000 AGXX40 KNHC 280751 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 351 AM EDT TUE MAY 28 2013 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: HIGH CONFIDENCE IN THE PREVIOUS FORECAST BLENDED EQUALLY WITH THE 00Z GFS AND ECMWF THROUGH WED WITH MEDIUM CONFIDENCE THU THROUGH SAT. MWW3 AND PREVIOUS FORECAST USED FOR WAVES. THE 00Z GFS AND ECMWF ARE RELATIVELY SIMILAR WITH THEIR WIND FIELDS OVER THE GULF THROUGH WED. THEY DIVERGE OVER THE EASTERN GULF BY 00Z THU WHEN THE GFS DEVELOPS A STRONGER TROUGH E OF FLORIDA AND INCREASES THE PRESSURE GRADIENT ACROSS THE NORTHEAST GULF MORE THAN THE ECMWF...PRODUCING 25 KT WINDS THERE. NONE OF THE OTHER MODELS ARE THAT STRONG AND THE GFS APPEARS TO HAVE GRID-SCALE FEEDBACK PROBLEMS THAT MAY BE INFLATING THE WIND FIELD ON THU. HOWEVER...A BLEND OF THE GFS AND ECMWF APPEARS CLOSER TO THE MODEL CONSENSUS FRI AND SAT AS THE WINDS OVER THE EASTERN GULF GRADUALLY DIMINISH. IN ADDITION...THE MODELS DIVERGE WITH THE REMNANTS OF AN EASTERN PACIFIC SYSTEM OVER THE SW GULF THU THROUGH SAT. THE 00Z GFS CARRIES A TROUGH OVER THE SW GULF BY 00Z FRI AND DEVELOPS 25 KT WINDS ON ITS E SIDE BY SAT NIGHT. THE ECMWF IS WEAKER AND CARRIES CONSIDERABLY BROADER TROUGHING THAT EATS INTO THE RIDGE OVER THE N GULF COASTAL PLAIN FRI AND SAT. THE NAVGEM SIDES HALF-HEARTEDLY WITH THE GFS AND THE UKMET SIDES HALF- HEARTEDLY WITH THE ECMWF. A BLEND OF THESE CAMPS SEEMS PERTINENT HERE. THE MWW3 WAS RELIED ON TO ADJUST WAVES WITH MANUAL EDITS MADE TO BE CONSISTENT WITH THE WIND FIELD. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: MEDIUM CONFIDENCE IN THE PREVIOUS OFFICIAL FORECAST BLENDED EQUALLY WITH THE 00Z GFS AND THE 00Z ECMWF THROUGH SAT. MWW3 AND PREVIOUS FORECAST USED AS A BASE FOR WAVE FORECAST. THE 00Z ECMWF HAS COME INTO BETTER AGREEMENT WITH THE CONSISTENTLY STRONGER GFS THROUGH WED ON BUILDING FRESH WINDS IN THE N CENTRAL CARIBBEAN IN RESPONSE TO THE TROUGHING OFF THE FLORIDA E COAST AS WELL AS OFF THE E COAST OF THE YUCATAN PENINSULA WHERE A POSSIBLE TROPICAL CYCLONE IN THE PACIFIC IS EXPECTED TO ENHANCE THE EASTERLY FLOW. BY LATE WED...THESE MODELS DIVERGE MORE WITH THE ECMWF AND UKMET DEVELOPING A BROAD AREA OF LOW PRESSURE OVER THE SW CARIBBEAN WHILE THE GFS AND NAVGEM HOLD ONTO A TIGHTER PRESSURE GRADIENT. THESE MODELS AGREE ON WEAKENING THIS LOW AND CARRYING SE FLOW ACROSS THE WESTERN GULF FRI...WITH THE GFS AGAIN SHOWING STRONGER WINDS ON THE E COAST OF THE YUCATAN PENINSULA IN ASSOCIATION WITH THE REMNANTS OF THE AFOREMENTIONED E PACIFIC SYSTEM. A BLEND OF THE GFS AND ECMWF WAS USED FOR THIS SYSTEM OVER THE GULF OF MEXICO AND CONTINUES TO BE VALID HERE. LONG-FETCH FRESH EASTERLY TRADE WINDS IN THE TROPICAL N ATLC SHOULD CONTINUE TO KEEP SEAS AT OR NEAR 8 FT THROUGH THE FORECAST PERIOD. THE MWW3 WAS BLENDED WITH THE PREVIOUS FORECAST TO ACCOUNT FOR WAVES...WITH SOME MANUAL EDITS MADE ALONG THE COAST OF COLOMBIA WHERE WINDS AND SEAS ARE SLIGHTLY HIGHER THAN THE MODELS INITIALLY AND SHOULD CONTINUE TO BE EARLY IN THE FORECAST PERIOD. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: MEDIUM CONFIDENCE IN THE PREVIOUS OFFICIAL FORECAST BLENDED WITH THE 00Z GFS/MWW3 THROUGH WED. THEN LOW CONFIDENCE IN THE OFFICIAL FORECAST BLENDED EQUALLY WITH THE 00Z GFS/MWW3 AND THE 00Z ECMWF/EC WAVE THU THROUGH SAT. THE STRONGER 00Z GFS FORECAST HAS THE BEST HANDLE ON THE 20-25 KT SHIP REPORTS IN THE BAHAMAS THIS MORNING. WITH HIGH PRESSURE BUILDING TO THE NORTHEAST...THE STRONGER GFS CONTINUES TO LOOK REASONABLE THROUGH WED. BY 00Z THU...THE GFS DEVELOPS GRID-SCALE FEEDBACK ALONG THE SURFACE TROUGH EXPECTED TO BE NEAR THE E COAST OF FLORIDA. FROM 00Z THU TO 00Z FRI...THE GFS GENERATES COPIOUS AMOUNTS OF PRECIPITATION OVER THE BAHAMAS. LESS THAN HALF OF THIS PRECIPITATION CAN BE ACCOUNTED FOR BY CONVECTIVE PROCESSES. AS A RESULT OF THE FEEDBACK...THE GFS BUILDS 30 KT WINDS OVER THE NORTHERN BAHAMAS AND RAPIDLY WEAKENS WINDS ALONG THE SOUTHERN PORTION OF ITS AMPLIFYING SURFACE TROUGH. NONE OF THE OTHER MODELS ARE THIS AGGRESSIVE...BUT THERE IS SOME SUPPORT FROM THE UKMET ON A CONSIDERABLY WEAKER VERSION OF THIS SCENARIO WHICH ALLOWS FOR STRONGER WINDS THAN THE 00Z ECMWF ALONE. A BLEND OF THE ECMWF AND GFS LOOKS LIKE THE UKMET HERE. THIS SOLUTION SEEMS LIKE A REASONABLE COMPROMISE. DESPITE THE FEEDBACK...HESITANT TO COMPLETELY DISREGARD THE GFS BECAUSE ITS STRONGER SOLUTIONS HAVE BEEN CLOSER TO OBSERVATIONS THE LAST FEW RUNS. A BLEND OF THE EC WAVE AND MWW3 ACCOUNTS FOR THE WIND FIELD PREFERENCE THU THROUGH SAT...RELYING MORE HEAVILY ON THE HIGHER RESOLUTION MWW3 WITH SOME MANUAL EDITS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER SCHAUER. NATIONAL HURRICANE CENTER.