909
FXUS62 KMLB 211054
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
654 AM EDT TUE JUL 21 2026
..NEW AVIATION
KEY MESSAGES
ISSUED AT 300 AM EDT TUE JUL 21 2026
- DRIER AIR WILL LIFT NORTHWARD ACROSS EAST CENTRAL FLORIDA
STARTING TODAY AS TROPICAL STORM BERTHA SHIFTS FARTHER WEST,
THOUGH ISOLATED SHOWERS AND STORMS CANNOT BE RULED OUT THIS
AFTERNOON. LOWER RAIN CHANCES ARE FORECAST THROUGH THE REMAINDER
OF THE WORK WEEK.
- MOISTURE IS FORECAST TO INCREASE THIS WEEKEND AND INTO EARLY
NEXT WEEK, CAUSING RAIN AND STORM CHANCES TO RETURN TO NEAR-
NORMAL VALUES SATURDAY ONWARD.
- NEAR TO ABOVE-NORMAL AFTERNOON TEMPERATURES WILL PERSIST THROUGH
THE PERIOD WITH PEAK HEAT INDICES EXCEEDING 100F EACH DAY.
PRACTICING HEAT SAFETY WILL BE KEY TO AVOID HEAT-RELATED
ILLNESS!
DISCUSSION
ISSUED AT 300 AM EDT TUE JUL 21 2026
TODAY-TONIGHT...TROPICAL STORM BERTHA REMAINS ACROSS THE
NORTHEASTERN GULF AND IS FORECAST TO LINGER, SLOWLY MOVING WEST-
NORTHWEST TODAY. WHILE THERE WILL CONTINUE TO BE NO DIRECT IMPACTS
ACROSS EAST CENTRAL FLORIDA, THIS PARTICULAR SET-UP WILL KEEP
SOUTH TO SOUTHEAST WINDS IN PLACE LOCALLY. THE TIGHT PRESSURE
GRADIENT DUE TO THE PROXIMITY OF BERTHA WILL ALSO KEEP CONDITIONS
BREEZY AND GUSTY AT TIMES, WITH WIND SPEEDS OF 10 TO 15 MPH AND
WIND GUSTS UP TO 20 MPH POSSIBLE. WIND ENHANCEMENTS DUE TO THE
DEVELOPMENT OF THE EAST COAST SEA BREEZE WILL ALSO BE POSSIBLE AT
TIMES. WHILE DRIER AIR IS LIFTING NORTHWARD ACROSS THE FLORIDA
PENINSULA AS SEEN ON THE GOES 19 TOTAL PWAT VIEWER AND WILL HELP
LIMIT RAIN AND STORM CHANCES TODAY, THERE CONTINUES TO BE HI-RES
GUIDANCE SUPPORTING ISOLATED TO SCATTERED DEVELOPMENT THIS
AFTERNOON, PRIMARILY DUE TO SEA BREEZE INTERACTIONS ACROSS THE
CENTRAL FLORIDA PENINSULA. HAVE KEPT A 20-30% CHANCE OF SHOWERS
AND STORMS ACROSS THE INTERIOR THIS AFTERNOON, WITH ISOLATED
NORTHWARD-MOVING SHOWERS AND STORMS POSSIBLE ACROSS THE LOCAL
ATLANTIC WATERS. STEEP LOW-LEVEL LAPSE RATES, SBCAPE OF 1500-2000
J/KG, AND DRIER AIR ALOFT PUSHING DCAPE VALUES TO 1000+ J/KG WILL
SUPPORT FREQUENT LIGHTNING STRIKES AND WIND GUSTS TO 50 MPH WITH
ANY STORMS THAT MANAGE TO DEVELOP. HEAVY DOWNPOURS AND MINOR,
LOCALIZED FLOODING ALSO CANNOT BE RULED OUT. ACTIVITY ACROSS THE
PENINSULA IS FORECAST TO DIMINISH INTO THE EVENING HOURS, WITH
LINGERING SHOWERS AND STORMS POSSIBLE ACROSS THE LOCAL WATERS.
ABOVE NORMAL TEMPERATURES IN THE MID 90S ARE FORECAST AREAWIDE
THIS AFTERNOON, COMBINING WITH HUMID CONDITIONS TO CREATE PEAK
HEAT INDICES OF 100-107F. ADEQUATE HYDRATION, FREQUENT BREAKS IN
THE SHADE OR AN AIR-CONDITIONED BUILDING, AND LIGHTWEIGHT, LIGHTLY
COLORED CLOTHING WILL ALL BE CRUCIAL FOR THOSE SPENDING EXTENDED
PERIODS OF TIME OUTDOORS TO REDUCE THE RISK OF DEVELOPING HEAT-
RELATED ILLNESS. LOWS REMAIN IN THE 70S.
WEDNESDAY-THURSDAY...TROPICAL STORM BERTHA WILL CONTINUE WESTWARD
ACROSS THE NORTHERN GULF THROUGH THE MIDDLE OF THIS WEEK, WHICH
WILL ALLOW THE ATLANTIC HIGH TO LIFT NORTHWESTWARD TOWARDS THE
FLORIDA PENINSULA. THE PRESSURE GRADIENT WILL GRADUALLY WEAKEN
ACROSS EAST CENTRAL FLORIDA, ESPECIALLY BY THURSDAY. SOUTH TO
SOUTHEAST WINDS WILL REMAIN BETWEEN 10 TO 15 MPH ON WEDNESDAY WITH
GUSTS TO 20 MPH POSSIBLE AT TIMES. BY THURSDAY, WIND SPEEDS FALL
TO 5 TO 10 MPH. WIND SPEED ENHANCEMENTS DUE TO THE SEA BREEZE WILL
BE POSSIBLE, PARTICULARLY ALONG THE COAST. A DRY AIR MASS IN THE
WAKE OF BERTHA IS ANTICIPATED TO REMAIN IN PLACE LOCALLY, HELPING
TO LIMIT RAIN AND STORM CHANCES TO AROUND 20% OR LESS ACROSS EAST
CENTRAL FLORIDA BOTH WEDNESDAY AND THURSDAY. ANY SHOWERS OR STORMS
THAT DO MANAGE TO DEVELOP WILL LIKELY BE ALONG OR AHEAD OF THE
SEA BREEZES, WITH ACTIVITY DIMINISHING INTO THE EVENING HOURS.
OVERALL, ANTICIPATE MOSTLY DRY CONDITIONS ACROSS EAST CENTRAL
FLORIDA THROUGH THURSDAY. THE DRIER AIR WILL ALSO HELP LIMIT
CLOUD COVERAGE, AND WITH THE RETURN OF HIGH PRESSURE OVERHEAD,
TEMPERATURES ARE FORECAST TO TREND WARMER LOCALLY. HIGHS IN THE
LOW TO MID 90S ARE ANTICIPATED, WITH THE WARMEST TEMPERATURES
FOCUSED NEAR AND NORTH OF THE I-4 CORRIDOR. PEAK HEAT INDICES OF
100-107F ARE FORECAST EACH AFTERNOON, SO THOSE SPENDING EXTENDED
PERIODS OF TIME OUTDOORS WILL NEED TO REMAIN ADEQUATELY HYDRATED
AND TAKE FREQUENT BREAKS IN THE SHADE OR AN AIR-CONDITIONED
BUILDING TO AVOID HEAT-RELATED ILLNESS. OVERNIGHT, NEAR-NROMAL
TEMPERATURES ARE FORECAST WITH LOWS IN THE 70S.
FRIDAY-MONDAY...BROAD MID-LEVEL RIDGING WILL REMAIN IN PLACE
ACROSS THE SOUTHERN US LATE THIS WEEK, WITH A TROUGH ACROSS THE
EASTERN US GRADUALLY DIGGING SOUTHWARD TOWARDS FLORIDA INTO THIS
WEEKEND AND EARLY NEXT WEEK. AT THE SURFACE, BROAD HIGH PRESSURE
IS FORECAST TO REMAIN SITUATED ACROSS THE LOCAL ATLANTIC WATERS ON
FRIDAY, WITH THE HIGH GRADUALLY PUSHING SOUTHWARD THIS WEEKEND AS
A LOW MOVES OFFSHORE THE CAROLINAS AND DRAGS A FRONTAL BOUNDARY
SOUTHWARD ACROSS THE SOUTHEASTERN US. THE BOUNDARY WILL STALL
ACROSS NORTH FLORIDA ON SUNDAY, CONTINUING TO DRIFT SOUTHWARD
TOWARDS THE PENINSULA INTO EARLY NEXT WEEK AS IT WEAKENS. LOCALLY,
LINGERING DRY AIR ACROSS THE AREA ON FRIDAY WILL KEEP RAIN
CHANCES A BIT LIMITED ACROSS THE NORTH, WITH INCREASING MOISTURE
ACROSS THE TREASURE COAST AND NEAR LAKE OKEECHOBEE CAUSING A
RETURN OF NEAR-NORMAL RAIN CHANCES. BY THIS WEEKEND, A MOIST AIR
MASS WILL OVERSPREAD THE FLORIDA PENINSULA AND THE TYPICAL DIURNAL
SUMMERTIME PATTERN IS FORECAST, WITH CONVECTIVE ACTIVITY PRIMARILY
BEING DRIVEN BY THE SEA BREEZES AND THEIR INTERACTIONS. A RETURN
OF WESTERLY FLOW WILL ALSO FAVOR HIGHER COVERAGE ACROSS THE
EASTERN PORTIONS OF THE PENINSULA NEAR THE COAST. BY MONDAY, THE
MOISTURE FROM THE DECAYING BOUNDARY WILL ARRIVE ACROSS EAST
CENTRAL FLORIDA, WITH CONTINUED NEAR-NORMAL RAIN CHANCES FORECAST
THROUGH THE AFTERNOON HOURS AREAWIDE. OVERALL, SHOWERS AND STORMS
ARE FORECAST TO DIMINISH EACH EVENING THROUGH THE OVERNIGHT HOURS,
WITH LINGERING ACTIVITY POSSIBLE ACROSS THE LOCAL ATLANTIC
WATERS.
