Marine Weather and Tide Forecast for Garden City, SC

KEY MESSAGES
1) Isolated storms possible this afternoon and evening.

2) Temperatures around 10 degrees above normal later this week.

DISCUSSION
KEY MESSAGE 1...Isolated storms possible this afternoon and evening.

KEY MESSAGE 1 DESCRIPTION...Remains of a weak front stalled across the area this morning will become even less defined today. The front and any lingering convective boundaries will have the potential to kick off afternoon storms, as will the sea breeze. Mixed signals from the environment concerning storm potential. Weakness in the mid- level ridge and a weak shortwave both enhance convective prospects, however still plenty of mid-level dry air and lapse rates are poor.
While a few storms are likely to develop, coverage will be limited, and mostly confined to northeast SC and possible extending north into NC west of the I-95 corridor. This is where the only real surface based instability will be found, basically along and south of what is left of the front. Closer to the NC coast northeast to east flow will spread the marine influence inland, keeping temps a bit cooler and limiting instability.

Outside of this afternoon and evening, storm potential will be very limited. The 5h ridge consolidates and strengthens slightly through Fri before weakening a bit for the weekend. Cannot rule out isolated diurnal convection any day this week, along the Piedmont trough or sea breeze, but think an afternoon/evening POP higher than 30 for the upcoming week is on the optimistic side.

KEY MESSAGE 2...Temperatures around 10 degrees above normal late this week.

KEY MESSAGE 1 DESCRIPTION...Mid-level ridging over the southern CONUS consolidates on Wed before expanding north and east Thu/Fri.
The combination of ridging aloft and some downslope component will lead to highs in the upper 90s pushing 100 away from the immediate coast(especially Fri). Sea breeze will have success moving inland Thu which will help tempera the heat a bit, although well inland areas will still see mid to upper 90s. On Fri west flow at 925 mb will help keep the sea breeze influence much closer to the coast, allowing for a larger portion of the area to see highs in the mid to upper 90s. Ridging is suppressed south by longwave troughing crossing the Great Lakes for the weekend. Temperatures remain well above normal Sat, but not as hot as Thu/Fri.

Large swath of triple digit heat indices Thu-Sat, although there is uncertainty with just how high the heat index goes. Guidance has a known bias toward higher dewpoints (especially the NBM) and the dewpoint is more of a driving factor in heat index than the temperatures. So for portions of the forecast where the NBM dewpoints are not being utilized, dewpoints and heat index values are going to take this bias into account. Some sites may flirt with heat advisory criteria Thu/Fri/Sat, but not confident much, if any, of the forecast area will actually hit 105 for 2 hours. Whether or not an advisory ends up being needed the key takeaway is Thu/Fri/Sat will be hot.

AVIATION /06Z TUESDAY THROUGH SATURDAY/
Mix of conditions this morning with coastal terminals MVFR/IFR and inland terminals VFR/MVFR. Do expect to see development of MVFR ceilings at both LBT in the next hour or so. Post front stratus will linger for a few hours after sunrise before mixing sets up and VFR returns for all sites. Isolated afternoon and evening storms possible, mainly affecting FLO and possibly LBT more in the evening.
Coverage will be quite limited by the marginal conditions. Therefore have not included SHRA or TSRA in the TAFs. Northeast to east winds through daybreak 5-10 kt veer to east and eventually southeast.
Speeds 10 kt or less outside of any isolated storms.

Extended Forecast.. MVFR/IFR ceilings possible Wed night.
Restrictions from isolated afternoon/evening storms possible each day, mainly inland. Otherwise VFR.

MARINE
Surface high building in from the north today leads to northeast flow this morning gradually veering to east and then southeast later this evening and tonight. Post front northeast surge weakens around daybreak with speeds dropping under 10 kt for today. The high then shifts southeast, taking up the typical Bermuda High position Wed.
South to southwest flow sets up in response and holds on into the weekend. Development of Piedmont trough and inland warming helps bump speeds over the waters later in the week. Winds will remain below advisory thresholds, but a solid 20kt+ is possible for 40-60 nm Thu/Fri and possibly Sat. Seas peak around 4 ft offshore Thu/Fri, but for most of the period seas will be 2-3 ft with occasional 4 ft thrown in.

ILM WATCHES/WARNINGS/ADVISORIES
NC...None.
SC...None.
MARINE...None.