000
FXUS62 KKEY 252003
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
403 PM EDT SAT MAY 25 2013
.DISCUSSION...
LATEST DOPPLER RADAR TRENDS SHOW AN ISOLATED CLUSTER OF SHOWERS AND
THUNDERSTORMS MOVING WESTWARD OFF EAST CAPE SABLE. ISOLATED
CONVECTIVE CELLS HAVE BEEN ABLE TO DEVELOP TODAY AGAIN WHERE
SUFFICIENT SURFACE CONVERGENCE HAS BEEN AVAILABLE...DESPITE SOME VERY
DRY AIR ALOFT...INCLUDING AT LOW ALTITUDES. IT SEEMS WEAKER
ENVIRONMENTAL SHEAR COMBINED WITH A SLIGHTLY CONFLUENT FLOW PATTERN
ON THE SYNOPTIC SCALE MAY BE ALLOWING THE CELLS TO DEVELOP AS SIMILAR
THERMODYNAMIC CONDITIONS ON DAYS WITH SLIGHTLY DIFFERENT SYNOPTIC
SETUPS RESULT IN COMPLETE SUPPRESSION OF CONVECTIVE ACTIVITY.
ANYWAY...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST
OVER PORTIONS OF THE GULF ZONES THIS EVENING...BEFORE DISSIPATING
LATE TONIGHT...WITH ONLY SLIGHT SHOWER CHANCES IN FLORIDA KEYS ISLAND
COMMUNITIES.
THE FORECAST FOR THE COMING WEEK WILL FEATURE A GENERALLY BREEZY
EASTERLY FLOW THROUGHOUT AS A LARGE HIGH PRESSURE CELL VACILLATES IN
BOTH POSITION AND INTENSITY NORTH OF THE KEYS. WE ARE FAIRLY CERTAIN
THAT EVEN DRIER AIR UPSTREAM WILL FILTER INTO THE REGION LATER
TONIGHT AND SUNDAY...THEREBY LARGELY SHUTTING DOWN DEEP...MOIST
CONVECTION AND KEEPING MEASURABLE RAIN CHANCES VERY LOW. A LARGE-
SCALE TROUGH IN THE WESTERLIES WILL APPROACH EARLY IN THE WEEK
RESULTING IN BOTH GEOPOTENTIAL HEIGHT FALLS/WEAK ASCENT OVER THE
FLORIDA PENINSULA DURING THE MONDAY NIGHT-THURSDAY TIME FRAME AS WELL
AS A SLIGHTLY MORE EAST-SOUTHEAST FLOW AT LOW LEVELS RESULTING IN
DEEPER CARIBBEAN MOISTURE ADVECTING IN. THE COMBINATION OF THESE
FACTORS SHOULD PRODUCE MORE CLOUDS AND PRECIPITATION WITH MESOSCALE
FEATURES GOVERNING DAILY PATTERNS. THEREFORE...WE HAVE INCREASED RAIN
CHANCES FOR THE MID-WEEK TIME FRAME.
&&
.MARINE...
SMALL CRAFT ADVISORIES ARE BEING POSTED FOR ALL ZONES DUE TO
INCREASING WINDS AND SEAS TONIGHT. WIND AND/OR WAVE CONDITIONS WILL
FLIRT WITH ADVISORY CRITERIA FOR MUCH OF THE WEEK. SHOWER AND STORM
CHANCES WILL INCREASE MID WEEK.
&&
.AVIATION...
THROUGH THIS EVENING...VFR CONDITIONS ARE EXPECTED TO PREVAIL AT
BOTH THE KEY WEST AND MARATHON TERMINALS. ISOLATED SHOWERS ARE
POSSIBLE IN THE LOWER KEYS LATE THIS AFTERNOON AND EARLY
EVENING...WHICH INCLUDES THE KEY WEST TERMINAL. THEREFORE...BRIEF
MVFR CONDITIONS MAY BE POSSIBLE AT THE KEY WEST TERMINAL FROM
PASSING SHOWERS DURING THESE HOURS. HOWEVER... NO RESTRICTIONS TO
VISIBILITY WILL BE INCLUDING IN THE TERMINAL FORECAST BECAUSE OF LOW
CONFIDENCE IN SHOWERS REACHING KEY WEST...AS WELL AS UNCERTAINTY IN
THE TIMING OF THE SHOWERS. WILL AMEND TAF IF NECESSARY. SURFACE
WINDS AT BOTH TERMINALS WILL BE GENERALLY EAST NEAR 10 KNOTS WITH
GUSTS OF 15 TO 20 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 78 87 78 87 / 10 10 20 20
MARATHON 78 90 78 90 / 10 10 20 20
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SMALL CRAFT ADVISORY IN EFFECT FOR GMZ031-GMZ032-GMZ033-GMZ034-
GMZ042-GMZ043-GMZ044-GMZ052-GMZ053-GMZ054-GMZ055-GMZ072-GMZ073-
GMZ074-GMZ075.
&&
$$
PUBLIC/MARINE.........KASPER
AVIATION/NOWCASTS.....DEVANAS
DATA COLLECTION.......BWC
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 251503
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1103 AM EDT SAT MAY 25 2013
.DISCUSSION...
A REVIEW OF MEAN SEA LEVEL PRESSURE ANALYSES OVER THE LAST 24 HOURS
SHOWS A LARGE-SCALE RIDGE BUILDING TOWARD THE SOUTH AND EAST OVER
THE GULF OF MEXICO AND FLORIDA PENINSULA. AS A RESULT...THE COL IN
THE PRESSURE FIELD WHICH WAS EVIDENT NEARBY BOTH YESTERDAY AND THE
DAY BEFORE HAS BEEN REPLACED BY ROUGHLY EAST-WEST ORIENTED ISOBARS
WHICH INCREASINGLY ARE PACKED CLOSER TOGETHER. THE SURFACE WIND
RESPONSE HAS LAGGED THE PRESSURE CHANGES. HOWEVER...WINDS ACROSS THE
FLORIDA KEYS SHIFTED OUT OF THE NORTHEAST OVERNIGHT...AND UPSTREAM
OBSERVATIONS HAVE SHOWN INCREASES IN WIND SPEED THIS MORNING. A WIND
SURGE BOUNDARY APPEARS TO BE ASSOCIATED WITH THE CONVERGENCE ZONE
AND BAND OF CLOUDINESS AND SHOWERS CURRENTLY EVIDENT IN
GEOSTATIONARY SATELLITE ANIMATIONS APPROACHING SOUTHEASTERN FLORIDA.
ONE OF THE SHOWERS AT THE LEADING EDGE OF THIS BAND WENT THROUGH THE
OCEAN REEF CLUB EARLIER.
AT PRESENT...MOSTLY SUNNY SKIES PREVAIL OVER MOST KEYS ISLAND
COMMUNITIES...WITH AIR TEMPERATURES RISING THROUGH THE 80S AFTER
MORNING LOWS IN THE MID-UPPER 70S. CURRENT DEWPOINTS ARE RIGHT AROUND
70F.
THE FIRST-PERIOD FORECAST CHALLENGES TODAY INCLUDE THE FOLLOWING...
1 - WILL A CUMULUS LINE FORM OVER OR NEAR THE LOWER FLORIDA KEYS IN A
FAVORABLE LOW-LEVEL WIND/SHEAR ORIENTATION BEFORE ONSET OF A EASTERLY
WIND SURGE AND INCREASED SHEAR THIS AFTERNOON?
2 - WILL SEA AND BAY BREEZES OVER SOUTHERN PENINSULAR FLORIDA BE
STRONG ENOUGH TO INITIATE THUNDERSTORMS WHICH THEN MOVE WESTWARD OVER
OUR SOUTHEASTERN GULF MARINE ZONES? AND...IF THIS HAPPENS...WILL
THERE BE ANY INTERACTION BETWEEN THE STORMS/OUTFLOW AND A LOWER KEYS
CUMULUS LINE/SHOWERS/OUTFLOW?
LIMITING FACTORS FOR CONVECTIVE RAINFALL INCLUDE...LIKE YESTERDAY...
VERY DRY AIR JUST ABOVE THE BOUNDARY LAYER AND SIGNIFICANT CONVECTIVE
INHIBITION BASED AT LOW ALTITUDES. UNLIKE YESTERDAY...ONSET OF AN
EASTERLY WIND SURGE LIKELY WILL IMPART SHEAR TO THE ENVIRONMENT WHICH
WILL EXACERBATE SIGNIFICANT DRY-AIR ENTRAINMENT.
EXISTING FORECASTS ARTICULATE THE APPROPRIATE LEVEL UNCERTAINTY AND
SHOW SLIGHTLY HIGHER RAIN CHANCES IN THE LOWER KEYS AND GULF REGIONS
WHERE MESOSCALE FORCING APPEARS TO BE MOST FAVORABLE FOR EVENTUAL
CONVECTIVE RAINFALL. SO...WE WILL ROLL WITH THE GOING FORECASTS...AND
UPDATE AS NECESSARY THIS AFTERNOON.
&&
.MARINE...
A NORTHEAST TO EAST WIND SURGE IS EXPECTED TO OVERSPREAD FLORIDA KEYS
COASTAL WATERS THIS AFTERNOON...AND SMALL CRAFT OPERATORS ARE URGED
TO EXERCISE CAUTION BEGINNING AROUND NOON. BREEZES SHOULD FRESHEN TO
A STEADY 20 KNOTS MOST AREAS TONIGHT...WHEN SMALL CRAFT ADVISORIES
LIKELY WILL BE REQUIRED FOR ALL ZONES. THIS WIND SURGE WILL USHER IN
A NEARLY WEEK-LONG PERIOD OF BREEZY CONDITIONS.
&&
.AVIATION...
THROUGH THIS AFTERNOON AND EARLY EVENING...VFR CONDITIONS ARE
EXPECTED TO PREVAIL AT BOTH THE KEY WEST AND MARATHON TERMINALS.
THERE IS A CHANCE OF SHOWERS OVER THE MIDDLE AND LOWER KEYS AFTER
NOON. EXPECT A LIGHT NORTH BREEZE EARLY THIS MORNING TO TURN MORE
TOWARDS THE EAST...AND INCREASE TO 10 TO 15 KNOTS WITH HIGHER
GUSTS DURING THE AFTERNOON.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........KASPER
AVIATION/NOWCASTS.....DEVANAS
DATA COLLECTION.......MSB
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 250920
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
520 AM EDT SAT MAY 25 2013
.DISCUSSION...IN THE UPPER LEVELS OF THE ATMOSPHERE...THE
CONTINENTAL UNITED STATES HAS BEEN BISECTED BY A SHARP AND
PROGRESSIVE UPPER LEVEL RIDGE...AS A RESULT...A SURFACE RIDGE EXTENDS
SOUTHWARD FROM A HIGH PRESSURE SYSTEM CENTERED NEAR THE GREAT LAKES.
MIMIC TPW IMAGERY REVEALS A SURGE OF DRY CONTINENTAL AIR RUSHING
SOUTHEASTWARD FROM THE CAROLINA COASTLINE. THE LOCAL WINDFIELD
REMAINS UNDECIDED WITHIN THE COL REGION OF THE RETREATING ATLANTIC
RIDGE...A WEAK SURFACE TROUGH...AND THE EXPANDING CONTINENTAL HIGH.
TEMPERATURES HAVE -COOLED- TO NEAR 80 DEGREES...AND SKIES ARE PARTLY
CLOUDY UNDERNEATH A FEW CIRRUS CLOUDS AND DEBRIS FROM EARLIER
CONVECTION.
.SHORT TERM (TODAY THROUGH MONDAY)...AN ARCING CONVERGENT BOUNDARY
WITH SCATTERED SHOWERS IS EVIDENT ON INFRARED IMAGERY NEAR GRAND
BAHAMA...EXTENDING WESTWARD TO STUART FLORIDA. A REINFORCING SHOT OF
NORTHEASTERLY WINDS LIES UPSTREAM SEVERAL HUNDRED MILES. WE EXPECT
THIS FIRST WIND SURGE TO PASS THROUGH EARLY THIS AFTERNOON...MAINLY
FROM EAST TO WEST AS IT PIVOTS AROUND THE DEFORMING BUBBLE OF
DIFFERENTIAL HEATING. PRECIPITATION WISE...THE WEST COAST SEABREEZE
OF FLORIDA SHOULD HAVE A MARGINAL COLLISION NEAR THE 10 THOUSAND
ISLANDS THIS AFTERNOON. BASED ON LAST NIGHTS PERFORMANCE AND ADD IN
STEERING FLOW FROM THE NORTHEAST...THE RESULTING SHOWER CLUSTER WILL
SEND OUT A HEALTHY COLD POOL INTO THE SOUTHEASTERN GULF WATERS. WE
HAVE INDICATED THIS LOW CONFIDENCE MESOSCALE EVENT IN THE GRIDS...AND
HAVE UPPED POPS IN THE LOWER KEYS TO ACCOUNT FOR THE PROPAGATION OF
ANY OUTFLOWS. ALSO...LOW LEVEL WIND PROFILES ARE MARGINAL FOR A CLOUD
LINE...BUT ONCE AGAIN...DIAGNOSIS OF DRY AIR INTRUSION NEAR THE LFC
REMAINS DIFFICULT. THROUGH THE REMAINDER OF THE SHORT TERM...TONIGHT
THROUGH MONDAY...BREEZY NORTHEAST TO EAST WINDS WILL PREVAIL.
