000 AXNT20 KNHC 120551 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE JAN 13 2015 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURE... A GALE WARNING IS IN EFFECT FOR THE SOUTH CENTRAL CARIBBEAN OFF THE COAST OF COLOMBIA THIS AFTERNOON. THE STRONG PRESSURE GRADIENT BETWEEN W ATLC HIGH PRESSURE AND THE RELATIVELY LOWER PRESSURE OVER THE CARIBBEAN IS GENERATING STRONG TRADE WINDS WHICH WILL PULSE TO GALE FORCE THROUGH EARLY AFTERNOON OFF THE COAST OF COLOMBIA. PLEASE SEE THE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 7N11W TO 6N15W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 4N29W 5N47W TO SOUTH AMERICA NEAR 4N52W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 3N-7N BETWEEN 30W-45W. ...DISCUSSION... GULF OF MEXICO... AN MID TO UPPER LEVEL TROUGH EXTENDS FROM THE N TEXAS COAST TO THE SW GULF OF MEXICO. A STALLED FRONT REACHES FROM WEAK 1019 MB LOW PRES JUST OF THE SABINE PASS NEAR 29N98W TO THE SW GULF ALONG THE MEXICAN COAST NEAR 18N93W. THE UPPER TROUGH IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 240 NM E OF THE FRONT NORTH OF 22N. MOIST LOW LEVEL SE FLOW ACROSS THE FRONT IS SUPPORTING FORMATION OF WIDESPREAD LOW CLOUDINESS ALONG THE COAST OF TEXAS AND OFF THE COAST OF MEXICO...AS NOTED IN CURRENT SATELLITE IMAGERY ALONG WITH OBSERVATIONS FROM COASTAL SITES AND OFFSHORE PLATFORMS. THE UPPER TROUGH WILL MIGRATE EASTWARD THROUGH THE CENTRAL GULF THROUGH LATE TODAY...ALLOWING THE FRONTAL BOUNDARY TO DRIFT EASTWARD ACCORDINGLY ALONG WITH THE SCATTERED SHOWERS AND THUNDERSTORMS. THE WEAK LOW OFF SABINE PASS WILL SHIFT INLAND AND DISSIPATE THROUGH THIS MORNING. ANOTHER MID TO UPPER IMPULSE WILL BRING A REINFORCING FRONT INTO THE NW GULF LATE MONDAY. CARIBBEAN SEA... AN ASCAT SATELLITE PASS FROM 0240 UTC ALONG WITH RECENT BUOY OBSERVATIONS INDICATE FRESH TO STRONG TRADE WINDS FROM THE TROPICAL N ATLC WATERS W OF 55W THROUGH THE EASTERN AND CENTRAL CARIBBEAN. THE ASCAT PASS ALSO CONFIRMED WINDS TO GALE FORCE ALONG THE COAST OF COLOMBIA BETWEEN CARTAGENA AND BARRANQUILLA. THE GALES ARE BEING ENHANCED BY LOCAL OVERNIGHT DRAINAGE FLOW AND ARE EXPECTED TO DIMINISH TO BELOW GALE FORCE LATER THIS MORNING AFTER SUNRISE. THE FRESH TO STRONG TRADE WILL PERSIST THROUGH EARLY THIS WEEK AS LONG AS THE HIGH PRES N OF THE AREA PERSISTS. WAVE HEIGHTS AT BUOY 42058 IN THE CENTRAL CARIBBEAN NEAR 15N74W ARE NEAR 11 FT...BUT SEAS TO 15 FT ARE LIKELY ONGOING OFF COLOMBIA IN THE AREA OF GALES. LOW TO MID LEVEL CLOUDINESS IS NOTED ALONG A WEAK SURFACE TROUGH IS NOTED ALONG THE LEADING EDGE OF THE TRADE WIND