Fernandina Beach to St. Augustine, FL 20 - 60 NM Marine Forecast
|Today...Northeast Winds Around 20 Knots. Seas 6 To 8 Feet With A Dominant Period Of 9 Seconds. A Chance Of Showers With A Slight Chance Of Thunderstorms.|
|Tonight...Northeast Winds 15 To 20 Knots. Seas 5 To 7 Feet With A Dominant Period Of 8 Seconds. A Chance Of Showers With A Slight Chance Of Thunderstorms.|
|Saturday And Saturday Night...Northeast Winds 15 To 20 Knots. Seas 5 To 6 Feet With A Dominant Period Of 8 Seconds. A Chance Of Showers With A Slight Chance Of Thunderstorms.|
|Sunday And Sunday Night...Northeast Winds Around 20 Knots. Seas 6 To 7 Feet With A Dominant Period Of 7 Seconds. A Chance Of Showers With A Slight Chance Of Thunderstorms.|
|Monday And Monday Night...Northeast Winds Around 20 Knots. Seas 7 To 8 Feet. A Chance Of Showers With A Slight Chance Of Thunderstorms.|
|Tuesday And Tuesday Night...Northeast Winds Around 20 Knots. Seas 8 To 9 Feet. A Chance Of Showers With A Slight Chance Of Thunderstorms. Winds And Seas Higher In And Near Thunderstorms.|
| Area Forecast Discussion|
National Weather Service Jacksonville FL
438am EDT Fri September 29 2023
...COASTAL FLOOD WARNINGS REMAIN POSTED ALONG THE ATLANTIC COAST NORTH OF PONTE VEDRA BEACH... ...EXTENDED PERIOD OF STRONG ONSHORE WINDS, DANGEROUS RIP CURRENTS, AND ELEVATED TIDES CONTINUES INTO NEXT WEEK... Synopsis
Issued at 437am EDT Fri September 29 2023
Early morning surface analysis depicts strong high pressure (1028 millibars) centered over New England and wedging southward down the southeastern seaboard. Meanwhile, low pressure (1012 millibars) was taking shape along a stalled frontal boundary to the east of the North Carolina Outer Banks, with this boundary extending southward across the Interstate 4 corridor in central FL. Otherwise, coastal troughing has shifted eastward over the Gulf Stream waters adjacent to our local coastline. Aloft...a potent shortwave trough was pivoting eastward across eastern portions of the Great Lakes and the Mid-Atlantic region, with a longer wave trough extending southwestward from this feature along the northern Gulf coast. Ridging was building in the wake of this trough over the Ozarks and Tennessee Valley, with this narrow ridge axis extending northward to western portions of the Great Lakes. Latest GOES-East derived Total Precipitable Water imagery shows a large moisture gradient across our region, with PWATS falling to around 1.5 inches for locations from Waycross northward, while values remain at or above 2 inches for locations south of the I-10 corridor. Multi-layered cloudiness prevails across most of northeast and north central FL, while mainly high cloudiness was in place across southeast GA. A few showers continue to advect onshore across Flagler County, with a few occasional sprinkles or mist advecting onshore along the rest of the northeast FL coast. Temperatures and dewpoints at 08Z were in the 60s throughout southeast GA and the Suwannee Valley, with temperatures in the lower to mid 70s along the northeast FL coast, where dewpoints were closer to 70.
(Today and Tonight) Issued at 437am EDT Fri September 29 2023
Potent troughing will dig southeastward across the Mid-Atlantic states as ridging expands from the Ozarks and Tennessee Valley into the southeastern states. This ridging will advect a drier air mass over southeast GA today, with filtered sunshine allowing highs to rebound to the mid 80s at most inland locations. A tight pressure gradient will otherwise remain in place at coastal locations as strong high pressure centered over New England gives way to organizing low pressure east of the North Carolina Outer Banks, with this feature expected to pivot slowly northward off the Mid-Atlantic coast tonight. Breezy onshore winds will advect thicker stratocumulus cloud cover onshore all along the Atlantic coast today, with erosion in these lower clouds taking place from north to south during the mid to late afternoon hours today. These lower clouds will also remain in place for inland locations to the south of the Interstate 10 corridor. Occasional, mainly light showers and sprinkles will continue to move onshore today, mainly from St. Augustine southward as the drier air mass advects across I-10 during the afternoon hours. Gusty onshore winds will keep coastal highs around 80, with highs across inland locations reaching the mid 80s.
Mid and high altitude cloudiness will begin to increase from southwest to northeast overnight as a shortwave trough takes shape near the FL panhandle coast, developing a weak wave along the stalled frontal boundary over central FL that will begin to strengthen isentropic lift/overrunning to the north of the stalled frontal boundary. A few showers will continue to occasional advect onshore, mainly for locations from around St. Augustine southward. Despite thickening mid and high level cloud cover, a drier low level air mass should allow lows to fall to the mid and upper 60s for locations along and north of I-10, with lower 70s elsewhere inland. Breezy onshore winds will keep coastal lows generally in the low to mid 70s.