SIGNIFICANT MOISTURE FLUX UNDERNEATH A STRONG INVERSION FORCES THE
RETENTION OF A SLIGHT CHANCE OF SHOWERS. HIGH TEMPERATURES WILL BE A
FEW TICKS BELOW WHAT THEY HAVE BEEN...MAINLY DUE TO MARINE MODERATED
AIR.
&&
.LONG TERM (MONDAY NIGHT THROUGH FRIDAY)...BREEZY CONDITIONS CONTINUE
INTO THE LONG TERM. ATMOSPHERIC MOISTURE INCREASES TUESDAY AS A
POSSIBLE INVERTED TROUGH TRANSLATES IN THE EASTERLIES UNDERNEATH A
MYSTERIOUSLY STALLED UPPER LEVEL LOW. OF PARTICULAR CLIMATOLOGICAL
NOTE...MEAN PRECIPITABLE WATER VALUES INCREASE FROM 1.38 INCHES IN
MAY TO 1.75 INCHES IN JUNE. ALSO...TROUGHS IN THE EASTERLIES ARE
INHERENTLY DIFFICULT TO PREDICT. SO WE WILL ERR ON THE SIDE OF
CAUTION WHEN PERCEIVING INCREASED PW...AND WILL NOT JUMP ON A SPIKE IN
POPS ADVERTISED BY MODEL GUIDANCE.
&&
.MARINE...A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTHWARD DOWN
THE FLORIDA PENINSULA TODAY...RESULTING IN INCREASING NORTHEAST TO
EAST BREEZES. FRESH TO STRONG NORTHEAST TO EAST BREEZES ARE EXPECTED
TONIGHT THROUGH WEDNESDAY NIGHT. A SMALL CRAFT ADVISORY IS LIKELY
TONIGHT FOR ALL COASTAL WATERS.
&&
.AVIATION...THROUGH THIS MORNING AND AFTERNOON...VFR IS EXPECTED TO
BE THE PREDOMINANT CONDITIONS AT THE KEY WEST AND MARATHON TERMINALS.
WILL NOT INCLUDE VCSH OR TEMPO AT THIS TIME FOR EITHER LOCATION...BUT
THERE IS A POSSIBILITY OF SHOWERS THREATENING THE MIDDLE AND LOWER
KEYS LATER IN THE AFTERNOON/EVENING AS THE STEERING FLOW TURNS TO THE
NORTHEAST. CLOSER TO THE SURFACE...EXPECT A LIGHT NORTH BREEZE EARLY
THIS MORNING TO TURN MORE TOWARDS THE EAST AFTER THE SUN RISES...AND
ACCELERATES TO 10 TO 15 KNOTS WITH HIGHER GUSTS DURING THE AFTERNOON.
&&
.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...IN 1985...3.34 INCHES OF RAIN
FELL IN KEY WEST. THIS SET THE DAILY RECORD FOR RAINFALL IN KEY WEST
FOR MAY 25TH.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 87 77 86 77 / 30 10 10 20
MARATHON 90 77 88 77 / 20 10 10 20
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........CLR
AVIATION/NOWCASTS.....04
DATA COLLECTION.......MSB
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 250225
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1025 PM EDT FRI MAY 24 2013
.DISCUSSION...
DURING THE LATE AFTERNOON AND EARLY EVENING...SCATTERED SHOWERS AND
THUNDERSTORMS...SEVERAL OF WHICH WERE STRONG MIGRATED SOUTHWARD OFF
THE SOUTH FLORIDA MAINLAND AND PUSHED THROUGH MOST OF FLORIDA
BAY...THE EASTERN PORTION OF THE MIDDLE KEYS...A GOOD PORTION
OF THE UPPER KEYS AND THE ADJACENT NEARSHORE ATLANTIC WATERS.
CURRENTLY...SKIES ARE MOSTLY CLEAR WITH TEMPERATURES IN THE UPPER
70S TO NEAR 80 DEGREES ALONG THE ISLAND CHAIN. LOCAL RADARS ARE ONLY
DETECTING A FEW MEAGER BOUNDARIES LINGERING IN OUR AREA. SURFACE
WISE...AN EXTREMELY LENGTHY RIDGE OF HIGH PRESSURE EXTENDS FROM THE
UPPER GREAT LAKES SOUTHWARD INTO THE SOUTHEAST UNITED STATES...AND
DOWN INTO THE EASTERN GULF OF MEXICO. ALSO...A TROUGH OF LOW
PRESSURE OFFSHORE OF THE EASTERN SEABOARD REACHES ACROSS NORTH
CENTRAL FLORIDA. ACROSS OUR MARINE DISTRICT...NORTH WINDS HAVE
ABATED APPRECIABLY...RANGING BETWEEN 5 AND 10 KNOTS. OTHERWISE...OUR
EVENING SOUNDING REVEALS AN EXTREMELY DRY AIRMASS (PWAT 1.06 INCHES)
BUT WITH LITTLE IN THE WAY OF CONVECTIVE INHIBITION ABOVE 900 MB. A
LIGHT NORTHERLY FLOW REACHES UP TO 650 MB...BEFORE TURNING NORTHWEST
AND INTENSIFYING ABOVE.
.SHORT TERM (REST OF TONIGHT)...
OUTSIDE OF A FEW SHOWERS ALONG LEFTOVER LINGERING
BOUNDARIES...CONSIDERABLE DRY AIR WILL LIMIT SHOWER COVERAGE.
HENCE...HAVE UPDATED THE PUBLIC FORECAST TO RETURN RAIN CHANCES BACK
TO A GENEROUS 10 PERCENT FOR THE ENTIRE ISLAND CHAIN. ALTHOUGH WINDS
WILL BE RELATIVELY LIGHT...DO NOT EXPECT WIDESPREAD FAVORABLE
RADIATIONAL COOLING CONDITIONS LIKE LAST NIGHT. THEREFORE...HAVE
OPENED UP A RANGE OF 75 TO 80 UNDER MOSTLY CLEAR SKIES.
&&
.MARINE...
WITH WINDS SLACKENING QUICKLY FROM EARLIER DEEP CONVECTION...EXPECT
WINDS TO SLOWLY TURN NORTHEAST TO EAST AT LESS THAN 10 KNOTS ACROSS
THE ENTIRE MARINE DISTRICT.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL AT BOTH THE KEY WEST AND MARATHON ISLAND
TERMINALS. WINDS WILL AVERAGE BETWEEN 5 AND 10 KNOTS FROM 360
DEGREES...BECOMING 070 DEGREES BY 12Z NEAR 10 KNOTS...THEN GRADUALLY
INCREASING TO BETWEEN 12 AND 14 KNOTS WITH GUSTS AROUND 20 KNOTS
AFTER 18Z. EXPECT A FEW TO SCATTERED CUMULUS CLOUDS WITH BASES AOA
FL020-025 AGL.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE/FIRE/DIGITAL...APA
AVIATION/NOWCASTS............DAF
DATA ACQUISITION.............BWC
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 241808
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
208 PM EDT FRI MAY 24 2013
.DISCUSSION...
A WARM AND SUNNY DAY IS UNDERWAY ACROSS THE FLORIDA KEYS AND ADJACENT
COASTAL WATERS. CURRENTLY...AIR TEMPERATURES IN MOST KEYS ISLAND
COMMUNITIES ARE IN THE 85-90F RANGE...WITH DEWPOINTS NEAR 70F. THE
LINE OF SHOWERS WHICH EARLIER WAS DETECTED BY KEY WEST DOPPLER RADAR
OVER THE STRAITS OF FLORIDA...IS NOW DISSIPATING JUST NORTH OF THE
CUBAN COAST. LARGE-SCALE SINKING PREVAILS WITH A LIGHT...DIFLUENT
SURFACE FLOW. GEOSTATIONARY SATELLITE IMAGES SHOW SEA BREEZES
INITIATING OVER MAINLAND SOUTH FLORIDA. HOWEVER...SHOWERS HAVE YET TO
FORM OVER MIAMI-DADE COUNTY.
THE OVERALL FORECAST REASONING REMAINS UNCHANGED FROM THE LAST FEW
CYCLES. THE WEATHER PATTERN OVER THE NEXT WEEK WILL BE DOMINATED BY
AN INTENSIFYING AND EXPANDING CONTINENTAL SURFACE HIGH PRESSURE CELL
WHICH CURRENTLY IS CENTERED NEAR THE GREAT LAKES WITH A RIDGE
EXTENDING SOUTHWARD TO THE GULF OF MEXICO. THIS SYSTEM WILL SHIFT
TOWARD THE EAST-SOUTHEAST WITH TIME...AND WILL BE CENTERED OVER THE
WESTERN NORTH ATLANTIC BY SUNDAY. AS A CONSEQUENCE OF THIS SHIFT...
LOCAL BREEZES WILL TURN NORTHEAST AND FRESHEN BEGINNING SATURDAY. THE
RAIN-FREE CONDITIONS OF PRESENT WILL BE REPLACED WITH A SLIGHTLY MORE
MOIST ENVIRONMENT LATER TONIGHT AND SATURDAY...SUPPORTING SLIGHT
SHOWER CHANCES. HIGHER SHOWER AND THUNDER CHANCES REMAIN FOR THE
TUESDAY AND WEDNESDAY TIME FRAME...BUT AT THIS POINT...TIMING IS
UNCERTAIN.
&&
.MARINE...
SMALL CRAFT CAUTION HEADLINES WILL BE NECESSARY AS EARLY AS SATURDAY
EARLY AFTERNOON...WITH PROBABLE SMALL CRAFT ADVISORIES BY SATURDAY
NIGHT. A BREEZY PERIOD OF NORTHEAST TO EAST WINDS IS ANTICIPATED FOR
MOST OF NEXT WEEK.
&&
.AVIATION...
THROUGH 25/18Z...PREVAILING VFR CONDITIONS ARE EXPECTED AT EYW AND
MTH. SURFACE WINDS SHOULD BE LIGHT AND VARIABLE TONIGHT...SHIFTING
OUT OF THE NORTHEAST EARLY SATURDAY AND INCREASING THROUGHOUT THE
DAY. AFTER RAIN-FREE WEATHER TODAY...VERY SLIGHT RAIN CHANCES ARE
EXPECTED TONIGHT AND SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 78 87 77 86 / 10 20 10 10
MARATHON 78 90 77 88 / 10 20 10 10
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........KASPER
AVIATION/NOWCASTS.....DEVANAS
DATA COLLECTION.......BWC
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 241500
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1100 AM EDT FRI MAY 24 2013
.DISCUSSION...
SUNNY SKIES PREVAIL OVER FLORIDA KEYS ISLAND COMMUNITIES THIS
MORNING. THE KEY WEST DOPPLER RADAR DETECTS A THIN...SOUTHWARD-
MOVING LINE OF LIGHT SHOWERS OVER THE STRAITS OF FLORIDA.
HOWEVER...FEW CLOUDS EXIST OTHERWISE ACROSS THE SERVICE AREA. A
SURFACE ANALYSIS SHOWS THE FLORIDA KEYS NEAR A COL IN THE PRESSURE
FIELD BETWEEN A RETREATING TROUGH ALONG THE EASTERN SEABOARD AND A
BUILDING RIDGE OVER THE CENTRAL UNITED STATES. WINDS ARE LIGHT AND
VARIABLE OVER MUCH OF THE STRAITS...AND LIGHT NORTHWEST OVER MOST OF
THE KEYS...FLORIDA BAY...AND THE EXTREME SOUTHEASTERN GULF OF MEXICO.
CURRENT AIR TEMPERATURES ARE RISING THROUGH THE 80S WITH DEWPOINTS
NEAR 70F.
THE KEY WEST MORNING RADIOSONDE BALLOON SAMPLED A VERY DRY ATMOSPHERE
ABOVE ABOUT 3000 FEET ELEVATION. OVERALL CONDITIONAL INSTABILITY WAS
MODERATE. HOWEVER...STRONG CONVECTIVE INHIBITION ENERGY WAS PRESENT
AT LOW ALTITUDES OWING TO A SUBSIDENCE INVERSION. OVERALL...THE
ATMOSPHERE SAMPLED BY THE BALLOON ALOFT THIS MORNING LOOKS QUITE
HOSTILE FOR DEVELOPMENT...ALTHOUGH BOUNDARY-LAYER CONVERGENCE
ASSOCIATED WITH SEA BREEZES OVER MAINLAND SOUTH FLORIDA MAY BECOME
SUFFICIENT FOR ISOLATED SHOWER DEVELOPMENT LATE THIS AFTERNOON.