SURFACE...SOUTHEAST OF JAMAICA. A FEW SHOWERS ASSOCIATED WITH THIS WEAK TROUGH SHOWED UP ON JAMAICA RADAR SOUTH OF THE ISLAND EARLIER THIS EVENING...BUT HAVE SINCE DISSIPATED. ADDITIONAL QUICK PASSING SHOWER ACTIVITY ASSOCIATED WITH TRADE WIND CONVERGENCE IS NOTED ON GUADELOUPE AND MARTINIQUE RADAR IMAGERY AS WELL AS FARTHER SOUTH INTO THE WINDWARD ISLANDS AS NOTED ON TRINIDAD RADAR. TRADE WINDS...ALONG WITH SHOWERS ASSOCIATED WITH THE TRADE WIND CONVERGENCE WILL DIMINISH BY MID WEEK AS HIGH PRES N OF THE AREA WEAKENS AND SHIFTS EASTWARD. ...HISPANIOLA... HIGH PRECIPITABLE WATER VALUES ASSOCIATED IN PART WITH A LOW TO MID LEVEL TROUGH CURRENTLY PASSING SW OF HAITI HAS BEEN SUPPORTING SCATTERED PASSING SHOWERS ACROSS THE ISLAND SINCE YESTERDAY. SLIGHTLY DRIER CONDITIONS TO THE EAST OF THE TROUGH WILL ALLOW SHOWER ACTIVITY TO DIMINISH ACROSS LEEWARD FACING AREAS OF HISPANIOLA TO INCLUDE CENTRAL AND SOUTHERN HAITI AND SOUTHERN DOMINICAN REPUBLIC. WINDWARD FACING AREAS ALONG NORTHERN HAITI...DOMINICAN REPUBLIC AND THE NORTHEAST AND EASTERN SLOPES OF THE CENTRAL MOUNTAINS WILL STILL SEE SOME TRADE WIND RELATED LOW TOPPED CLOUDINESS AND A FEW SHOWERS THROUGH LATE TODAY...ALTHOUGH OVERALL DIMINISHING. ATLANTIC OCEAN... A WEAK SURFACE TROUGH PERSISTS ALONG 70W FROM 24N TO 30N. THIS FEATURE IS RELATED TO A NEGATIVELY TILTED UPPER TROUGH EXTENDING FROM 28N67W TO 23N63W. A FEW SHOWERS ARE ONGOING NEAR THE BASE OF THE UPPER TROUGH NEAR 24N65W...ALTHOUGH OVERALL CONVECTION APPEARS MINIMAL AT THIS TIME. BUOY AND ASCAT SATELLITE DATA FROM THE PAST SEVERAL HOURS INDICATES FRESH TO STRONG EASTERLY FLOW ACROSS THE REGION W OF 55W. BUOYS SHOW SEAS OF MOSTLY 7 TO 8 FT OUTSIDE OF THE BAHAMAS. ANOTHER SURFACE TROUGH IS NOTED OFF THE NE COAST OF FLORIDA FROM NEAR ST AUGUSTINE TO NORTHEASTWARD TO OFF THE SOUTH CAROLINA COAST NEAR HILTON HEAD. A FEW RELATED SHOWERS ARE NOTED ON MELBOURNE FLORIDA RADAR MOVING ONSHORE NEAR CAPE CANAVERAL. THE TROUGH WILL MOVE INLAND THIS MORNING AND DISSIPATE. ELSEWHERE E OF 55W...SHIP AND BUOY OBSERVATIONS ALONG WITH MULTIPLE ASCAT AND RAPIDSCAT SATELLITE PASSES FROM THE PAST SEVERAL HOURS INDICATE A LARGE AREA OF FRESH TO STRONG TRADE WINDS S OF 20N TO THE ITCZ. AN UPPER CYCLONE REMAINS CENTERED NW OF THE CAPE VERDE ISLAND NEAR 30N20W WITH AN UPPER TROUGH REACHING SOUTHWESTWARD TO 18N45W...SUPPORTING MODEST CONVECTION ALONG THE ITCZ E OF 45W. A SURFACE TROUGH ASSOCIATED WITH THE UPPER FEATURE EXTENDS ALONG 30N/31N NEAR THE CANARY ISLANDS SOUTHWARD INTO WESTERN MAURITANIA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CHRISTENSEN