Scientific Forecaster Discussion

000 fxus62 kilm 200106 afdilm Area forecast discussion National Weather Service Wilmington NC 806 PM EST Tue Feb 19 2019 Synopsis... high pressure will wedge in from the north through Wednesday bringing with it much cooler temperatures and the threat for light rain or drizzle. A front stalled south of the area will track northward as a warm front, crossing the area by Thursday. The mild temperatures on Thu will be temporary as a cold front will quickly follow with yet another wedge of high pressure. Cooler temps, overcast skies and the threat of light rainfall will occur Fri thru Sat. A warm front will track northward across the area by sun with widespread 70s expected for the latter half of the upcoming weekend. && Near term /through Wednesday night/... As of 330 PM Tuesday...latest surface analysis shows 1038 mb high pressure centered over upstate New York with a stationary frontal boundary off the Florida coast. The cad setup favors NE winds and a cloudy sky tonight. As far as chances for rain, aside from a scattered sprinkle early this evening, isentropic lift increases after midnight when pops ramp up from west to east across the area. Any precip will be light at the onset, with only up to about a tenth of an inch expected tonight. The rain lingers into Wednesday, before a drying trend ensues from west to east Wednesday afternoon as the best moisture profiles and isentropic lift push off to the east. As for temps, a coastal trough is progged to approach the beaches during the afternoon hours. The front is not expected to make it too far inland during the day due to the strength of the cad, so generally favored the cooler NAM/met numbers inland (highs in the mid 40s to lwr 50s there), with some greater warming near the coast...upr 50s to near 60. There will be quite a gradient in temps and at this point it's tough to pinpoint exactly where it will setup. Patchy fog also possible during the day. Best chance for some inland propagation of sea fog is Wednesday night with the front still in the vicinity. Maintained slight chance to chance pops with some weak lift still over the area, but any precip will be light. Low temps similar to daytime highs Wednesday, with temps at night fairly stagnant or potentially rising slightly depending on the exact location of the coastal front. && Short term /Thursday through Friday night/... as of 345 PM Tuesday...The Wedge will break down long enough on Thu to allow some temporary milder temperatures ie. 70s, for daytime highs across the majority of the ilm County Warning Area. The far northwest portions of the ilm County Warning Area may hold in the 60s due to The Wedge and cloudiness holding on longer. The immediate coast will even break 70 with the exception for locations exposed to a SW wind that is considered an onshore flow given the coastline configuration ie. Along the Brunswick County coast. Overall, temps running 10+ degrees above normal. The frontal boundary will do an about face and drop back to the south as a fresh 1035mb high with Canadian origins, ridges down the east side of the Appalachians. The accompanying cold air advection will also aid the ridging with, you guessed it, another wedge ie. Cad, sets up shop for Thu night thru Fri night. Looking at stratiform low clouds, patchy to areas of light rain or drizzle and fog accompanied by a brisk NE to east-northeast wind. The moisture depth is similar to the previous wedge except the upper ridging extending from the Bahamas is slightly flatter which results in a more west-southwest to east-northeast rainfall orientation as opposed to the SW to NE. The models prog slightly hier accumulated rainfall amounts for this period which is basically around one quarter of an inch or less. And no pcpn type issues just not cold enough. Temps during this 2nd wedge will run 5 to 10 degrees below the norm. && Long term /Saturday through Tuesday/... as of 345 PM Tuesday...for Sat into sun time-line, will be looking at the breakdown of another cad wedge. With sun having the potential to observe widespread 70s after the previous couple of days with highs in the 50s. Rainfall will remain on the light side Sat into sun with mainly light rain or drizzle. Could see embedded showers along the coastal trof/front as it lifts inland and eventually north of the forecast area by sun. Going into early next week, the longwave pattern aloft modifies. Whether this modification becomes permanent or resorts back to the pattern of the past couple of weeks is still in question. What does occur is a break in these cad/wedge events for the forecast area. This the result of the upper ridge extending from the Bahamas flattening out. In addition, the upper trof over the desert SW also flattens out. This after the last S/W trof rotating around it, basically takes/picks up this trof and both together track to the NE, toward the Great Lakes by the end of this period. && Aviation /01z Wednesday through Sunday/... as of 0z....currently VFR with scattered light rain over the inland areas. Expect rain to become more widespread shortly after midnight and low level moisture is advected from the south with isentropic lift. Ceilings will begin to fall shortly after to MVFR overnight from south to north, before IFR ceilings develop tomorrow morning. Inland terminals could see LIFR cigs. Look for visibilities to drop to 3-4 miles tomorrow, especially within stratiform rain. Rain chances begin to decrease in the last few hours of the taf period. Winds to remain strong out of the northeast overnight around 10kts. For inland terminals, winds will die down at end of taf period and become more northerly. Wind forecast for coastal terminals will be more tricky, depending on timing and how far inland a coastal front GOES. Look for easterly winds at coastal terminals tomorrow afternoon before becoming light and variable. Extended outlook...likely IFR on Wednesday. Unsettled weather Wednesday evening through Sunday with continued IFR/LIFR conditions possible at times. && Marine... as of 800 PM Tuesday...marine statement has been issued regarding low water action stage offshore related to more extreme tidal behavior with the full moon. Astronomical low tides will result in abnormally low water levels overnight. The lowest levels will occur between midnight and 3 am Wednesday, dropping between 1 and 2 feet below the normal low tide. Boaters should use spotlights at night if navigating the Intracoastal Waterway where the width of inlets and entrances become narrower. Exposed sand bars and shoaling will be noticeable. Remain near the intracoastal waterway's center channel line to avoid running aground. If navigating near-shore on the ocean, keep in mind, the surf zone usually extends farther offshore during very low water levels. Tonight thru Wednesday night... A Small Craft Advisory remains in effect through Wednesday night. Strong high pressure to the north will allow for 20-30 kt NE winds tonight, with occasional gusts up to 35 kt possible especially over the southern coastal waters. Seas up to 7 ft out 20 nm. Seas remain elevated through Wednesday night hence the Small Craft Advisory, while winds decrease on Wednesday and Wednesday night with a coastal trough in the vicinity. Expect variable directions depending on where exactly the front is located, with speeds mainly under 15 kt. Sea fog expected as well, potentially dense at times, Wednesday afternoon through night. Thursday thru Sunday... The Small Craft Advisory will have ended by daybreak Thu but seas will remain somewhat elevated during the day on Thu eventhough winds will have switched to the SW. The SW winds over adjacent land areas will likely run up to 5 kt hier especially if enough insolation occurs. The seas will subside-some but winds further offshore will have been east-southeast to south-southeast across a decent fetch which will have produced an 8 to 9 second period east-southeast swell that will continue to push into the local waters thruout this period. The hier dewpoints during Thu into Thu evening may be enough to produce sea fog over the waters but at this point have limited the dense sea fog to patchy in the fcst. The next cad or wedge Thu night into Sat will result in similar conditions to the ongoing one attm. The ridging and cold air advection surge combine late Thu night thru Fri to produce Small Craft Advisory conditions from both winds and significant seas during the Fri aftn thru Sat morning time-line. The inverted trof/coastal trof over the offshore waters will push toward the coast while also lifting northward during Sat into Sat night. Winds will drop off as they veer to the southeast to an eventual and overall SW direction on sun. Gusty SW winds combined with continued elevated seas may breach Small Craft Advisory levels during sun. && Tides/coastal flooding... as of 800 PM Tuesday...astronomical high tide associated with the full moon will create larger swings in The Tides the next several days. Tides tonight will fall between 1 and 2 feet below mean lower low water, which will create additional chances for running aground with exposed sand bars and shoaling. Minor flooding to area beaches is also expected Wednesday morning. Low lying water front streets, swashes and tidal creeks will see minor flooding. Additional minor flooding will be possible beyond Wednesday morning with the next several high tide cycles. && Ilm watches/warnings/advisories... SC...coastal flood advisory from 7 am to 10 am EST Wednesday for scz054-056. NC...coastal flood advisory from 7 am to 10 am EST Wednesday for ncz106>108-110. Marine...Small Craft Advisory until 7 am EST Thursday for amz250-252- 254-256. && $$ Synopsis...iii near term...mck short term...dch

Return to Current Conditions


Weather Apps


Weather Underground Apps
Check out our wide variety of mobile and setup applications.

Weather Underground Applications

Top of Page

© Copyright 2019
The Weather Company, LLC