Charleston Harbor Marine Forecast
| Today...Sw Winds 5 Kt, Becoming S 15 Kt With Gusts To 20 Kt Late. |
| Tonight...Sw Winds 10 To 15 Kt With Gusts To 20 Kt, Diminishing To 5 To 10 Kt After Midnight. |
| Mon...W Winds 5 To 10 Kt, Becoming Sw 10 To 15 Kt In The Afternoon. |
| Mon Night...Sw Winds 10 To 15 Kt, Diminishing To 5 Kt After Midnight. |
| Tue...W Winds 5 Kt, Becoming Sw 10 To 15 Kt In The Afternoon. |
| Tue Night...S Winds 10 Kt. |
| Wed...Sw Winds 5 To 10 Kt. |
| Wed Night...Sw Winds 10 Kt. |
| Thu...Sw Winds 10 To 15 Kt. |
| Thu Night...S Winds 10 To 15 Kt. Unless Otherwise Noted, Waves 1 Foot Or Less. Charleston Harbor Water Temperature 81 Degrees. |
| Area Forecast Discussion National Weather Service Charleston SC 401am EDT Sunday May 26 2019 ...ALL TIME RECORD HIGHS FOR THE MONTH OF MAY COULD BE CHALLENGED TODAY AS THE A PROLONGED, EARLY SEASON HEAT WAVE CONTINUES... Synopsis: High pressure and unseasonably hot conditions will persist most of this week. Some relief from the oppressive heat is expected by next weekend. Near Term - Through Today It will be another hot and oppressively hot day as the stagnant synoptic pattern featuring anomalously strong deep-layered high pressure will remain largely unchanged across the Southeast States. Mid-level heigheights will fall about 10dm across Southeast South Carolina and Southeast Georgia as the center of the mean anticyclone retrogrades ever so slightly to the south/southwest, but H8 temperatures are forecast to rise another 1C through the day. This will yield a modest westerly flow which will pin the sea breeze to the immediate coast until late in the afternoon. A pinned sea breeze coupled with ongoing dry soil/drought conditions, warmer 1000-850 hPa temperatures and a slightly warmer start to the day, should allow highs to warm about 1-2 degrees higher than what was observed Saturday afternoon. The warmest conditions look to occur the Metter-Reidsville-Savannah- Springfield-Beaufort corridor where H8 temperatures are forecast to reach 21-22C. Expect highs to range from from 100-103 inland to the upper 80s/lower 90s at the beaches. It appears the all time record highs for May could be challenged at both KCHS and KSAV. NAEFS once again shows 1000 hPa temperatures peaking 2-3 standard deviations above the daily mean. Dewpoints are expected to mix out in the lower 60s inland from the sea breeze, then pool back into the lower-mid 70s across the coastal counties as the sea breeze moves inland. Heat indices are expected to peak 103-107F in a large corridor from Reidsville to Charleston with 100-103F at the beaches and locations well inland adjacent to the CSRA and Southern Midlands. A combination of an impact-based and criteria-based Heat Advisory will be issued for most zones from 11am until 8 PM. Although the advisory looks marginal for many areas, widespread record, early season heat and ongoing Memorial Day weekend activities where may folks will be outside support the issuance of a cautionary advisory. Warm mid-level temperatures, a deep dry column, and broad subsidence aloft should negate the development of any convection today. Could see a very brief shower try and form along the sea breeze across mid-upper Charleston County where low-level convergence will be the strongest, but any moist updraft that can develop should quickly dissipate as extensive dry air gets entrained. Will show a small areas of probability of precipitation around 5% across parts of mid- upper Charleston County as well as eastern Berkeley County mid- late afternoon with 0% probability of precipitation elsewhere. Sunny skies this morning will give way to another shallow, high- based cumulus field this afternoon yielding mostly sunny to partly cloudy conditions Short Term - Tonight Through Wednesday Tonight: Warm and humid with lows in the lower 70s well inland to around 80 at the beaches and Downtown Charleston. Memorial Day through Wednesday: The mid-levels will consist of strong high pressure centered over the FL Panhandle Monday morning. The center of the high is forecasted to drift into the northeastern Gulf of Mexico late Monday, then remain there through Wednesday. Heigheights over our area will slowly drop through Tuesday. But then they may rise a bit Wednesday as the periphery of the high tries to build back into the Southeast. NAEFS still shows 500 mb heigheights peaking at about 2 standard deviations above normal Monday and above normal temperatures at almost all levels of the atmosphere at that time. At the surface, areas of high pressure will stretch from the western Atlantic into the Southeast states through Wednesday. Each afternoon weak thermal troughing will develop either over or nearby our inland areas each day. But strong subsidence