.SHORT TERM... (Saturday and Sunday) Issued at 437am EDT Fri September 29 2023
Drier air will remain in place over southeast Georgia this weekend, with slightly higher than average PWATs (Precipitable Waters) lingering over northeast Florida, allowing for overall scattered showers and isolated thunderstorms. Saturday, a front will be stalled over central Florida, enhancing the coverage of onshore moving precipitation, especially over north central Florida. By Sunday, the front will shift southward, lowering Probability of Precipitation to the 15-40% range over the northeast Florida coast and north central Florida. With partly cloudy skies, temperatures will be just below normal, and due to a tighter local pressure gradient, northeast winds will be elevated, especially near the coast.
(Monday through Thursday) Issued at 437am EDT Fri September 29 2023
Similar temperatures and precipitation coverage will exist each day during this period as strong high pressure to our north sinks south into the Mid Atlantic region through Tuesday and then shift to our NE over the waters off the Mid Atlantic and NE US coastline by Wednesday. This setup will lower PWATs (Precipitable Waters) and allow elevated northeasterly winds to continue through midweek. Each day, scattered showers will be possible mainly over the Atlantic coast, and drifting inland over north central Florida. Isolated thunderstorms will be possible as well, mainly in the afternoons.
Issued at 437am EDT Fri September 29 2023
Strong high pressure centered over New England will continue to wedge down the southeastern seaboard today before retreating eastward on Saturday as low pressure organizes off the Mid- Atlantic coast. Small Craft Advisory conditions will prevail through around sunset near shore, as speeds will remain near 20 knots, with seas of 5-8 feet both near shore and offshore. Elevated seas may extend into the evening hours offshore, with winds expected to fall back to Caution levels of 15-20 knots near shore, with seas subsiding to 4-6 feet. Caution conditions are expected to prevail both near shore and offshore on Saturday and Saturday night.
Meanwhile, coastal troughing over the offshore waters will continue to develop scattered showers and a few thunderstorms today and tonight, with a few showers developing over the near shore waters from St. Augustine southward. Coastal troughing will then push towards the near shore waters on Saturday, with showers and a few thunderstorms briefly increasing in coverage, especially across the northeast Florida waters. Another high pressure center will then build over the eastern Great Lakes on Sunday and will wedge down the southeastern seaboard through midweek, resulting in northeasterly winds restrengthening and seas rebuilding to Small Craft Advisory levels by Sunday afternoon and evening throughout our local waters. Coastal troughing will redevelop offshore on Monday and will push westward across the near shore waters on Monday night and Tuesday, accompanied by another round of showers and a few thunderstorms.
High Surf / Rip Currents
Breakers of 5-7 feet will prevail through at least Saturday at the northeast FL beaches, where a High Surf Advisory remains posted. Breakers of 3-5 feet are forecast at the southeast GA beaches. A high risk of deadly rip currents will continue during the next several days at all area beaches.
Issued at 437am EDT Fri September 29 2023
Tide levels peaked just below moderate flood levels during the Thursday evening high tide along the Atlantic coast from Fernandina Beach northward, while levels were mostly in the minor flood category for locations along the Atlantic coast to the south of Fernandina Beach as well as within the St. Johns River basin and the Intracoastal Waterway (ICWW). The higher of the two daily high tides along the Atlantic coast will shift to the mid to late morning high tide beginning today and extending through the weekend, and we expect water levels to approach moderate flood levels from Jacksonville Beach northward, where a Coastal Flood Warning remains posted. Water levels will continue to reach minor flood levels around the times of high tide for locations from Ponte Vedra Beach southward, as well as within the ICWW and the St. Johns River basin, where Coastal Flood Advisories remain posted. Astronomically high tides associated with lunar perigee and the full moon will peak during the weekend, with moderate flooding possible all along the Atlantic coast during the late morning and early afternoon hours. We may need to extend the Coastal Flood Warning southward tonight for these expected higher weekend tides. Water levels should peak at minor flood levels for locations along the ICWW and within the St. Johns River basin through the weekend, with some risk for a few locations south of downtown Jacksonville approaching moderate flood levels by late in the weekend or early next week.
NOAA Jacksonville FL Office: Watches - Warnings - Advisories
FL...Coastal Flood Advisory until 4am EDT Saturday for FLZ033-038- 132-133-137-138-225-325.
Coastal Flood Warning until 11pm EDT this evening for FLZ124- 125.
High Rip Current Risk through late Saturday night for FLZ124-125- 133-138.
High Surf Advisory until 8pm EDT Saturday for FLZ124-125-133- 138.
GA...Coastal Flood Warning until 11pm EDT this evening for GAZ154- 166.
High Rip Current Risk through late Saturday night for GAZ154-166.
AM...Small Craft Advisory until 8pm EDT this evening for AMZ450-452- 454-470-472-474.