textproduct: Melbourne

KEY MESSAGES

Issued at 145 PM EST Thu Dec 18 2025

- Poor to hazardous boating conditions will exist across portions of the coastal waters into tonight and Friday morning.

- Rain chances increase slightly into tonight (up to 20-40 percent), with isolated lightning storms also possible, mainly over the coastal waters.

- Highs will be above normal through Friday, in the upper 70s to low 80s for much of the region, then turning cooler behind a cold front Friday night.

DISCUSSION

Issued at 145 PM EST Thu Dec 18 2025

Current-Tonight...Scattered (gusty) showers moving northward early this afternoon, with steering flow expected to veer thru the afternoon and evening (SW --> NE). An increase in moisture ahead of an approaching weak cold front will promote a 20-40pct chance of offshore-moving showers thru tonight. PWAT values will surge to 1.45-1.65" across ECFL late today into tonight. Isolated lightning storms are possible, though instability remains marginal at best and expect greatest chances to remain over the coastal waters. Primary storm impacts include lightning strikes, gusty winds locally, and brief downpours. Cell movement should be SW to NE at 25-35 mph. Showery precip diminishes thru late evening and overnight. A weakening mid-level trough will push a weak cold front into the FL Panhandle tonight nudging high pressure across the western Atlc further seaward. The pressure gradient will be a little tighter this afternoon with SERLY winds increasing to 10-15 mph over the interior and 15-20 mph (at times) along the coast with higher gusts. Winds decrease this evening while continuing to veer S/SW.

After highs in the U70s to L80s this afternoon, expect a mild night out ahead of the approaching front with mins generally in the 60s areawide and conditions humid. Forecast models are suggesting some low stratus and fog towards morning, but with 925 mb winds at 20-25 kts, tend to be more comfortable with low clouds vs fog, though will not be surprised by some patchy fog in spots.

Fri-Sun...The front will approach the area Fri morning, moving thru ECFL during the day and evening (north --> south). Suspect there will be some low stratus clouds around during the morning in association with the front before improvement in skies during the afternoon. Passage of the front will be mainly dry, except some lingering showers - perhaps an ISOLD storm over the local coastal waters. Winds continue to veer WRLY/NWRLY with approach/passage of the boundary as speeds average 10-15 mph. Speeds decrease to 5-10 mph Fri night. High pressure builds into the region behind the front while on a weakening trend into the weekend, but ridging will be reinforced across the Appalachians/mid Atlc states by late Sun/Sun night. Light northerly early morning winds on Sat veer onshore during the day continuing NNE/NE thru the weekend.

Highs Fri remaining above normal in the U70s with some L80s south from Orlando. Only slightly cooler into Sat/Sun and still above climo with M70s coastal Volusia and U70s and a few L80s southward. The coldest night will be Fri overnight with U40s to around 50F north/west of I-4 and L-M50s for much of the rest of the interior, except U50s to L60s along the coast - M-U60s possible for coastal St. Lucie/Martin counties. Generally 50s and L60s for Sat/Sun overnight periods. Conditions mainly dry - though could see some light (ISOLD) shower activity develop over the coastal waters for Sun/Sun night.

Mon-Wed...Previous Modified...A strong area of high pressure builds toward the Mid-Atlantic region and further into the southeast U.S. into mid-week, with a weak "backdoor" front moving in from the north- northeast and pushing south-southwest across the area. This will lead to a breezy E/NE flow developing, transporting isolated to scattered showers over the waters onshore. For now continue PoPs around 20 percent along the coast for Mon. Pressure gradient looks to then gradually relax through mid-week, with high pressure just north of the area, maintaining onshore winds and mostly dry conditions Tue/Wed. Temperatures remain near to above normal, with highs in the 70s and lows in the M50s to L60s.

MARINE

Issued at 145 PM EST Thu Dec 18 2025

Afternoon-Tonight...Poor to hazardous boating conditions present across the local waters - mainly offshore/Gulf Stream. SERLY winds 15-20 kts with seas building to 4-6 ft and a little higher over the Gulf Stream. Winds continue to veer S/SW tonight with speeds increasing to 20 kts offshore Volusia/Brevard and seas building to 5-7 ft here where a Small Craft Advisory goes into effect now at 21Z/4PM thru the overnight and into Fri morning. Cautionary Statements will continue for Treasure Coast offshore waters and may have to drag back to near shore Treasure Coast waters for a while this evening as seas/winds here remain elevated. Scattered, gusty showers, continue with ISOLD lightning storms possible late today and tonight well out ahead of an approaching weak cold front. Cell movement will veer to become offshore-moving later this afternoon and tonight.

Fri-Fri night...A cold front approaches the northern waters by late morning continuing to press southward during the day/early evening (south). ISOLD-WDLY SCT showers/ISOLD lightning storms will continue during the morning and early afternoon - primarily offshore. Poor to hazardous boating conditions continue during the period for offshore marine zones. WRLY winds will slowly decrease into the afternoon and Fri night as the front passes and winds continue to veer to NW. Seas 5-6 ft may linger (well) offshore north of Sebastian Inlet thru Fri aftn-night. Seas 3-5 ft elsewhere.

Sat-Mon...Previous Modified...Boating conditions improve into the weekend, as winds veer onshore Sat and then become N/NE into Sun. Wind speeds drop to 5-10 kts, with seas falling to 3-5 ft Sat and 2- 4 ft through the daytime Sun. It will be mostly dry through the weekend, but isolated showers will be possible at times Sun into Mon.

Another front is forecast to push through the waters from the northeast to southwest into early next week, with a strong area of high pressure moving in toward the Mid-Atlantic states. This will increase winds out of the E/NE by early Mon, with seas quickly building, leading to another round of poor to hazardous boating conditions. Trends from latest model run are for stronger winds Sun overnight and Mon with seas building higher as well!

AVIATION

(18Z TAFs) Issued at 1255 PM EST Thu Dec 18 2025

Scattered SHRA lifting N/NW across the area in breezy/gusty SE flow with a few cloud layers. Conds have become mostly VFR but SHRA will produce brief MVFR conds as well as gust up to 30 knots possible in the more robust shallow convection. Flow veers S to SW overnight and model guidance is pinging on stratus across the northern terminals. Have inserted TEMPO for IFR stratus at LEE/SFB/DAB late tonight/early Fri where NBM probs are near 40% for IFR conds. At MCO, NBM probabilities are 40-50% for MVFR and around 30% for IFR. So inserted a TEMPO MVFR conds there around sunrise. May eventually need to lower the CIGs at MCO.

PRELIMINARY POINT TEMPS/POPS

DAB 65 78 52 73 / 20 0 0 0 MCO 68 80 54 78 / 20 10 0 0 MLB 66 81 59 76 / 20 10 0 0 VRB 66 82 61 78 / 20 10 0 0 LEE 65 78 48 74 / 30 0 0 0 SFB 66 80 51 75 / 20 0 0 0 ORL 67 79 53 75 / 20 10 0 0 FPR 66 83 60 78 / 20 10 0 10

MLB WATCHES/WARNINGS/ADVISORIES

FL...None. AM...Small Craft Advisory until 10 AM EST Friday for AMZ570-572.