000 AXNT20 KNHC 221749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON APR 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 03N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N16W TO THE EQUATOR NEAR 25W TO 03N37W TO 02N51W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 01N-05N BETWEEN 10W-24W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF A LINE FROM 03N29W TO 07N52W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES GENERALLY WESTERLY MIDDLE TO UPPER LEVEL FLOW IS OVER THE GULF BASIN THIS AFTERNOON AS WEAK LONGWAVE MIDDLE TO UPPER LEVEL TROUGHING CONTINUES TO SHIFT EASTWARD INTO THE SW NORTH ATLC. THIS UPPER LEVEL FEATURE SUPPORTS SURFACE TROUGHING THAT EXTENDS ACROSS THE FLORIDA PENINSULA INTO THE SE GULF WATERS GENERATING MULTILAYERED CLOUDINESS AND ISOLATED SHOWERS ACROSS THE FLORIDA KEYS AND A PORTION OF THE SE GULF S OF 25N E OF 86W. A SURFACE TROUGH IS ALSO ANALYZED FROM 25N89W TO THE WESTERN YUCATAN PENINSULA COAST NEAR 19N91W THAT COTNINUES TO LACK ANY SIGNIFICANT PRECIPITATION OCCURRING WITHIN ITS VICINITY. THE REMAINDER OF THE NORTHERN AND WESTERN GULF IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING FROM THE CAROLINAS THROUGH THE MISSISSIPPI RIVER DELTA REGION TO EAST-CENTRAL MEXICO NEAR 22N98W. MOSTLY FAIR CONDITIONS EXIST UNDER SCATTERED TO BROKEN LOW-LEVEL CLOUDINESS. THE SURFACE TROUGHING ACROSS THE SW NORTH ATLC AND SE GULF WILL SLOWLY DRIFT EAST OF THE BASIN THROUGH EARLY TUESDAY...HOWEVER THEREAFTER EAST-SOUTHEAST WINDS IN THE RANGE OF 10 TO 20 KT WILL PREVAIL THROUGH EARLY WEDNESDAY AS THE NEXT WEAK COLD FRONT IS FORECAST TO EMERGE OFF THE TEXAS AND LOUISIANA COAST MID-DAY WEDNESDAY. CARIBBEAN SEA... OVERALL DRY AND STABLE AIR IN WEST-NORTHWESTERLY FLOW ALOFT DOMINATES OVER MUCH OF THE CARIBBEAN THIS AFTERNOON KEEPING CONDITIONS ACROSS THE BASIN FAIRLY TRANQUIL. SATELLITE AND TOTAL PRECIPITABLE WATER IMAGERY INDICATE A SWATH OF LOWER LEVEL MOISTURE AND CLOUDINESS EXTENDING FROM THE WINDWARD ISLANDS AND SE CARIBBEAN NEAR 13N61W TO 14N70W TO 19N75W AND THE SOUTHERN APPROACHES TO THE WINDWARD PASSAGE. ISOLATED LOW-TOPPED SHOWER ARE POSSIBLE WITHIN 120 NM EITHER SIDE OF A LINE FROM THE GRENADINES NEAR 13N61W TO 15N74W...AND N OF 15N BETWEEN 72W- 77W...INCLUDING WESTERN HISPANIOLA AND EASTERN JAMAICA. TRADE WINDS REMAIN IN THE RANGE OF 10 TO 20 KT THIS AFTERNOON AND ARE EXPECTED TO PERSIST IN THAT RANGE THROUGH MUCH OF THE WEEK. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LONGWAVE TROUGH IS OVER THE SW NORTH ATLC THAT SUPPORTS A WEAK 1016 MB LOW CENTERED OFF THE FLORIDA PENINSULA NEAR 29N80W. A WARM FRONT EXTENDS NE FROM THE LOW TO 31N78W WITH THE FRONT BECOMING STATIONARY BEYOND 32N77W. A SURFACE TROUGH IS ANALYZED SOUTH FROM THE LOW CENTERED ACROSS THE SOUTHERN PORTION OF THE FLORIDA PENINSULA TO NEAR 25N81W. WITH A WARM AND STATIONARY FRONT IN PLACE AT THE SURFACE GENERALLY EAST OF THE MIDDLE TO UPPER LEVEL TROUGHING... SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 27N BETWEEN 72W- 80W IN THE AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 23N-27N BETWEEN 74W-80W AS THE BASE OF THE TROUGH BEGINS TO SWING N-NE OVER THE NEXT 12 TO 24 HOURS. THE REMAINDER OF THE SW NORTH ATLC BETWEEN 50W-72W IS UNDER THE INFLUENCE OF A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 28N63W THAT SUPPPORTS SURFACE RIDGING AND OVERALL FAIR CONDITIONS THIS AFTERNOON. FARTHER EAST...A BROAD AND COMPLEX MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 31N38W THAT SUPPORTS A 1007 MB SURFACE LOW CENTERED NEAR 29N37W. MOST PRECIPITATION GENERATED BY THIS SYSTEM IS LOCATED WITHIN THE NE QUADRANT WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 27N-34N BETWEEN 27W-38W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN