textproduct: Melbourne

KEY MESSAGES

Issued at 314 PM EDT Fri Jul 18 2025

- Very warm and humid conditions with peak afternoon heat indices up to 110 and Major HeatRisk impacts continue across portions of East Central Florida through early next week.

- Rain and lightning storm chances remain below normal through the weekend, then chances increase once again next week as a weakening front and high moisture approach from the north.

DISCUSSION

Issued at 314 PM EDT Fri Jul 18 2025

Currently...Quite the stark contrast to only a couple days ago, with just a few weak showers developing on lake breeze boundaries across the northern counties where where the environment remains more favorable for deep convection. The main headline is now the heat, as mid-level high pressure moves overhead and subsidence increases temperatures, which combined with the lingering surface moisture and low rain chances, is making for some gross conditions this afternoon.

Rest of Today...A Heat Advisory remains in effect for all of East Central Florida through 6 PM for heat indices up to around 108 and Moderate to Major HeatRisk impacts, due to the combination of humidity and temperatures pushing into the L-M90s this afternoon. While PWATs are much higher to the north (still up to around 2") than down south (around 1.6" and dropping to near 1.4" along the coast), most of the drier air contribution in the the mid-levels and the surface remains pretty humid. Dewpoint temperatures are fairly consistent across the area as is the cu-field, expect along the coast behind the sea breeze, with the higher heat indices and greater HeatRisk impacts across the north due to more southerly flow and little to no onshore relief. The drier mid- levels, especially to the south, have been very hostile to deep convection. Continuing 20-40 pct chances for showers and storms this afternoon and evening, highest (such as the are) across the interior in the late evening with the sea breeze collision, but these chances may turn out to be on the optimistic as entrainment kills updrafts. That said, any storms that manage to develop will be capable of producing frequent lightning strikes, wind gusts to 45 mph, and brief heavy downpours. Activity diminishes late this evening, with drier air beginning to slowly move across the area during the overnight hours.

Saturday-Sunday...(Modified Previous Discussion) The mid-level ridge remains situated overhead of Florida through this weekend, with the Atlantic high and its ridge axis centered across the peninsula. Light southerly winds are forecast to become more southeasterly along the coast each afternoon as the east coast sea breeze develops and moves inland, with a low chance for shower and storm development along the sea breeze. The greatest chances for any shower and storm activity is focused near and north of the I-4 corridor on Saturday and across the interior west of I-95 on Sunday. Confidence in storm development also remains low (40 percent), but if any were to develop, they may be capable of producing lightning strikes, gusty winds, and brief heavy downpours. Any activity that manages to develop is anticipated to diminish into the late evening hours, with dry conditions prevailing overnight.

Hot and humid conditions persist across the area into the weekend, especially with limited cloud coverage allowing for greater daytime heating. While temperatures increase a bit more this weekend, slightly drier air filtering in especially Saturday will provide a small offset, complicating the prospect of reaching Heat Advisory conditions. Afternoon highs climb into the low 90s along the coast and into the mid 90s across the interior, and could push towards the upper 90s on Sunday. Peak heat indices are again forecast to near and/or exceed advisory criteria each day, so will continue to monitor the need for any Heat Advisories over the next few days. Additionally, Moderate to Major HeatRisk is forecast across east central Florida, meaning residents and visitors alike should take proper precautions to prevent heat stress. Adequate hydration, frequent breaks in the shade and air conditioning, wearing light colored clothing, and shifting outdoor activities away from the hours of peak heat will be key to preventing heat-related illnesses through this weekend. Lows remain seasonable in the low to mid 70s each night.

Monday-Thursday...(Modified Previous Discussion) The mid-level ridge shifts westward out across the Gulf into the work week, allowing a weakening frontal boundary to push southward towards Florida and the local Atlantic waters through mid to late week. This will lead to a return of PWATs exceeding 2 inches and greater locally, allowing for greater shower and storm coverage across east central Florida. Stuck closer to climatology with a 50 to 70 percent chance of rain and a 50 percent chance of storms each afternoon. It is still too early to determine exact storm threats with any activity that does develop, but lightning strikes, gusty winds, and heavy downpours leading to minor, localized flooding will all be possible.

Heat concerns persist into Monday, with highs reaching the mid 90s and peak heat indices still forecast near advisory criteria. By Tuesday and beyond, the greater moisture and increased cloud coverage will help limit daytime heating, with highs reaching the low 90s. Peak heat indices remain just below advisory criteria at 100 to 107 in the extended, but will continue to monitor. Overnight lows remain seasonable in the low to mid 70s.

MARINE

Issued at 314 PM EDT Fri Jul 18 2025

Generally favorable albeit hot boating conditions expected through the weekend as the ridge axis of the Atlantic high slides slowly south across Florida and the local Atlantic waters. Winds veer from SE-S south of the ridge axis to S-SW to the north, backing to the SE-E each afternoon as the east coast sea breeze develops and moves inland, at 5-15 kts. The Atlantic high weakens and slides further south early next week as a weakening front pushes south through the western Atlantic towards the Southeast Seaboard and Florida. Winds become more westerly Monday and Tuesday between these two features. Increasing moisture will once again return very high storms chances and cloud cover, which could disrupt formation of the sea breezes in the afternoons. Seas 1-3 ft.

AVIATION

(18Z TAFs) Issued at 145 PM EDT Fri Jul 18 2025

Mostly VFR. Shower and storm coverage forecast to be lower today, ranging from isolated to scattered, and mainly focused across the interior late afternoon through early evening. Have kept VCTS at KMCO/KSFB/KISM due to lower rain chances today (up to 30-40%), and have continued a tempo group for MVFR TSRA impacts at KLEE from 22-24Z. Will continue to monitor in case additional tempo groups are needed for any shra/tsra later today. Winds S/SE around 5-8 knots, becoming E/SE behind the sea breeze up to 10-15 knots, with some gusts up to 20-25 knots possible along the coast. Winds then diminish into tonight to 5 knots or less.

PRELIMINARY POINT TEMPS/POPS

DAB 75 92 75 94 / 10 20 0 20 MCO 76 96 76 97 / 20 20 0 30 MLB 77 91 76 93 / 10 10 0 20 VRB 75 91 74 92 / 10 10 0 10 LEE 77 94 77 94 / 30 30 0 30 SFB 76 95 76 96 / 20 20 0 30 ORL 77 96 77 96 / 20 20 0 30 FPR 75 91 73 92 / 10 10 0 10

MLB WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory until 6 PM EDT this evening for FLZ041-044>046-053- 058-141-144-154-159-164-247-254-259-264-347-447-547-647-747.

AM...None.