textproduct: Melbourne

KEY MESSAGES

Issued at 250 AM EDT Thu Jun 18 2026

- Hot and humid conditions continue this week and into the weekend with a Heat Advisory in Effect today, as well as a Major to Extreme HeatRisk for all of East Central Florida through Friday. Residents and visitors should remain well-hydrated and seek breaks in the shade or A/C during the heat of the day.

- A Marginal Risk for Severe Storms exists on Friday. A Marginal Risk for Excessive Rainfall exists each day through Saturday.

- Increasing storm coverage is expected this afternoon through late week as deeper moisture moves across central Florida from the north. Storms will move from inland areas toward the Atlantic coast each afternoon with the potential for a few strong storms today and a few severe storms on Friday.

- A Moderate Risk of life-threatening rip currents persists at all central Florida Atlantic beaches into late week. Always swim near a lifeguard and never enter the water alone!

DISCUSSION

Issued at 250 AM EDT Thu Jun 18 2026

Currently-Tonight... KMLB radar imagery shows dry weather over east central Florida. GOES-16 satellite imagery and local observations indicate generally mostly clear to party cloudy skies. Current temperatures are in the mid 70s to around 80 degrees with dew points in the low to upper 70s.

Scattered to numerous generally east-southeast moving showers and lightning storms are forecast to develop this afternoon/evening as the east coast sea breeze pushes inland and converges with the west coast sea breeze, as well as outflow from previous storms. The greatest chance (40-70%) showers and lightning storms is from Brevard/Osceola counties northwards (20-40% to the south) where the greatest surface convergence is expected. Rain chances gradually diminish towards sunset as showers and storms push offshore. There is the potential for a few strong storms this afternoon with model guidance showing MLCAPE between 2,000-3,200J/kg, 0-6km shear as high as 20-40kts, and PWATs up to 1.7-2.4". A Marginal Risk for Excessive Rainfall exists today with the potential (5-14%) for minor flooding of roadways and low-lying areas. The main hazards with storms this afternoon will be frequent to excessive lightning, wind gusts up to 40-55mph, and heavy rainfall (2-4" with a 1-10 chance in excess of 4" up to 5"). Afternoon highs in the mid 90s are forecast this afternoon. A Heat Advisory is in effect from 11AM-7PM today for heat index values up to 108F-110F degrees. Remember to stay hydrated, wear light colored clothing, shift outdoor work away from 10am to 7pm, and take frequent breaks from the heat. Above normal to near record low temperatures in the mid 70s to around 80 degrees are forecast.

Friday-Sunday... A shortwave trough is forecast to track east- southeast over the southeastern US and northern Florida on Friday. Guidance shows upper-level perturbations pivoting ahead of and along the base of the trough from Brevard county northwards Friday afternoon and evening which will provide additional lift for strong to severe storms to develop. Scattered to numerous generally east-southeast moving showers (30-70%) and storms are forecast to develop into the afternoon and evening hours as surface coverage increases between the sea breezes and outflow from previous storms. Hi-res guidance indicates MLCAPE between 2,000-4,000 J/kg, 0-6km shear between 20- 50kts, 0-3km helicity up to 200-450 m^2/S^2, SHIP up to 1.0, SCP between 1-2, EHI as high as 1-3, and absolutely unstable mid-level lapse rates, coupled with PWATs between 1.7"-2.4" over east central Florida Friday afternoon and evening. Thus, a Marginal Risk for severe storms exists on Friday from northern Indian River county northwards. The time period for severe storms is from 2PM-9PM on Friday. Additionally, Marginal Risk for Excessive Rainfall exists Friday from Brevard county southward with the potential (5-14%) for minor flooding of roadways and low-lying areas. The main hazards with storms Friday afternoon will be frequent to excessive lightning, wind gusts up to 60 mph (5-14%), hail up to 1", and heavy rainfall (2-3" with a 1-10 chance in excess of 3" up to 4-6").

