565
FXUS62 KMFL 050846
AFDMFL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
346 AM EST FRI MAR 5 2021
SHORT TERM (TODAY THROUGH SATURDAY)
MODELS DEPICT A PROGRESSIVE WEATHER PATTERN FOR THE BEGINNING OF THE
WEEKEND WITH A MID LEVEL TROUGH DEEPENING OVER THE CENTRAL/EASTERN
GOMEX, WHICH PUSHES AN ASSOCIATED SFC SHORT WAVE TROUGH/FRONTAL
BOUNDARY INTO THE FLORIDA PENINSULA FROM FRIDAY NIGHT THROUGH
SATURDAY.
TIMING WINDOW FOR THE MORE SIGNIFICANT IMPACTS OVER SOFLO ON
SATURDAY, INCLUDING WIDESPREAD RAIN, REMAINS FOCUSED ON THE LATE
MORNING THROUGH THE AFTERNOON HOURS. MODEL SOLUTIONS SEEM IN BETTER
AGREEMENT IN THIS REGARD, HAVING THE LEADING EDGE OF THE FRONTAL
BOUNDARY REACHING SOFLO BY THE EARLY AFTERNOON HOURS. BUT SOME PRE-
FRONTAL CONVECTION SHOULD BRING BOUTS OF RAIN AS SOON AS THE EARLY
MORNING HOURS, ESPECIALLY OVER THE LAKE REGION AND PALM BEACH
COUNTY.
EXPECT SCATTERED TO NUMEROUS SHOWERS ACROSS MUCH OF SOFLO, ALONG
WITH SOME ISOLATED THUNDERSTORMS. HOWEVER, MODEL CONSENSUS REMAINS
CONSISTENT IN KEEPING THE BEST MID/UPPER LEVEL DYNAMIC SUPPORT WELL
NORTH OF THE AREA. ALSO, CLOUD COVERAGE MAY COMBINE WITH AN
UNIMPRESSIVE MOISTURE PROFILE TO KEEP SIGNIFICANT CONVECTIVE
ACTIVITY RATHER LIMITED. THEREFORE, MAIN HAZARD SHOULD BE POTENTIAL
FOR LOCALIZED FLOODING UNDER HEAVY DOWNPOURS, BUT CERTAINLY A FEW
STRONG STORMS ARE STILL POSSIBLE. AS MENTIONED EARLIER, HIGHEST POPS
REMAIN OVER THE LAKE REGION AND PALM BEACH COUNTY AREA WHERE
TEMPERATURES ALOFT WILL BE AROUND -15 CELSIUS AT THE HEIGHT OF THE
EVENT, ALONG WITH THE STEEPEST LAPSE RATES. CURRENT GRIDS CARRY UP
TO 80 PERCENT CHANCES OF RAIN FOR THOSE AREAS, AND 50 TO 60 PERCENT
FOR THE REST PF SOFLO.
MODELS PUSH THE BOUNDARY ACROSS THE PENINSULA FAIRLY QUICKLY,
EXITING THE STATE BY SATURDAY EARLY EVENING, WITH THE BULK OF THE
SHOWERS AND STORMS MIGRATING INTO THE ATLANTIC WATERS.
TEMPERATURES WARM UP A BIT TODAY WITH AFTERNOON HIGHS BACK INTO THE
LOW 80S FOR INTERIOR AND WEST COAT AREAS, WHILE THE MIAMI METRO
AREAS HIT THE UPPER 70S. BUT WITH THE AFOREMENTIONED SYNOPTIC
SCENARIO, TEMPS COOL DOWN A LITTLE AGAIN ON SATURDAY, WITH AFTERNOON
HIGHS IN THE LOW-MID 70S NORTH AND EAST COAST AREAS, AND UPPER 70S
OVER THE WEST COAST AND INTERIOR.
LONG TERM (SATURDAY NIGHT THROUGH NEXT WEEK)
THE PREVIOUSLY MENTIONED AMPLIFIED NEUTRAL TO POSITIVELY TILTED
MID/UPPER-LEVEL TROUGH WILL BE LOCATED OVER THE EASTERN STATES,
WITH ITS AXIS EXTENDING SOUTH-SOUTHWESTWARD INTO THE EASTERN GULF
OF MEXICO. AN ACCOMPANYING STRAIGHT UPPER-LEVEL JET STEAK WILL BE
ROUNDING THE BASE OF THE MEAN TROUGH, ALLOWING IT TO LIFT EAST-
NORTHEASTWARD AND PHASE WITH A NORTHERN STREAM TROUGH PRIOR TO
EJECTING INTO THE WESTERN ATLANTIC WATERS LATE ON SUNDAY.
PRESENT INDICATIONS ARE THAT ISOLATED CONVECTION WILL BE ONGOING
FROM SATURDAY NIGHT INTO SUNDAY MORNING, SUPPORTED BY WEAK WARM
AIR ADVECTION AND A LOW-LEVEL MASS FLUX ACCOMPANYING THE THERMALLY
DIRECT RIGHT-ENTRANCE REGION CIRCULATION OF THE AFOREMENTIONED
STRAIGHT UPPER-LEVEL JET STREAK. THE PRIMARY CONCERN WITH THE
OVERNIGHT CONVECTION WILL BE LOCALLY HEAVY RAINFALL WHICH COULD
RESULT IN MINOR FLOODING OF VULNERABLE LOW-LYING URBAN AREAS OF
SOUTH FLORIDA. THIS SCENARIO COULD POTENTIALLY BE EXACERBATED BY
ENHANCED LOW-LEVEL EASTERLIES IMPINGING ON THE EAST COAST OF
SOUTH FLORIDA, FOSTERING LOCALIZED CORRIDORS OF MESOSCALE ASCENT
IN ASSOCIATION WITH FRICTIONAL/COASTAL CONVERGENCE. WITH THAT
SAID, INSTABILITY WILL BE GREATLY LACKING AND RAPID UPPER-LEVEL
DRYING COULD MITIGATE THESE CONCERNS.
