Area Forecast Discussion
Issued by NWS Wilmington, NC
Issued by NWS Wilmington, NC
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085 FXUS62 KILM 081932 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 332 PM EDT Wed May 8 2024 .SYNOPSIS... A typical summer time pattern will lead to daily showers and thunderstorms through Friday, sparked by a series of shortwaves moving across the area. A cold front Friday night will bring much cooler and drier air for the weekend and start of next week. Rain chances return for the middle of next week. && .NEAR TERM /THROUGH THURSDAY/... A Severe Weather Watch has been issued for our inland counties (mainly along I-95) through 10pm this evening. Convective activity has been over-performing just east of the Appalachians this afternoon, and will continue moving east-southeastward ahead of a weak shortwave. How far into our CWA storms get is still questionable. Chances are best along I-95 with lower confidence closer to the coast where drier air lingers aloft (as seen by shallow diurnal cu field). MLCAPE values are already above 2000 J/kg, with MUCAPE over 3000. Any storms that do make it into our area have a decent chance of becoming severe, with large hail and strong winds main threat. Well above normal low temps tonight around 70F with partly cloudy skies. A cluster of storms, possibly MCS, will be moving across the Carolinas overnight. Given time of day, any workover of the environment this evening, and storms moving over the mountains, not expecting the cluster/MCS to maintain strength as it reaches our area. Any rain that does move through overnight/early morning has low chance for thunder and even lower chance of any severe threat. Yet another shortwave/storm cluster is progged to move across the Southeast tomorrow morning into the afternoon, this time with more of a focus for our northeast SC counties. Our entire CWA is in a slight risk (2 out of 5) for severe weather again Thursday. Confidence isn`t the greatest - will have a better idea after any activity moves across through morning and if there is lingering cloud coverage early Thursday. Forecasted CAPE isn`t as abundant as today, but still near 2000 J/kg Thursday afternoon. Bit more shear Thursday, with winds over 30 kts not far above the surface (which will also contribute to a breezy day). High temps Thursday near 90F. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... Flat flow aloft will move a series of weak shortwaves across the area. The first moves overhead Thu night with any associated convection shifting offshore during the evening hours Thu. Post wave subsidence arrives Thu night, ending any convective threat for the remainder of the overnight. Some clearing Thu night, but still at least some cloud cover will hang around into Fri. Forecast soundings show the post wave subsidence and dry air very well, with precipitable water dropping under 1" Thu night. Strong southwest flow Fri morning ramps up moisture, increasing precipitable water to near 1.7" for early afternoon. Surface based instability "only" peaks around 2k J/kg, due to cloud cover and the mid-level support, associated with the second shortwave, arriving around midday instead of around peak heating. Low level jet will be 35-40kt at 3k ft on Fri with LIs around -6. All of this suggests the potential for an isolated strong to severe storms in the area midday to early afternoon Fri. The big question remains down to the timing. Several factors will need to come in line to warrant more than the current marginal risk. If timing were to be delayed a few hours and parameters instead came in line mid to late afternoon, the severe threat could be higher. Something to keep an eye on. The second shortwave moves east of the area late Fri afternoon with a cold front crossing the area in the evening. A significant amount of cool/dry air moves in Fri night into Sat with temps dropping from above climo temps Thu night and Fri to near climo by Sat morning. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Much cooler and drier for the weekend and start of next week following the passage of a cold front late Fri. Weak troughing at 5h on Sat is reinforced by shortwave crossing the Mid-Atlantic Sat night into Sun. This feature helps drive a dry, secondary cold front across the area Sun morning. Front is dry because precipitable water drops under 0.50" Sat and remains below the 10th percentile, about 0.70", into Mon afternoon. Additionally, most of the dynamics with the shortwave pass north of the area. Moisture does start to increase late Mon as surface high slips off the coast and weak shortwave ridge at 5h shifts offshore. Increasing southwest flow, at the surface and aloft, ahead of southern stream shortwave pushes pwats over 1.8" Tue into Wed. Although forcing is limited Tue/Wed given the path of the shortwave Tue/Wed, instability, decreasing heights and abundant moisture will lead to elevated rain chances for the middle of next week. Temperatures will be near to below climo through Wednesday. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... Predominantly VFR through this TAF period. Breezy SW winds will weaken around sunset. There is still a chance for thunderstorms to move into the area late afternoon/early evening (around 21z-2z), mainly along and west of I-95, but confidence is low in terms of where any storms may impact. Have a few hours of VCTS at KLBT during this timeframe. Any storms that do develop may produce hail and/or strong winds. A second round of precipitation possible overnight into tomorrow morning as a cluster of storms weakens as they approach our area, with fairly low chance of thunder. On Thursday, may be lingering cloudiness in the morning due to any overnight activity. There is a chance for ceilings to be MVFR across inland southeast NC early Thursday, but not confident enough to include in TAFs at this time. Southwest winds will be breezy tomorrow, with gusts up to 25-30 kts possible towards end of TAF period. Thunderstorm chances pick up again tomorrow afternoon, though at this time confidence is low in timing and coverage so have only included VCTS for inland TAF sites for now. Extended Outlook...Threat of more widespread strong convection with periodic flight restrictions possible later Thu into Fri ahead of a strong CFP. High pressure to prevail late Fri into the weekend with VFR dominating. && .MARINE... Through Thursday: Southwest winds continue to prevail across the local coastal waters around offshore high pressure. Tightened gradient tomorrow afternoon will increase winds a bit, with SW winds sustained around 15-20 kts and gusts to 25-30 kts possible for a few hours tomorrow afternoon. Given the brief window and forecasted sustained winds below 25 kts, have held off on any SCA during this forecast package. Seas around 4 feet tonight through tomorrow, with a few 5 footers Thursday afternoon, primarily as a SSW fresh swell and a persisting weak E long period swell mixed in. Chance for thunderstorms to move off the coast over the waters late Thursday afternoon. Thursday night through Monday: Southwest flow around 20 kt Thu night into Fri will become offshore late Fri evening as cold front moves across the waters. Offshore flow 15-20 kt Fri night drops to around 10 kt Sat. Winds briefly back to southwest later Sat but then a dry cold front moves across the waters Sat night. Winds briefly increase to 10-15 kt ahead of the front, but then drop back to 10 kt Sun and stay 10 kt or less through Mon. Offshore flow returns and persists into Sun night. Surface high to the north slowly shifts east early next week, with offshore flow veering to northeast late Sun night into Mon. Onshore flow sets up Mon with weak gradient allowing the sea breeze to be the main driver of wind direction. Seas 3-5 ft Thu night and Fri starts to decrease Fri night as offshore flow sets up, ending up 2-4 ft daybreak Sat. Seas continue trending Sat, dropping to around 2 ft and staying around 2 ft through Mon. A weak easterly swell will persist through Monday, but the wind wave will be dominant. Initially it will be the southerly wind wave, but with offshore flow developing Fri night the wind wave will be more northerly. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ106- 108. Coastal Flood Advisory from 10 PM this evening to 1 AM EDT Thursday for NCZ107. SC...Beach Hazards Statement until 8 PM EDT this evening for SCZ054- 056. MARINE...None. && $$ SYNOPSIS...ILM NEAR TERM...VAO SHORT TERM...III LONG TERM...III AVIATION...VAO MARINE...VAO