000
AGXX40 KNHC 180856 AAA
MIMATS

MARINE WEATHER DISCUSSION...UPDATED
NWS NATIONAL HURRICANE CENTER MIAMI FL
455 AM EDT FRI APR 18 2014

UPDATED TO ADD MENTION OF SWELLS TO SW N ATLC AND CARIBBEAN SEA
AND TROPICAL N ATLC SECTIONS AS REPORTED IN LATEST
OBSERVATIONS...AND TO INCLUDE MENTION OF LATEST DETECTED
LIGHTNING WITH GULF TSTMS

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN
SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND
64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS.

...GULF OF MEXICO...
MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS FORECAST. FOR WAVES
USED AN EVEN BLEND OF OFFICIAL WITH 00 UTC MWW3 AND NWPS WAVE
PARAMETERS. AVERAGE CONFIDENCE THROUGH SAT...THEN HIGH CONFIDENCE
THEREAFTER.

A WARM FRONT EXTENDS FROM NEAR TAMPA FLORIDA TO A 1012 MB LOW AT
28N88W. A COLD FRONT EXTENDS FROM THE LOW SW TO NEAR 24N91W. HIGH
PRES IS PRESENT TO ELSEWHERE OVER THE GULF. LATEST IR SATELLITE
IMAGERY AND NWS MOSAIC RADAR ANIMATION SHOW A LARGE AREA OF
NUMEROUS STRONG TSTMS IN THE WARM SECTOR OF THE FRONTS COVERING
THE AREA FROM 22N TO 29N BETWEEN 83W-89W. A VIGOROUS UPPER
TROUGH OVER THE NW GULF SUPPORTS THE COLD FRONT AND LOW PRES.
DIVERGENCE ALOFT E OF THE TROUGH WILL ASSIST IN PROLONGING THE
TSTM ACTIVITY THROUGH TODAY AS IT TRANSLATES EASTWARD ACROSS THE
EASTERN GULF. LATEST LIGHTNING DETECTION DATA SHOWS FREQUENT
LIGHTNING STRIKES ASSOCIATED WITH THIS TSTM ACTIVITY. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE ELSEWHERE N OF 21N AND E OF 92W.
BOTH BUOY AND AN ASCAT PASS FROM 0346 UTC INDICATE STRONG NE-E
WINDS N OF THE WARM FRONT...AND STRONG NE WINDS W OF THE COLD
FRONT TO 92W. FRESH TO STRONG NE-E WINDS ARE ELSEWHERE W OF THE
COLD FRONT. BUOYS AND A FEW SHIPS SHOW SEAS OF 8-9 FT IN THE NE
GULF N OF THE WARM FRONT. A TIGHTENING PRES GRADEINT BETWEEN
HIGH PRES OVER THE SE U.S AND THE LOW PRES WILL CONTINUE TO
STRENGTHEN THE NLY WINDS TO THE NW OF THE LOW WITH WINDS
EXPECTED TO REACH GALE FORCE OVER A PORTION OF THE NW QUADRANT
OF THE LOW TODAY. LATEST MEAN GFS GALE FORCE PROBABILITIES
SUGGEST 20 PERCENT FOR THE FAR NORTHERN GULF AREA BETWEEN THE
WESTERN FL PANHANDLE AND MOBILE ALABAMA AREA FOR TODAY. AHEAD OF
THE COLD FRONT SLY WINDS ARE EXPECTED TO BE IN THE 20-30 KT
RANGE TODAY WITH PROBABLE FREQUENT GUSTS TO GALE FORCE MAINLY
ATTRIBUTED TO THE GRADIENT INDUCED BY THE STRONG TSTM ACTIVITY
MENTIONED PREVIOUSLY. SEAS AHEAD OF THE COLD FRONT ARE EXPECTED
TO BUILD TO AROUND 10 FT.

THE FORECAST CALLS FOR THE THE WARM FRONT TO CONTINUE TO LIFT
NORTHWARD THROUGH THIS MORNING WITH THE LOW PRES EXPECTED TO BE
NEAR 29N87W BY EARLY THIS AFTERNOON...AND COLD FRONT FROM LOW TO
25N90W AND TO EASTERN BAY OF CAMPECHE. THE LOW WILL MOVE ENE
THROUGH THIS AFTERNOON REACHING NEAR 30N86W THIS EVENING WITH THE
COLD FRONT TO 25N86W TO NEAR 21N92W. MINIMAL GALE FORCE WINDS ARE
EXPECTED OVER A PORTION OF THE NW QUADRANT OF THE LOW TODAY...WITH
FREQUENT GUSTS TO GALE FORCE OVER THE NE GULF AHEAD OF THE LOW
AND COLD FRONT...AND DIMINISHING BY THIS EVENING. BY SAT
MORNING...THE LOW WILL BE OVER NORTHERN FLORIDA WITH THE COLD
FRONT EXTENDING SSW OVER THE FAR EASTERN GULF. THE LOW WILL
CONTINUE EASTWARD AWAY FROM FLORIDA DURING SAT AFTERNOON PUSHING
THE FRONT E OF THE AREA. IN ITS WAKE...A RIDGE WILL THEN EXTEND
ACROSS THE GULF SAT NIGHT THROUGH TUE NIGHT.

.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS FORECAST. FOR WAVES
USED AND EVEN BLEND OF OFFICIAL WITH 00 UTC MWW3 AND NWPS WAVE
PARAMETERS. HIGH CONFIDENCE.

THE 0202 ASCAT PASS SHOWED NE WINDS OF 20-25 KT S OF ABOUT 14N
BETWEEN 72W AND 77W WITH A SMALL POCKET OF 25-30 KT VERY NEAR THE
COAST OF COLOMBIA. ELSEWHERE...NE-E WINDS ARE IN THE MODERATE TO
FRESH RANGE...EXCEPT W OF 83W WHERE E-SE WINDS OF 10-15 KT ARE
NOTED WITH THE EXCEPTION OF THE HIGHER E WINDS IN THE 20-25 KT
RANGE S OF 18N AND W OF 85W...INCLUDING THE GULF OF HONDURAS. HIGH
PRES N OF THE REGION WILL MAINTAIN FRESH TO LOCALLY STRONG TRADES
NEAR THE COAST OF COLOMBIA WITH MODERATE TO LOCALLY FRESH TRADES
ELSEWHERE THROUGH SAT. THE PRES GRADIENT WILL WEAKEN SLIGHTLY SUN
AS A WEAK LOW PRES MOVES ACROSS THE SW N ATLC...CONTINUING TO
WEAKEN MON AND TUE. THE E WINDS OF 20-25 KT S OF 18N W OF 85W
WILL DIMINISH TO 10-15 KT LATE THIS MORNING OR EARLY AFTERNOON
AS THE GULF OF MEXICO COLD FRONT PROGRESSES EASTWARD.

...SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS FORECAST. FOR WAVES
USED AND EVEN BLEND OF OFFICIAL WITH 00 UTC MWW3 AND NWPS WAVE
PARAMETERS. HIGH CONFIDENCE...EXCEPT AVERAGE CONFIDENCE WITH
WINDS ASSOCIATED WITH FRONT OVER THE NORTHERN PORTION.

THE 06 UTC SURFACE ANALYSIS HAS A STATIONARY FRONT EXTENDING FROM
31N74W TO NEAR VERO BEACH FLORIDA...WHILE HIGH PRES IS PRESENT
ELSEWHERE. THE FRONT WILL BEGIN TO LIFT NORTHWARD AS A WARM FRONT
THIS MORNING. THE 0206 UTC ASCAT PASS SHOWED A LARGE SWATH OF
STRONG NE-E WINDS N OF THE STATIONARY FRONT W OF ABOUT 76W. SEAS
THERE HAVE REACH TO A MAX OF 9 FT. NE-E SWELLS WITH SEAS IN THE
7-9 FT RANGE WILL CONTINUE TO HAMPER MUCH OF THE EASTERN WATERS
INTO SUN BEFORE SUBSIDING.

LOW PRES OVER THE NE GULF OF MEXICO WILL SLOWLY MOVE EASTWARD
ACROSS NORTHERN FLORIDA THIS WEEKEND DRAGGING A COLD FRONT ACROSS
THE REGION THROUGH EARLY NEXT WEEK. STRONG NORTHERLY WINDS WILL
DEVELOP BEHIND THE COLD FRONT IN THE FAR NW WATERS SUN INTO MON
THEN DIMINISHING MON NIGHT AND TUE.

NE SWELLS WITH SEAS OF 7-9 FT WILL CONTINUE TO PLAGUE MUCH OF
TROPICAL N ATLC WATERS INTO EARLY NEXT WEEK BEFORE SUBSIDING.

$$

.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.GULF OF MEXICO...
.GMZ013...N CENTRAL GULF INCLUDING FLOWER GARDEN BANKS MARINE SANCTUARY...
GALE WARNING N OF 28N E OF 89W.
.GMZ015...NE GULF N OF 27N
GALE WARNING TODAY.

.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
NONE.

.SW N ATLANTIC INCLUDING THE BAHAMAS...
NONE.

$$

*FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT:
HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF

NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE
NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT:
HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP

FOR ADDITIONAL INFORMATION PLEASE VISIT:
HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE

$$

.FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.