A FEW SHOWERS LIKELY WILL DEVELOP OVER PORTIONS OF MIAMI- DADE
COUNTY THIS AFTERNOON AND SUBSEQUENTLY MOVE SOUTHWARD OVER PORTIONS
OF FLORIDA BAY AND THE UPPER KEYS. THIS IS ALREADY INDICATED IN
EXISTING FORECASTS. MORNING UPDATES FEATURED ONLY MINOR CHANGES TO
WIND AND SKY COVER TRANSITIONS.
&&
.MARINE...
LIGHT BREEZES WILL PREVAIL THIS AFTERNOON ACROSS FLORIDA KEYS COASTAL
WATERS. A FEW SHOWERS MAY DEVELOP LATE OVER PORTIONS OF FLORIDA BAY
AND THE WATERS ADJOINING THE UPPER KEYS.
&&
.AVIATION...
THROUGH 25/12Z...PREVAILING VFR CONDITIONS ARE EXPECTED AT EYW AND
MTH. SURFACE WINDS SHOULD BE LIGHT AND VARIABLE FOR THE MOST PART.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........KASPER
AVIATION/NOWCASTS.....DEVANAS
DATA COLLECTION.......MSB
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 240858
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
458 AM EDT FRI MAY 24 2013
.DISCUSSION...A CONFLUENT BOUNDARY EXTENDS FROM EAST OF THE MIAMI
AREA...THROUGH THE FLORIDA STRAITS...TO NORTHWEST OF THE WESTERN
CUBAN COAST. ENOUGH MOISTURE REMAINS IN THE ATMOSPHERIC COLUMN NEAR
MIAMI TO ALLOW FOR SHOWERS...WHILE CLOSER TO THE FLORIDA KEYS...THE
BOUNDARY REMAINS DORMANT. MIMIC TPW IMAGERY AND LAST EVENINGS 00Z
SOUNDING PORTRAY THE SAME ANALYSIS...DRY AIR HAS WREAKED HAVOC ON
LOCAL SHOWER ACTIVITY. UNDER MOSTLY CLEAR SKIES...TEMPERATURES ARE IN
THE MID TO UPPER 70S...AND WINDS HAVE BEEN LIGHT AND VARIABLE.
.SHORT TERM (TODAY THROUGH SUNDAY)...THE SPLIT RIDGE SURFACE PATTERN
WILL DEGRADE TODAY...AS THE WEAK HIGH PRESSURE CENTER IN THE NORTHERN
GULF PHASES WITH A MORE ROBUST CONTINENTAL CELL EMERGING FROM THE
MISSISSIPPI RIVER VALLEY. THE PATTERN CHANGE WILL BE IN RESPONSE TO A
SHARPENING UPPER RIDGE AXIS BUILDING OUT OF THE ROCKIES. AS THE
UPPER PATTERN PROGRESSES EAST...THE CONTINENTAL CELL WILL BUILD INTO
THE WESTERN NORTH ATLANTIC. LIGHT AN VARIABLE WINDS WILL TAKE ON MORE
OF A NORTHERLY CHARACTER THIS AFTERNOON...THEN WILL TURN TO THE
NORTHEAST AND STRENGTHEN LATE SATURDAY AFTERNOON. BREEZY CONDITIONS
WILL PERSIST SATURDAY NIGHT AND SUNDAY AS THE CONTINENTAL HIGH
STRENGTHENS...TRANSFORMS...AND EXPANDS IN THE WESTERN ATLANTIC. RAIN
CHANCES WILL REMAIN SLIM THROUGH THE SHORT TERM. BASED ON NORTHERLY
STEERING FLOW THIS AFTERNOON...THE FORECAST INCLUDES THE POSSIBILITY
OF MICRO COLD POOLS PROPAGATING FROM THE SOUTHERN FLORIDA PENINSULA.
NEVERTHELESS...THESE GUST FRONTS WILL STRUGGLE WITH DRY CONTINENTAL
AIR...AND DEEP CONVECTION SEEMS UNLIKELY. AS WINDS CLOCK AROUND TO
THE NORTHEAST SATURDAY AFTERNOON...WOULD NOT BE SURPRISED TO SEE A
FEW SHOWERS ASSOCIATED WITH THE WIND SURGE. HAVE RETAINED NEAR CLIMO
POPS TO ACCOUNT FOR THESE CHANCES. THROUGH THE SHORT
TERM...TEMPERATURES WILL REMAIN NEAR NORMAL...86/77.
&&
.LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...BREEZY CONDITIONS ARE
EXPECTED THROUGH THE LONG TERM AS THE FLORIDA KEYS REMAIN ON THE
SOUTHWESTERN PERIPHERY OF THE HIGH PRESSURE CELL. AS THE CELL CREEPS
TO THE EAST...SUBTROPICAL SUBSIDENCE RELAXES AND MOISTURE THROUGH THE
COLUMN INCREASES...ADD IN A TUTT-LIKE UPPER LEVEL TROUGH...AND RAIN
CHANCES WILL INCREASE. THE FORECAST ADVERTISES POPS A CATEGORY ABOVE
CLIMO TO ACCOUNT FOR WHAT APPEARS TO BE A WETTER THAN NORMAL MID-WORK
WEEK.
&&
.MARINE...A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTHWARD DOWN
THE FLORIDA PENINSULA TONIGHT AND SATURDAY...RESULTING IN INCREASING
NORTHEAST TO EAST BREEZES. FRESH TO STRONG NORTHEAST TO EAST BREEZES
ARE EXPECTED SATURDAY NIGHT THROUGH TUESDAY NIGHT.
&&
.AVIATION...XPECT VFR CONDITIONS AT THE KEYW AND KMTH TERMINAL
TODAY. WINDS WILL BE LIGHT AND VARIABLE.
&&
.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...IN 2008...THE DAILY RECORD
WARM LOW TEMPERATURE OF 82F WAS LAST RECORDED. THIS IS ALSO TIED FOR
THE WARMEST LOW TEMPERATURE EVER RECORDED IN MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 87 78 87 77 / - 10 20 10
MARATHON 91 78 90 77 / - 10 20 10
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........CLR
AVIATION/NOWCASTS.....04
DATA COLLECTION.......MSB
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 240224
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1023 PM EDT THU MAY 23 2013
.DISCUSSION...
THIS AFTERNOON AND EVENING HAS BEEN THE TOTAL ANTITHESIS FROM
YESTERDAY...WITH STRONG MID AND UPPER LEVEL SUBSIDENCE(ARM AND
HAMMER) SHUTTING DOWN ANY CUMULUS CONGESTUS FORGET PRECIPITATION
ECHOES. HENCE...LOCAL RADARS ARE DETECTING ONLY A FEW BOUNDARIES IN
THE OUTER STRAITS BEYOND 20 NM SOUTHEAST OF THE LOWER AND MIDDLE
KEYS. UNDER MOSTLY CLEAR SKIES WITH LIGHT AND VARIABLE
WINDS...TEMPERATURES ARE HOVERING AROUND 80 DEGREES ALONG THE
FLORIDA KEYS. SURFACE WISE...AN ELONGATED RIDGE OF HIGH PRESSURE
LIES FROM EXTREME SOUTHEAST LOUISIANA TO THE EXTREME SOUTHEAST GULF
OF MEXICO...AND ACROSS OUR AREA. IN OUR COASTAL WATERS...WINDS ARE
NORTHWEST AT AROUND 5 KNOTS. OTHERWISE...OUR EVENING SOUNDING
REVEALS SCANT MOISTURE (PWAT 1.21 INCHES) UNDERNEATH A SHALLOW 1
DEGREE C INVERSION BASED AT 950 MB. A UNIDIRECTIONAL NORTHWEST
TRAJECTORY GRADUALLY INCREASES WELL UP IN THE TROPOSPHERE.
.SHORT TERM (REST OF TONIGHT)...
GIVEN A DEEP LAYERED RIDGE CENTERED IN THE SOUTH CENTRAL UNITED
STATES REACHING ACROSS THE SOUTHEAST GULF OF MEXICO...AND THROUGH
OUR REGION AND THE ARCHIPELAGO OF CUBA...LARGE SCALE DESCENT WILL
PREDOMINATE OVER THE NEXT 12 TO 24 HOURS. WITH THAT SAID...AN
ABSENCE OF MOISTURE ABOVE 950 MB ALONG WITH A WEAKENING LOW LEVEL
FLOW WILL PRECLUDE SHOWERS. MOSTLY CLEAR SKIES ALONG WITH LIGHT AND
VARIABLE WINDS WILL ALLOW TEMPERATURES TO FALL BETWEEN 75 AND 80
DEGREES...WITH A FEW INTERIOR SECTIONS OF THE LARGER ISLANDS
DROPPING INTO THE LOWER TO MID 70S. SINCE THE CURRENT FORECAST
HANDLES THE SITUATION WELL...NO UPDATE IS PLANNED.
&&
.MARINE...
OUR EVENING SOUNDING INDICATES NORTHWEST WINDS OF 6 KNOTS AT 1 AND 2
THOUSAND FEET RESPECTIVELY WHICH MATCHES THE KBYX VWP. WITH OUR
REGION LYING ON THE OUTER PERIPHERY OF THE REGION OF HIGH PRESSURE
IN THE GULF OF MEXICO...WINDS WILL BE BELOW 10 KNOTS FROM THE
NORTHWEST TO NORTH OR VARIABLE. OUTSIDE OF A FEW SHOWERS...OUR
MARINE DISTRICT WILL BE VOID OF ANY PRECIPITATION ECHOES.
&&
.AVIATION...
OVERNIGHT...VFR CONDITIONS WILL PREVAIL AT THE KEY WEST AND MARATHON
TERMINALS. LIGHT AND VARIABLE WINDS ARE EXPECTED.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE/FIRE/DIGITAL...APA
AVIATION/NOWCASTS............DAF
DATA ACQUISITION.............BWC
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 231953
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
353 PM EDT THU MAY 23 2013
.DISCUSSION...
A FEW SHOWERS AND THUNDERSTORMS DEVELOPED OVER MIAMI-DADE COUNTY
EARLIER TODAY...AND MOVED SOUTHEASTWARD OVER PORTIONS OF FLORIDA BAY
AND THE EXTREME UPPER KEYS NEAR OCEAN REEF. HOWEVER...RECENT RADAR
TRENDS INDICATE THAT SHOWERS HAVE DISSIPATED...AND IT APPEARS THAT A
LARGE POCKET OF DEEP DRY AIR ALOFT OVER THE EASTERN GULF OF MEXICO
AND MOST OF THE FLORIDA PENINSULA IS BEGINNING TO MOVE ACROSS THE
FLORIDA KEYS AND ADJACENT COASTAL WATERS. CURRENTLY...AIR
TEMPERATURES ARE IN THE UPPER 80S IN MOST ISLAND COMMUNITIES...WHILE
DEWPOINTS ARE IN THE 70-75F RANGE UNDER MOSTLY SUNNY SKIES. WINDS
RANGE FROM WEST TO NORTH NEAR 10 MPH OR LESS AT MOST PLATFORMS.
AN AFTERNOON SURFACE ANALYSIS SHOWS THE FLORIDA KEYS NEARLY IN A COL
REGION IN THE MEAN SEA LEVEL PRESSURE FIELD WITH THE ATLANTIC RIDGE
LOCATED JUST EAST OF THE FLORIDA PENINSULA AND ANOTHER SMALLER HIGH
PRESSURE CELL CENTERED OVER THE NORTH-CENTRAL GULF OF MEXICO.
THE WEATHER OVER THE NEXT WEEK WILL BE DOMINATED BY THE
INTENSIFICATION...EXPANSION...AND EASTWARD EVOLUTION OF A CONTINENTAL
SURFACE HIGH PRESSURE CELL WHICH WILL BUILD BENEATH AND EVOLVE WITH A
LARGE-SCALE UPPER RIDGE. BY EARLY NEXT WEEK...THIS SYSTEM WILL BE
CENTERED OVER THE WESTERN NORTH ATLANTIC. INITIALLY LIGHT AND
VARIABLE BREEZES DEVELOPING OVERNIGHT AND FRIDAY...WILL TURN
NORTHEAST AND FRESHEN ON SATURDAY...WITH BREEZY CONDITIONS EXPECTED
FOR MUCH OF THE SATURDAY NIGHT-WEDNESDAY TIME FRAME. MOSTLY RAIN-FREE
CONDITIONS TONIGHT THROUGH FRIDAY EVENING WILL GIVE WAY TO A
TEMPORARILY INCREASED RAIN CHANCE SATURDAY-SATURDAY EVENING AS AN
INITIAL WIND/MOISTURE SURGE MOVES THROUGH. RAIN CHANCES WILL INCREASE
FURTHER NEXT WEEK AS THE MOIST LAYER GRADUALLY DEEPENS.
&&
.MARINE...
LIGHT AND VARIABLE BREEZES AND SLIGHT SEAS WILL PERSIST FOR ANOTHER
24-36 HOURS BEFORE A NORTHEAST WIND SURGE ENSUES ON SATURDAY. SMALL
CRAFT ADVISORIES LIKELY WILL BE NEEDED BY SATURDAY NIGHT...PERSISTING
THROUGH A GOOD PORTION OF NEXT WEEK.
&&
.AVIATION...
THROUGH 24/18Z...PREVAILING VFR CONDITIONS ARE EXPECTED AT EYW AND
MTH. CONFIDENCE IS HIGH IN A RAIN-FREE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 78 87 78 87 / - - 10 20
MARATHON 78 90 78 90 / - - 10 20
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........KASPER
AVIATION/NOWCASTS.....BS
DATA COLLECTION.......BWC
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 231128
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
728 AM EDT THU MAY 23 2013
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY FRIDAY MORNING AT THE KEY
WEST AND MARATHON TERMINALS. THERE IS SOME POTENTIAL FOR A REVERSE CU
LINE TO FORM ALONG THE ISLAND CHAIN DURING THE MID MORNING THROUGH
EARLY AFTERNOON HOURS. DRY AIR ENTRAINMENT ALOFT SHOULD PREVENT ANY
DEEP CONVECTION ALONG THIS LINE...BUT AT LEAST A FEW SHOWERS WILL BE
POSSIBLE. THIS ACTIVITY WOULD PROBABLY REMAIN EAST OF THE KEY WEST
TERMINAL...AND CONFIDENCE IS STILL TOO LOW TO INCLUDE A VCSH IN
MARATHON AT THIS POINT. HAVE MAINTAINED A TEMPO FOR MVFR CIGS AT
MARATHON FROM 14Z TO 18Z. SOUTHWEST SURFACE WINDS AROUND 5 KNOTS WILL
BECOME LIGHT AND VARIABLE THIS MORNING...THEN NORTHWEST AT 5 TO 8
KNOTS DURING THE AFTERNOON.
&&
$$
AVIATION...JACOBSON
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 230933
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
533 AM EDT THU MAY 23 2013
.DISCUSSION...THE RADAR REMAINS ECHO FREE THIS MORNING SAVE FOR A FEW
LEFTOVER BOUNDARIES LUNGING NORTHWARD. CLOUD COVER RANGES FROM MOSTLY
CLEAR TO PARTLY CLOUDY UNDERNEATH THE SAME TRANSIENT BOUNDARIES.
TEMPERATURES HAVE COOLED TO NEAR 80 DEGREES...AND WINDS HAVE BEEN
MOSTLY VARIABLE AND UNDER 10 KNOTS. THE UPPER LEVEL TROUGH TO THE
EAST OF FLORIDA HAS BECOME MORE PROGRESSIVE AND CONTINUES TO PUSH
NORTHEAST. WATER VAPOR IMAGERY AND WIND PROFILES FROM LAST EVENINGS
RAOB SOUNDING REVEAL WESTERLY FLOW IN THE MID TO UPPER LEVELS. AT THE
SURFACE...THE WESTERN EXTENSION OF THE BERMUDA HIGH PRESSURE CELL
REMAINS FRACTURED IN ITS REACH ACROSS FLORIDA.
.SHORT TERM (TODAY THROUGH SATURDAY)...BASED ON YESTERDAYS WINNING
BATTLE OVER THE DRY AIR...A PERSISTENCE FORECAST SEEMS REASONABLE FOR
TODAY. IN FACT...THERE MAY BE LESS DRY AIR IN THE MID LEVELS TODAY AS
THE UPPER TROUGH PROPAGATES AWAY. WIND AND LOW LEVEL MOISTURE
PROFILES ARE FAVORABLE AND SIMILAR TO YESTERDAYS REVERSE CLOUD LINE
DEVELOPMENT. STEERING FLOWS LATE THIS AFTERNOON AND TONIGHT WILL
TEND TO BE TO THE EAST...SO DO NOT EXPECT MAINLAND CONVECTION TO HAVE
AN INFLUENCE. FOR FRIDAY AND FRIDAY NIGHT...LOW LEVEL MOISTURE
DECREASES AS CONTINENTAL AIR FILTERS ACROSS THE FRACTURED RIDGE AXIS.
STEERING FLOWS ARE A LITTLE MORE FAVORABLE TOMORROW AFTERNOON AND
EVENING FOR MAINLAND CONVECTIVE PROPAGATION...SO HAVE INCLUDED A
SLIGHT CHANCE OF THUNDER FOR ISLAND COMMUNITIES. BY SATURDAY...MAINLY
LIGHT AND VARIABLE WINDS WILL BEGIN A LEGITIMATE VEER TO THE NORTH TO
NORTHEAST AND WILL INCREASE IN RESPONSE TO AN EXPANDING RIDGE IN THE
SOUTHEASTERN UNITED STATES. HEATING ON THE MAINLAND WILL COMPLICATE
THE EXPANSION OF THE RIDGE. AS THE THERMODYNAMICS TAKE ON MORE OF A
CONTINENTAL CHARACTER...LOW LEVEL CONFLUENCE AND CONVERGENCE WILL
INCREASE AS WINDS SURGE FROM THE NORTHEAST. HENCE...COMPETING
VARIABLES WILL MAKE FOR A CHALLENGING FORECAST FOR THE END OF THE
SHORT TERM. WE HAVE ADDED THUNDER TO THE GRIDS SATURDAY
AFTERNOON...AS MAINLAND CONVECTION PROPAGATES TO THE SOUTHWEST.
OTHERWISE...NO OTHER CHANGES.
&&
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...THE LONG TERM CAN BE
SUMMED UP WITH ONE WORD...BREEZY. THE CONTINENTAL HIGH WILL SLOWLY MERGE
WITH THE BERMUDA CELL TO ITS EAST. NORTHEAST TO EAST BREEZES WILL
REMAIN TRAPPED UNDERNEATH SIGNIFICANT SUBSIDENCE THROUGH MONDAY.
RAIN CHANCES WILL BE SCANT UNTIL THE SURFACE HIGH SHIFTS
NORTHEAST...WEAKENING THE INVERSION ENOUGH TO ALLOW THE LOW LEVEL
MOISTURE FLUX TO EFFECTIVELY DESTABILIZE THE COLUMN. WE HAVE TRIMMED
POPS AND THUNDER SUNDAY THROUGH MONDAY...AND RETAINED THE POPS
THROUGH THE REMAINDER OF THE LONG TERM. WITH VERY FEW CHANGES TO THE
LOW LEVEL WIND FIELD IN THE LONG TERM...WE HAVE EXTENDED BREEZY
THROUGH DAY 7.
&&
.MARINE...A WEAK PRESSURE PATTERN WILL PREVAIL TODAY THROUGH FRIDAY.
