FXUS62 KILM 111731 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1232 PM EST Mon Dec 11 2023 .SYNOPSIS... High pressure will build in for most of the week bringing cool and dry weather to the region. Rain chances could increase late in the period due to a possible storm system to the south. && .UPDATE... Made some minor adjustments to cloud cover for the day, expecting that clouds will become scattered at worst all areas by about noon. Otherwise, no changes were made this update. Still expecting a cool and decreasingly breezy December day more like mid January than mid December. && .NEAR TERM /THROUGH TONIGHT/... Much cooler temperatures have arrived behind a strong cold front which brought gusty winds across the CWA early this morning. Expect morning lows to bottom out in the low 40s driven by cold advection out of the NNW. Clearing will take place from west to east early this morning with stratocumulus hanging on the longest near and north of Cape Fear, where Pender and New Hanover counties may not break out of the clouds until late morning or early afternoon. Otherwise, expect mostly sunny skies to dominate across the remainder of the region, with the shallow sun angle and continued cold advection causing temps to struggle to reach the low 50s. If low clouds hang on long enough in Pender and New Hanover counties, temps may not breach 50F. Tonight, broad surface high pressure to the west builds closer to the region while shortwave energy aloft helps to keep general troughing in place at the mid-levels. With clear skies, low dewpoints, and a weak pressure gradient, am expecting great radiational cooling conditions. Thus, have opted to go on the lower side of guidance, which brings lows into the upper 20s to low 30s away from the immediate coast. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Sprawling surface high and progressive pattern aloft in place from Tue into Wed night. A backdoor cold front arrives late Wed night, providing a reinforcing shot of cold air for the end of the week. The air mass is quite dry with precipitable water under 0.50" through Wed night and under 0.30" through Wed. Along with being very dry the air mass is chilly. Partial thickness values suggest an airmass where highs will struggle to reach mid 50s on Tue and upper 50s Wed despite sunny skies. As for lows, there should be enough boundary layer mixing Tue night to limit the effectiveness of radiational cooling. The approach of a dry, backdoor cold front Wed night will lead to an increase in wind after midnight. Most areas will be lower 30s Tue night with slightly warmer temps Wed night. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Northern stream shortwave drives a dry backdoor cold front across the area right before the start of the long term. This sets up enhanced northerly flow and cold advection for Thu. Temperatures end up about 5 degrees below climo Thu and Thu night. High pressure settles over the region Fri, slightly modifying as coastal trough develops. At this point uncertainty starts increasing. The cutoff emerges over the western Gulf of Mexico over the weekend and interacts with the remains of a stalled front. The timing of the 5h low will be the key to how quickly unsettled conditions are able to spread north over the Southeast. The range of solutions offered by the CMC/ECMWF/ICON/GFS are not unusual given the struggle the guidance routinely has with split flow. Given the amplified nature of the system the solutions with slower timing may end up winning out. Current forecast brings in precip chances Sat night but would not be shocked to see this delayed by about a day. Weekend temperatures will range from near climo during the day to above climo at night. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Overall expect VFR conditions at area terminals this TAF period with diminishing NW to N winds this afternoon becoming light overnight and turning toward the NNE by daybreak Tuesday. We may see Tempo MVFR cigs for another hour or two, particularly at ILM, before VFR completely sets in all areas. Extended Outlook...VFR predominantly expected as high pressure dominates through the period. && .MARINE... Through Tonight: Subsiding winds and seas will be the main story as offshore flow dominates and the pressure gradient weakens. Gale-force gusts associated with the frontal passage are coming to an end, with SCA-level gusts expected to persist through late morning. Seas should fall below 6 ft around noon in the NC waters. Seas will continue subsiding into the 3-5 ft range by evening and these 3-5 ft waves should continue through the night, driven mainly by a SE swell at 9 sec. Tuesday through Friday: North to northeast flow will persist through Fri as high pressure builds in from the north. Backdoor cold front moves south across the area late Wed night, followed by a northeast surge Thu into Thu night. Speeds will be around 15 kt for much of the period, the exception being 20-25 kt Thu and Thu night with the aforementioned surge. Seas 3-4 ft Tue into Thu ramp up on Thu following the arrival of the northeast surge. Seas 4-7 will be possible with potential for 6 ft seas lingering into Fri. Conditions could be quite treacherous this week. A southeast swell will be present with the growing northeast wind wave becoming dominant by mid-week. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...31 NEAR TERM...ABW SHORT TERM...III LONG TERM...III AVIATION...31 MARINE...III/ABW