textproduct: Charleston

WHAT HAS CHANGED

All sections have been updated.

KEY MESSAGES

- 1)Unsettled weather is expected from Wednesday into the weekend, with daily chances for showers and thunderstorms and the potential for locally heavy rainfall.

DISCUSSION

KEY MESSAGE 1: Unsettled weather is expected from Wednesday into the weekend, with daily chances for showers and thunderstorms and the potential for locally heavy rainfall.

Today: Our soggy end to the week has arrived as a rather wet and unsettled pattern begins today. Broad upper troughing continues to be firmly planted over the Great Lakes extending down towards the Tennessee valley today as a subtle shortwave lifts across the deep south. Broad southwesterly flow remains in place as PWATS continue to range in the 2.0 to 2.1 inch range. We will likely see a rather early start to showers and storms this afternoon compared to earlier in the week as the seabreeze moves inland and the upper shortwave provides enough kick to get things started early. Best chances for showers and thunderstorms will mainly be along and east of I-95 during the mid to late afternoon and like most summer days, a couple storms could get strong to severe as they cluster up. However, conditions are not quite as favorable for strong to severe storms as compared the last few and things look to be more towards a heavy rainfall threat. With PWATS greater than 2 inches and deep moist profiles, warm rain processes will be prevalent with these storms resulting in rather heavy rain rates. While storms may not linger over an area for too long, they will be able to put down 1 to 2 quick inches of rainfall if they do last longer than a half hour or so. If this were to happen over poor drainage areas around the metro then some minor flooding would be expected. As a result a good portion of the area is under a Marginal (level 1 of 5) risk for excessive rainfall. Storms should subside by the early evening with significantly soggier days coming later in the week.

Thursday through the Weekend: Upper level trough deepens across the Ohio River Valley Thursday, as a stationary front remains at the sfc. As noted in days past, will then see a pronounced cold front begin its journey southeastward across the Tennessee River Valley Friday, before stalling out across our area this weekend. Given all the boundaries in place, there will certainly be enough lift to work with, on top of PWATs near 2 inches, which is well above normal for this time of year. This combined with regional and mesoscale processes is expected to yield daily chances for showers and thunderstorms - especially in the afternoon and evenings. While most guidance generally agrees that coverage should remain scattered to numerous, overall confidence in exact timing and location still remain rather low. Thus, further refinements to the forecast are expected in the coming shifts as model consistency improves.

In regard to severe weather, can't rule out seeing a few isolated storms becoming strong to severe, and producing damaging winds and frequent lightning. However, think the main hazard to watch for in the coming days will be heavy rainfall - given the potential for slow moving, training, or back building storms. If these setups were to occur, could easily see locally high rainfall totals occur in a short period of time, increasing the potential for localized flooding or flash flooding, particularly in urban and low-lying areas.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Isolated thunderstorms have developed this morning in the vicinity of JZI/CHS. These showers and thunderstorms should move through the area over the next hour or so and could result in localized restrictions to MVFR or IFR. Elsewhere VFR conditions should prevail through the morning and into the afternoon. Scattered showers and storms should develop along the seabreeze around 17-18Z and possibly impact the TAF sites over the next few hours. Winds will be light out of the south.

Extended Aviation Outlook: Daily chances for showers and thunderstorms will continue through the weekend, with storms potentially producing temporary flight restrictions, reduced visibility, gusty winds, and brief periods of heavier rainfall each afternoon.

MARINE

Today: Winds will turn southerly by the morning and persist throughout the day around 10 knots becoming southwesterly at around 10 to 15 knots overnight. Seas will remain around 2 to 3 feet. Expect scattered to numerous showers and thunderstorms to develop overnight tonight across the marine waters. These storms will be capable of producing frequent lighting, gusty winds and increased seas.

Thursday through Sunday: South/southwesterly winds continue through the period, with winds averaging 15 knots or less and seas 2 to 3 feet. While Small Craft Advisories are not expected at this time, do want to highlight that any showers or thunderstorms moving over the waters will be capable of producing higher gusts and frequent lightning..

CHS WATCHES/WARNINGS/ADVISORIES

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