Area Forecast Discussion
Issued by NWS

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
000
FXUS62 KKEY 010127
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
930 PM EDT SAT APR 30 2016

.DISCUSSION...IN THE MID AND UPPER LEVELS...700-200 MB...LATEST
AVAILABLE IR IMAGERY AS OF 900 PM...OVERLAID WITH MODEL STREAMLINE
ANALYSIS DEPICT SEVERAL LOW PRESSURE GYRES OVER THE WESTERN AND
CENTRAL CONUS...WITH UPPER RIDGING ACROSS THE EASTERN CONUS. A 75 TO
100 KNOT SOUTHERN STREAM OF THE JET AT 250 MB EXTENDS FROM BAJA
CALIFORNIA EASTWARD TO ACROSS TEXAS THENCE NORTHEAST TO NEW ENGLAND.
WELL TO THE SOUTH OF THAT...SOUTH FLORIDA AND THE KEYS ARE BENEATH
THE NORTHEAST PERIPHERY OF DEEP MIDDLE AND UPPER RIDGING CENTERED
OVER CENTRAL AMERICA...WITH ONLY HIGH LEVEL CIRRUS IS MOVING ACROSS
THE AREA.

AT THE SURFACE AND IN THE LOWER TO MIDDLE LEVELS...SURFACE TO 700
MB...LATEST IR IMAGERY OVERLAID WITH LATEST AVAILABLE LAND AND
MARINE SURFACE OBSERVATIONS AND ANALYSIS AS OF 900 PM DETAIL A COLD
FRONT EXTENDING INTO DEEP SOUTH TEXAS FROM LOW PRESSURE OVER
NORTHERN MISSOURI. CLOSER TO THE KEYS...SURFACE RIDGING IS PARKED
OVER THE MID-ATLANTIC STATES. AS A RESULT THE 00Z SOUNDING AT KEY
WEST ILLUSTRATED GENTLE TO FRESH EAST WINDS UP TO 900 MB...THEN
GENTLE ABOVE THAT...WITH (PWAT AT .80 INCHES) AND AN INVERSION ABOVE
900 MB AND VERY DRY AIR ABOVE THAT.

.CURRENTLY...AS OF 900 PM...SKIES ARE PARTLY CLOUDY ACROSS THE
ISLANDS AND SURROUNDING WATERS OWING MOSTLY TO CIRRUS. TEMPERATURES
ACROSS THE ISLAND CHAIN ARE IN THE UPPER 70S WITH DEWPOINTS IN THE
UPPER 60S. C-MAN STATIONS ALONG THE FLORIDA REEF ARE REGISTERING
EAST WINDS BETWEEN 15 AND 20 KNOTS...AND 15 KNOTS IN FLORIDA
BAY...WITH SMITH SHOAL RECORDING 15 TO 20 KNOTS AS WELL.

.SHORT TERM...OVERNIGHT...COMBINATION OF DEVELOPING LOW PRESSURE
ALONG AFOREMENTIONED COLD FRONT OVER THE MIDDLE SOUTH...WITH
SURFACE RIDGING OVER THE MID ATLANTIC STATES WILL ALLOW FOR A SURGE
IN THE BREEZE FOR THE FIRST PART OF THE OVERNIGHT PERIOD. THIS IS
INDICATED IN THE LATEST HRRR AND HINTED AT IN THE LAST FEW HOURS OF
SAND KEY OBS. WILL JUST DO A MINOR UPDATE IN BOTH ZONES AND COASTALS
IN INCLUDE BREEZY CONDITIONS ACROSS THE ISLANDS...WITH 15 TO 20 MPH.

&&

.MARINE...OVERNIGHT...WILL SEE A GOOD PORTION OF THE STRAITS INCREASE
TO NEAR 20 KNOTS FOR MOST OF THE STRAITS THROUGH THE REST OF THIS
EVENING AND FOR SEVERAL HOURS AFTER MIDNIGHT. SMALL CRAFT WILL STILL
NEED TO EXERCISE CAUTION ACROSS THE REST OF THE MARINE DISTRICT
EXCEPT FLORIDA BAY AND THE SHALLOW WATERS INSIDE THE FIVE FATHOM
LINE. THEREAFTER...A LULL IS EXPECTED SUNDAY...BUT WILL PICK UP AGAIN
TO A LESSER EXTENT SUNDAY NIGHT.

&&

.AVIATION...OVERNIGHT...VFR CONDITIONS WILL PREVAIL OVERNIGHT AT THE
KEY WEST AND MARATHON INTL ISLAND TERMINALS. SURFACE WINDS WILL
AVERAGE FROM 100-110 DEGREES AOA 12-14 KTS WITH GUSTS TO AROUND 20
KNOTS. EXPECT FEW-SCATTERED CLOUDS AOA FL030 WITH CIRRUS AOA FL200-
250.

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SCA FOR GMZ052-055&GMZ072-075 THRU 10Z.
&&

$$

PUBLIC/MARINE....................FUTTERMAN
AVIATION/NOWCASTS................FUTTERMAN
DATA COLLECTION/UPPER AIR........DEVANAS

VISIT US ON THE WEB AT WEATHER.GOV/KEY

FOLLOW US ON FACEBOOK AND TWITTER AT...
WWW.FACEBOOK.COM/NWSKEYWEST
WWW.TWITTER.COM/NWSKEYWEST



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