Marine Weather Net

Biscayne Bay Marine Forecast


REST OF TODAY

ESE
WINDS
15
KNOTS

TONIGHT

ESE
WINDS
15
KNOTS

SUNDAY

ESE
WINDS
10 - 15
KNOTS

SUNDAY NIGHT

SE
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
AMZ630 Forecast Issued: 857 AM EST Sat Feb 27 2021

SMALL CRAFT SHOULD EXERCISE CAUTION
Rest Of Today...East Southeast Winds Around 15 Knots With Gusts To Around 20 Knots. Bay Waters A Moderate Chop.
Tonight...East Southeast Winds Around 15 Knots With Gusts To Around 20 Knots. Bay Waters A Moderate Chop. Slight Chance Of Sprinkles After Midnight.
Sunday...East Southeast Winds 10 To 15 Knots With Gusts To Around 25 Knots. Bay Waters A Moderate Chop.
Sunday Night...Southeast Winds 10 To 15 Knots. Bay Waters A Moderate Chop.
Monday...South Southeast Winds 5 To 10 Knots. Bay Waters A Light Chop.
Monday Night...East Southeast Winds 5 Knots. Bay Waters Smooth.
Tuesday...East Winds 5 To 10 Knots. Bay Waters A Light Chop.
Tuesday Night...Southeast Winds Around 10 Knots. Bay Waters A Light Chop.
Wednesday...South Southwest Winds 10 To 15 Knots. Bay Waters A Moderate Chop.
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AMZ600: Synopsis for Jupiter Inlet to Ocean Reef FL out to 60 nm and for East Cape Sable to Bonita Beach FL out to 60 nm
857 AM EST Sat Feb 27 2021

An area of high pressure will dominate the weather pattern over the Atlantic and Gulf coastal waters through the weekend. A moderate southeasterly wind will increase through the weekend as the pressure gradient over the local waters tightens. This could cause seas to increase over the Atlantic waters where cautionary conditions are expected.

Gulf Stream Hazards: Wind gusts to around 25 kt and locally higher seas.
The approximate location of the west wall of the Gulf Stream as of Feb 27, 2021 at 1200 UTC...
- 9 nautical miles northeast of Fowey Rocks.
- 13 nautical miles east northeast of Port Everglades.
- 5 nautical miles east of Lake Worth.
- 8 nautical miles east southeast of Jupiter Inlet.
Area Forecast Discussion
National Weather Service Miami FL
1229pm EST Sat Feb 27 2021

UPDATE... A stout anticyclone aloft was centered over Cuba and the southeast Gulf of Mexico this morning with surface high pressure to our east over the Atlantic waters. Upstream troughing was located well away from our area over the western Gulf of Mexico. This setup will provide South Florida with warm and breezy conditions today. The 27.12z MFL sounding reveals a shallow layer of moisture at and below 850 mb which is supportive of this morning's isolated brief showers over the Atlantic waters and adjacent coastal areas of Palm Beach County. These showers should gradually dissipate through the late morning hours with dry weather for most areas this afternoon. Made a few small tweaks to dewpoints/relative humidity for this afternoon given possible fire weather concerns. It still appears the western inland areas should remain above critical relative humidity levels but will continue monitoring. Otherwise the primary concern for this weekend remains the high rip current risk for the Atlantic beaches. With that in mind... * Here are a few Rip Current safety tips:

- Remember that rip currents can sweep even the best swimmers away from shore into deeper water.

- Swim near a lifeguard (if possible).

* If caught in a rip current:

- Relax and float. Don't swim against the current.

- If able, swim in a direction paralleling the shoreline

- Once out of the rip current swim back to shore.

- If unable to escape, face the shore and call or wave for help.

The rest of the forecast is in good shape an no other meaningful changes are anticipated.

Patchy fog this morning along with the small chance for a coastal shower. Otherwise dry/VFR. ESE winds should trend SE this afternoon while increasing to around 15 kt. Gusts of 20-25 kt are expected after 14-15z and lasting until around sunset.

Short Term - Today Through Sunday
A little quieter this morning on KAMX. Most of the shower activity has ended, however, a few additional diurnally driven showers are still possible. For now, think the silent 10 POPs work well, but keep in mind it's not impossible for a rogue shower to develop and move into the Atlantic metro this morning. Still a small signal for shallow ground fog this morning across sheltered areas over the interior, but this should quickly dissipate after sunrise.

The dome of high pressure aloft will strengthen over Cuba this weekend. This will have a few implications on our local weather here in South Florida. For starters this will increase temperatures, especially across the interior with the favored southeasterly flow (almost summerlike). With subsidence/dry air aloft, intense surface heating will help mix down some drier air (see the Fire Weather Section below). Finally, outside of the low possibility of a rogue shower or two within the rich southeasterly flow and diurnal influences, precipitation will be very limited. In addition, southeasterly flow will further increase as pressure gradient from the strengthening surface high pressure over the Western Atlantic continues. Given the signals for well above average temperatures, kept the temperatures slightly above guidance across the interior and western Atlantic metros.

Tonight through Sunday the same story will unfold. After decoupling tonight, winds will still be around 8-12mph, which will limit the fog potential. Continued rogue shower or two over the Atlantic still expected and then Sunday breezy conditions, conditional fire weather concerns, and relatively intense surface heating all will continue similar to Saturday.

Long Term - Sunday Night through Friday
The extended period opens with a compact closed low impinging on the ridge anchored across western Cuba as the low traverses eastward. In response to the mid-upper level feature, a frontal boundary reflected at the surface unfurls across the Gulf Coast States and Northern Florida, which lies along the northern periphery of a surface high that is centered across the western Atlantic. This synoptic setup will help to maintain southeasterly to southerly flow across South Florida, reinforcing mostly dry and warm conditions through mid-week.

Compared to yesterday's divergence between global models, the latest iteration of the ECMWF (European Centre for Medium-Range Weather Forecasts) has come into somewhat better agreement with the GFS, which exhibits the ridge becoming shunted southward in response to the mid-upper low and zonal flow with weak embedded troughing becoming established aloft thereafter. Effectively, this will permit southward propagation of the aforementioned front towards South Florida, slightly increasing rain chances mid-week. Therefore, have reintroduced mentionable PoPs, mainly across Palm Beach County and the adjacent Atlantic waters. However, confidence in coverage remains on the lower side given the Euro's switch in scenario and disparities that persist between models thereafter for the end of the week. Consistency in agreement among future model runs will continue to be monitored each forecast cycle, along with the evolution of the weather pattern for the latter portion of the week.

With that said, the main story -- at least for the first portion of the extended period -- continues to be toasty daytime highs and "feel-like" temperatures. The warmest day is currently forecast to be Monday, with heat indices in the mid to upper 80s over the east coast metro areas to the lower 90s over portions of Glades, Hendry, and inland Collier Counties during the afternoon hours. These temperatures and heat indices should gradually decrease as the week progresses and the upper level ridging weakens.

VFR conditions will prevail through this cycle. There could be some interior patchy ground fog, but this shouldn't impact the primary TAF sites across South Florida. The highlight will be winds as southeasterly flow increases. Some gusts up to 20-25kt (especially Atlantic terminals) will be possible Saturday afternoon before decreasing around or shortly after sunset.

Marine Discussion
Southeasterly flow is on the increase. This increase in winds has led to the need for cautionary headlines across portions of the Atlantic. At times we will approach SCA (Small Craft Advisory) thresholds across the Atlantic waters. Winds will need to be closely monitored in case a short fused SCA (Small Craft Advisory) would need to be issued, especially the offshore Atlantic waters where winds will slightly be higher. Winds will decrease by late Tuesday as pressure gradient relaxes in closer proximity to a frontal boundary.

Fire Weather
With strong surface heating across interior Collier, Hendry, and Glades Counties, drier air will likely mix to the surface this afternoon. This drier air will drop relative humidity values to around 40 percent. Southeasterly winds will also begin to increase. Although critical fire weather thresholds aren't currently expected to be met, quick ignition and spread of fire would likely occur during the afternoon hours.

BEACHES... There will be a high risk of rip currents through the weekend as onshore flow increases along the Atlantic beaches. Remember that rip currents can sweep even the best swimmers away from shore into deeper water. If you plan to go into the water be sure to swim near a lifeguard. If caught in a rip current, relax and float. Don't swim against the current. If able, swim in a direction paralleling the shoreline...once out of the rip current swim back to shore. If unable to escape, face the shore and call or wave for help.


NOAA Miami FL Office: Watches - Warnings - Advisories
FL...High Rip Current Risk through Monday evening for FLZ168-172-173.

AM...None. GM...None.