BY LATE SUNDAY INTO MONDAY, THE ABOVE MENTIONED MID/UPPER-LEVEL
TROUGH WILL BE LIFTING OUT OF THE AREA AS CONTINENTAL HIGH PRESSURE
BUILDS IN ITS WAKE. SOUTH FLORIDA WILL REMAIN ON THE SOUTHEASTERN
PERIPHERY OF THIS AIR MASS THROUGH THE WEEK, ALLOWING FOR THE
MAINTENANCE OF LOW-LEVEL MOISTURE AND ASSOCIATED LINGERING SCATTERED
CLOUD COVERAGE THROUGH THE WEEK. PRESENT INDICATIONS ARE THAT
DRY AND STABLE CONDITIONS ALOFT WILL LIMIT PRECIPITATION
POTENTIAL, THOUGH THE LOW-LEVEL MOISTURE AND PERSISTENT EASTERLY
FLOW COULD RESULT IN ISOLATED SPRINKLES HERE AND THERE. A TIGHT
PRESSURE GRADIENT PERIPHERAL TO THE AFOREMENTIONED SURFACE HIGH
WILL SUPPORT BREEZY CONDITIONS ACROSS SOUTH FLORIDA AND THE LOCAL
WATERS THROUGH THE WEEK, RESULTING IN HAZARDOUS MARINE AND BEACH
CONDITIONS (SEE MARINE AND BEACH SECTIONS BELOW).
AVIATION(06Z TAFS)
VFR SHOULD PREVAIL AT ALL TERMINALS DURING THE NEXT 24 HOURS.
CONDITIONS WILL GRADUALLY CHANGE FROM LATER TONIGHT AND THROUGH
SATURDAY AS A COLD FRONT BRINGS POTENTIAL FOR MVFR/IFR PERIODS
UNDER HEAVY RAIN. WINDS SHIFT TO A MORE NE FLOW TODAY, THEN BACK
TO LIGHT AND VARIABLE AFTER 06/00Z.
MARINE
HIGH PRESSURE WILL DOMINATE TODAY WITH WINDS SEAS SUBSIDING TO
BELOW ADVISORY LEVELS OVER THE NORTHERN ATLANTIC WATERS. ANOTHER
COLD FRONT BOUNDARY IS EXPECTED TO REACH THE COASTAL WATERS LATE
TONIGHT AND INTO SATURDAY, BRINGING INCREASING HAZARDOUS SEAS AND
UNSETTLED WEATHER. LOCALLY HAZARDOUS MARINE CONDITIONS COULD OCCUR
IN SHOWER AND THUNDERSTORM ACTIVITY. BY SUNDAY, CONDITIONS WILL
BE SUBSIDING IN THE WAKE OF THE FRONT, BUT STILL SOME ACTIVITY IS
POSSIBLE OVER THE ATLANTIC OFFSHORE WATERS.
FIRE WEATHER
HIGH PRESSURE ACROSS THE AREA WILL HELP IN KEEPING
RELATIVELY DRY CONDITIONS IN PLACE TODAY WITH LOWEST RH VALUES OVER
WESTERN PORTION OF SOUTH FLORIDA POSSIBLY DROPPING INTO THE MID TO
UPPER 30S. LOWEST RH VALUES ARE EXPECTED OVER PORTIONS OF GLADES,
HIGHLANDS, AND COLLIER COUNTIES. WINDS SHOULD SHIFT TO A MORE NE OR
E FLOW LATER TODAY.
ANOTHER FRONT REACHES THE AREA DURING THE OVERNIGHT HOURS AND INTO
SATURDAY MORNING WITH AN INCREASE IN SHOWER AND THUNDERSTORM
ACTIVITY.
BEACHES
HIGH RISK OF RIP CURRENTS IS NOW IN EFFECT FOR PALM BEACH COUNTY,
WHILE BROWARD BEACHES WILL EXPERIENCE MODERATE LEVELS TODAY.
ELEVATED RISK OF RIP CURRENTS IS EXPECTED TO CONTINUE FOR ALL
ATLANTIC BEACHES DURING THIS WEEKEND DUE TO INCREASED SEAS AND WINDS
ASSOCIATED WITH AN APPROACHING FRONTAL SYSTEM.
PRELIMINARY POINT TEMPS/POPS
MIAMI 79 66 79 63 / 0 20 70 60
WEST KENDALL 81 63 80 62 / 0 20 70 60
OPA-LOCKA 79 63 78 62 / 0 20 70 60
HOMESTEAD 79 64 78 62 / 0 20 60 60
FORT LAUDERDALE 79 67 79 63 / 0 20 70 70
N FT LAUDERDALE 78 67 77 63 / 0 20 70 70
PEMBROKE PINES 79 64 79 62 / 0 20 70 60
WEST PALM BEACH 77 64 76 62 / 0 20 80 70
BOCA RATON 79 66 78 62 / 0 20 70 70
NAPLES 80 61 77 58 / 0 20 70 40
MFL WATCHES/WARNINGS/ADVISORIES
FL...HIGH RIP CURRENT RISK THROUGH SATURDAY EVENING FOR FLZ168.
AM...NONE.
GM...NONE.
TODAY THROUGH SATURDAY AND AVIATION/MARINE...AR
SATURDAY NIGHT THROUGH THURSDAY...WEINMAN
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