000 AGXX40 KNHC 041801 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 200 PM EDT MON AUG 4 2014 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: GLOBAL MODEL CONSENSUS. HIGH CONFIDENCE. EASTERN U.S. UPPER TROUGH EXPECTED TO EVOLVE INTO AN ELONGATED NARROW TROUGH NE TO SW ACROSS CENTRAL GULF NEXT 36 HOURS. THIS WILL BE REFLECTED AT LOWER LEVELS AS DIVERGENT ASYMPTOTE ACROSS CENTRAL NE PORTIONS OF THE GULF...WITH LOW LEVEL CONVERGENCE ACROSS FLORIDA AND W OF 90W. WEAK SYNOPTIC PRESSURE PATTERN CONTINUES IN THE REGION. ASCAT PASSES SHOW LIGHT WINDS ACROSS ENTIRE BASIN EXCEPT FOR FLORIDA COASTAL WATERS. LITTLE CHANGE EXPECTED NEXT 1-2 DAYS...WITH VERY WEAK FLOW AND SLIGHT SEAS PERSISTING THROUGH TUE THEN ATLC RIDGE BUILDS SW UNDERNEATH EXITING BERTHA THROUGH THE FLORIDA STRAITS. RIDGE WILL DRIFT SLOWLY N THOUGH THE WEEK WITH HIGH CENTER DEVELOPING ACROSS ERN GULF...GRADUALLY ALLOWING FOR MODERATE RETURN FLOW TO SET UP W AND NW PORTIONS...AND LEAD TO ACTIVE YUCATAN LATE AFTERNOON THERMAL TROUGH. THIS WILL ALSO ALLOW FOR MORE MOISTURE AND ENERGY OF TROPICAL WAVES MOVING ACROSS THE CARIB TO PROPAGATE ACROSS THE YUCATAN AND INTO S GULF TUE NIGHT THROUGH FRI. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS. HIGH CONFIDENCE. TUTT LOW ACROSS YUCATAN SHIFTING SLOWLY WEST WHILE E TO SE FLOW ALOFT IS INCREASING ACROSS EASTERN CARIBBEAN AT PRESENT. TRADES ARE STRENGTHENING ACROSS CENTRAL CARIBBEAN AS BERTHA LIFTS NORTH AND RIDGING TAKES OVER. VERY BROAD TROPICAL WAVE WITH AXIS ALONG 55W WILL MOVE RAPIDLY W THEN WNW ACROSS THE REGION NEXT 2-3 DAYS WHILE LEADING TROPICAL WAVE ALONG 66W BECOMES MORE ILL-DEFINED AND EVENTUALLY MERGES WITH THE SECOND WAVE BY WED NIGHT OR THU. GFS CONTINUES TO SHOW WINDS PULSING TO 30 KT THIS EVENING AND TONIGHT OFFSHORE OF COLOMBIA BEFORE GRADIENT THERE BEGINS TO WEAKEN TUE. GFS AND UKMET SUGGEST SLIGHT POTENTIAL FOR BRIEF GALES TONIGHT THERE...WHILE ECMWF DOES NOT...AND THUS NOT GOING WITH GALE WARNING. AFTER SECOND WAVE PASSAGE ACROSS E CARIB TUE AND INTO CENTRAL CARIB WED...LOOK FOR MODERATE TO FRESH TRADE WIND FLOW TO BECOME ESTABLISHED THROUGH REMAINDER OF THE WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. MODERATE CONFIDENCE. LARGE AREA OF MOIST LOWER LEVEL ENVIRONMENTAL AIR DRIFTING NW ACROSS THE FLORIDA PENINSULA W OF HURRICANE BERTHA. ACTIVE CONVECTION WILL CONTINUE TO ERUPT OVER THE GULF STREAM E OF FLORIDA AS A RESULT. BERTHA WILL LIFT NORTHWARD THROUGH TUE AND EXIT THE AREA NEXT 18-24 HOURS. ATLC RIDGE WILL BUILD SW UNDER THE EXITING BERTHA NEXT FEW DAYS THEN SHIFT SLOWLY NORTHWARD TO BE ESTABLISHED ALONG 26-27N BY END OF THE WEEK. FETCH OF ENE WINDS AROUND 20 KT OCCURRING WITH AND N OF BROAD TROPICAL WAVE MOVING INTO TROPICAL N ATLC WATERS WILL INCREASE ENE SWELL AND RAISE SEAS ACROSS SE WATERS TO AROUND 7 FT TONIGHT THROUGH TUE NIGHT BEFORE FADING. EXPECT MODERATE TO LOCALLY FRESH TRADES TO DOMINATE THE BASIN BY THE MIDDLE TO THE END OF THE WEEK WITH 4-6 FT SEAS MAINLY E OF 77W AND 1-3 FT SEAS W OF 77W AND INSIDE THE BAHAMAS IN THE WAKE OF BERTHA. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... TROPICAL STORM WARNING EARLY TODAY INTO TONIGHT. .AMZ119...ATLANTIC FROM 22N TO 27N E OF BAHAMAS TO 70W... TROPICAL STORM WARNING EARLY TODAY INTO TODAY. $$ *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 MUNDELL. NATIONAL HURRICANE CENTER.