ABOVE NORMAL TEMPERATURES ARE FORECAST TO CONTINUE ACROSS EAST
CENTRAL FLORIDA THROUGH SUNDAY, WITH SOME INDICATION THAT THE
INCREASING MOISTURE AND CLOUD COVERAGE WILL HELP KEEP TEMPERATURES
CLOSER TO NORMAL ON MONDAY AFTERNOON. PEAK HEAT INDICES WILL
CONTINUE TO EXCEED 100F AREAWIDE, WITH SOME LOCATIONS POTENTIALLY
NEARING HEAT ADVISORY CRITERIA. CONFIDENCE IN THIS REMAINS LOW
THOUGH, SO WILL CONTINUE TO MONITOR. LOWS GENERALLY IN THE 70S.
MARINE
ISSUED AT 300 AM EDT TUE JUL 21 2026
A TIGHT PRESSURE GRADIENT ACROSS THE LOCAL ATLANTIC WATERS FROM
TROPICAL STORM BERTHA IN THE GULF WILL LEAD TO CONTINUED POOR
BOATING CONDITIONS THROUGH AT LEAST TODAY. SOUTH-SOUTHEAST WINDS
OF 15 TO 20 KNOTS ARE FORECAST ACROSS THE WATERS AT TIMES, WITH
SEAS OF 2 TO 4 FEET. SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS
MOST OF THE LOCAL WATERS THROUGH TONIGHT AND ACROSS NORTHERN
PORTIONS OF THE WATERS INTO WEDNESDAY. BY WEDNESDAY NIGHT,
TROPICAL STORM BERTHA WILL MOVE FARTHER WEST ACROSS THE NORTHERN
GULF, WITH THE PRESSURE GRADIENT FORECAST TO WEAKEN ACROSS THE
LOCAL WATERS AS BROAD HIGH PRESSURE RETURNS OVERHEAD. SOUTH TO
SOUTHEAST WINDS WILL SUBSIDE TO 10 TO 15 KNOTS, WITH SEAS
RESPONDING BY DECREASING TO 1 TO 3 FEET.
SHOWERS AND STORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE LOCAL
ATLANTIC WATERS EACH DAY, THOUGH DRIER AIR MOVING INTO THE AREA
WILL LIMIT SOME POTENTIAL THROUGH AT LEAST THURSDAY. FRIDAY
ONWARD, EXPECT A RETURN OF GREATER RAIN AND STORM CHANCES AS
MOISTURE INCREASES.
AVIATION
(12Z TAFS)
ISSUED AT 608 AM EDT TUE JUL 21 2026
SOUTHEAST WINDS 5-10 KT WILL INCREASE TO 10-15 KT WITH GUSTS
AROUND 20 KT BY MID-MORNING. ISOLATED TO SCATTERED SHOWERS AND
LIGHTNING STORMS ARE FORECAST IN THE AFTERNOON, MAINLY AFTER 18Z.
HAVE INCLUDED VCTS FOR MCO, ISM, SFB STARTING AT 20Z AND LEE
STARTING AT 18Z. HAVE MAINTAINED PROB30 FOR LEE STARTING AT 18Z
AND HAVE ADDED PROB30 FOR MCO, ISM AND SFB STARTING AT 22Z FOR
MVFR CONDITIONS WITH TSRA. VCSH FOR ALL THE COASTAL SITES,
STARTING 20/22Z. SOUTHEAST WINDS WILL DECREASE INTO LATE
AFTERNOON, BECOMING AROUND 10 KT, BEFORE INTERIOR SITES SETTLE
AROUND 5 KT INTO THE EVENING AND OVERNIGHT HOURS. ANY LINGERING
SHOWERS AND STORMS WILL DISSIPATE OR MOVE OUT OF THE AREA AROUND
03Z, WITH MOSTLY DRY CONDITIONS FORECAST OVERNIGHT. VFR CONDITIONS
OUTSIDE OF CONVECTION THROUGH THE TAF PERIOD.
PRELIMINARY POINT TEMPS/POPS
DAB 93 76 93 76 / 20 20 10 0
MCO 95 76 96 77 / 30 20 10 0
MLB 92 77 91 77 / 20 20 10 0
VRB 93 75 92 76 / 20 20 10 0
LEE 93 76 95 77 / 40 20 10 10
SFB 95 76 95 77 / 30 20 10 0
ORL 95 77 95 77 / 30 20 10 0
FPR 92 75 91 75 / 20 20 20 0
MLB WATCHES/WARNINGS/ADVISORIES
FL...NONE.
AM...NONE.
DISCUSSION...TOLLEFSEN
AVIATION...WATSON
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