FXUS62 KILM 051821 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 121 PM EST Tue Mar 5 2024 .SYNOPSIS... High pressure will lose influence through this evening and tonight as the next storm system approaches. This will bring rain for tonight into Wednesday. High pressure returns for Thursday and Friday before the next round of rain arrives Friday night into Saturday. High pressure follows behind a strong cold front early on Sunday. && .UPDATE... Forecast remains largely on track with mainly sunny conditions boosting temperatures into the upper 60s to low 70s early this afternoon away from the immediate coast. High cloudiness remains thin enough that additional warming by 1-3 deg seems probable through peak heating. Onshore flow has permitted a distinct sea breeze to advance inland, with a thin line of cumulus visible where the strongest convergence exists. A shallow cumulus field inland will continue through peak heating before quickly collapsing as insolation decreases and high cloudiness increases in thickness. && .NEAR TERM /THROUGH TONIGHT/... Low pressure has moved over eastern Virginia and should continue to lift northeastward and away from the Carolinas. The back edge of the swirl of low clouds associated with low should move out of southeastern North Carolina by daybreak, leaving skies mostly sunny for the morning hours. Increasing cirrus will overspread the area this afternoon ahead of the next synoptic low already beginning to take shape across Louisiana. Given yesterday's considerable cold bias I had with high temperatures, I'm boosting forecast highs to near the upper edge of the guidance ensembles with mid 70s expected for all locations away from the beaches where a weak seabreeze should hold those locations 65-70 degrees. The stream of Gulf moisture will deepen with time tonight with skies becoming completely overcast by midnight across the Pee Dee region. Models have slowed a bit with their depiction of a shield of rain with some embedded heavier showery elements arriving from the southwest. By sunrise on Wednesday I still expect rain to cover the Pee Dee region, but it may not reach the Cape Fear area until after sunrise. Due to increasing clouds forecast lows are in the mid to upper 50s. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A rather disorganized shortwave will be pushing low pressure northeastward through the area on Wednesday. Whatever light isentropic rain that may still be around first thing will give way to some more dynamically forced showers of moderate intensity and about categorical-worthy coverage. Lapse rates still don't look so great for thunder but the 'isolated' modifier for convection still hard to argue with especially for areas east of the surface low. PW values will range from 1.3-1.5" according to most guidance but given the moderate strength of the forcing QPF prospects are close to half of these values, most of which should fall by midday. Deep layer moisture will be offshore by afternoon but lingering low level moisture paired with a few vorticity centers traversing the area call for lower POPs to continue. The main trough axis swings through around midnight after which time the rain should shut off completely. The mid level flow in place on Thursday will bring a fair amount of sunshine as PW values drop to 0.75". && .LONG TERM /FRIDAY THROUGH MONDAY/... Guidance continues to slow a bit with the progression of the next system late in the week and given the mid level ridge off of most of the East Coast this seems perfectly plausible. As such Friday now appears to be rain-free during the daytime hours. POPs will then increase Friday night. Trajectories out of the Gulf and less so, the Bahamas should favor a very high chance for rain and perhaps some appreciable QPF, the latter slightly limited by a good eastward progression of the system in the low levels. Saturday will also be quite breezy, with some good gusts possible in pockets of moderate rain due to downward momentum transfer. Cool and dry advection in the wake of Saturday's system keep the area dry Sunday and knock temperatures down to climo if not a bit below with some very minor recovery possible as early as Monday. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... VFR conditions are expected through the remainder of today and into the first half of tonight as clouds lower/thicken and precipitation approaches from the southwest and southeast. Showers begin spreading in from the southeast with more steady rain spreading in from the southwest after midnight while ceilings quickly lower through MVFR to the IFR-LIFR range before sunrise. Visibilities also fall as rain intensity increases and sea mist/fog spreads into the coastal terminals due to increasing dewpoints moving over the chilly shelf waters. A warm front should lift through around or just beyond the end of the 18Z TAF period, behind which rain coverage will decrease, visibilities will increase, and ceilings should lift at least out of LIFR territory. Extended Outlook...MVFR to IFR ceilings appear likely to persist into Wednesday night with MVFR to IFR fog possible due to light winds and excess low-level moisture. High pressure building in on Thursday will bring improving conditions which should return to VFR by noon and continue through Friday. Another storm system will bring rain Friday night through Saturday, with additional ceiling and visibility restrictions likely. High pressure should bring a return to VFR on Sunday. && .MARINE... Near Term (Through Tonight)... Weather conditions should be almost ideal on the coastal waters today. Low pressure has shifted north across eastern Virginia and a weak ridge of high pressure will cover the coastal Carolinas. This supports a forecast of light winds through this evening. Wind directions should initially be offshore this morning, but will turn onshore around noon as the high moves overhead and a weak seabreeze develops. Attention will then shift to low pressure developing along the Gulf Coast that will spread clouds across the area tonight with rain becoming possible late. Seas ranging from 2-4 feet in a 10 second east-southeast swell will only begin to build higher late tonight due to increasing southeast wind. Wednesday through Saturday...An approaching cold front and upper disturbance will bring increased winds and seas Wednesday, the latter ramping up to advisory levels. Visibility-limiting rain and sea fog also appear to further worsen conditions. The veering winds associated with the approaching cold front appear to divert the swell energy that had been reaching the area up til Wednesday just outside of the forecast zones and then further offshore following FROPA later Wednesday. Much lighter and veering winds Thursday should allow headlines to drop. Flow turns back to southerly on Friday as the next system gears up to approach from the west. This system will have good support aloft and so have enough of a surface reflection along the front to ramp either winds or seas back to advisory levels Friday night or Saturday. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...ABW NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...ABW MARINE...ILM