Rain chances remain high Saturday (50-80%) and Sunday (40-60%) as a "cool" front sags south just to the north or over far northern east central Florida. Scattered to numerous generally east-southeast showers and lightning storms are forecast into each afternoon and evening. A Marginal Risk for Excessive rainfall exists on Saturday for all of east central Florida with the potential(5-14%) for minor flooding of roadways and low-lying areas. There is the potential for a few strong storms each day which will be capable of frequent to excessive lightning, wind gusts up to 40-55mph, and heavy rainfall (2-3" with a 2-5% chance in excess of 3" up to 4-6"). Afternoon highs in the mid 90s are forecast Friday with a Major HeatRisk, as well as small portions of Brevard, Osceola, and St. Lucie counties in an Extreme HeatRisk. Afternoon highs in the low to mid 90s are forecast with a Moderate to Major HeatRisk. A Major and Extreme Heat Risk affects anyone without adequate cooling and hydration. Low temperatures in the mid to upper 70s are forecast.

Monday-Wednesday... Drier conditions are forecast into next week as high pressure develops over the eastern Gulf of America. Isolated to scattered showers (20-30/40%) and lightning storms are forecast into each afternoon as a weak east coast sea breeze moves inland and converges with weak west-southwest flow. Above normal (2-5F+) temperatures are expected to continue into next week with a Major HeatRisk Monday and a Major to Extreme HeatRisk Tuesday and Wednesday.

MARINE

Issued at 250 AM EDT Thu Jun 18 2026

Today-Friday... Favorable boating conditions are expected to become choppy into this evening with the western Atlantic ridge extended over southern Florida. Scattered to numerous generally offshore moving showers and lightning storms with the greatest potential from Brevard county northwards (some of which will have the potential to become strong today and severe on Friday) are forecast today. Southwest winds are forecast to back south- southeast into this afternoon at 10-15kts (up to 20kts over the offshore Volusia to Brevard county offshore waters this evening) with gusts to 20kts. Generally, south-southwest winds at 10-15kts with gusts to 20kts are forecast to back southeast into the afternoon from Brevard county southwards on Friday. Small Craft Should Exercise Caution over the Volusia to Brevard county offshore (20-60nm) waters this evening. Seas of 1-2ft with up to 3ft offshore are expected.

Saturday-Monday... Favorable boating conditions are expected. Isolated to scattered generally offshore moving showers and lightning storms are forecast into Saturday and Sunday afternoons/ evenings. The potential for a few strong storms exists. Southwest winds at 10-15kts with gusts to 20kts are expected to generally back south on Saturday before veering west and then east- southeast into Sunday as a "cool" front sags across the far northern waters or just to the north of the waters. Seas to 1-2ft are forecast.

AVIATION

(12Z TAFs) Issued at 735 AM EDT Thu Jun 18 2026

VFR at ECFL terminals outside of convection. SRLY flow increasing to around 10 kts by late morning will allow the east coast sea breeze to develop after 16z and gradually push inland, shifting winds along the coast SSE-SE at 10-15 kts with gusts to around 20 kts from KTIX-KSUA, and remaining around 10 kts to the north. A few SHRA/TSRA may develop on the east coast sea breeze, but pretty good agreement from hi-res models most activity will initially come from the west coast sea breeze (ISO-SCT) after 19Z, with high (50-70%) chances for SCT/NUM TSRA INVOF most ECFL terminals from KMLB-KMCO/KISM north after 21Z along the sea breeze collision. SWRLY steering flow will push TSRA/SHRA back towards the coast through the evening.

Added TEMPOs for TS impacts to KMCO and other inland terminals (except LEE), and along the coast from KDAB-KMLB. Timing trends on the earlier side of guidance. Kept KLEE and KVRB-KSUA at VC due to lower chances. TSRA/SHRA could linger well past 00Z, especially at KTIX-KMLB. Quiet overnight once convection dissipates or moves offshore.

PRELIMINARY POINT TEMPS/POPS

DAB 95 77 93 76 / 70 30 60 10 MCO 96 78 95 77 / 50 40 50 10 MLB 93 79 94 78 / 60 50 70 40 VRB 94 79 95 77 / 30 30 60 40 LEE 95 79 93 78 / 40 20 30 10 SFB 97 78 95 77 / 70 40 60 10 ORL 96 79 94 78 / 50 40 50 10 FPR 94 78 94 76 / 30 20 60 40

MLB WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory from 11 AM this morning to 7 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.