000 AXNT20 KNHC 170557 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE 17 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 0615 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE CARIBBEAN... A GALE WARNING WILL GO INTO EFFECT FOR THE SW CARIBBEAN FROM 10N- 12.5N BETWEEN 72W-77W TONIGHT AND IS ASSOCIATED WITH THE TIGHT PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE OVER THE W ATLC AND THE LOWER PRESSURE OVER THE CARIBBEAN. THE WINDS WILL BE BELOW GALE FORCE LATER THIS AFTERNOON. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...GALE WARNING FOR THE W ATLC... A GALE WARNING WILL GO INTO EFFECT FOR THE AREA N OF 30N W OF 74W AT 1200 UTC AND IS ASSOCIATED WITH A COLD FRONT THAT IS CURRENTLY MOVING ACROSS THE GULF OF MEXICO. THIS GALE WARNING WILL SLIDE E AS THE FRONT CONTINUES TOWARD THE CENTRAL ATLC. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...GALE WARNING FOR THE GULF OF MEXICO... A GALE WARNING WILL GO INTO EFFECT OVER THE SW GULF OF MEXICO FROM 19N-21N W OF 95W EARLY WED MORNING THROUGH WED AFTERNOON ASSOCIATED WITH THE STRONG FRONT AND SURFACE RIDGE THAT WILL BUILD IN THE WAKE OF THE FRONT CURRENTLY MOVING ACROSS THE NW GULF OF MEXICO. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 6N11W AND EXTENDS TO 3N14W TO 8N19W WHERE THE ITCZ BEGINS AND CONTINUES S OF THE EQUATOR TO 2S30W AND INTO SOUTH AMERICA NEAR 38W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 4S-4N BETWEEN 16W-31W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGING COVERS THE GULF AS AN UPPER TROUGH MOVES E ACROSS TEXAS. THE UPPER TROUGH SUPPORTS LOW PRESSURE OVER ALABAMA WITH A COLD FRONT EXTENDING SW FROM THE LOW AND OVER THE GULF NEAR 30N91W TO THE MEXICO COAST NEAR 25N98W. SCATTERED TO NUMEROUS SHOWERS ARE WITHIN 50 NM OF THE FRONT E OF 92W. ISOLATED SHOWERS ARE WITHIN 50 NM OF THE FRONT W OF 92W. N TO NW WINDS OF 20 TO 25 KT ARE N OF THE FRONT. S TO SE WINDS OF 15 TO 20 KT ARE S OF THE FRONT ACROSS THE REMAINDER OF THE BASIN. THE COLD FRONT WILL MOVE QUICKLY SE AND WILL TRAVERSE THE ENTIRE BASIN WITHIN THE NEXT 36 HOURS. BY WEDNESDAY MORNING THE FRONT IS EXPECTED TO REACH THE FL STRAITS AND EXTEND TO THE YUCATAN WITH SHOWERS ONGOING ALONG THE FRONT. STRONG HIGH PRESSURE WILL BUILD ACROSS THE GULF BEHIND THE FRONT. THE TIGHT PRESSURE GRADIENT PRODUCED BETWEEN THE HIGH AND DEPARTING COLD FRONT WILL BRING GALE FORCE WINDS TO THE SW GULF BY EARLY WEDNESDAY MORNING. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. CARIBBEAN SEA... AN UPPER RIDGE DOMINATES THE CARIBBEAN WITH AN AXIS THAT EXTENDS N ACROSS CENTRAL CUBA TO OVER THE FLORIDA PENINSULA COVERING THE GULF OF MEXICO AND THE W ATLC. A SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS THE VIRGIN ISLANDS NEAR 18N65W TO 16N72W WITH SCATTERED SHOWERS WITHIN 140 NM NW OF THE SURFACE TROUGH INCLUDING PUERTO RICO. THE EASTERLY SURFACE FLOW IS BRINGING SCATTERED SHOWERS TO THE CENTRAL AND NW CARIBBEAN FROM 15N-21N BETWEEN 76W-85W. SCATTERED SHOWERS ARE ALSO OVER THE SOUTHERN LEEWARD ISLANDS. A COLD FRONT WILL MOVE INTO THE NW CARIBBEAN WEDNESDAY REACHING FROM CENTRAL CUBA TO THE GULF OF HONDURAS WED NIGHT. A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRESSURE N OF THE CARIBBEAN AND LOWER PRESSURE OVER S AMERICA WILL PRODUCE GALE FORCE WINDS THIS MORNING INTO THE AFTERNOON OVER THE SE CARIBBEAN. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. ...HISPANIOLA... LINGERING LOW LEVEL MOISTURE FROM THE SURFACE TROUGH TO THE E IS GENERATING SCATTERED SHOWERS ACROSS THE ISLAND. THIS MOISTURE WILL REMAIN ACROSS THE ISLAND THROUGH THE DAY TODAY. A COLD FRONT WILL BRING ADDITIONAL SHOWERS TO THE ISLAND ON THURSDAY. ATLANTIC OCEAN... SURFACE HIGH PRESSURE OF 1023 MB IS CENTERED NEAR 30N71W. AN UPPER TROUGH ALONG 55W SUPPORTS A COLD FRONT THAT EXTENDS THROUGH 32N46W TO 25N60W TO 23N69W WHERE IT TRANSITIONS TO A DISSIPATING STATIONARY FRONT TO THE BAHAMAS NEAR 25N78W. SCATTERED SHOWERS ARE POSSIBLE WITHIN 50 NM S OF THE FRONT...AND WITHIN 100 NM N OF THE FRONT. A SURFACE TROUGH EXTENDS FROM 30N48W TO 24N55W TO THE VIRGIN ISLANDS NEAR 18N65W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM E OF THE TROUGH N OF 25N. S OF 25N...SCATTERED SHOWERS ARE WITHIN 50 NM SE OF THE TROUGH ...AND WITHIN 120 NM NW OF THE TROUGH. RIDGING DOMINATES THE EASTERN ATLANTIC. THE COLD FRONT OVER THE GULF WILL MOVE EAST OVER THE WESTERN ATLANTIC TUESDAY WITH GALE FORCE WINDS DEVELOPING E OF THE FRONT LATER THIS MORNING. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO