textproduct: Charleston

WHAT HAS CHANGED

Aviation Discussion was updated for the 12z TAFs.

KEY MESSAGES

- 1) A risk for isolated showers and patchy drizzle will linger today with cloudy skies keeping temperatures well below normal for early February.

DISCUSSION

KEY MESSAGE 1: A risk for isolated showers and patchy drizzle will linger today with cloudy skies keeping temperatures well below normal for early February.

Low pressure located over the South Carolina Midlands early this morning will quickly translate offshore prior to daybreak, passing south of Cape Hatteras by mid-morning. Local radars show the main band of rain has shifted well out into the Atlantic, but as the cold front clears the coast over the next few hours, the risk for isolated showers along with patches of drizzle will linger for much of the day, especially north of the I-16 corridor. Strong wedge-like conditions will fill in from north- south behind the front and these conditions will persist until this evening before steady clearing occurs with the passage of the upper trough offshore. A blend of the CONSShort with hourly RAP/H3R output were favored to construct today's high temperatures. Daytime highs will occur just after daybreak with temperatures holding steady or falling as the day progress. They will range from the lower 40s across northern portions of interior Southeast South Carolina to the mid-upper 40s elsewhere. By mid- afternoon, temperatures should range from the mid-upper 30s across the Charleston Tri-County to the mid 40s closer to the Altamaha River.

There is still a low-end chance that a period of sub-freezing temperatures could work south into northern portions of Berkeley County later this morning, most likely from daybreak to late-morning. HREF and NBM probabilities for reaching freezing are running about 10-30% in the Saint Stephen to Jamestown corridor. Should freezing temperatures occur, forecast soundings at KMKS and KCKI suggest freezing rain/drizzle could occur given the lack of sufficient ice nucleation in the cloud. This scenario is still considered an outlier solution, but trends are being monitored.

AVIATION /12Z THURSDAY THROUGH MONDAY/

05/12z TAF Discussion: KCHS/KJZI/KSAV: The cold front will clear both KCHS and KJZI prior to 12z and should clear KSAV by 13-14z. Brief fog ahead of the front should clear after FROPA. Widespread LIFR cigs with patches of drizzle should gradually settle in to IFR with continued patches of drizzle by mid-morning. IFR cigs should then persist through late afternoon/early evening with cigs lifting and scattering out by mid-late evening as a pronounced clearing line moves through.

Extended Aviation Outlook: MVFR cigs could persist into mid-late afternoon Thursday at CHS/JZI/SAV terminals. VFR conditions should then return Thursday night and prevail during the weekend.

MARINE

A cold front will move offshore this morning, followed by High pressure building in from the west. This will cause winds to clock around to the northwest and increase. A Small Craft Advisory is in effect for the GA waters beyond 20 nm this afternoon into part of tonight, mainly due to winds. Following a brief lull Friday morning, conditions deteriorate later Friday, with another cold front moving through early Saturday. Small Craft Advisories will be needed for all of the ocean zones late Friday into early Saturday. There could be near gale conditions for the GA waters beyond 20 nm Friday night. Conditions improve later Saturday as High pressure builds into the region, then prevails through early next week.

EQUIPMENT

Repairs to the KCLX are complete and the radar is operational. Final calibration work will be required later today, so additional downtime is likely.

CHS WATCHES/WARNINGS/ADVISORIES

GA...None. SC...None. MARINE...Small Craft Advisory from 1 PM this afternoon to 1 AM EST Friday for AMZ374.