000 AXNT20 KNHC 121156 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED NOV 12 2014 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...THE ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W TO 9N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N33W TO SOUTH AMERICA NEAR 2N51W. A SURFACE TROUGH IS IN THE W TROPICAL ATLC EXTENDING FROM 16N46W TO 7N49W WITH SCATTERED MODERATE CONVECTION FROM 12N-16N BETWEEN 38W-46W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 10W-13W INCLUDING THE COAST OF LIBERIA AND WITHIN 90/120 NM N OF ITCZ BETWEEN 25W-32W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE DOMINATES THE GULF ANCHORED IN THE CARIBBEAN THE OVER GULF OF HONDURAS NEAR 18N87W AND EXTENDING A RIDGE AXIS N THROUGH THE YUCATAN CHANNEL ACROSS THE GULF AND THE FLORIDA PANHANDLE TO SOUTH CAROLINA SUPPORTING A WEAK 1017 MB HIGH NEAR 29N87W. AN UPPER TROUGH OVER CENTRAL PLAIN STATES TO NEW ENGLAND IS BRINGING A COLD FRONT INTO THE GULF AT 12/0900 UTC OVER THE MISSISSIPPI COAST NEAR BILOXI ACROSS FAR SE LOUISIANA ALONG 26N95W THEN S TO INLAND OVER MEXICO NEAR TAMPICO. ABUNDANT MOISTURE IS BEING ADVECTED ACROSS THE N GULF BY THE UPPER RIDGE GENERATING CLUSTERS OF SCATTERED SHOWERS W OF LINE FROM THE ALABAMA/MISSISSIPPI BORDER ALONG 25N90W 23N95W TO MEXICO NEAR 18N95W. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES THIS MORNING. FRONT WILL REACH FROM TAMPA FLORIDA TO VERACRUZ MEXICO BY LATE THU AND FROM THE FLORIDA KEYS TO CENTRAL BAY OF CAMPECHE BY LATE FRI. STRONG WINDS BEHIND THE FRONT OVER THE FAR W GULF WILL REACH GALE FORCE ALONG THE MEXICAN COAST S OF 23N TO VERACRUZ THU AND THU NIGHT. CARIBBEAN SEA... THE UPPER RIDGE ANCHORED IN THE GULF OF HONDURAS NEAR 18N87W COVERS THE CARIBBEAN W OF 75W WITH STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT N OF 12N W OF 75W. AN UPPER TROUGH OVER THE W ATLC DIPS S OVER NE CARIBBEAN TO N OF 17N E OF 75W INCLUDING HISPANIOLA TO THE VIRGIN ISLANDS. THIS UPPER TROUGH IS SUPPORTING A COLD FRONT THAT EXTENDS FROM THE W ATLC TO OVER E CUBA AND A WEAK SURFACE TROUGH THAT EXTENDS FROM 20N79W ACROSS THE CAYMAN ISLANDS TO 17N84W. A SURFACE TROUGH PRECEDES THE FRONT EXTENDING FROM THE W ATLC NEAR 20N71W ACROSS HISPANIOLA ALONG 16N74W TO 13N77W. LINGERING MOISTURE AND THE SURFACE TROUGH ARE GENERATING SCATTERED SHOWERS OVER HISPANIOLA WITH ISOLATED SHOWERS POSSIBLE WITHIN 60 NM EITHER SIDE OF THE REMAINDER OF THE TROUGH AXIS. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N74W ALONG 11N78W TO ACROSS COSTA RICA NEAR 10N83W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 11N E OF 81W. THE REMAINDER OF THE CARIBBEAN IS UNDER FAIR SKIES THIS MORNING. THE SURFACE TROUGH OVER HISPANIOLA WILL SHIFT E AND DISSIPATE THROUGH THU. HISPANIOLA... A SURFACE TROUGH PRECEDES W ATLC FRONT EXTENDING FROM THE W ATLC NEAR 20N71W ACROSS HISPANIOLA ALONG 16N74W TO 13N77W. LINGERING MOISTURE AND THE SURFACE TROUGH ARE GENERATING SCATTERED SHOWERS OVER THE ISLAND. THESE SHOWERS ARE BEGINNING TO WEAKEN. THE COLD FRONT OVER THE W ATLC WILL WEAKEN AS IT MOVES E AND REACHES FROM NEAR BERMUDA TO THE WINDWARD PASSAGE LATE TODAY BEFORE BECOMING DIFFUSE THU. THE SURFACE TROUGH WILL WILL SHIFT E AND DISSIPATE THROUGH THU. THIS TROUGH PLUS ANY LINGERING MOISTURE WILL CONTINUE TO GIVE THE ISLANDS SHOWERS AND POSSIBLE THUNDERSTORMS THROUGH TODAY TAPERING OFF ON THU. ATLANTIC OCEAN... A SHARP UPPER TROUGH EXTENDS THROUGH 32N72W TO OVER HISPANIOLA TO THE VIRGIN ISLANDS SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N69W ALONG 26N71W ACROSS THE TURKS AND CAICOS TO THE E CUBA NEAR 20N77W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM E OF THE FRONT N OF 26N. A SURFACE TROUGH PRECEDES THE FRONT EXTENDING FROM 26N69W TO NEAR 20N71W THEN ACROSS HISPANIOLA INTO THE CARIBBEAN. SCATTERED SHOWERS ARE WITHIN 120 NM E OF THE TROUGH AXIS. A SECOND UPPER TROUGH IS IN THE CENTRAL ATLC EXTENDING FROM 27N43W ALONG 23N50W 17N55W THEN S TO SOUTH AMERICA NEAR 5N56W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 27N55W TO 21N56W AND A SECOND WEAK SURFACE TROUGH THAT EXTENDS FROM 30N42W TO 26N44W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 16N-26N BETWEEN 49W- 56W. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A PAIR O 1022 MB HIGHS NEAR 31N49W AND 30N38W. THE W ATLC COLD FRONT WILL WEAKEN AS IT MOVES E AND REACHES FROM NEAR BERMUDA TO THE WINDWARD PASSAGE LATE TODAY BEFORE BECOMING DIFFUSE THU. ANOTHER FRONT WILL MOVE OFF THE COAST OF NE FLORIDA TONIGHT REACHING FROM 32N74W TO SE FLORIDA LATE THU AND FROM 32N71W TO THE STRAITS OF FLORIDA BY LATE FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW