Marine Weather Net

Altamaha Sound, GA to Fernandina Beach, FL 20 - 60 NM Marine Forecast


15 - 20


10 - 15


10 - 15


5 - 10

The Marine Weather Forecast In Detail:
AMZ470 Forecast Issued: 911 PM EDT Sat Mar 28 2020

Rest Of Tonight...South Winds 15 To 20 Knots...Shifting To The Southwest Toward Early Morning. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 5 Seconds.
Sunday...South Winds 10 To 15 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 5 Seconds.
Sunday Night...South Winds 10 To 15 Knots Becoming West Southwest After Midnight. Seas 2 To 4 Feet. Dominant Period 5 Seconds.
Monday...Northwest Winds 5 To 10 Knots Becoming Northeast In The Afternoon. Seas 2 To 3 Feet. Dominant Period 5 Seconds.
Monday Night...Southeast Winds 5 To 10 Knots Becoming South Southwest After Midnight. Seas 2 To 3 Feet. Dominant Period 8 Seconds.
Tuesday...South Southwest Winds 10 To 15 Knots. Seas 2 To 4 Feet. Dominant Period 8 Seconds. A Chance Of Showers And A Slight Chance Of Thunderstorms.
Tuesday Night...West Winds 15 To 20 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Showers Likely And A Chance Of Thunderstorms.
Wednesday...Northwest Winds 15 To 20 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet.
Wednesday Night...North Winds 10 To 15 Knots. Seas 2 To 4 Feet.
Thursday...North Northeast Winds 5 To 10 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet.
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AMZ400: Synopsis for Altamaha Sound GA to Flagler Beach FL out to 60 nm
911 PM EDT Sat Mar 28 2020

Surface high pressure ridge will be located south of the area through the weekend. A south to southwest flow will continue, becoming southeast near the coast each afternoon. A weak, dry cold front will push through the area late Sunday night and Monday morning with another stronger cold front pushing through the local waters Tuesday night with potential for Small Craft Advisory conditions. High pressure will build north of the area Wednesday and Thursday.

Gulf Stream
The approximate location of the west wall of the Gulf Stream as of Mar 28, 2020 at 1200 UTC...
- 71 nautical miles east of Flagler Beach. 79 nautical miles east of Saint Augustine Beach.
- 90 nautical miles east of Jacksonville Beach.
- 102 nautical miles east southeast of St Simons Island.
Area Forecast Discussion
National Weather Service Jacksonville FL
926pm EDT Sat Mar 28 2020

After record highs again today, temps are back down into the 70s at 9pm this evening with clear skies. Another hot and dry day expected for Sunday.

Satellite imagery shows some thin high cirrus over the area, with a large mid-upper level ridge located over FL and eastern GOMEX. Similar to prior nights, moist southwest flow above the surface will usher in some low stratus to portions of the area late tonight and early Sunday morning, with potential for some dense fog. The highest chance of dense fog and stratus appears to be across the Suwannee Valley again into parts of inland southeast GA. Main update change was to add in some dense fog wording for these areas around the 5AM-9AM Sunday time frame. Otherwise...only minor tweaks to the forecast.

SCEC headline for the marine waters looks good. At 9 PM, C-MAN SAUF1 south at 18 knots, with JAX beach at 17G22kt. Consensus of model guidance shows winds should shift around the southwest later tonight and slowly decrease. Rest of the forecast is on track.

Near Term - Through Tonight
Synopsis...High pressure aloft will remain over the region through the weekend, keeping well above normal temperatures and rain-free conditions in place.

Tonight: Moist Low level flow off the NE GOMEX will help to develop another round of dense fog across the Suwannee Valley/I-75 corridor of inland North FL, spreading northward into inland SE GA through sunrise and dense fog advisories may be needed again if it becomes widespread. Lows will be in the mid 60s.

Short Term - Sunday Through Monday Night
Sunday: Strong mid/upper level ridging over the Central Gulf of Mexico through the Florida peninsula continues to dominate our weather pattern. The region will remain characterized as hot and dry as a subsidence inversion above the surface keeps our region suppressed and rain free. Seabreeze development will be pinned mainly along the coast somewhat dampening the effects of heating near the beaches, but overall all locations will experience very warm and above average and record temperatures. Highs once again in the lower/middle 90s inland and the beaches will be in the upper 80s/near 90 degrees as sea breeze struggles to develop late in the day.

Sunday night: High pressure ridge at the surface and aloft gets shunted a tad southward as weak frontal boundary with very little moisture pushes south near the FL/ GA border region Sunday Night. Lack of moisture will keep rain chances near nil. Minimums will be above normal with lows in the 60s.

Monday and Monday night: The frontal boundary will linger and around the I-10 corridor as a weak residual boundary. A zonal flow aloft will persist over the region as a short wave trough moves into the Lone Star State. Weaker SW flow will allow for sea breeze fronts to push further inland for slightly cooler temps at the Atlantic beaches in the lower 80s, but highs into the lower 90s will continue over far inland areas. By Monday night, the aforementioned short wave trough moves into the ArkLaMiss region with attendant front moving into western Mississippi. High clouds will start increasing late Monday night. Lows Monday night will be in the 60s.

Long Term - Tuesday through Saturday
Tuesday and Tuesday night: A low pressure system will develop over the SE US on Tuesday and deepens as it tracks into the Carolinas Tuesday evening. This will lead to one more day of above normal heat with highs in the mid to upper 80s area-wide with breezy SW flow ahead of the trailing cold frontal passage expected by Tuesday Night. Storm Prediction Center has portions of the Suwannee Valley and SE GA in the Day 4 outlook for a severe potential. Precipitable water values rapidly increase Tuesday afternoon and evening between 1.50 and 1.75 inches with CAPES increasing (750-1000 J/kg) with decent low level shear. Pre-frontal showers and storms can be expected with potential for isolated severe storms, with best chances of rainfall and localized severe weather across SE GA with lessening storm impacts and rainfall coverage into NE FL. The front should push south of the area Tuesday night with cooler and drier air filtering into the area.

Wed-Sat...overall cooler conditions mid week as high pressure system builds north of the area over the TN and Ohio Valleys. behind the cold front. Generally progress flow aloft with ridge aloft moving through the eastern U.S. Thursday night and Friday. As a result, a surface ridge will push offshore of the Carolinas allowing low level winds to veer and airmass to moisten and warm a bit. A series of shortwaves will push into the MS and Ohio Valleys early Friday and into the southeast states Friday night through Saturday. Associated isentropic ascent aloft and an approaching cold front will lead to increasing rain chances into Friday and Saturday. Have capped POPs at 20-30 percent for now due to a few differences in how the GFS and ECMWF (European Centre for Medium-Range Weather Forecasts) handle this system. Temps will be closer to climatology with highs in the 70s to some lower 80s. Min temps in the 40s to lower 50s Thursday morning will moderate to the lower to middle 50s as clouds increase through latter portions of this period.

NOAA Jacksonville FL Office: Watches - Warnings - Advisories
FL...None. GA...None. AM...None.