Area Forecast Discussion
Issued by NWS Miami, FL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KMFL 240519 AAC
AFDMFL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
119 AM EDT THU JUL 24 2014

.AVIATION...
THE WINDS EARLY THIS MORNING WILL BE LIGHT AND VARIABLE BEFORE
INCREASING TO 5 TO 10 KNOTS FROM THE SOUTHEAST AFTER 15Z FOR THE
EAST COAST TAF SITES. THE WINDS AT KAPF TAF SITE WILL ALSO REMAIN
LIGHT AND VARIABLE UNTIL 16Z THEN SWING TO A WESTERLY DIRECTION AS
THE WEST COAST SEA BREEZE DEVELOPS AND PUSHES INLAND.

DRIER AIR WILL CONTINUE TO WORK INTO SOUTH FLORIDA TODAY FROM THE
ATLANTIC WATERS. THIS WILL REDUCE THE SHOWER AND THUNDERSTORM
COVERAGE OVER SOUTH FLORIDA TODAY WITH THE BEST COVERAGE OVER THE
INTERIOR AND WEST COAST METRO AREAS. THEREFORE...THE EAST COAST
TAF SITES WILL HAVE ONLY VCSH IN FOR TODAY AFTER 15Z WHILE KAPF
TAF SITE WILL SEE VCTS AFTER 16Z.

THE CEILING AND VIS WILL ALSO REMAIN IN VFR CONDITIONS TODAY FOR
ALL OF THE TAF SITES. HOWEVER...KAPF TAF SITE MIGHT NEED A TEMPO
GROUP FOR THE CEILING AND VIS LATER THIS MORNING INTO EARLY THIS
AFTERNOON ONCE THE SHOWERS AND THUNDERSTORMS DEVELOP.

&&
.AVIATION...54/BNB


.PREV DISCUSSION... /ISSUED 927 PM EDT WED JUL 23 2014/

UPDATE...
OUTSIDE OF A FEW MINOR TWEAKS WITHIN THE GRIDDED FORECAST PACKAGE
BASED ON THE LATEST OBSERVATIONS AROUND THE LOCAL AREA...NO MAJOR
UPDATES ARE ANTICIPATED AS THE PREVIOUS FORECAST PACKAGE REMAINS
ON TRACK. THE BEST CHANCE FOR OVERNIGHT SHOWERS WILL REMAIN OVER
THE ADJACENT ATLANTIC WATERS.

&&
85/AG

PREV DISCUSSION... /ISSUED 801 PM EDT WED JUL 23 2014/

AVIATION...
VFR CONDITIONS TO PREVAIL AT ALL SITES THROUGH THE NEXT 24 HOURS.
WINDS SHOULD REMAIN GENERALLY SOUTHEASTERLY OVERNIGHT. LATEST
WATER VAPOR IMAGERY SHOWS A DRIER MID LEVEL AIR MASS PUSHING INTO
THE AREA FROM THE EAST. THIS SHOULD INHIBIT AFTERNOON CONVECTION
ACROSS THE AREA TOMORROW. STILL KEPT VCTS AT ALL EAST COAST SITES
AFTER 18Z EXCEPT FOR KFXE AND KPBI BUT BELIEVE CONVECTION WILL BE
ISOLATED AND IN SHORT DURATION.

