Marine Weather Net

Fernandina Beach to St. Augustine, FL Out 20 NM Marine Forecast


REST OF TODAY

NNE
WINDS
15 - 20
KNOTS

TONIGHT

NNE
WINDS
15 - 20
KNOTS

FRIDAY

NNW
WINDS
15 - 20
KNOTS

FRIDAY NIGHT

NW
WINDS
20 - 25
KNOTS

The Marine Weather Forecast In Detail:
AMZ452 Forecast Issued: 929 AM EST Thu Nov 14 2019

SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 PM EST THIS AFTERNOON
Rest Of Today...North Northeast Winds 15 To 20 Knots. Seas 5 To 7 Feet With Occasional Seas Up To 9 Feet. Dominant Period 8 Seconds. Inland Waters Choppy. A Chance Of Showers.
Tonight...North Northeast Winds 15 To 20 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 8 Seconds. Inland Waters Choppy. Showers And A Chance Of Thunderstorms.
Friday...North Northwest Winds 15 To 20 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 7 Seconds. Inland Waters Choppy. Showers And A Slight Chance Of Thunderstorms.
Friday Night...North Northwest Winds 20 To 25 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 7 Seconds. Inland Waters Choppy. Showers Likely.
Saturday...North Northwest Winds 20 To 25 Knots With Gusts To Around 35 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet Building To 6 To 9 Feet With Occasional Seas Up To 11 Feet In The Afternoon. Dominant Period 7 Seconds. Inland Waters Rough. A Chance Of Showers.
Saturday Night And Sunday...North Winds 20 To 25 Knots. Seas 6 To 8 Feet With Occasional Seas Up To 10 Feet. A Chance Of Showers And A Slight Chance Of.
Sunday Night...North Northwest Winds 10 To 15 Knots. Seas 5 To 7 Feet With Occasional Seas Up To 9 Feet.
Monday...North Northwest 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
929 AM EST Thu Nov 14 2019

A coastal trough over the waters will continue to produce moderate winds and hazardous seas for small craft through rest of today. This trough will move onshore and lift slowly northward over the Georgia waters tonight as weak low pressure develops over the southeast Gulf of Mexico. A low pressure center will lift northeastward across north Florida on Friday morning, entering the northeast Florida waters Friday afternoon. Low pressure will then become stationary over the Gulf Stream waters off the Georgia coast this weekend as it strengthens, bringing strong northerly winds and building seas to our waters.

Gulf Stream
The approximate location of the west wall of the Gulf Stream as of Nov 14, 2019 at 1200 UTC...
- 53 nautical miles east northeast of Flagler Beach.
- 48 nautical miles east of Saint Augustine Beach.
- 53 nautical miles east of Jacksonville Beach.
- 71 nautical miles east southeast of St Simons Island.
Area Forecast Discussion
National Weather Service Jacksonville FL
946am EST Thu Nov 14 2019

Complex forecast with overrunning cloud and increasing chance of precipitation today, with front to our south and approaching shortwave trough from our west. Current forecast handles situation well with increasing rain chances starting over our west zones over the next few hours and then spreading eastward in the afternoon and well into tonight. With any precipitation we have today, it is expected to be light...but then picks up tonight with widespread rainfall. Sharp inverted surface trough near the coast will gradually fade during the day but should continue to see some shower activity near this trough before it moves out. A few changes to the temps to lower highs a bit over parts of northeast FL and over most of southeast GA...given the current low cloud cover and the increase mid level clouds streaming in from the west.

Marine
Main change was to increase seas a bit this morning and based on this have extended the nearshore SCA (Small Craft Advisory) into this afternoon. Coastal trough near the coast is culprit for the stronger winds near the coast. But this trough will tend to break down this afternoon and by tonight. Rest of forecast on track.

.NEAR TERM [Today through Tonight]...Surface high pressure ridge to the north will shift east today. A coastal trough has sharpened over the Atlantic waters and will linger today producing a few coastal showers and gusty winds along the coast. To the west a southern stream upper trough now located over northern Mexico will move east and phase in with northern stream trough over the lower Ms River Valley tonight. This will form a surface low over the eastern Gulf of Mexico which will move across north Florida tonight reaching the Fl east coast by late tonight. Widespread rain will develop across the area this evening as isentropic lift combines with the approach of surface low and upper trough. Weak elevated instability may result in isolated embedded thunder over ne Fl late tonight. PWAT (Precipitable Water) values will surge to near 1.8" tonight which will likely result in rainfall amounts reaching 1-2 inches by early Friday morning.

