000
AGXX40 KNHC 181825
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
230 PM 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...
HIGH PRES CENTER 1020 MB HAS RIDGE EXTEND TO SW GULF WITH LIGHT 
TO MODERATE SE WINDS OVER ENTIRE GULF...EXCEPT A FRESH E BREEZE 
OVER STRAITS OF FLORIDA.  SCATTERED SHOWERS AND ISOLATED TSTMS 
LINGER OVER NW GULF WATERS FROM PREVIOUS TROUGH PASSAGE.  DRIER  
MID AND UPPER LEVEL AIR MOVING INTO AREA INHIBIT CONVECTION 
ELSEWHERE.  PRES GRADIENT TIGHTEN OVER EASTERN AND CENTRAL GULF 
TUE BETWEEN HIGH PRES OVER AND TROUGH MOVING INTO SE GULF ACROSS 
YUCATAN PENINSULA.  MODEL GUIDANCE IN GOOD AGREEMENT WITH 
SCENARIO WITH GFS GIVING MOST AGGRESSIVE SOLUTION WITH STRONG E 
BREEZE OVER ALONG STRAITS OF FLORIDA THROUGH THU.  ECMWF AND 
UKMET INDICATE WINDS INCREASING TO MODERATE BREEZE.  FORECAST 
FAVORS ECMWF/UKMET SOLUTIONS THROUGH THU.  ALL MODELS SOLUTIONS 
POINT TO A WEAK LOW PRES CENTER OR TROUGH EMERGING OFF W YUCATAN 
INTO SW GULF LATE THU OR FRI.  OFFICIAL FORECAST BLENDS GFS AND 
ECMWF WITH MODERATE TO FRESH CYCLONIC FLOW IN BROAD SWATH AROUND 
LOW PRES.  EXPECT PERSISTENT CONVECTION ACROSS SRN GULF THU AND 
FRI AS LOW PRES MOVES INTO AREA.

CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W...
BROAD LOW PRES 1008 MB AT 16N84W OFF NE COAST OF HONDURAS  
REMAINS THE MOST CRITICAL FEATURE AS UNCERTAINTY OF POSITION MAY 
THROW A WRENCH INTO MODEL SOLUTIONS.  THERE MAY BE MORE THAN ONE 
CENTER IN BROAD CYCLONIC CIRCULATION WHICH MAY THEN TRACK 
ERRATICALLY FROM EXPECTED.  ONE CERTAIN FACT IS ENORMOUS AMOUNT 
OF MOISTURE COMBINED WITH MODERATE TO STRONG DIVERGENT FLOW 
ALOFT WHICH ENHANCES LARGE AREA OF DEEP CONVECTION...WHICH STILL 
REMAINS MOSTLY OVER WRN CARIBBEAN WATERS.  MODEL GUIDANCE TRACKS 
FAVORS STRENGTHENING LOW PRES TO MOVE ACROSS BELIZE AND YUCATAN 
PENINSULA INTO BAY OF CAMPECHE BY LATE THU OR FRI.    HOWEVER 
...STATIONARY UPPER LEVEL CYCLONE OVER S CENTRAL GULF OF MEXICO 
BRINGS WLY WIND SHEAR OVER LOW PRES CENTER KEEPING CONVECTION ON 
ITS E SIDE WITH JAMAICA AND SMALLER ISLANDS GETTING THE BLUNT OF 
RAINFALL.  EXPECT CONTINUED HEAVY CONVECTION OVER WRN CARIBBEAN 
INTO THU AS LOW PRES AND ITS ACCOMPANYING SURFACE TROUGH DRIFT 
W.  FURTHER E...TROPICAL WAVE ALONG 56W CROSSES TROPICAL N ATLC 
TODAY AND ENTERS SE CARIBBEAN LATE TONIGHT...REACHING S CENTRAL 
CARIBBEAN LATE TUE BEFORE BECOMING DIFFUSE OVER SW CARIBBEAN 
WED.  SECOND TROPICAL WAVE CROSSES 55W LATE THU AND REACH S 
CENTRAL CARIBBEAN LATE FRI.  STRONG E BREEZE EXPECTED ALONG AXIS 
OF EITHER TROPICAL WAVE.

SOUTHWEST NORTH ATLC S OF 31N W OF 55W...
LONG SURFACE TROUGH STRETCH FROM LOW PRES CENTER 1004 MB WELL N 
OF AREA AT 36N62W...SW TO E TIP OF CUBA WHERE IT IS IN PHASE 
WITH SECOND TROUGH OVER CARIBBEAN.  DRY SUBSIDENT AIR COVERS 
AREA W OF SURFACE TROUGH BUT PLENTY OF TROPICAL MOISTURE IS 
ADVECTED WITHIN 300-500 NM E OF AXIS RIDING STRONG JET CORE. 
STRONG CONVECTION EMERGING ACROSS WINDWARD PASSAGE ENTERS BASIN. 
SURFACE TROUGH DRIFTS NE...REACHING FROM 30N60W THROUGH CENTRAL 
BAHAMAS AND E CUBA LATE WED ACCOMPANIED BY SWATH OF DEEP  
CONVECTION.  THU AND FRI...SE FLOW ACROSS AREA DIMINISHES AS 
HIGH PRES BUILDS W IN WAKE OF TROUGH EXIT. 

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 WALLY BARNES