Area NWS Forecast Discussion
000 FXUS62 KILM 061611 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1210 PM EDT Mon Apr 6 2020 .SYNOPSIS... A warmup will begin today as high pressure moves off the coast. Upper level disturbances may bring isolated showers and storms this afternoon and again on Tuesday. A cold front arrives late Thursday with a return of seasonable weather for the weekend. && .UPDATE... Hi-res models continue to show scattered development of thunderstorms this afternoon despite dry air in both the surface layer and cloud layer. While there is expected to be some storm coverage this afternoon, their coverage should be more isolated than models are depicting. Coverage is likely to be concentrated to areas in NC with lingering showers possible in areas of NE SC. A few storms could reach the severe threshold (details below). && .NEAR TERM /THROUGH TUESDAY NIGHT/... Latest sfc analysis shows 1020 mb high pressure centered directly over the area with a cold front just off to the NW. The front is expected to stay N of the area today, allowing for temps to remain above normal...highs in the lwr 80s most inland areas with 70s right at the coast. Despite the front staying off to the N, small perturbations in the WNW flow aloft will allow for the development of shras/tstms this aftn/eveng. Still capped PoPs in the chance range though due to plenty of dry air in mid levels limiting coverage. Any tstms that do form have the potential to be strong to severe, due to very steep low-level lapse rates and 35-40 kt deep layer shear. The greatest threat is over NC where the rain chances are highest. Any rain dissipates overnight tonight, with temps only bottoming out in the upr 50s to lwr 60s. Not much change in the overall pattern into Tue. SPC has the entire area in a Marginal Risk for severe wx, and will highlight this threat in the HWO. Again...coverage will just be isolated to scattered, but any storms that do form have severe potential due to the favorable parameters in place. Temps Tue very similar to those of today...highs in the lwr 80s inland. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... A weak southern stream shortwave will pass south of the area Tue night into Wed. Southern portions of the forecast area may see isolated showers linger into the first half of Tue night, but then the region will dry out. Clouds in the area early Wed decrease through the day and into Wed night as deep west to northwest flow sets up. Inversion around 4k ft suggest minimal chance for convection during peak heating. Temperatures will run well above climo through the period with region under the influence of surface high off the southeast coast and along the northern edge of a flat ridge over the Gulf States. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Northern stream mid-level trough will push a cold front into the region Thu night. Ahead of the front strong warm advection will keep temps well above climo. Fropa appears dry at this time, due to an absence of moisture. Following the front, cool surface high builds in from the northwest as the front stalls along the Gulf Coast and across northern FL. Potential for weak southern stream shortwave and frontal wave moving east late week into early next week with potential for unsettled weather along or just off the coast. However, confidence is extremely low at this juncture. - Above climo temperatures Thu dropping below climo Fri and Sat following passage of dry cold front Thu night. - Rainfall chances appear limited for much of the long term with perhaps best chance being late Sat or Sun. - Temps above climo Sat night and Sun as warm advection sets up. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... A weak disturbance is expected to drop southeast into the CWA by late afternoon. Storms are expected to be isolated, however storms that due form could have gusty winds. West southwest winds this afternoon will diminish tonight, however some speed shear is expected just off the deck. Extended Outlook...Flight restrictions again possible with isolated TSTMs on Tuesday. Flight restrictions lift mid-week, and look clear through at least Thursday. && .MARINE... Sub-Small Craft Advisory conditions expected through at least Tue as sfc high pres slides off the SE coast and a frontal boundary remains just off to the N. Expect primarily SW flow of 10-20 kt through Tue, with 2-4 ft seas, which includes a 1-2 ft 12 second Easterly swell. Southwest flow will persist Tue night through Thu night with pinched gradient Tue night relaxing Wed into Thu before tightening back up later Thu. Period of strongest southwest flow will be Tue night and late Thu into Thu night. Seas 3 to 5 ft will be possible with the strongest winds Tue night and Thu night, otherwise 2 to 4 ft is more likely. Seas will be mostly made up of south to southwest wind wave with a weak easterly swell component at times. Passage of dry cold front Thu night into Fri veers winds to northwest for Fri. Offshore component will knock seas back to 2 to 3 by afternoon. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...Coastal Flood Advisory until 11 PM EDT this evening for NCZ107. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...21 NEAR TERM...MAS SHORT TERM...III LONG TERM...III AVIATION...43 MARINE...MAS/III