A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTHWARD DOWN THE FLORIDA
PENINSULA FRIDAY NIGHT AND SATURDAY...RESULTING IN INCREASING
NORTHEAST TO EAST BREEZES. FRESH TO STRONG NORTHEAST TO EAST BREEZES
ARE EXPECTED SATURDAY NIGHT THROUGH MONDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE REQUIRED FOR ALL KEYS COASTAL WATERS SATURDAY
NIGHT THROUGH MONDAY NIGHT.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING AT THE
KEY WEST AND MARATHON TERMINALS. THERE IS SOME POTENTIAL FOR A
REVERSE CU LINE TO FORM ALONG THE ISLAND CHAIN DURING THE MID MORNING
THROUGH EARLY AFTERNOON HOURS. DRY AIR ENTRAINMENT ALOFT SHOULD
PREVENT ANY DEEP CONVECTION ALONG THIS LINE...BUT AT LEAST A FEW
SHOWERS WILL BE POSSIBLE. THIS ACTIVITY WOULD PROBABLY REMAIN EAST OF
THE KEY WEST TERMINAL...AND CONFIDENCE IS TOO LOW TO INCLUDE A VCSH
IN MARATHON AT THIS POINT. HAVE INCLUDED A TEMPO FOR MVFR CIGS AT
MARATHON FROM 14Z TO 18Z. LIGHT AND VARIABLE SURFACE WINDS WILL
BECOME NORTHWEST AT 5 TO 8 KNOTS DURING THE AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 88 78 87 78 / 20 10 10 20
MARATHON 92 78 90 78 / 20 10 10 20
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........CLR
AVIATION/NOWCASTS.....JACOBSON
DATA COLLECTION.......VICKERY
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
000
FXUS62 KKEY 230243
AFDKEY
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1040 PM EDT WED MAY 22 2013
.DISCUSSION...
CONSIDERABLE DRY AIR ALOFT KEPT THE CLOUD LINE FLAT FOR MOST OF
THE ISLAND CHAIN...EXCEPT FROM 5 TO 10 NM NORTH OF THE ISLAND CHAIN
BETWEEN THE SEVEN MILE BRIDGE AND LONG KEY. THIS NARROW BAND FORMED
IN THIS AREA BEFORE DISINTEGRATING FOR A BRIEF SPELL. HOWEVER...IT
REGENERATED SHORTLY BEFORE 3 PM WITH A SOLID...ALBEIT FAIRLY SHORT
SEGMENT OF SHOWERS...THUNDERSTORMS ALONG WITH SEVERAL WATERSPOUTS
FROM BAHA HONDA TO NEAR MARATHON INCLUDING THE SEVEN MILE BRIDGE.
THIS CYCLICAL...EXTREMELY DEEP AND ACTIVE CLOUD LINE PERSISTED FROM
AROUND 245 PM TO 520 PM. ELSEWHERE...NO PRECIPITATION IMPACTED THE
FLORIDA KEYS UNTIL LATE THIS EVENING WHEN A PERSISTENT BAND OF
SHOWERS AND THUNDERSTORMS SLIPPED SOUTHWARD INTO THE EXTREME UPPER
KEYS...BETWEEN NORTH KEY LARGO AND ANGELFISH KEY. CURRENTLY...IN
ADDITION TO THE DEEP CONVECTION IN THE EASTERNMOST UPPER KEYS AND
THE ADJACENT NEARSHORE ATLANTIC WATERS...SHOWERS ARE DECAYING ON THE
OFFSHORE WATERS BEYOND 20 NM SOUTH OF THE LOWER KEYS. IN
ADDITION...SEVERAL BOUNDARIES ARE LINGERING JUST NORTH AND SOUTH OF
THE ISLAND CHAIN. ACROSS OUR MARINE DISTRICT...WINDS ARE VARIABLE AT
LESS THAN 10 KNOTS AWAY FROM ANY SHOWERS AND THUNDERSTORMS.
OTHERWISE...OUR EVENING SOUNDING REVEALS LIMITED MOISTURE (PWAT 1.30
INCHES) BUT WITH LITTLE IF ANY CONVECTIVE INHIBITION. LIGHT AND
VARIABLE WINDS TURN QUICKLY WEST TO NORTHWEST AND INTENSIFY ABOVE
400 MB.
.SHORT TERM (REST OF TONIGHT)...
DESPITE CONSIDERABLE MID AND UPPER LEVEL DRY AIR ABOVE 700 MB...A
PLETHORA OF BOUNDARIES COMBINED WITH LITTLE IN THE WAY OF CONVECTIVE
INHIBITION WILL POSE A 20 TO 30 PERCENT CHANCE FOR SHOWERS AND
POSSIBLE THUNDERSTORMS ACROSS THE ISLAND CHAIN. LIGHT AND VARIABLE
WINDS UNDER MAINLY PARTLY CLOUDY SKIES WILL ALLOW TEMPERATURES TO
FALL BETWEEN 75 AND 80 DEGREES ALONG THE FLORIDA KEYS. SINCE THE
CURRENT FORECAST HANDLES THE FORECAST ELEMENTS FAIRLY WELL...NO
ADJUSTMENTS ARE PLANNED.
&&
.MARINE...
OUR EVENING SOUNDING INDICATES NORTHWEST AND WEST WINDS OF 6 AND 2
KNOTS RESPECTIVELY WHILE THE KBYX VWP DEPICTS NORTHWEST AT 10 KNOTS
AT 1 THOUSAND FEET. WITH OUR REGION LYING BETWEEN A WESTERN ATLANTIC
RIDGE LYING JUST EAST OF THE FLORIDA PENINSULA AND ANOTHER AREA OF
HIGH PRESSURE IN THE EASTERN GULF OF MEXICO...WINDS WILL BE VARIABLE
AT LESS THAN 10 KNOTS ON ALL KEYS COASTAL WATERS OUTSIDE OF SHOWERS
AND THUNDERSTORMS.
&&
.AVIATION...
THROUGH 24/00Z...VFR CONDITIONS SHOULD PREVAIL AT THE KEY WEST AND
MARATHON TERMINALS. IN THE SHORT TERM...THE ONLY EXCEPTION TO THAT
SHOULD BE THE POSSIBILITY OF LIGHT SHOWERS OR BRIEF MVFR CIGS FROM A
PASSING BOUNDARY SOMETIME AFTER 04Z. WITH AMPLE REMNANT BOUNDARIES
IN THE VICINITY OF THE ISLAND CHAIN...THERE WILL BE A CONTINUAL
SLIGHT CHANCE OF SHOWERS IN THE AREA THROUGH THURSDAY...BUT
CONFIDENCE IS LACKING IN THE EXACT TIME PERIOD OF THOSE SHOWERS.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE/FIRE/DIGITAL...APA
AVIATION/NOWCASTS............MSB
DATA ACQUISITION.............BWC
VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
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