000
AGXX40 KNHC 180758
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
358 AM EDT MON JUN 18 2012

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA
AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W.

GULF OF MEXICO...
THE WEAK SURFACE TROUGH THAT HAD BEEN MOVING THROUGH THE NW GULF
APPEARS TO HAVE DAMPENED OUT AS OF 18/06Z. THIS LEAVES A SURFACE
RIDGE EXTENDING FROM THE CAROLINAS TO THE SW GULF WITH GENERALLY
LIGHT TO MODERATE SE WINDS OVER THE ENTIRE GULF. THE EXCEPTION IS
THE STRAITS OF FLORIDA WHERE 15 TO 20 KT EAST WINDS ARE NOTED.
SCATTERED SHOWERS AND A FEW THUNDERSTORMS LINGER OVER THE N
CENTRAL GULF...ON THE NORTH EDGE OF THE LOOP CURRENT AND UNDER AN
AREA OF UPPER DIVERGENCE. DRIER MID AND UPPER LEVEL AIR MOVING
INTO THIS AREA WILL INHIBIT CONVECTION THROUGH THE REMAINDER OF
THE DAY. THE PRES GRADIENT WILL TIGHTEN OVER THE EASTERN AND
CENTRAL GULF TUE BETWEEN THE HIGH PRES OVER THE CAROLINAS AND A
TROUGH MOVING TOWARD THE YUCATAN ACROSS THE NW CARIBBEAN. THE GFS
REMAINS THE STRONGEST SOLUTION SHOWING WINDS TO 25 KT OVER THE
EASTERN AND CENTRAL GULF THROUGH THU. THE ECMWF AND UKMET ON THE
OTHER HAND INDICATE WINDS INCREASING BUT STAYING IN THE 15 TO 20
KT RANGE. THE GFS HAS BEEN TRENDING WEAKER SHOWING THE AREA OF
FRESH TO STRONG WINDS DECREASING SOMEWHAT COMPARED TO EARLIER
RUNS AND IS MORE IN LINE WITH THE OTHER MODELS. THE FORECAST
FAVORS THE ECMWF/UKMET SOLUTIONS THROUGH THU. BOTH THE GFS AND
ECMWF SHOW AN AREA OF LOW PRES EMERGING OFF THE YUCATAN INTO THE
S CENTRAL GULF BY LATE THU...FURTHER EAST THAN EARLIER
RUNS...THEN SHIFTING WESTWARD TOWARD THE SW GULF FRI. THE
OFFICIAL FORECAST IS A BLEND OF GFS AND ECMWF WITH MODERATE TO
FRESH CYCLONIC FLOW IN A BROAD SWATH AROUND THE LOW...ALTHOUGH
FAVORING THE STRONGER GFS SHOWING N WINDS TO 25 KT BY FRI
AFTERNOON OFF THE COAST OF VERACRUZ AHEAD OF THE ADVANCING LOW
PRES. MODEL CONSENSUS HOLDS THE PRES TO 1007 MB BY LATE FRI.
EXPECT PERSISTENT CONVECTION ACROSS THE SOUTHERN GULF BY THU AND
FRI AS THE LOW MOVES INTO THE AREA.

CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W...
1008 MB LOW PRES IS CENTERED NEAR 15N82W...HAVING MOVED NNW FROM
ITS POSITION OF THE N COAST OF PANAMA YESTERDAY. THE LOW IS JUST
OFF THE COAST NEAR THE NICARAGUA/HONDURAS BORDER AND APPEARS TO
BE STAYING OVER THE WATERS AS OPPOSED MAKING AN EARLY LANDFALL
FURTHER WEST. THIS IS ALLOWING THE LOW TO STAY INTACT AND DEEPEN
SLIGHTLY. HOWEVER...AN UPPER LOW IS PARKED OVER THE S CENTRAL
GULF OF MEXICO AND IS DELIVERING WESTERLY SHEAR ACROSS THE
SURFACE LOW. STRONG CONVECTION FLARING CURRENTLY SOUTH OF
JAMAICA...IS DISPLACED TOO FAR EAST TO ASSIST THE DEVELOPMENT OF
THE LOW. GLOBAL MODEL CONSENSUS INDICATES THE LOW WILL TRACK MORE
WNW AND HUG THE HONDURAN COAST THROUGH TUE...IN RESPONSE TO ATLC
RIDGING BUILD WEST TOWARD THE CARIBBEAN...BEFORE CROSSING THE
TERRAIN OVER BELIZE...NORTHERN GUATEMALA AND SOUTHERN YUCATAN WED.
THE UPPER SHEAR BACKS MORE TO THE SW AND DIMINISHES SOMEWHAT AS
THE UPPER LOW DRIFTS WEST THROUGH WED. HOWEVER THE MODEST SHEAR
ALONG WITH TERRAIN EFFECTS WILL KEEP THE LOW FROM DEEPENING
APPRECIABLY THROUGH WED. EXPECT CONTINUAL CONVECTION OVER THE NW
CARIBBEAN INTO THU AS THE THE LOW AND ITS ACCOMPANYING SURFACE
TROUGH MIGRATE TO THE NW. FURTHER EAST...A WEAK TROPICAL WAVE
THAT IS POORLY DEFINED AT THE SURFACE WILL MOVE THROUGH THE
TROPICAL N ATLC TODAY AND ENTER THE SE CARIBBEAN THIS
EVENING...REACHING THE S CENTRAL CARIBBEAN BY LATE TUE BEFORE
BECOMING DIFFUSE OVER THE SW CARIBBEAN WED. A SECOND TROPICAL
WAVE WILL MOVE W OF 55W BY LATE TUE...AND REACH THE S CENTRAL
CARIBBEAN BY WED NIGHT BEFORE ALSO BECOME DIFFUSE BY THU. THE
MAIN PLAYER IS THE ATLC RIDGE TO THE NORTH...MAINTAINING FRESH E
TO SE FLOW FROM 55W TO THE CENTRAL CARIBBEAN THROUGH FRI.
FORECAST FAVORS STRONGER GFS SOLUTION WITH WINDS TO 25 KT OVER S
CENTRAL PORTIONS OF THE CARIBBEAN IN CONCERT WITH TROPICAL WAVE
PASSAGES.

SOUTHWEST NORTH ATLC S OF 31N W OF 55W...
A LONG SURFACE TROUGH EXTENDS FROM A DEEP 1005 MB LOW PRES SYSTEM
CENTERED NEAR 35N62W...SW TO THE WINDWARD PASSAGE WHERE IT IS IN
PHASE WITH TROUGH OVER THE CARIBBEAN. THE SUPPORTING UPPER LOW
IS CENTERED N OF THE AREA NEAR 33N67W...WITH AN UPPER TROUGH
EXTENDING SW TO THE STRAITS OF FLORIDA. DRY SUBSIDENT AIR COVERS
THE AREA GENERALLY TO THE NW OF THE SURFACE TROUGH. RICH DEEP
LAYER MOISTURE IS BEING DRAWN THE WESTERN CARIBBEAN TO JUST E OF
BERMUDA. ALONG WITH FAVORABLE JET DYNAMICS ALOFT ASSOCIATED WITH
THE UPPER TROUGH...STRONG CONVECTION IS EMERGING FROM ROUGHLY THE
MONA PASSAGE IN THE WATERS N OF PUERTO RICO. THE UPPER LOW WILL
MOVE NE OF THE AREA TOWARD THE N CENTRAL ATLC THROUGH TUE...WITH
THE TRAILING TROUGH IN TOW. THE SURFACE TROUGH DRIFTS TO THE
NW...REACHING A POSITION FROM 30N70W THROUGH THE NORTHERN BAHAMAS
AND S FLORIDA BY LATE WED ACCOMPANIED BY A RIBBON OF SHOWERS AND
THUNDERSTORMS. FORECAST IS A BLEND OF THE STRONGER GFS AND THE
ECMWF MAINTAINING 15 TO 20 KT...BUT FAVORING STRONGER GFS OVER
THE NORTHERN BAHAMAS BY LATE TUE WITH E WINDS 20 TO 25 KT JUST
AHEAD OF THE ADVANCING TROUGH. BY THU...SE FLOW ACROSS THE AREA
DIMINISHES AS HIGH PRES BUILDS W IN THE WAKE OF THE TROUGH. 

NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT 
WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE)

GULF OF MEXICO...
.NONE.

CARIBBEAN SEA...
.NONE.

SW N ATLANTIC...
.NONE.
    
FOR ADDITIONAL INFORMATION PLEASE VISIT
WWW.HURRICANES.GOV/MARINE

$$
FORECASTER CHRISTENSEN