and a very dry atmosphere will stop any convection from forming. The only moisture will be fair weather clouds each afternoon. The heat wave will continue with temperatures forecasted to reach or exceed record values throughout the short term. For the high temperatures, we continued the blend of models, thickness values, and accounted for the location of the sea breeze. Monday appears to be the hottest day in the short term because the sea breeze may be pinned to the coast for most of the day, allowing most temperatures away from the beaches to reach at least 100 degrees. Tuesday highs may be a degree or two cooler. What helps is the sea breeze may make it farther inland earlier in the day. This same trend is expected again on Wednesday. Lows each night will only cool down into the 70s. Dew points will initially mix out each afternoon, then increase along the coastal corridor as the sea breeze moves inland. Heat indices will be close to 105 degrees on Monday and Tuesday, which is Heat Advisory criteria Long Term - Wednesday Night Through Saturday The mid-level ridge will remain in place Wednesday night, then finally flatten out Thursday night followed by zonal flow Friday and Saturday. Surface high pressure will continue to dominate our weather pattern through Thursday. The models still show a cold front approaching our area Friday or Saturday. They have trended wetter, which seems a little suspicious considering the front will be running into our very dry airmass. We opted to only introduce slight chance POPs Friday and Saturday. But early indications are rainfall amounts won't put much of a dent in our drought. Temperatures will trend downwards each day. However, they are still forecasted to remain above normal. Marine Discussion Through Tonight: South to southwest winds will prevail through the period. Directions will locally back to the southeast along parts of the Georgia coast with the formation of the sea breeze. Speeds will be 10-15 kt today, then rise to about 15 kt to locally 15-20 kt tonight with a nocturnal surge. Seas will average 1-3 ft. Monday through Thursday: Atlantic high pressure will remain the dominant synoptic feature. Winds will mostly be from the SW, backing a bit during the day with the sea breeze and veering a bit at night with the the nocturnal low level jet. Away from the gusty sea breeze, winds will mainly stay at or below 15 kt through midweek. Seas will peak at 3-4 ft Climate The ongoing heat wave will challenge or break many of these records: EARLIEST 100 DEGREE TEMPERATURES: KCHS: June 2, 1985. KSAV: May 25, 2019 and 1953. KCXM: June 1, 1985. ALL TIME RECORD HIGHS FOR MAY: KCHS: 99 set May 21, 1938. KSAV: 101 set May 30, 1898 and May 31, 1945. KCXM: 99 set May 21, 1938 and May 26, 1953. RECORDS FOR SUN 05/26... Station Record High Year(s) ------- ----------- ------- KCHS 98 1953 KSAV 100 1953 Station Record High Min Year(s) ------- --------------- ------- KCHS 75 1998 KCXM 79 1998 RECORDS FOR MON 05/27... Station Record High Year(s) ------- ----------- ------- KCHS 98 1989 KSAV 98 1989, 1962 KCXM 95 1962, 1926 Station Record High Min Year(s) ------- --------------- ------- KCHS 76 1991 KSAV 77 1878 KCXM 78 1991 RECORDS FOR TUE 05/28... Station Record High Year(s) ------- ----------- ------- KCHS 97 1967, 1964 KSAV 96 1964, 1898 KCXM 93 2000 Station Record High Min Year(s) ------- --------------- ------- KCHS 76 2000 KSAV 76 1885 KCXM 80 2000 RECORDS FOR WED 05/29... Station Record High Year(s) ------- ----------- ------- KCHS 95 1945 KSAV 98 1945, 1898 Station Record High Min Year(s) ------- --------------- ------- KCHS 76 2018 KSAV 75 1885 KCXM 77 1998 RECORDS FOR THU 05/30... Station Record High Year(s) ------- ----------- ------- KCHS 95 2004 KSAV 101 1898 Station Record High Min Year(s) ------- --------------- ------- KCHS 75 1982 KSAV 75 1924 KCXM 78 1998 RECORDS FOR FRI 05/31... Station Record High Year(s) ------- ----------- ------- KCHS 98 1953 Station Record High Min Year(s) ------- --------------- ------- KCHS 77 2004 KSAV 75 2004 RECORDS FOR SAT 06/01... Station Record High Min Year(s) ------- --------------- ------- KCHS 77 1974 KSAV 76 1880 Equipment The Downtown Charleston (KCXM) observation will be unavailable until further notice. The cause of the outage is unknown. Technicians will address the outage on Tuesday. WFO Charleston will only conduct upper-air soundings at 12Z until further notice due to a shortage of helium NOAA Charleston SC Office: Watches - Warnings - Advisories GA...Heat Advisory from 11am this morning to 8pm EDT this evening for GAZ099>101-114>119-137-138-140. SC...Heat Advisory from 11am this morning to 8pm EDT this evening for SCZ042>045-047>052. MARINE...None |
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