Marine Weather Net

Altamaha Sound to Fernandina Beach FL Marine Forecast


REST OF TODAY

S
WINDS
15 - 20
KNOTS

TONIGHT

S
WINDS
15 - 20
KNOTS

THURSDAY

SE
WINDS
15 - 20
KNOTS

THURSDAY NIGHT

S
WINDS
15 - 20
KNOTS

The Marine Weather Forecast In Detail:
AMZ450 Forecast Issued: 1216 PM EDT Wed Jul 08 2026

SMALL CRAFT EXERCISE CAUTION IN EFFECT FROM 4 PM THIS AFTERNOON TO 11 PM EDT THIS EVENING
Rest Of Today...Southwest Winds Around 10 Knots, Becoming South 15 To 20 Knots This Afternoon. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Southeast 3 Feet At 5 Seconds And East 2 Feet At 9 Seconds. Intracoastal Waters Choppy. A Slight Chance Of Showers And Thunderstorms This Afternoon.
Tonight...South Winds 15 To 20 Knots, Becoming Southwest 10 To 15 Knots After Midnight. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Southeast 4 Feet At 5 Seconds. Intracoastal Waters Choppy. A Slight Chance Of Showers And Thunderstorms In The Evening.
Thursday...Southwest Winds 10 To 15 Knots, Becoming Southeast 15 To 20 Knots In The Afternoon. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: South 3 Feet At 5 Seconds And East 2 Feet At 9 Seconds. Intracoastal Waters Choppy.
Thursday Night...South Winds 15 To 20 Knots, Becoming Southwest 10 To 15 Knots After Midnight. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Southeast 4 Feet At 5 Seconds. Intracoastal Waters Choppy.
Friday...Southwest Winds 5 To 10 Knots, Becoming South 15 To 20 Knots In The Afternoon. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Southeast 3 Feet At 6 Seconds And East 2 Feet At 9 Seconds. Intracoastal Waters Choppy.
Friday Night...South Winds 15 To 20 Knots, Becoming Southwest 10 To 15 Knots After Midnight. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: South 4 Feet At 5 Seconds. Intracoastal Waters Choppy.
Saturday...Southwest Winds 10 To 15 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Intracoastal Waters A Moderate Chop. A Chance Of Showers And Thunderstorms. Winds And Waves Higher In And Near Thunderstorms.
Sunday...Southwest Winds 10 To 15 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Intracoastal Waters A Moderate Chop. A Chance Of Showers And Thunderstorms. Winds And Waves Higher In And Near Thunderstorms.
SHARE THIS PAGE:           
Area Forecast Discussion
National Weather Service Jacksonville FL
1218pm EDT Wednesday July 8 2026

.KEY MESSAGES... For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

- Isolated To Widely Scattered Afternoon Thunderstorms Today,

- Decreasing Chances Through the Week. Wednesday: Peak Heat Index 105-111 Most Areas. Major Heat Risk through the rest of the Week

- Moderate Rip Current Risk Beaches Today

Near Term - Through Tonight
Main Highligheights through Tonight:

- Heat Advisory most areas today - Lower convective chances today

No major changes to the ongoing forecast as mid level ridge remains south of the local area with a hot and humid west to southwest steering flow across the region. PWATs (Precipitable Waters) still remain in the 1.7 to 1.9 inch range, so will still support widely scattered showers and storms this afternoon/evening, with a few strong storms still possible with gusty winds to 40-50 mph. The W-SW flow will keep the East Coast sea breeze pinned along the I-95 corridor this afternoon and will support the current Heat Advisory in place as Max temps still reach into the mid/upper 90s with peak Heat Indices in the 105- 110F range area-wide, and even some 110-115F readings into Coastal SE GA counties. Any lingering isolated storms this evening should fade after sunset with all activity ending by midnight or at least pushed into the Atlantic Coastal waters. Above normal temps continue overnight with lows in the mid/upper 70s inland and near 80F along the St. Johns River/Atlantic Coastal areas.

