuesday and highs rise to just above normal by mid-next week. Low temperatures will also dip to below seasonal normals, with widespread 30s expected this weekend, and slightly higher temperatures into the middle of next week. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... As of 1158 PM Tuesday... VFR conditions, with mostly high level cigs will hold through sunrise Wed morning. But a deterioration is expected thereafter, from W to E, through Wed, as a strong storm system moves in from the W. MVFR cigs are expected in the Triad by 13z, then INT/GSO will see cigs drop to IFR and occasionally LIFR as showers and isolated storms move in by 15z, persisting through the 24 hr TAF period, although showers/storms will start to taper down by 03z at INT/GSO. Winds will strengthen from the ground up through the mid levels as well, with INT/GSO seeing sustained surface speeds from the S at 12- 18 kts gusting to 20-25 kts. To the E, everything will be delayed by a few hours, with RDU trending to MVFR cigs by 15z then to mostly IFR after 22z as showers and isolated storms move in by afternoon. Surface winds at RDU will also ramp up after 13z, from the S sustained at 12-18 kts gusting to 20-25 kts through the end of the period. Finally, further E, RWI/FAY will see periodic MVFR cigs today, but otherwise VFR cigs will dominate until after 22z, when these sites will have trend to MVFR then quickly IFR by 01z. Surface winds there will be S at 9-14 kts gusting to 15-20 kt after sunrise. While low level wind shear criteria is not expected to be reached this morning, Winds just aloft at 1500-2500 ft AGL will strengthen from the S and SSW to 35-40 kts this morning at INT/GSO and by mid afternoon further E, so aircraft handling may prove difficult given increased mechanical turbulence. Vsbys will be mostly VFR but drop to MVFR or briefly IFR within showers/storms, mainly this afternoon through evening. Looking beyond 06z Thu, showers/storms will continue to decrease at INT/GSO 06z-12z but will persist further E, with winds remaining strong and gusty, shifting to a more SW direction but still increasing with height overnight. Showers and isolated storms will continue to dominate through much of Thu at RDU/RWI/FAY, with surface winds decreasing gradually but winds aloft staying from the SW at 30-40 kt for much of the day. Rain and wind will trend downward W to E 21z-04z late Thu/early Fri, with VFR conditions likely to return by daybreak Fri. VFR conditions should dominate Fri- Sun, although brisk/gusty W winds are possible Sat. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Green/JJT NEAR TERM...PWB/JJT SHORT TERM...CA LONG TERM...JJT AVIATION...Hartfield