textproduct: Charleston

WHAT HAS CHANGED

Afternoon/evening convective coverage and timing refined.

Workweek forecast discussion updated, with increased confidence in seasonable/diurnal convective pattern.

KEY MESSAGES

- 1) A fairly typical summertime pattern is forecast with daily shower and thunderstorm chances through the week.

DISCUSSION

KEY MESSAGE 1: A fairly typical summertime pattern is forecast with daily shower and thunderstorm chances through the week.

Isolated convection is mainly focused across the Lowcountry early this afternoon, where more sunshine and destabilization occurred through the morning. CAPE values around 2000 J/kg support a few stronger storms, but developing upper subsidence in the wake of a passing shortwave and limited shear will bring northing more than a very localized wet microburst potential.

Later this evening, cold-pool driven convection from storms across northern Florida - where mid-level shortwave energy is overlapping peak heating to a greater extent - is expected to push into Southeast Georgia, extending the threat for rainfall and thunder into the evening, though the severe and flooding threat will remain very low. Mainly dry conditions are then expected by midnight, with the focus for convection shifting offshore.

Monday and Tuesday will feature hot an humid conditions, but limited upper forcing and westerly deep layer flow will limit coverage to isolated to scattered, mainly diurnally driven. Both days will be warm, with temps reaching well into the 90s and heat index values into the 100s, though not likely hot enough to solicit Heat Advisories. Seasonable combination of offshore ridging/inland troughing reestablishes through the day Wednesday and persists into next weekend, with ridging/subsidence aloft maintaining mainly isolated to scattered diurnal daily convection. A few stronger storms and locally heavy rainfall are possible each afternoon, but there is no apparent significant severe or flooding threat at this point.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

21/18z TAF Discussion: KCHS/KJZI: Afternoon convection focuses across the Lowcountry. KCHS could see a period of thunderstorms, but less likely at JZI as the sea breeze has already progressed inland. VFR conditions prevail this evening through at least Monday morning.

KSAV: Confidence is low in afternoon convective threat, with most thunderstorm activity remaining north of the terminal this afternoon, then south of the terminal this evening. VFR expected overnight through at least Monday morning.

Extended Aviation Outlook: Brief flight restrictions are possible with mainly afternoon showers and thunderstorms.

MARINE

Through Tonight: A southerly flow regime near 10 kt with seas 1-2 ft will prevail through tonight with the waters positioned along the western flanks of Atlantic high pressure.

Monday through Friday: The coastal waters will become positioned between high pressure centered well offshore and an approaching cold front Monday night, leading to increasing winds and building seas. Gusts could approach 25 knots at times Monday evening into Tuesday evening, but looks fairly marginal for Small Craft Advisories. Conditions should stay below advisory levels through Friday.

CLIMATE

Record High Minimum Temperatures:

June 23: KCHS: 78/2024 KCXM: 82/1998 KSAV: 77/2017

CHS WATCHES/WARNINGS/ADVISORIES

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