Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 241040 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 530 AM EST Thu Jan 24 2019 .SYNOPSIS... Showers and isolated thunderstorms will precede a cold front that will cross the area this morning. Seasonably cool and dry air will build across the region in wake of the front through the weekend. A slight warming trend will bring milder daytime temperatures Monday and Tuesday. Another cold front, which may be accompanied by showers, will move across the area during the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... As of 3 AM Thursday...A fast-moving 500 mb shortwave will push a surface cold front across the area this morning, then offshore this afternoon. Upstream radars indicate a large area of rain with embedded heavier convective showers moving quickly northeast. Precipitation will certainly survive (and thrive) as it moves east given a very healthy inflow of low and mid level moisture from the Gulf plus excellent upper divergence within the right-entrance region of a 250 mb jet extending from eastern Kentucky up into southern Ontario. Forecast GFS and NAM soundings indicate there should be small elevated instability present up through the time of frontal passage, however the equilibrium level of today`s convective parcels may be too low to allow for significant ice aloft and subsequent charge separation for lightning. A low level jet will bring 50 kt winds as low as 1000 feet AGL this morning, and could help produce 35-40 mph wind gusts even outside of the shallow convection. This is not quite enough for a wind advisory but could still bring dead or weak tree limbs. Winds should become lighter this afternoon in the 15-20 mph range. Temperatures this morning are quite mild for mid-January, and will probably rise another ~5 degrees before the front arrives, peaking in the 65-69 degree range. Temperatures should fall behind the front, but then may rise again to a second lower peak during the afternoon hours as sunshine develops on drier westerly winds. A secondary cold front will ease down from the north overnight with much lighter winds allowing temperatures to fall into the 30s all the way down to the beaches. GFS lows appear to be too warm, and I`ve followed the colder NAM/ECMWF blend. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 3 AM Thursday...Broad mid-level trough remains over the region Fri and Sat with a weak cold front passing dry Fri night into Sat. Front briefly reinforces cold advection, but surface high quickly shifts offshore with weak return flow developing later Sat. Temperatures will end up below climo with highs in the upper 40s to lower 50s and lows in the upper 20s to lower 30s. Precipitable water remains under 0.30" through the period with periods of time where it drops under 0.20". Forecast soundings do show an increase in moisture around 30k ft Fri afternoon, as jet streak approaching 150 kt crosses the area. This will likely lead to fairly thick veil of cirrus but little else. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 3 AM Thursday...Pattern aloft will remain amplified through the period, with 2 distinct areas of low pressure, one passing northwest of the area and one passing off the Southeast Coast early next week. -Temperatures slightly below climo Sun warm slightly Mon and Tue as high slips off the coast and warm advection sets up. A cold front Tue night will drop temperatures back below climo on Wed. -Flattened mid-level trough will limited moisture return into the middle of next week, precipitable water will be under 0.50" through Tue with mostly clear skies. -Narrow band of moisture preceding cold front Tue night pushes precipitable water close to an inch and has the look of a high shear/low CAPE event. Still a week out, but something to watch. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... As of 12Z...Moderate to heavy showers, associated with a cold front, will continue through around 15Z, and will end from west to east as the cold front pushes through the CWA. Visibilities will drop as low as a mile in heavy showers with precipitable water around 1.8 inches. Strong pressure gradient will keep winds gusting near 30 kts, particularly in convection. Look for rapidly improving conditions this afternoon with a west wind. Cold air will begin pouring in by late afternoon and evening. && .MARINE... NEAR TERM /THROUGH THURSDAY/... As of 3 AM Thursday...Strong south winds gusting to 35-40 knots are expected for the remainder of the morning hours in advance of a cold front. This front should reach the coastal waters between 10 AM and noon and will be followed by lighter westerly winds through the afternoon. Ahead of the front widespread rain is expected with embedded heavier showers. A dry secondary cold front will slide south across the area overnight, veering westerly winds around to the north. A Gale Warning will remain in effect until the front arrives. Behind the front winds in the 10-20 kt range won`t even technically meet Small Craft Advisory criteria, however it will take until tonight for seas to subside below 6 feet across the South Carolina coastal waters, and it could take until tomorrow for conditions to improve across the Cape Fear area waters. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 3 AM Thursday...Small Craft Advisory headlines will likely continue through Fri morning, mainly for seas. Decreasing northwest flow on Fri will see speeds drop close to 10 kt by midday. Winds from the northwest pick back up late Fri night into Sat as weak, dry cold front crosses the area. Speeds may briefly hit 15 kt early Sat morning before weak high pressure moves into the region and winds weaken as they veer to northeast. Light and variable winds Sat will continue Sat night. Seas over 6 ft will linger through Fri morning before subsiding to 3 to 4 ft in the afternoon. Seas drop to 3 ft or less Fri evening and will be around 2 ft Sat and Sat night. LONG TERM /SUNDAY THROUGH MONDAY/... As of 3 AM Thursday...Elongated surface ridge axis in the area Sun and Mon will keep wind speeds 10 kt or less with direction varying due to the location and orientation of the ridge axis. Light winds will keep seas around 2 ft through the period. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...Gale Warning until 1 PM EST this afternoon for AMZ250-252-254- 256. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...43 is the U.S. government's official web portal to all federal, state and local government web resources and services.