000 AXNT20 KNHC 070605 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED AUG 07 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 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE AXIS EXTENDS FROM 19N63W TO 09N64W MOVING W NEAR 5 KT. TOTAL PRECIPITABLE WATER IMAGERY DEPICT A DRY ENVIRONMENT AHEAD OF IT WHILE MODERATE MOISTURE LIES BEHIND ITS AXIS. DRY AIR SUBSIDENCE AS WELL AS STRONG DEEP LAYER WIND SHEAR ARE HINDERING CONVECTION AT THE TIME. THE WAVE IS EXPECTED TO CONTINUE A WESTWARD TRACK AND BE S OF THE WINDWARD PASSAGE THURSDAY MORNING. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR 14N17W TO 09N27W 07N33W. THE INTERTROPICAL CONVERGENCE ZONE AXIS STARTS NEAR 07N33W AND CONTINUES ALONG 07N40W TO 10N46W. SCATTERED MODERATE CONVECTION IS FROM 07N-17N E OF 20W. SIMILAR CONVECTION IS FROM 05N-11N BETWEEN 23W-28W AS WELL AS WITHIN 120 NM EITHER SIDE OF THE AXES BETWEEN 29W-40W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 0300 UTC...ANTICYCLONIC FLOW IN THE RANGE OF 5-15 KT SPREADS ACROSS MOST OF THE BASIN ANCHORED BY A 1016 MB HIGH NEAR 25N91W WHICH IS BEING SUPPORTED BY A BROAD MIDDLE TO UPPER LEVEL RIDGE CENTERED OVER THE NW GULF. A 1018 MB HIGH PRESSURE CENTER HAS DEVELOPED IN THE NE GULF CENTERED NEAR 30N87W. A STATIONARY FRONT EXTENDS FROM THE FLORIDA PANHANDLE TO 29N84W 28N82W TO A 1014 MB LOW OVER CENTRAL FLORIDA. A PREFRONTAL TROUGH EXTENDS FROM THE SAME LOW TO TAMPA BAY TO 26N85W 27N90W. RADAR IMAGERY SHOW RAINSHOWERS AND ISOLATED TSTMS WITHIN 50 NM OF THE NE GULF COAST E OF 89W. ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS. ANOTHER SURFACE TROUGH EXTENDS FROM THE NORTHERN BAHAMAS TO THE FLORIDA STRAITS TO NEAR 23N84W IN THE SE GULF. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE AXIS AS WELL AS IN THE YUCATAN CHANNEL. OTHERWISE...DRY AIR SUBSIDENCE IS SUPPORTING FAIR WEATHER OVER THE WESTERN GULF W OF 90W. THE CENTER OF HIGH PRESSURE IS EXPECTED TO DRIFT NW AND THEN DISSIPATE EARLY ON THURSDAY. THE SURFACE TROUGH THAT EXTENDS OVER THE SE GULF IS EXPECTED TO DRIFT WESTWARD AND MOVE TO THE PENINSULA OF YUCATAN THURSDAY NIGHT. RAINSHOWERS ARE LIKELY TO CONTINUE OVER THE EASTERN GULF. THE CARIBBEAN SEA... AS DEPICTED IN TOTAL PRECIPITABLE WATER AND WATER VAPOR IMAGERY...DRY AIR SPREADS ACROSS THE BASIN MAINLY S OF 18N PROVIDING A STABLE...CONVECTION FREE ENVIRONMENT. N OF 18 N...A MODERATE MOIST ENVIRONMENT AND UPPER LEVEL DIFFLUENCE FROM A BROAD RIDGE EXTENDING TO THE W CARIBBEAN AND A LOW CENTERED N OF THE HISPANIOLA ARE ENHANCING SCATTERED MODERATE CONVECTION AND TSTMS OVER HAITI...NW DOMINICAN REPUBLIC...THE WINDWARD PASSAGE AS WELL AS BETWEEN SE CUBA AND JAMAICA. A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS CURRENTLY JUST E OF THE VIRGIN ISLANDS. ALL THE LESSER ANTILLES HAS REPORTED RAINSHOWERS WITHIN THE LAST HOUR ASSOCIATED WITH THE PASSAGE OF THIS WAVE. TRADEWINDS UP TO 20 KT ARE OVER THE CENTRAL-SOUTHERN CARIBBEAN NEAR THE COAST OF COLOMBIA WHILE WINDS OF 5-15 KT DOMINATE ELSEWHERE IN THE BASIN. ISOLATED MODERATE CONVECTION IS S OF 10N ASSOCIATED WITH THE MONSOON TROUGH AXIS. WINDS OVER THE CENTRAL-SOUTHERN CARIBBEAN ARE EXPECTED TO SUBSIDE TO 15 KT WEDNESDAY AFTERNOON. RAINSHOWERS ACTIVITY IS EXPECTED FOR THE GREATER ANTILLES AND ADJACENT WATERS DURING THE NEXT 48 HOURS...ASSOCIATED WITH THE WESTWARD PASSAGE OF THE TROPICAL WAVE AS WELL AS A FAVORABLE UPPER LEVEL SYNOPTIC PATTERN. HISPANIOLA... IN THE UPPER LEVEL...A LOW EXTENDS A TROUGH ACROSS THE ISLAND FROM THE W ATLC TO THE SW CARIBBEAN. THIS IS SUPPORTING LOW VALUES OF WIND SHEAR OVER THE ISLAND WHICH ALONG WITH MODERATE MOISTURE AVAILABILITY AND UPPER LEVEL DIFFLUENCE ARE ENHANCING SCATTERED MODERATE CONVECTION AND TSTMS OVER HAITI...THE DOMINICAN REPUBLIC AND THE WINDWARD PASSAGE. RAINSHOWERS ARE EXPECTED FOR THE ISLAND AND ADJACENT WATERS DURING THE NEXT 48 HOURS...ASSOCIATED WITH THE WESTWARD PASSAGE OF A TROPICAL WAVE AS WELL AS A FAVORABLE UPPER LEVEL SYNOPTIC PATTERN. THE ATLANTIC OCEAN... AS OF 0900 UTC...A DISSIPATING STATIONARY FRONT EXTENDS OVER THE SW N ATLC FROM 29N74W TO 29N78W TO A 1014 MB LOW OVER CENTRAL FLORIDA. A PREFRONTAL TROUGH EXTENDS FROM THE NORTHERN BAHAMAS TO THE FLORIDA STRAITS TO NEAR 23N84W IN THE SE GULF. AT THE MOMENT THERE IS NO CONVECTION ASSOCIATED EITHER WITH THE TROUGH OR FRONT. FURTHER EAST...A SURFACE TROUGH FORMERLY PART OF THE TROPICAL WAVE AXIS IN THE E CARIBBEAN IS MOVING W-NW AROUND THE PERIPHERY OF A RIDGE WITH AXIS EXTENDING FROM 27N61W TO 23N64W. SCATTERED MODERATE CONVECTION ASSOCIATED WITH THIS TROUGHINESS IS FROM 23N-30N BETWEEN 57W-67W. A SURFACE TROUGH IS E OF THE LESSER ANTILLES FROM 16N56W TO 09N57W WITH SCATTERED MODERATE CONVECTION FROM 08N-14N BETWEEN 56W-61W. ANOTHER SURFACE TROUGH ASSOCIATED WITH A 1013 MB LOW EXTENDS FROM 14N51W TO 08N50W WITH NO CONVECTION ASSOCIATED WITH IT. OTHERWISE...SURFACE RIDGING AND FAIR WEATHER SUPPORTED BY LOWER-MIDDLE LEVEL DRY AIR DOMINATE THE REMAINDER BASIN. A NEW TROPICAL WAVE COULD BE COMING OFF THE WEST AFRICAN COAST LATER TODAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS