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MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
400 AM EDT MON JUL 25 2016

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: FOR WINDS USED BLEND OF 00Z GFS WITH PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF 00Z MWW3 AND TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE.

THE MID TO UPPER LEVEL LOW THAT WAS E OF FL THE PAST FEW DAYS IS PRESENTLY OVER THE FAR SE GULF. THIS FEATURE IN COMBINATION WITH AN INVERTED TROUGH OVER THE SW GULF ARE LEADING TO AMPLE INSTABILITY RESULTING IN SCATTERED SHOWERS AND TSTMS OVER MUCH OF ERN AND CNTRL WATERS. THIS ACTIVITY HAS AMOUNTED TO MORE THAN EARLIER ANTICIPATED. THE NRN PORTION OF A TROPICAL WAVE AXIS OVER THE EASTERN PACIFIC ALONG 95W EXTENDS N TO 20N IN THE BAY OF CAMPECHE AREA. SCATTERED SHOWERS AND TSTMS WITH FREQUENT LIGHTNING STRIKES ARE OBSERVED WITHIN 180 NM E OF THE AXIS. THE WEAK ATLC RIDGE AXIS THAT WAS OVER THE NRN GULF THE PAST SEVERAL DAYS HAS SHIFTED S TO NEAR 27N E OF 88W.

LATEST BUOY OBSERVATIONS AND RECENT ASCAT DATA INDICATE THAT THE PRES GRADIENT OVER THE AREA IS SUPPORTING GENERALLY GENTLE ELY WINDS...EXCEPT FOR THE FAR EASTERN PART OF BAY OF CAMPECHE ALONG THE YUCATAN PENINSULA WHERE WINDS OF MODERATE INTENSITY FROM THE NE-E IN DIRECTION ARE NOTED. THE BUOY OBSERVATIONS ALONG WITH RECENT ALTIMETER PASSES SHOW RELATIVELY LOW SEAS OF 1-2 FT RANGE.

THE MID TO UPPER LEVEL LOW IS FORECAST TO WEAKEN AS IT CONTINUES WESTWARD TO THE CENTRAL GULF OVER THE NEXT 24-36 HRS. THE ATLC RIDGE WILL THEN SHIFT BACK N TO THE NRN PORTION OF THE GULF THROUGH THE END OF THE WEAK...WITH THE ASSOCIATED GRADIENT EXPECTED TO SUPPORT GENERALLY GENTLE TO MODERATE E-SE WINDS THROUGHOUT. THE AFOREMENTIONED TROPICAL WAVE WILL MOVE W OF THE GULF TONIGHT. OTHERWISE...THE TYPICAL CLIMO THERMAL TROUGH IN THE YUCATAN PENINSULA WILL PUSH OFFSHORE INTO THE SW GULF EACH NIGHT THROUGH THE PERIOD ATTENDANT BY A BRIEF PERIOD OF FRESH N TO NE WINDS AND A SLIGHT INCREASE OF SEAS.


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

MODEL PREFERENCE: FOR WINDS USED BLEND OF 00Z GFS WITH PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF 00Z MWW3 AND TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE.

THE PRES GRADIENT BETWEEN HIGH PRES ACROSS THE CENTRAL ATLC AND LOWER PRES IN NRN PORTIONS OF S AMERICA...AND ALSO IN THE SW CARIBBEAN WHERE THE ERN PORTION OF THE E PACIFIC MONSOON TROUGH IS LOCATED IS MAINTAINING FRESH TO STRONG ELY WINDS ACROSS A SMALL PORTION OF THE FAR S CENTRAL CARIBBEAN AS WELL AS WITHIN ABOUT 90 NM OF THE COAST OF COLOMBIA. THE GRADIENT PRODUCING THESE WINDS WILL TIGHTEN BEGINNING ON TUE...AND CONTINUE TO DO SO THROUGH MUCH OF FRI. THIS WILL ALLOW FOR THESE WINDS TO EXPAND IN COVERAGE N TO JUST S OF HISPANIOLA...AND EASTWARD TO NEAR 69W BY THU WITH RESULTANT SEAS BUILDING TO 10 FT. AS THE GRADIENT THEN RELAXES SOME ON FRI...THE WINDS WILL RESPOND BY DECREASING IN BOTH COVERAGE AND SPEEDS. HOWEVER...SEAS TO 10 FT WILL BE SLOW IN SUBSIDING IN THE CENTRAL CARIBBEAN ON DAY 5 (FRI).

A TROPICAL WAVE OVER THE CENTRAL TROPICAL N ATLC WITH AXIS ANALYZED ALONG 56W S OF 21N IS RACING W AT ABOUT 30 KT. THIS WAVE WILL MOVE ACROSS THE LESSER ANTILLES AND EASTERN CARIBBEAN TONIGHT INTO TUE...THEN OVER THE CENTRAL CARIBBEAN DURING THE REMAINDER OF TUE AND THROUGH WED NIGHT...AND THE WESTERN CARIBBEAN THU THROUGH EARLY FRI. THE WAVE WILL HELP ADD MOMENTUM TO THE EXPECTED TIGHTENING PRES GRADIENT IN THE CENTRAL CARIBBEAN.


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

MODEL PREFERENCE: FOR WINDS USED BLEND OF 00Z GFS WITH PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF 00Z MWW3 AND TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE.

A RIDGE AXIS EXTENDING ALONG 27N/28N IS THE MAIN FEATURE OVER THE BASIN. A WEAK SURFACE TO LOW-LEVEL TROUGH IS ANALYZED AS OF 06Z ALONG 69W S OF 22N. ONLY ISOLATED SHOWERS AND TSTMS ARE NOTED WITHIN 120 NM W OF THE TROUGH AT THIS TIME.

THE 06Z ANALYSIS REVEALS A RATHER WEAK PRES GRADIENT THROUGHOUT WITH LIGHT TO GENTLE E-SE WINDS ACROSS MUCH OF THE BASIN...EXCEPT FOR THE NE PORTION WHERE WINDS ARE LIGHT MAINLY S- SW IN DIRECTION. BOTH BUOY AND ALTIMETER DATA SHOW SEAS IN THE RANGE OF 2-4 FT E OF THE BAHAMAS...0-1 FT SW OF THE BAHAMAS...AND 1-2 FT N OF 27N W OF 70W. A SMALL POCKET OF SEAS IN THE 4-5 FT RANGE ARE NOTED BETWEEN THE SE BAHAMAS AND HISPANIOLA.

THE RIDGE IS FORECAST TO RE-ALIGN ITSELF ROUGHLY ALONG A PSN FROM 29N69W NW TO NE FL BY TUE NIGHT WITH A 1020 MB HIGH FORECAST TO BE NEAR 29N69W. THIS HIGH WILL WEAKEN SLIGHTLY IN RESPONSE TO A FRONTAL TROUGH THAT BRUSHES THE FAR NE WATERS. THE FLOW PATTERN S OF THE RIDGE WILL BECOME E-SE WITH WINDS IN THE GENTLE TO MODERATE RANGE...EXCEPT FOR THE STRONGER PULSING E WINDS TO THE STRONG CATEGORY BETWEEN THE BAHAMAS AND HISPANIOLA. SEAS ARE EXPECTED TO BUILD TO 8 FT BETWEEN THE SE BAHAMAS AND HISPANIOLA TONIGHT BEFORE SUBSIDING TO 5-6 FT ON TUE.

$$


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


.GULF OF MEXICO... NONE.


.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.

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