000 AXNT20 KNHC 132356 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE APR 13 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC... ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 4N22W 2N34W CROSSING THE EQUATOR NEAR 39W AND INTO NE BRAZIL NEAR 1S46W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM THE EQUATOR TO 6N BETWEEN 14W-28W. ISOLATED MODERATE CONVECTION IS FROM 2N-6N BETWEEN 31W-44W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL SHORTWAVE TROUGH IS LOCATED OVER THE WESTERN GULF WITH AXIS FROM 25N94W TO OVER SOUTHERN MEXICO NEAR 18N93W AND SUPPORTS A SURFACE TROUGH ANALYZED OVER THE SW GULF FROM 19N-24N ALONG 95W. LOW-LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER A LARGE PORTION OF THE S/CENTRAL AND SW GULF S OF 26N W OF 88W. ELSEWHERE ACROSS THE REMAINDER OF THE GULF...A BROAD SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED OVER NORTHERN GEORGIA REMAINS ACROSS THE NORTHERN GULF AND FLORIDA PENINSULA WITH STRONG EASTERLY WINDS UP TO 25 KT. LOW-LEVEL CONVERGENCE AND INCREASED INSTABILITY OVER THE FAR NW GULF AND INLAND OVER EXTREME SOUTHERN TEXAS ARE RESULTING IN SCATTERED SHOWERS AND TSTMS N OF 24N W OF 97W. WITH AN UPPER LEVEL RIDGE ACROSS THE SE CONUS...THE SURFACE RIDGE IS FORECAST TO REMAIN NEARLY STATIONARY ACROSS THE GULF THROUGH FRIDAY...SLIDING INTO THE W ATLC WATERS BY SATURDAY WITH EASTERLY WINDS DIMINISHING BELOW 20 KT. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER IN ASSOCIATION WITH MODERATELY DRY AIR ALOFT IN UPPER LEVEL SW TO WESTERLY FLOW. EASTERLY TRADES DOMINATE AT THE SURFACE W OF 64W WITH ONLY A FEW ISOLATED SHOWERS NOTED THIS EVENING ACROSS EASTERN CUBA...JAMAICA...AND PORTIONS OF HISPANIOLA DUE TO LOW-LEVEL CONVERGENCE AND MAXIMUM DAYTIME HEATING AND INSTABILITY. OVER THE EASTERN CARIBBEAN HOWEVER...A SURFACE TROUGH EXTENDS FROM 14N-18N ALONG 62W AND OVER THE LEEWARD ISLANDS. THIS IS PROVIDING A FOCUS FOR CONVERGENCE OF TRADEWINDS THAT IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS NE OF A LINE FROM MARTINIQUE TO THE MONA PASSAGE NEAR 18N68W. ANOTHER SURFACE TROUGH IS LOCATED NORTH OF PUERTO RICO OVER THE SW NORTH ATLC FROM 19N67W TO 23N65W AND IS ALSO PROVIDING INCREASED MOISTURE AND SHOWER ACTIVITY NORTH OF PUERTO RICO THIS EVENING. RECENT MODEL GUIDANCE FROM THE GFS AND ECMWF INDICATE THESE WEAK SURFACE TROUGHS WILL MERGE OVER THE NEXT 24 HOURS AND DEVELOP A WEAK LOW NEAR 20N65W BY WEDNESDAY EVENING THAT WILL DRIFT NE INTO THE CENTRAL ATLC. BY THURSDAY...AS THE LOW MOVES OFF TO THE NE...ANOTHER ROUND OF BRISK NE WINDS ARE EXPECTED ACROSS THE NE CARIBBEAN. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH DIPS SOUTH ACROSS THE W ATLC WATERS TO 26N WITH AXIS FROM 35N69W TO 26N77W AND SUPPORTS A SURFACE TROUGH ANALYZED FROM THE CENTRAL BAHAMAS NEAR 25N75W NE ALONG 30N64W TO BEYOND 32N62W. LOW-LEVEL CONVERGENCE IN THE VICINITY OF THE SURFACE TROUGH ALONG WITH A LARGE AREA OF UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL TROUGH AXIS IS GENERATING SCATTERED SHOWERS FROM 20N-32N BETWEEN 57W-72W. S OF THIS AREA A PAIR OF SURFACE TROUGHS ARE IMPACTING THE TROPICAL NORTH ATLC...ONE ANALYZED ACROSS THE LEEWARD ISLANDS AND THE OTHER NORTH OF PUERTO RICO FROM 19N67W TO 23N65W. CONVERGENCE SE SURFACE WINDS ARE GENERATING SCATTERED SHOWERS FROM 15N-23N BETWEEN 54W-70W. ACROSS THE CENTRAL ATLC...A SURFACE RIDGE AXIS EXTENDS FROM 32N51W TO 20N45W TO SW OF THE CAPE VERDE ISLANDS NEAR 14N27W AND IS PROVIDING GENERALLY FAIR WEATHER N OF 10N BETWEEN 30W-52W. OVER THE NE ATLC...A SMALL PORTION OF A DYING COLD FRONT EXTENDS FROM 25N17W TO 20N26W. A PAIR OF SURFACE TROUGHS EXTEND NW OF THE DYING FRONT IN ASSOCIATION WITH A 998 MB LOW CENTERED NEAR 32N21W. THE FIRST TROUGH EXTENDS ALONG 32N18W 28N20W 24N32W WHILE THE SECOND TROUGH EXTENDS ALONG 31N21W TO 28N26W. FALLING UNDER THE COOL WATERS OF THE CANARY CURRENT...MOSTLY STABLE CONDITIONS PREVAIL...HOWEVER ISOLATED SHOWERS ARE POSSIBLE WITHIN 30 NM EITHER SIDE OF EACH OF THESE BOUNDARIES. THE ENTIRE SYSTEM IS SUPPORTED BY AN UPPER LEVEL TROUGH AXIS EXTENDING FROM 35N20W TO 27N28W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN