textproduct: Melbourne

KEY MESSAGES

Issued at 1207 AM EST Tue Nov 18 2025

- Patchy morning fog and a moderate risk of life-threatening rip currents are our notable hazards this week.

- Temperatures continue to nudge above normal as high pressure stays in control.

- Outdoor plans will be greeted with plenty of sunshine. Most locales will remain rain-free for at least the next week.

DISCUSSION

Issued at 1207 AM EST Tue Nov 18 2025

-----------Synoptic Overview-----------

As expected, broad and flat upper-level ridging is making its way eastward and is now centered over the Gulf. This feature is bookended by an unusually deep trough over California and the stout Rex Block over the Canadian Maritimes and Greenland. The Rex Block is forecast to weaken as additional energy reinvigorates the trough over the West, all but ensuring that H5 heights will continue to build over the Southeast U.S. through the course of the work week.

A rather classic split-flow jet configuration develops over the Western and Central U.S. late this week with downstream confluence over the Ohio Valley. As disturbances are dampened by the mid-latitude confluent flow to our north, one should anticipate continued quiet and warm conditions over Florida. A weak feature passes through the Tennessee Valley on Saturday, slightly decreasing heights over Florida late in the weekend. However, ensemble means suggest the ridge will strengthen yet again early next week. Overall confidence is high through early next week, lifted by a relatively low spread in the 17/12Z membership.

A weak front is dissipating over Central Florida tonight. It's easiest to analyze with the gradual dew point discontinuity over the peninsula. High pressure over the Appalachians this morning will push offshore by tonight, its axis stretching westward to Florida for the latter portion of the week. Modest onshore breezes will keep a modified mT air mass over much of the state for the remainder of the week. Another weak front is expected to reach Florida late Sunday into Monday. Once again, the front is forecast to dissipate overhead as continental surface high pressure pushes toward the Eastern Seaboard by Monday, thwarting any change in air mass.

Since we remain relatively quiet and the holiday season is approaching, let's peek beyond the 7-day. The 17/12Z ensembles show two distinct mid-latitude disturbances over the U.S. for Thanksgiving week. The first signal passes through the Eastern U.S. around Tuesday the 25th; this feature should be on a weakening trend, with a majority of members showing little/no impacts to east central Florida. The second signal approaches the state sometime around Black Friday; there is a little better potential for a clean frontal passage with this disturbance. However, any sort of a cool down behind the Thanksgiving weekend disturbance looks short-lived: additional Pacific energy is likely to reach the U.S. West Coast as a ridge emanating from the Antilles attempts to expand poleward - all consistent with the (expected) MJO phase 7 analog.

Bottom line: any individual model runs showing a significant, lasting cold air outbreak over Florida over the next couple of weeks should be greeted with a dose of skepticism. Extended/weekly guidance persistently suggests that cold risks will increase by mid- December; this corresponds with a potential for both MJO phase 8 and a weak and/or displaced polar vortex in the wake of a stratospheric warming event.

-------Sensible Weather & Impacts-------

Remainder of the Work Week...

A bit of lingering moisture from the old front may be just enough to spark a few showers today through early Wednesday, primarily along the Treasure Coast. These rain chances are 20% or less, so most places will remain dry. Status quo weather is then expected over the coming days as high pressure dominates. Temperatures will remain above normal, particularly in the afternoons, with many spots reaching the low/mid 80s.

Patchy fog is forecast each overnight and early morning as winds remain light. There is a low risk for dense fog development. However, this forecast is tricky as some modestly drier air sneaks into the boundary layer late today through Wednesday - near and north of Interstate 4. For this reason, have deviated slightly lower than statistical guidance for dew points in the afternoon hours.

Weekend - Next Week...

Winds attempt to turn offshore this weekend as a front approaches from the north, ensuring continued warm 80s each afternoon (perhaps upper 70s behind the sea breeze at the coast). Patchy morning fog will remain possible, especially over rural locations. Guidance pushes the front into Central Florida and dissipates it by Monday, briefly turning winds northerly before switching back onshore. Despite the front, statistical guidance keeps us rain-free with negligible change in temperatures.

Aside from a low potential for some coastal showers today and again during the middle of next week, the odds of receiving measurable rain remain quite low through at least Thanksgiving Day. The front arriving late next week may provide our next "best" chance for rain - but there are a lot of questions to answer before we can say that with any confidence.

MARINE

Issued at 1207 AM EST Tue Nov 18 2025

High pressure over the Central Appalachians will drift offshore of Cape Hatteras over the next 24 hours, allowing onshore breezes enhanced nearshore by the daily sea breeze. The axis of this high pressure system will extend westward to Florida later this week before being displaced southward this weekend. Aside from a few showers through Wednesday, no significant weather is forecast this week, leading to favorable conditions for nearshore boating.

Nearshore seas 1-3 FT through Wednesday, lessening to 2 FT or less on Thursday and Friday. Seas offshore will be slightly higher, 3-4 FT, through early Thursday. Afternoon breezes NE to E 5-10 KT, subtly enhanced at the coast as the sea breeze develops. Winds turn offshore less than 5 KT overnight.

AVIATION

(18Z TAFs) Issued at 1220 AM EST Tue Nov 18 2025

Weak high pressure is producing a relaxed pressure gradient with L/V winds gradually transitioning to light onshore component. Winds will become L/V to calm this evening and overnight. Skies MClear. A few light Atlc showers may approach the coast later today/tonight and will monitor - but for now keeping "Vicinity" mention out of coastal TAFs. Patchy fog (MVFR/local IFR conds) possible late overnight into early Wed morning. Inclusion into TAF sites may eventually be necessary.

FIRE WEATHER

Issued at 1207 AM EST Tue Nov 18 2025

Over the next couple of days, seasonably deep mixing (4+ KFT) should tap into some drier air aloft over northern portions of east central Florida. Away from the coast and along the I-4 corridor, RH minima are forecast to range from 35-45% both afternoons today and Wednesday. Afternoon breezes becoming NE less than 10 mph. Light to calm winds and excellent RH recovery are forecast each night, so smoke from any fires will have the potential to mix with patchy fog.

RH values are expected to remain above elevated or critical thresholds beginning Thursday in all areas.

PRELIMINARY POINT TEMPS/POPS

DAB 59 81 58 80 / 10 0 0 0 MCO 60 83 60 83 / 0 0 0 0 MLB 61 80 61 80 / 0 0 0 0 VRB 61 81 62 81 / 10 0 0 0 LEE 58 82 58 83 / 0 0 0 0 SFB 59 83 59 83 / 0 0 0 0 ORL 60 82 61 82 / 0 0 0 0 FPR 61 81 62 81 / 10 0 0 0

MLB WATCHES/WARNINGS/ADVISORIES

FL...None. AM...None.