textproduct: Charleston

WHAT HAS CHANGED

An update was issued around 02/20z to introduce a mention of isolated showers across parts of the Charleston Tri-County, mainly over central/upper portions of Charleston County and southern/eastern portions of Berkeley County. KCLX shows isolated to scattered showers, mostly light in nature, poised to move onshore there. The risk for some light measurable rainfall will persist until about an hour or two after sunset.

The Aviation Section was updated to reflect the 03/00z TAFs.

KEY MESSAGES

- 1) Warm temperatures will continue, with isolated to scattered showers and thunderstorms possible through Saturday.

- 2) A cold front could bring increased rain chances late this weekend into early next week.

DISCUSSION

KEY MESSAGE 1: Warm temperatures will continue, with isolated to scattered showers and thunderstorms possible through Saturday.

Strong mid-level ridging centered over the Atlantic will continue to extend across the forecast area through the first part of the weekend. At the surface, the sub-tropical high will continue to be the primary influence. There are hints in hi-res guidance that we could see a bit of diurnal convection, especially on Friday. However model soundings aren't particularly impressive showing weak instability and warm profiles. Within the broader onshore flow, we could see isolated to scattered convection develop beginning around midday or early afternoon, then progress inland through the late afternoon. Hard to expect much more than isolated to scattered coverage, with only limited potential of seeing a thunderstorm or two. Saturday looks even less supportive, with a notable mid- level inversion. Temperatures will remain well above normal for early April, with low to mid 80s inland of the coastal corridor.

KEY MESSAGE 2: A cold front could bring increased rain chances late this weekend into early next week.

As noted in days past, a broad mid-level trough and sfc cold front will settle across the eastern U.S. late this weekend into early next week, resulting in increased chances for precipitation. That being said, should see largely dry conditions prevail at least through late-morning Sunday as the aforementioned front lingers across the Tennessee River Valley. Rain chances then increase through the afternoon and evening as the boundary pushes southeastward toward the Atlantic. While wind fields do look to gradually increase, there isn't much instability to work with, which should keep the threat for severe weather low. In regard to precipitation, overall moisture with this system still remains rather meager, with most guidance supporting accumulations less than 0.5 inch. Thus, do not expect to see any significant improvements to the ongoing drought conditions at this time.

Notably cooler temperatures look to return Monday in the wake of FROPA, with afternoon highs in the upper 60s to 70s continuing through the end of the period. A secondary mid-level wave may dive across the southeast CONUS late Monday into Tuesday, resulting in a weak low pressure and additional rain chances. However, model certainty with this feature remains poor, making it difficult to put too much confidence behind any one solution just yet. Certainly something to keep an eye on in the coming days.

AVIATION /21Z THURSDAY THROUGH TUESDAY/

03/00z TAF Discussion: KCHS/KJZI/KSAV: VFR for much of the period. The risk for an isolated showers near KCHS and KJZI will linger through about 02z. Shallow ground fog could develop just before daybreak, mainly at KSAV. No major impacts are expected. There is a low- end risk for a shower or tstm to impact mainly KCHS and KSAV with the sea breeze Friday afternoon. Probabilities are too low this far out to include a mention at this time.

Extended Aviation Outlook: There will be increased chances for flight restrictions associated with FROPA Sunday into early Monday.

MARINE

Through Saturday Night: Overall, conditions should remain pretty quiet and below Small Craft Advisory thresholds. Winds will continue to be primarily onshore with speeds mostly topping out in the 10-15 knot range. Seas are expected to be 2-4 feet across the nearshore waters and 3-5 feet across the outer waters.

Sunday through Tuesday: A cold front will push through the region late Sunday into Monday, producing gusty northeasterly winds and building seas across our waters early next week. Small Craft Advisories are likely across a majority of our local waters starting Monday and could persist with a second front/enhanced pressure gradient arriving/developing into the middle of next week.

CHS WATCHES/WARNINGS/ADVISORIES

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