textproduct: Charleston

WHAT HAS CHANGED

Key message 1 and the aviation section have been updated.

KEY MESSAGES

- 1) Patchy fog possible across portions of the South Carolina Lowcountry this morning and again tonight.

- 2) Unseasonably warm temperatures expected through late week, with scattered showers and a thunderstorm or two possible on Friday.

DISCUSSION

KEY MESSAGE 1: Patchy fog possible across portions of the South Carolina Lowcountry this morning and again tonight.

Surface dewpoints will remain in the mid to upper 60s through daybreak this morning, providing very narrow dewpoint depressions. Given light to calm winds and thin mid and high clouds, patchy fog and ground fog may develop across portions of the SC Lowcountry this morning. REFS indicate that the probability of visibility falling to around half mile will range between 40-60% around daybreak. The forecast will feature a mention of fog early this morning. Any fog that develops should dissipate during the first hour or two of daylight.

A cold front will approach from the west tonight. Light return flow should continue across the forecast area overnight, maintaining sfc dewpoints in the mid to upper 60s. Forecast soundings from the RRFS indicate nearly saturated conditions below a BL inversion. In addition, MOS and ensemble guidance indicate several hours of fog tonight, especially over the I-26 corridor.

KEY MESSAGE 2: Unseasonably warm temperatures expected through late week, with scattered showers and a thunderstorm or two possible on Friday.

Temperatures are forecast to warm into the mid 80s this afternoon. In fact, high temperatures could near record high values, see Climate section below. High resolution guidance indicates that a sea breeze will develop early this afternoon, drifting inland through early this evening. The sea breeze may trigger isolated showers, generally along and west of the I-95 corridor.

Friday will start with a weak cold front just west of the area. The front will progress through the area during the day, pushing offshore in the evening. The better forcing passes by to the north, but guidance is consistent in showing a broken line of showers and a couple embedded thunderstorms moving through with the front. Significant rainfall is not expected, but a few spots could pick up 0.50-1". An axis of higher instability will develop closer to the coast, east of I95, but will remain fairly weak, so the threat for severe weather is low despite increasing wind fields. Dry weather will return for the weekend and early next week.

Temperatures on Friday will remain above normal, generally peaking in the upper 70s to lower 80s. These values will remain shy of any records.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Prior to the 12Z TAFs, various degrees of ground fog to patchy fog has been observed across KCHS and KJZI. Fog could briefly become dense. Conditions should become VFR by 13Z. Temperatures are forecast to warm into the mid 80s this afternoon. High resolution guidance indicates that a sea breeze will develop early this afternoon, drifting inland through early this evening. The sea breeze may trigger isolated showers, potentially near or over KSAV, highlighted with a mention of VCSH. Any showers should dissipate or shift inland by early this evening.

A cold front will approach from the west tonight. Light return flow should continue across the forecast area overnight, maintaining sfc dewpoints in the mid to upper 60s. Forecast soundings from the RRFS indicate nearly saturated conditions below a BL inversion. In addition, MOS and ensemble guidance indicate several hours of fog tonight, especially over KCHS and KJZI after 7Z.

Extended Aviation Outlook: Brief flight restrictions are possible in scattered showers/thunderstorms on Friday.

MARINE

Today through Tonight: The forecast pattern will support southeast winds generally less than 10 kts. Seas should range between 2 to 4 ft.

Friday through Tuesday: Marine conditions will remain below Small Craft Advisory criteria through the period. A weak cold front will push into the waters Friday evening, with high pressure returning thereafter. Winds will peak around 15 knots following fropa over the weekend, with seas 3-5 feet. Winds will settle around 10 kt or less and seas 2-4 feet for early next week.

CLIMATE

Record High Temperatures:

November 5: KCHS: 87/2003 KCXM: 81/1992 KSAV: 85/2003

November 6: KCXM: 81/2003

Record High Minimum Temperatures:

November 5: KCHS: 69/2003 KCXM: 71/2024 KSAV: 70/2003

CHS WATCHES/WARNINGS/ADVISORIES

GA...None. SC...None. MARINE...None.