Area NWS Forecast Discussion
000 FXUS62 KILM 171433 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 933 AM EST Sun Feb 17 2019 .SYNOPSIS... Cool and cloudy conditions will prevail today, with patchy drizzle at times. Another cold front will bring a chance of rain tonight and Monday. A stalled front and increasing Gulf moisture will maintain unsettled conditions through the end of week. && .NEAR TERM /THROUGH MONDAY/... As of 930 AM Sunday...Cloudy and cool conditions expected today with a surface ridge in place across the Carolinas. The old front positioned across GA this morning will creep northward later today and tonight allowing for a nocturnal increase in temperatures. Meanwhile, a subtropical jet is spreading moisture from TX into the Appalachians. Isentropic lift at 295k is shown to increase across the Carolinas during today while lift at 300k increases more-so tonight. Based on the orientation of the isentropic lift the best rainfall chances will be inland areas today, then remaining areas tonight. During Monday, the deeper moisture shifts off the coast with the old front to shift back off the coast later in the day. Some clearing is expected as a result along with diminishing rain chances. Temperatures are expected to be well above normal ahead of the boundary. No major changes made to the current forecast today through Monday with the latest update. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... As of 3 AM Sunday...Period begins with front south of the area and expansive high building in from the Upper Midwest. Progressive flow aloft shifts the high over the Great Lakes Tue and the Northeast Tue night. This allows weak coastal trough to develop over the nearshore waters Tue into Tue night. Initially isentropic lift will be weak and moisture below 7k ft is limited. On Tue the influence of the high starts to weaken as low pressure starts to organize along the boundary in the Lower MS Valley. Clouds will thicken and lower on Tue with isentropic lift increasing late in the day. Light rain will slowly spread over the forecast area from southwest to northeast late Tue and Tue night. Forcing is not particularly strong and low level dry air will be reluctant to modify. Best rainfall chances will be late Tue night for most of the area. Cold advection and cloud cover will keep highs below climo on Tue but cloud cover and mixing will keep lows a little above climo both nights. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 3 AM Sunday...Unsettled conditions will be the theme of the long term with the forecast area in a wavering frontal zone through Saturday. Mid-level ridging over the Bahamas and Southwest troughing will prevent any features really capable of removing the frontal zone while allowing a series of developing low passage through the TN and OH Valleys. -Although precip chances will be elevated for much of the period, total rainfall for the week will be limited. -Most areas will see a quarter to half an inch of rainfall during the period. It is very unlikely that any day will be a washout. -Although the front will be south of the area at times cold air will be lacking and high temperatures will be near to slightly above climo. -Cloud cover and moisture will keep lows above to well above climo. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... As of 12Z....A wedge will prevail through the day, then break down tonight as a warm front begins to wave northward. Look for IFR/near IFR ceilings to continue through much of the day. Tonight, as the winds shift back to the south, expect some fairly dense fog to set up a few hours after dark. Some showers are possible at the end of the forecast period. Extended Outlook...In general, unsettled weather through Wednesday with IFR/LIFR conditions possible at times. && .MARINE... As of 930 AM Sunday...A surface ridge currently remains in control across the Carolinas supporting NEly flow initially. The ridge will break down and the old front will lift northward allowing the winds to veer to a S-SW direction overnight. This fetch will increase but is currently expected to support winds just below Small Craft criteria. The front will shift back off the coast during the day on Monday allowing for winds to become offshore. However, a weakening pressure gradient in the wake of the boundary along with nominal cold air advection supports weakening winds by the afternoon. Seas of 4-5 ft are expected tonight into early Monday morning, otherwise they will be 3 ft or less. Weak coastal trough starts to take shape Tue, becoming more defined Tue night. Trough develops as surface high, over the Upper Midwest Mon night, quickly shifts east Tue and Tue night. Cold front that building high pushes south of the waters will return north Wed into Thu, shifting northeast winds to southwest for the middle of the week. Front will linger just north of the area through Thu. Gradient will be pinched at times, with wind speeds close to 20 kt. Seas build to 3 to 5 ft late Mon night or early Tue in response to northeast flow increasing to near 20 kt and seas in excess of 6 ft will be possible Tue night into Wed. The development of southwest winds later Wed will create chaotic seas, but decreasing speeds should allow seas to fall during the mid to late week period. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...SRP SHORT TERM...III LONG TERM...III AVIATION...TRA