Short Term - Thursday Through Friday Night
Main Highligheights During This Period:

- Heat Advisory potential for Thursday and Friday Afternoons - Lower convective chances

Upper air ridging strengthens, limiting convection for the end of the work week. Precipitation chances Thursday remain isolated over north central Florida and the northeast FL coast south of St. Augustine in the afternoon and evening where some moisture lingers, with northeast Florida and southeast Georgia likely remaining dry on Friday. With mostly sunny skies and very limited showers and storms, dangerous heat will be the main concern both days. High temperatures will rise into the mid to upper 90s, even at the immediate Atlantic coast as southwesterly winds continue. Afternoon heat indices will approach 102-110 degrees both days, Heat Advisories may be necessary for portions of northeast Florida and the southeast Georgia coast.

Long Term - Saturday Through Wednesday
Main Highligheights During This Period:

- Heat Advisory potential Saturday Afternoon - Convective chances increase Sunday Onward

Convection will gradually increase daily Saturday onward, with coverage Saturday mainly isolated to scattered as both sea breezes push inland. Sunday, stronger southwest flow will bring higher convective chances closer to the I-95 corridor to the coast where the Gulf sea breeze meets the pinned Atlantic sea breeze later in the afternoon. Afternoon max heat index values remain dangerously high Saturday, approaching Heat Advisory conditions. By Sunday, temperatures drop a few degrees area-wide as more storms are expected.

Monday and Tuesday, precipitation chances increase to near 60-70% as a front approaches from the north. Higher cloud cover and storm chances will lower temperatures back to near normal in the lower to mid 90s to start off the new week.

Marine
High pressure ridge will remain anchored across central and south Florida this week as low pressure troughing develops to the north. This pattern will maintain a southwest flow through early afternoon followed by late afternoon and evening wind surges from the south to Small Craft Exercise Caution wind speeds. The offshore flow will allow for a slight chance of afternoon and evening thunderstorm over the local coastal waters each day through the week. Mariners should expect locally strong wind gusts and frequent lightning with any developing thunderstorms.

Rip Currents
Low to moderate risk of rip currents continues through the end of the week due to fairly low surf conditions from prevailing offshore flow. Some enhanced potential still looks likely for the northern beaches by late afternoon from Mayport northward due to stronger southeast wind component each day. Surf remains generally in the 1-2 feet range.

Fire Weather
PATCHY TO AREAS OF HIGH DISPERSION MAINLY NORTH OF I-10 FROM - Wednesday Through Saturday

High pressure will be the prevailing weather feature through Monday, with drier than normal conditions forecast through Saturday. This will lead to above average temperatures and dangerous maximum afternoon heat index values through Saturday. Southwesterly surface winds continue through Sunday, with patchy to areas of high afternoon dispersion north of I-10 expected each day. Despite drier air in place, minRH will remain above critical values. Precipitation chances increase early next week as a front approaches from the north.

Fog Potential and other remarks: Significant fog potential is not expected Tonight. Erratic wind gusts possible in and near thunderstorms, and at times, at a distance due to outflows.

Climate
Summer heat is certainly here. There is potential for some locations to get to the century mark today with probability of this occurrence at about 20-30 percent. These probabilities look a bit higher for Thursday and Friday.

For the next few days, here are the record high temperatures that are within 3 degrees of the current forecast:

July 8th: KJAX: 100/1879 KAMG: 100/1986 KCRG: 100/2016

July 9th: KJAX: 101/1879 KGNV: 99/1932 KAMG: 100/1986 KCRG: 101/2016

July 10th: KJAX: 102/1879 KGNV: 99/1914 KAMG: 99/1980 KCRG: 99/2016

July 11th: KGNV: 100/1900 KAMG: 100/1980 KCRG: 99/1998

July 12th: KGNV: 99/1902 KCRG: 99/1981

NOAA Jacksonville FL Office: Watches - Warnings - Advisories
FL...
Heat Advisory until 7pm EDT this evening for FLZ021-023-024- 030-031-035-038-120-124-125-132-136>138-140-220-225-232- 233-236-237-240-322-325-333-340-422-425-433-522-533-633. GA...
Heat Advisory until 7pm EDT this evening for GAZ132>136-149- 151>154-162-163-165-166-250-264-350-364.

Marine
None..