&&

PREV DISCUSSION... /ISSUED 205 PM EDT WED JUL 23 2014/

SHORT TERM (TONIGHT-FRIDAY NIGHT)...
SOMEWHAT OF AN INTERESTING PATTERN WILL BE DEVELOPING OVER THE NEXT
SEVERAL DAYS. BUT IN THE SHORT TERM PERIOD, ATLANTIC RIDGE BOTH AT
THE SURFACE AND ALOFT WILL BUILD BACK TO THE WEST THROUGH THURSDAY
WITH A DRYING TREND. THIS ALREADY EVIDENT THIS AFTERNOON WITH THE
WATER VAPOR IMAGERY SHOWING THE DRY AIR ALOFT PUSHING IN FROM THE
BAHAMAS AND THE 12Z MFL SOUNDING ALSO SUPPORTED THIS. CONVECTION WAS
ABLE TO GET AN EARLY START DUE TO LOW LEVEL INSTABILITY ALONG WITH
PLENTY OF MOISTURE THROUGH 10-15K BUT IT IS BEING SUPPRESSED BY THE
DRYER AIR ALOFT. THIS TREND SHOULD CONTINUE OVER THE NEXT 24 HOURS.
THEN, A MID LEVEL TROUGH THAT IS CURRENTLY LOCATED OVER THE MOUTH OF
THE MISSISSIPPI WILL GET SANDWICHED ON FRIDAY IN BETWEEN THE HIGH
BUILDING IN FROM THE EAST AND ANOTHER BUILDING RIDGE OVER THE DESERT
SOUTHWEST EXTENDING INTO THE SOUTHERN ROCKIES. THIS WILL IN TURN
COOL THE 500MB TEMPERATURES OVER SOUTH FLORIDA TO AROUND -7C WHICH
IS BACK CLOSE TO AVERAGE FOR LATE JULY VERSUS THE -4.5C THIS
MORNING. SO EVEN THOUGH THE COVERAGE MIGHT NOT CHANGE MUCH THURSDAY
AND FRIDAY, STORMS ON FRIDAY WITH THE COLDER TEMPERATURES ALOFT WILL
LIKELY BE MORE ROBUST AND HAVE A BETTER CHANCE OF PRODUCING STRONG
AND GUSTY WINDS.

LONG TERM (SATURDAY-WEDNESDAY)...
THE INTERESTING PART OF THE FORECAST WILL BEGIN IN THE EXTENDED
PERIOD. BY SATURDAY, THE TROUGH OVER THE GULF COAST REGION WILL FILL
IN AS THE RIDGE OVER THE DESERT SOUTHWEST BUILDS EAST. A STRONG MID
LEVEL TROUGH WILL THEN MOVE OUT OF CANADA INTO THE GREAT LAKES
REGION AND WILL BEGIN TO CARVE OUT A MAJOR COUNTER-CLOCKWISE FLOW
ACROSS THE EASTERN U.S. EARLY NEXT WEEK. BOTH THE GFS AND ECMWF ARE
SHOWING THIS OVERALL EVOLUTION OVER THE COURSE OF THE NEXT SEVEN
DAYS. THE QUESTION IS JUST HOW MUCH OF AN EFFECT WILL ALL OF THIS
PLAY OUT FOR SOUTH FLORIDA. THE GFS SHOWS THE SURFACE BOUNDARY
ASSOCIATED WITH THE LARGE SCALE TROUGH TO REACH CENTRAL FLORIDA BY
WEDNESDAY WHILE THE ECMWF KEEPS IT OVER NORTH FLORIDA. STILL, QUITE
IMPRESSIVE TO HAVE TWO SURFACE FRONTAL BOUNDARIES REACH THE STATE OF
FLORIDA IN THE MONTH OF JULY! EVEN IF IT IS NORTH OF LAKE
OKEECHOBEE. OF COURSE, IT WILL ALL DEPEND ON HOW DEEP THE TROUGH
BECOMES AS TO HOW THIS REFLECTS ON THE MID LEVEL TEMPERATURES AND
LAPSE RATES AND THEREFORE HOW ACTIVE OF A WEATHER PATTERN DEVELOPS
ACROSS SOUTH FLORIDA.

MARINE...
TRANQUIL BOATING CONDITIONS WILL CONTINUE THROUGH THE PERIOD WITH
A MOSTLY LIGHT SOUTHEAST WIND FLOW AND SEAS OF 2 FEET OR LESS. OF
COURSE, ANY THUNDERSTORM DEVELOPMENT COULD CREATE LOCALLY ROUGH
SEAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  77  90  77  90 /  10  30  20  30
FORT LAUDERDALE  79  91  80  90 /  10  30  20  30
MIAMI            78  91  78  91 /  10  30  20  30
NAPLES           77  90  76  92 /  10  40  20  30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$

SHORT TERM...13/SI
LONG TERM....30/KOB
AVIATION...54/BNB


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.