textproduct: NWS Wilmington

WHAT HAS CHANGED

Guidance showing increasing potential for some spotty showers with the passing cold front on Saturday. Aviation discussion updated below for the 18Z TAFs.

KEY MESSAGES

- 1) Dry forecast dominates through Friday, with temperatures nearing record highs each day.

- 2) Most significant cooldown of the season so far expected this weekend.

DISCUSSION

KEY MESSAGE 1...Dry forecast dominates through Friday, with temperatures nearing record highs each day.

Latest surface analysis shows an elongated surface high that stretches from the Gulf coast through the coastal Carolinas. This surface ridge is associated with the upper ridge that's tucked slightly more to the west along the Gulf coast from TX to the FL panhandle. This ridge will continue to push northward and elongate from ArkLaMiss into the Carolinas today, and then into the western Atlantic by Thursday. Upper heights and thicknesses soar, allowing for widespread subsidence, which keeps the forecast dry.

500 mb heights hang around 592-594 dam, which easily rank in climatological maximums in this area, per SPC Sounding Climatology along KCHS, KMHX, and KHAT. This means very unseasonably warm temperatures that look a lot more like mid- to-late June than mid-October. Widespread highs in the upper 80s inland and mid 80s at the coast expected today through Friday. Record-tying or record-breaking high temperatures are in play here. Please see Climate section below for the possible record highs.

KEY MESSAGE 2...Most significant cooldown of the season so far expected this weekend.

Trade in the shorts and sweat towels for flannel and boots, for the famous fall cold front is coming. A trough out of Alberta and Saskatchewan amplifies by the time it enters the upper Midwest Thursday, meeting up with an upper low that ejects out of the Four Corners region. This trough continues to deepen as it sweeps through the Great Lakes and Ohio Valley region by Friday. The jet streak bottoms out near the NC/SC border as it sweeps through Friday night, sending the heat ridge offshore for good, and sweeping a cold front through the area. Interesting change with that jet streak, as data showed it bottoming out along the NC/VA border 24 hours ago. Bringing that streak's trough axis into the forecast area gives a lot more energy and forcing aloft to work with.

Overall, guidance continues to show an overall lack of moisture with this front, but chc of pcp has been added to northern and eastern portion of forecast area Sat morning with some shwrs possible before the extremely dry air makes it into the area by Sat evening. Dewpoints in the mid 60s to near 70 overnight Fri night will drop out through Sat down into the 50s and even some 40s by late Sat. This drying trend will continue through Sat night with gusty northerly winds allowing dewpoints to bottom out early Sun in the 30s to around 40 close to the coast. Plenty of CAA will bring temps down quite a few degrees below normal Sat into Sun. Temps Sat aftn will resemble overnight temps just 12 hrs before, but the stiff northerly winds will make it feel even cooler. Expect overnight lows Sat night in the 40s inland to near 50 at the coast. Overall, fall-like weather will arrive Sat with a gradual warming through early next week.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Predominantly VFR through the 18Z TAF period. Expect light S to SW wind up to 5 to 7 kts this afternoon. Ground fog may start to form again in the pre-dawn hours Thursday morning, but chances are slightly lower than they are for this morning. Guidance showed potential at all coastal sites last night, but tonight it seems more confined to the southern Grand Strand area.

Extended Outlook...VFR prevails through Monday. Only exception could be some MVFR ground fog in the early mornings late this week. Also, there is a limited potential for a brief shower on Saturday, but flight restrictions are not expected.

MARINE

Through Sunday...Benign winds and seas through at least Friday morning. Gentle SW breeze continues, remaining that way through Friday morning. Seas linger at 1-2 ft under a dry forecast.

Pattern starts to change throughout the day Friday, as gradient winds increase significantly ahead of a cold front. Moderate breeze builds in by midday Friday, becoming a fresh to strong breeze by the evening. Front moves through overnight Friday night, allowing the winds to quickly veer to the N, gradually veering even more to the NE throughout the day Saturday through Sunday. Seas will ramp up in increasing winds ahead of the front and will peak Saturday night into Sunday morning, ranging from 4-6 ft over the coastal waters out 20 nm, to 6-10 ft over the offshore waters out 60 nm.

Small Craft Advisory conditions appear to be a slam dunk Friday night through Sunday. Certainly cannot rule out gale conditions, particularly over the offshore waters 20-60 nm out.

CLIMATE

Current forecast vs. records: Wednesday, October 14: - Wilmington, NC (KILM): 88F (89F in 1928) - North Myrtle Beach, SC (KCRE): 84F (86F in 1959) - Florence, SC (KFLO): 89F (88F in 2021) - Lumberton, NC (KLBT): 89F (91F in 1928)

Thursday, October 15: - Wilmington, NC (KILM): 88F (88F in 1985) - North Myrtle Beach, SC (KCRE): 84F (85F in 2008) - Florence, SC (KFLO): 89F (89F in 2021 and 1985) - Lumberton, NC (KLBT): 89F (91F in 1919)

Friday, October 16: - Wilmington, NC (KILM): 87F (87F in 2021, 2018, and 1975) - North Myrtle Beach, SC (KCRE): 83F (88F in 1990) - Florence, SC (KFLO): 88F (91F in 2021) - Lumberton, NC (KLBT): 88F (92F in 1925)

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...None.