textproduct: Charleston

WHAT HAS CHANGED

All sections have been updated.

KEY MESSAGES

- 1) A tornado and flash flooding threat will persist across portions of Southeast Georgia and the South Carolina Lowcountry into this evening.

- 2) Minor to moderate coastal flooding expected again this evening along the South Carolina coast. Additional minor coastal flooding possible possible with the high tide cycles Sunday.

DISCUSSION

KEY MESSAGE 1: A tornado and flash flooding threat will persist across portions of Southeast Georgia and the South Carolina Lowcountry into this evening.

A localized corridor of tornado potential has developed along the SC/GA border, in proximity to an effective warm front. A strong tornado is possible.

Several supercells have developed ahead of a confluence zone, with reports of possible tornado damage noted in Bulloch County GA. The CAE VAD continues to show a large, curved hodograph and 400+ m2/s2 0-3 km SRH, with 200+ m2/s2 effective SRH preceding the supercells in the 18Z mesoanalysis. Tornado potential should continue with these supercells, and an EF2 intensity-equivalent tornado could occur as these storms approach the warm front.

Additional tornado development is possible later this afternoon as another semi-continuous line of showers and thunderstorms moves across the Altamaha River into Southeast Georgia and mainly inland portions of southeast South Carolina. The current tornado watch continues through 8 PM.

Additionally, deep tropical moisture remains in place as slow moving supercells are bringing locally heavy rainfall. While individual cells are likely moving fast enough to preclude a widespread flash flooding threat, local training of cells could still result in flash flooding through this evening.

KEY MESSAGE 2: Minor to moderate coastal flooding expected again this evening along the South Carolina coast. Additional minor coastal flooding possible possible with the high tide cycles Sunday.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Scattered showers and thunderstorms this afternoon have resulted in a mix of VFR, MVFR, and IFR ceilings, with localized sub VFR-visibilities. Most visibility restrictions associated with convection will remain east of the terminals this afternoon, but could push into the SAV/CHS/JZI areas this evening.

Look for MVFR to VFR to prevail tonight as we become more entrenched within the warm sector.

Extended Aviation Outlook: No high confidence concerns through the upcoming week.

MARINE

The strongest 850 mb winds have pushed north of the area a bit faster than expected this afternoon, and winds are mostly moderate across the waters, with a relatively relaxed gradient expected to persist through this evening. As such, Gale Warnings have been downgraded to Small Craft Advisories. Winds begin to increase again overnight ahead of an approaching cold front, with gusts to 25 kt common across the coastal waters again by the early morning hours.

Sunday into Tuesday: Remnants of Isaias combined with a surface high pressure offshore should keep winds breezy on Sunday and Small Craft Advisory will likely persist for portions of the coastal waters into Sunday night, with the potential for continuing into Monday. Thereafter, expect these marine conditions to become almost tranquil as we head into early next week.

CLIMATE

Record Precipitation:

October 10: KCHS: 1.82/1990 KCXM: 2.13/1990

CHS WATCHES/WARNINGS/ADVISORIES

GA...Flood Watch until 2 AM EDT Sunday for GAZ087-088-099>101-114- 115-137-216>219-238>241. High Risk for Rip Currents until 8 PM EDT this evening for GAZ217- 219-239-241. SC...Flood Watch until 2 AM EDT Sunday for SCZ040-042>045-147>152. High Risk for Rip Currents until 8 PM EDT this evening for SCZ148- 149-151. High Risk for Rip Currents through Sunday evening for SCZ150. MARINE...Small Craft Advisory until 11 PM EDT Sunday for AMZ360-362. Small Craft Advisory from 11 PM this evening to 2 PM EDT Sunday for AMZ364. Small Craft Advisory until 8 PM EDT Sunday for AMZ384.