Short Term
FRI THROUGH SUN... Synopsis...Cloudy & wet Fri-early Sat, then dry Sat night into Sun. Below normal temperatures, no frost/freeze. Cloudy and wet as a surface low lifts NE from near the local FL Atlantic coast Fri morning to offshore of the Carolina Coast through midday while the parent upper level trough continues to dig across the eastern Gulf Coast states. Plenty of moisture and dynamical lift to support widespread rainfall, with a sliver of instability along a surface trough axis across our coastal waters extending south across Flagler & Putnam counties to produced isolated t'storms Fri morning. As surface low tracks farther NE away from the local area Fri afternoon, expect persistent rainfall to tapper off from west to east.

As parent upper level low approaches from the west Fri afternoon into Fri evening, another surface low is expected to form offshore of the SE Atlantic coast Fri night with a return of more persistent, widespread rainfall along a surface trough axis pivoting southward across the local area around this secondary surface low into Saturday. High moisture and strong dynamical lift will override a cool, stable low level airmass with t'storms not expected. Locally heavy rainfall will be possible, with a blustery NNE developing Sat afternoon into Sat evening with gusts 25-35 mph at times along the local coast as the second surface low deepens offshore of the local coast as it phases with the upper level system. The bulk of rainfall with this system is expected to fall over SE GA where storm total rainfall amounts from 00Z Fri (Thu night) through 00 Sunday (Sat night) range from 2-4 inches amongst 00Z operational GFS/ECMWF/NAM12 with generally 0.5-1.5 inches across much of NE FL.

This low will lift NE away from the local waters Sat evening, with local rain chances ending from west to east Sat afternoon. Brief mid level ridge builds over the local area Sat night into Sunday night with mostly dry conditions and a cool northerly flow over the local area, with breezy conditions continuing near the Atlantic coast.

Temperatures will trend below normal this period with highs in the mid/upper 50s across SE GA to the low/mid 60s across NE FL, possible some low 70s only on Fri across our SE FL zones in the morning...then cooling into the afternoon into the 60s trailing wake trough frontal passage. Low temperatures will also trend below normal with 40s/50s Fri night, then temperatures cooling into the mid/upper 30s across SE GA Sat night to the low/mid 40s across NE FL. Too much wind and lingering low clouds for frost formation Sat night.

Long Term
MON THROUGH THU... Cool and dry Monday as weak surface ridge builds over the local area, then a brief shot of showers Monday night into Tuesday as the last long wave trough and surface front cross the the SE region. Pattern transitions Wed-Fri with drier conditions and moderating temperatures as stacked high pressure builds over the SE region. A chance of coastal showers returns Thu as onshore flow develops. A cooler airmass will remain in place this period with temperatures remaining below normal values with highs generally in the 60s to near 70 and lows in the 40s inland to 50s coast.

Marine
Strong northeast winds will continue Small Craft Advisory today as coastal trough has sharpened which will maintain strong NNE winds near the coast this morning. Seas will stay elevated and Advisory will continue offshore through this evening. The pressure gradient will begin to tighten again late Friday through the weekend as a low pressure system moves off the southeast coast and intensifies. Gusts to gale force possible Friday night through Saturday. Winds and seas will decrease below headline criteria by Monday.

Rip Currents
A high risk of rip currents today due to strong onshore winds and rough surf. Moderate risk on Friday as winds become offshore.

Coastal Flooding: Minor coastal flooding still possible near times of high tides today as strong NNE winds persist. Tides expected to peak around 1.5 feet above MHHW.

NOAA Jacksonville FL Office: Watches - Warnings - Advisories
FL...Coastal Flood Advisory until 5pm EST this afternoon for Clay- Coastal Duval-Coastal Flagler-Coastal Nassau-Coastal St. Johns-Inland Duval-Inland Flagler-Inland Nassau-Inland St. Johns-Putnam.

High Rip Current Risk until 7pm EST this evening for Coastal Duval-Coastal Flagler-Coastal Nassau-Coastal St. Johns.

GA...Coastal Flood Advisory until 5pm EST this afternoon for Coastal Camden-Coastal Glynn-Inland Camden-Inland Glynn.

High Rip Current Risk until 7pm EST this evening for Coastal Camden-Coastal Glynn.

AM...Small Craft Advisory until 10pm EST this evening for Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM- Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM.

Small Craft Advisory until 2pm EST this afternoon for Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM- Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM-Coastal waters from St. Augustine to Flagler Beach FL out 20 NM-Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM..