Area Forecast Discussion

WHAT HAS CHANGED

All sections have been updated.

KEY MESSAGES

- 1) Locally heavy rainfall is possible this evening.

- 2) Hot and humid conditions return to the South Carolina Lowcountry and Southeast Georgia during the middle of this week.

DISCUSSION

KEY MESSAGE 1: Locally heavy rainfall is possible this evening. The atmosphere cross the Charleston Tri-County into much of Colleton County has been pretty well worked over in the wake of flooding rains earlier in the afternoon. No additional flooding is expected in this region for the remainder of the night, although a low-end flood risk will linger for a bit across western Colleton County through 8-9 PM or so. The Flood Watch will likely be cancelled prior to 8 PM as a result.

A well defined outflow boundary moving southwest across the Lowcountry will continue to zipper-line down the sea breeze and intersect a number of lingering mesoscale boundaries across Southeast Georgia over the next few hours. There is a continued risk for locally heavy rainfall and possibly a strong tstm or two, possibly even a marginal severe tstms given the amount of lingering instability in these areas.

KEY MESSAGE 2: Hot and humid conditions return to the South Carolina Lowcountry and Southeast Georgia in the middle of this week.

A strong mid-lvl ridge will continue to situate itself over the Rockies and the Plains through the mid-week, while a troughing will be apparent along the Eastern Seaboard. At the surface, weak high pressure will also prevail through the mid-week. This will yield hot and humid conditions throughout the week, with Tuesday and Wednesday being the hottest days of the week. Expect daytime highs to reach into the mid to upper 90s. There is a chance that some spots could reach the 100 degree mark across far inland Georgia. Dewpoints are expected to be in the low 70s far inland, and then increasing into the mid to upper 70s at the coastline with the afternoon sea breeze. This will equate to afternoon heat indices ranging from 100-105F inland, and 108-114F across the coastal counties on Tuesday and Wednesday. If this forecast trend continues, we'll likely need to issue a heat headlines for both days. Thereafter, the heat and humidity will drop near normal values on Thursday with the arrival of another front.

AVIATION /00Z MONDAY THROUGH FRIDAY/

27/00z TAF Discussion: KCHS/KJZI/KSAV: The risk for tstms has ended at KCHS and KJZI, but will linger through about 03z at KSAV as boundary interactions to the north of that terminal may drive convection south to within 10 NM. Expect VFR to prevail otherwise and prevail through the remainder of the 00z TAF cycle at all three sites. Isolated convection may fire near KCHS during the afternoon Monday, so PROB30s were introduced 20-00z to account for this. Chances look too low to include a mention at KJZI or KSAV at this time.

Extended Aviation Outlook: Brief flight restrictions are possible Wednesday and Thursday due to showers and thunderstorms.

MARINE

Through tonight: A quasi-stationary front will linger nearby as light southwesterly flow persists across the local waters. This set- up will likely yield isolated to scattered showers and thunderstorms into the afternoon/evening hours. As southeasterly swell continues to surge into the local waters, expect seas to range from from 2 to 3 ft.

Monday though Friday: Light to moderate winds should continue across the local waters on Monday, before a cold front approaches from the region. As this front inches closer, expect wind speeds to increase on Tuesday afternoon with gusts reaching up to 25-27 kts. Therefore, Small Craft Advisories will likely be needed for a portion of the waters on Tuesday and Wednesday. Thereafter, marine conditions will remain rather benign on Thursday and Friday. Seas will range from 2- 3 ft through most of period, except for briefly surging to 3-5 ft (possible 6 footers in the offshore waters) on Tuesday evening through Thursday morning.

CLIMATE

Record High Temperatures:

July 28: KCHS: 101/1949 KCXM: 100/1936 KSAV: 102/1949

July 29: KCHS: 100/1993 KCXM: 99/1999 KSAV: 103/1993

Record High Minimum Temperatures:

July 29: KCHS: 80/2016 KCXM: 85/1999 KSAV: 82/1878

CHS WATCHES / WARNINGS / ADVISORIES

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