000 AXNT20 KNHC 040529 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU APR 04 2013 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 0445 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 7N12W AND CONTINUES ALONG 3N14W TO THE EQUATOR NEAR 22W WHERE THE ITCZ BEGINS AND CONTINUES ALONG THE EQUATOR TO 30W THEN ALONG 1N36W THEN S OF THE EQUATOR NEAR 39W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N TO JUST S OF THE EQUATOR BETWEEN 5W-25W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 1N-3N BETWEEN 30W-36W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER TROUGH DIPS S FROM THE CENTRAL PLAIN STATES OVER MEXICO AND THE FAR NW GULF WHILE A BROAD UPPER RIDGE COVERS THE REMAINDER OF THE GULF ANCHORED OVER SOUTH AMERICA. A COMPLEX SURFACE PATTERN EXISTS OVER THE GULF AT 04/0300 UTC WITH A 1011 MB LOW OFF THE COAST OF LOUISIANA NEAR 28N90W AND A COLD FRONT EXTENDING SW ALONG 25N93W TO INLAND OVER MEXICO N OF TAMPICO NEAR 23N98W. A WARM FRONT EXTENDS E FROM THE 1011 MB LOW ALONG 29N86W TO 28N83W. A 1008 MB LOW IS S OF THE FRONT NEAR 23N94W WITH A SURFACE TROUGH EXTENDING S TO INLAND OVER S MEXICO NEAR VERACRUZ. SCATTERED TO HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS ARE OVER THE N/CENTRAL GULF FROM 24N-28N W OF 86W TO THE COLD FRONT. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS COVER THE REMAINDER OF THE N GULF N OF A LINE FROM TAMPA FLORIDA TO TUXPAN MEXICO. THIS IS LEAVING THE S GULF UNDER MOSTLY CLEAR SKIES TONIGHT. THE 1011 MB LOW WILL SHIFT NE OF THE GULF TO 31N85W WHILE DEEPENING TO 1006 MB BY THU EVENING WITH THE FRONT EXTENDING FROM THE LOW TO 26N86W TO 18N94W THEN FROM SW FLORIDA TO THE YUCATAN PENINSULA FRI MORNING BEFORE SHIFTING SE OF THE GULF BY FRI AFTERNOON. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH SOUTHERLY RETURN FLOW ACROSS THE GULF LATE SAT THROUGH MON. CARIBBEAN SEA... A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN AND MOST OF THE GULF OF MEXICO ANCHORED INLAND OVER SOUTH AMERICA. RELATIVE TIGHT PRESSURE GRADIENT EXISTS BETWEEN THE LOWER PRESSURE OF SOUTH AMERICA AND THE SURFACE RIDGE OVER THE W ATLC PRODUCING FRESH TO STRONG EASTERLY TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN WITH MODERATE TRADE WINDS ELSEWHERE. THE MONSOON TROUGH EXTENDS ACROSS PANAMA INTO THE EXTREME SW CARIBBEAN CROSSING COSTA RICA INTO THE E PACIFIC REGION. SCATTERED SHOWERS ARE S OF 11N BETWEEN COLOMBIA AND COSTA RICA. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE ACROSS MOST OF THE BASIN GIVING THE CARIBBEAN FAIR CONDITIONS ACROSS THE REMAINDER OF THE AREA. TRADE WINDS WILL PREVAIL THROUGH SUN. AN EXCEPTION WILL BE FRESH TO STRONG WINDS IN THE GULF OF HONDURAS WHICH WILL OCCUR THROUGH THU MORNING. A WEAK COLD FRONT WILL MOVE SE OF THE YUCATAN CHANNEL LATE THU NIGHT GRADUALLY WEAKENING OVER THE NW CARIBBEAN AND DISSIPATING BY SAT. ATLANTIC OCEAN... SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER THE FAR W ATLC N OF 27N W OF 76W ASSOCIATED WITH THE FRONTAL SYSTEM IN THE GULF OF MEXICO. BROAD UPPER RIDGE FROM THE CARIBBEAN COVERS THE W ATLC. A WEAK SURFACE RIDGE COVERS THE ATLC ANCHORED BY A 1024 MB HIGH W OF BERMUDA NEAR 32N67W. AN UPPER TROUGH EXTENDS OVER THE W/CENTRAL ATLC N OF 24N FROM 44W- 60W SUPPORTING A WEAK COLD FRONT THAT ENTERS THE REGION NEAR 32N53W TO 24N63W. ISOLATED SHOWERS ARE WITHIN 90 NM E OF THE FRONT. A LARGE SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A 1029 MB HIGH NEAR 31N39W GIVING THE REMAINDER OF THE ATLC FAIR WEATHER TONIGHT. SOUTHERLY RETURN FLOW WILL INCREASE THROUGH THU OVER THE W ATLC AHEAD OF A SURFACE LOW CURRENTLY IN THE GULF OF MEXICO THAT WILL TRACK NE OVER THE N ATLC LATE THU NIGHT DRAGGING A COLD FRONT INTO THE W ATLC FRI. THE FRONT WILL REACH FROM 32N74W TO THE STRAITS OF FLORIDA FRI EVENING THEN FROM NEAR BERMUDA TO NEAR THE WINDWARD PASSAGE SAT EVENING WHILE WEAKENING. THE FRONT WILL STALL OUT AS IT MOVES INTO THE CENTRAL ATLC SUN DISSIPATING BY MON AS HIGH PRESSURE BUILDS IN OVER THE W ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW