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Show Area Forecast Discussion - Wilmington, NC (Wilmington, NC Area) Selection: |
| #1209041 (Received by flhurricane at: 3:54 AM 21.Nov.2024) AFDILM Area Forecast Discussion National Weather Service Wilmington NC 347 AM EST Thu Nov 21 2024 .SYNOPSIS... Colder end to the week expected behind a strong cold front, possibly leading to frost or even freezing conditions inland each night. High pressure will move off the coast early next week with warmer temperatures expected. A weaker cold front could move through toward mid week. && .NEAR TERM /THROUGH TONIGHT/... A strong cold front has moved offshore early this morning with gusty NW winds and dew points mainly in the 30s across the region. Expect these winds to slow down late tonight into early this morning as the pressure gradient relaxes. After sunrise, the growing boundary layer (expected to reach up to around 850mb at peak heating) will tap into faster winds aloft and allow for gusty west winds up to around 20-25 kts to develop around midday and continue through the afternoon. High temps will struggle to reach 60F amidst persistent cold advection and a robust subsidence inversion. With the loss of heating, gusty winds driven by vertical mixing will subside late this afternoon into this evening. However, another surge of WNW flow with even drier dew points behind a secondary cold front is expected to push in between 23-04Z this evening, which should bring some temporary gusty winds back into the mix, although speeds will be less than during the day. A weakening pressure gradient will allow for winds to decrease during the latter half of the night, and with clear skies in place, temperatures have the potential to drop to around the freezing mark, particularly across the northern tier of counties in our CWA. Therefore, a Freeze Watch has been issued to account for this possibility. Dew points depressions should be large enough to preclude widespread frost, but preferred areas near a water source or irrigated land may be able to yield frost due to locally higher dew points. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Highlights: *Dry w/ below normal temperatures *Frost/freeze conditions possible inland Fri/Sat nights Confidence: *Moderate to High Details: General troughing will prevail through Friday night with high pressure returning thereafter. Temperatures will stay below normal through the period with highs only in the lower to mid 50s Friday and lower 60s Saturday. Overnight lows will be in the 30s away from the coast each night, possibly near freezing in spots. Such temperatures could support frost as well, although there is some uncertainty regarding temps, humidities and winds. Also, should note that the issuance of Freeze Watches/Warnings and Frost Advisories will be predicated on whether freezing temperatures occur tonight which would end the growing season in these areas. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Highlights: *Warming trend early in the week w/ above normal temps starting Mon *Cold front could bring cooler temps and a few showers toward mid week Confidence: *Moderate Details: High pressure will be shifting offshore bringing moderating temps and moisture levels. A cold front looks to approach toward mid week, possibly moving into and/or through the area as early as Tuesday. Moisture and forcing appear weak so not expecting much rainfall with this feature, although some showers will be possible. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... A strong cold front has crossed through all terminals as of this writing with gusty northwest winds at all terminals. As the pressure gradient relaxes behind this initial surge, expect winds to gradually slow down as the night progresses. Mid-level cloudiness will clear out over the next 2-3 hours, leaving VFR conditions for the remainder of the period. After sunrise, a growing boundary layer will promote a return of breezy west winds with gustiness returning around midday with gusts expected to reach around 20-25 kts during the afternoon as the boundary layer reaches up to around 850mb. Winds will relax again after sunset, but remain steady westerly. Extended Outlook...Expect VFR through the period as high pressure maintains control. Gusty winds will be the only concern on Friday and Saturday afternoons. && .MARINE... Through Tonight... Breezy NW winds will gradually subside this morning and back to westerly as the pressure gradient weakens and a weak surface ridge passes through. Winds and gustiness increase again this afternoon and veer to WNW this evening as another surge of cold advection pushes in. Seas will be dominated by wind waves with 2-4 ft waves temporarily subsiding this morning and early afternoon before rebounding to 3-5 ft this evening as a result of the increase in winds later in the day. Some 6 ft waves may be found in outer portions of the coastal waters near 20nmi offshore of Cape Fear during the first half of the night before gradually subsiding thereafter. Friday through Monday...A tight pressure gradient and cold advection will keep winds/seas elevated through Friday night and a Small Craft Advisory remains in effect through this period. High pressure will then build into the area this weekend leading to a relaxation of the pressure gradient and thus improving marine conditions. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Freeze Watch from late tonight through Friday morning for NCZ087-096-105. SC...Freeze Watch from late tonight through Friday morning for SCZ017-023-024. MARINE...Small Craft Advisory until 7 AM EST Saturday for AMZ250-252- 254-256. && $$ |
| #1209028 (Received by flhurricane at: 1:12 AM 21.Nov.2024) AFDILM Area Forecast Discussion National Weather Service Wilmington NC 106 AM EST Thu Nov 21 2024 .SYNOPSIS... A strong cold front will move across the Carolinas tonight bringing colder weather for the second half of the week. There is potential for frost or even freezing temperatures in spots Thursday, Friday, and Saturday nights. High pressure will move off the coast next week with warmer temperatures expected. && .UPDATE... The sharp cold front has crossed all SC zones and is nearing the Cape Fear coast at this time, with a sharp wind shift and strong, gusty winds up to 40-45mph as it pushes through. Much cooler and drier air will rapidly follow behind it before winds relax gradually as the night progresses. Leftover mid-level clouds will clear out over the next 2-3 hours or so, leaving clear skies for the rest of the night. && .NEAR TERM /THROUGH TODAY/... Satellite imagery clearly shows the main front this afternoon still west of the area but making good progress east. Shower activity has decreased and really don`t expect much until the mid level trough moves across this evening via really good dynamics. Beyond this clearing with blustery conditions will develop. While the heart of the cold air arrives beyond this period there is some cold air advection and lows tonight will drop into the lower to middle 40s with readings struggling to reach 60 Thursday afternoon. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... Will see the coldest air of the season through late in the work week into this weekend. Overnight lows will be down in the 30s Thu night through Sat night. Frost will be possible but may be limited in coverage by dry air with dewpoints falling into the 20s. An impressive vort max rotating around a cold upper low across the Great Lakes will swing across the Carolinas on Friday. Moisture starved, it will act only as a secondary surge of cold air and will dip our 850 mb temps down to -3C to -5C during the day. Friday`s highs are forecast to stay in the mid 50s, potentially the coldest day since February 25 when Wilmington`s high was 55 and Myrtle Beach`s high was 54. The airmass will very slowly moderate Friday into Saturday, however with lighter wind speeds expected with approaching surface high pressure, better developed nocturnal inversions should keep low temps in the 30s with the potential for frost or even isolated freezing temperatures Friday night and Saturday night. Climate note: Florence, SC has a short period of climate records only going back to 1948, but this year`s growing season length of 271 days (2/23 through today) is the second longest on record, exceeded only by 1997`s 273 day growing season. Myrtle Beach`s 285 day growing season length (2/9 through today) is also the second longest on record exceeded only by 2009`s 286 day growing season. Wilmington and Lumberton aren`t approaching record territory yet... && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... A more zonal upper level pattern will develop next week with upper disturbances confined to the northern Plains, Great Lakes, and Canada. High pressure should move across Florida on Sunday, then offshore Monday. This should replace the Canadian airmass with a milder southwest flow off the Gulf of Mexico. High temperatures should return to normal by Sunday and into the lower 70s beginning Monday. A cold front may drop south into the area Tues into Wed. Should see an increase in clouds, but may not be too much moisture with it. Looks like best chc of any pcp will be Tues night into Wed, && .AVIATION /06Z THURSDAY THROUGH MONDAY/... A strong cold front has crossed through all terminals as of this writing with gusty northwest winds at all terminals. As the pressure gradient relaxes behind this initial surge, expect winds to gradually slow down as the night progresses. Mid-level cloudiness will clear out over the next 2-3 hours, leaving VFR conditions for the remainder of the period. After sunrise, a growing boundary layer will promote a return of breezy west winds with gustiness returning around midday with gusts expected to reach around 20-25 kts during the afternoon as the boundary layer reaches up to around 850mb. Winds will relax again after sunset, but remain steady westerly. Extended Outlook...Expect VFR for Thursday through Sunday, but breezy NW winds could gust near 20-25 mph during the daytime hours each day. && .MARINE... Through Thursday...Conditions still benign enough this afternoon with a very light southwest flow across the waters. The first of several cold fronts and or troughs is on the move however and in twelve hours or so winds will be west to northwest at 20-25 knots. Seas will build across the outer waters with the trajectory of winds to 3-5 feet then diminish a bit later in the day Thursday as winds take a brief respite as well. No changes to the timing/onset of the small craft advisory headline. Thursday night through Monday...Small Craft Advisory conditions will be ongoing and will last through at least Friday night. The highest seas will be in the outer waters in strong offshore winds up to 20 to 25 kts with higher gusts. Low pressure swirling across the northeastern U.S. and Canadian high pressure building southeastward out of the northern Plains will maintain a flow of cold, dry air across the Carolinas. The high will reach the Deep South on Saturday as low pressure moves out of New England into Canada. This should finally allow our wind speeds to diminish. Wind directions will back to the southwest on Sunday as the high move off the Florida east coast. Seas up to 3 to 6 ft Thurs night will drop down to 2 to 4 ft by Sun with minimal long period easterly swells mixing in. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...Small Craft Advisory until 7 AM EST Saturday for AMZ250-252- 254-256. && $$ |
