textproduct: Charleston

WHAT HAS CHANGED

Updated the Aviation section for the 12Z TAFs and key message 1.

KEY MESSAGES

- 1) Patchy dense fog this morning.

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

DISCUSSION

KEY MESSAGE 1: Patchy dense fog this morning.

Early this morning, IR nighttime microphysics RGB indicated an expanding area of stratus across portions of SE GA and the SC Lowcountry. In addition, KCLX detected patches of light returns drifting onshore over Charleston and Colleton Counties around dawn, likely falling a drizzle or sprinkles. Based on web cams and sfc based observations, patchy dense fog has developed across portions of the SC Lowcountry, highlighted with a Special Weather Statement until 7 AM. Near- term guidance has struggled with the timing, placement, and density of the fog this morning. We will continue to monitor the fog, if the coverage of dense fog increases, then a Dense Fog Advisory could be needed.

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

Mid level heights will lower late week as a larger scale trough shifts into the eastern U.S. At the surface, a weak front will slowly move towards the region, eventually getting pushed offshore later Friday or Friday night. Rain potential looks rather unimpressive. Despite increasing moisture, the best forcing passes to the north. Thursday could see an isolated shower, but most of the area will be dry. A bit higher coverage is expected on Friday with a weakening band of precip likely moving into the area during the day. Significant rainfall is not expected. Probabilities for rainfall greater than 0.25" are generally less than 20%, except slightly higher over interior South Carolina. Weak instability could support an isolated thunderstorm or two, but severe weather is not anticipated. Drier air returns following fropa, with a rain-free forecast in place for the weekend and early next week.

Outside of rain chances, the other forecast item of note is the unseasonably warm temperatures. Highs today through Friday are mostly in the low to mid 80s. These values are around 10 degrees above early November normals and are within a few degrees of records (see climate section below).

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Prior to the 12Z TAFs, IR nighttime microphysics RGB showed expansive stratus and patchy fog across SE GA/SC. Sfc based observations indicated VLIFR to LIFR conditions across KCHS, KJZI, and KSAV. In addition, KCLX detected patches of drizzle across KCHS and KJZI this morning. The TAFs will highlight the restrictive ceilings and visibility through 14Z. Low clouds are expected to become SCT to FEW between 14-15Z. By mid-morning, a weak sea breeze should begin to push inland, resulting in winds to turn from the southeast and increasing to 10 to 15 kts at KJZI, KCHS, and KSAV. The weak seabreeze should keep dewpoints in the mid to upper 60s this evening and tonight. Another round of fog or low ceilings may develop over the terminals late tonight.

Extended Aviation Outlook: Isolated to scattered showers, and possibly a thunderstorm or two, could impact the area Thursday and Friday. Any flight restrictions should be brief.

MARINE

Today through Tonight: The forecast pattern will support southeast winds generally between 10 to 15 kts across the marine zones. Seas will begin the day between 3 to 5 ft, decreasing to 3 to 4 ft tonight. All Small Craft Advisories have been removed from the forecast area.

Thursday through Monday: Conditions are expected to remain below Small Craft Advisory levels late week through the weekend. A cold front will approach the region and eventually push offshore Friday night. No significant wind surge is expected behind it. Speeds will generally top out at 15 knots with seas peaking 3-5 feet.

CLIMATE

Record High Temperatures:

November 4: KSAV: 85/2012

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

November 6: KCXM: 81/2003

Record High Minimum Temperatures:

November 4: KCHS: 67/2015 KCXM: 69/1992 KSAV: 71/2003

November 5: KCHS: 69/2003

CHS WATCHES/WARNINGS/ADVISORIES

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