000 AXNT20 KNHC 081756 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUL 08 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLC WITH AXIS ALONG 18W/19W FROM 08N TO 20N...MOVING W AT AROUND 10 KT. FORWARD SPEED ESTIMATES WERE BASED ON LONG-TERM SATELLITE TRENDS. THIS WAVE POSITION WAS RE-ANALYZED BASED OFF THE 1200 UTC DAKAR SOUNDING THAT INDICATED A MID LEVEL WIND SHIFT LATE TUES NIGHT...AND THIS POSITION IS IN AGREEMENT WITH SURROUNDING OBS FROM THE CAPE VERDE ISLANDS CONFIRMING THAT THE WAVE HAS NOT YET ARRIVED. THIS WAVE IS EMBEDDED IN A SURGE OF HIGH MOISTURE S OF 18N WHICH SUPPORTS CLUSTERS OF MODERATE CONVECTION FROM 05N TO 12N BETWEEN 16W AND 22W. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN SEA WITH AN AXIS ALONG 72W/73W...MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. MODERATE MOISTURE IS IN THE WAVE ENVIRONMENT S OF 17N. HOWEVER...DEEP LAYER SHEAR IS INHIBITING ANY DEEP CONVECTION WITH THIS WAVE. A TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN WITH AXIS ALONG 82W/83W...MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. THIS WAVE IS EMBEDDED IN AN ENVIRONMENT OF MODERATE MOISTURE N OF 13N AND HIGH MOISTURE S OF 13N. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE FROM 09N TO 13N BETWEEN 78W AND 85W. THIS CONVECTION IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE OVER THIS PORTION OF THE CARIBBEAN AND NOT SOLELY DUE TO THE PRESENCE OF THE TROPICAL WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH CROSSES OVER THE COASTAL REGIONS OF AFRICA NEAR 11N15W AND CONTINUES OVER THE TROPICAL ATLC TO 08N25W TO 09N34W...WHERE THE ITCZ BEGINS AND CONTINUES THROUGH 07N45W TO THE COAST OF S AMERICA NEAR 07N59W. OTHER THAN CONVECTION ASSOCIATED WITH THE EASTERN ATLC TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS FROM 06N TO 14N BETWEEN 50W AND 60W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LOW IS CENTERED NEAR 25N93W OVER THE WESTERN GULF. UPPER LEVEL DIFFLUENCE BETWEEN THIS UPPER LOW AND ANOTHER UPPER LOW OVER THE WESTERN ATLC...COMBINED WITH MODERATE MOISTURE...SUPPORTS SCATTERED THUNDERSTORMS OVER THE NE GULF FROM 26N TO 31N BETWEEN 83W AND 88W. A DIURNAL AND CONVECTION FREE SURFACE TROUGH EXTENDS FROM 22N91W TO 19N91W. OTHERWISE...GENERALLY FAIR WEATHER COVERS THE GULF BASIN DUE TO THE PRESENCE OF DRY AIR. A NEARLY STATIONARY SURFACE HIGH OF 1021 MB CENTERED NEAR 29N85W IS A WESTERN EXTENSION OF ATLC RIDGING WITH AN AXIS THAT EXTENDS ACROSS N FL TO LOUISIANA. VARIABLE SURFACE WINDS OF 5 TO 10 KT ARE OVER THE NE GULF. SE WINDS OF 10 TO 15 KT COVER THE REMAINDER OF THE GULF. OVER THE NEXT 24 HOURS...MODERATE MOISTURE OVER THE EASTERN GULF WILL SUPPORT SCATTERED THUNDERSTORMS. A MOISTURE INCREASE OVER THE SW GULF IS EXPECTED AS A TROPICAL WAVE NEARS THE AREA ON THURSDAY. THIS WILL INCREASE CHANCES FOR CONVECTION ACROSS THAT PORTION OF THE BASIN. CARIBBEAN SEA... TWO TROPICAL WAVES ARE OVER THE CARIBBEAN SEA. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. UPPER LEVEL DIFFLUENCE OVER THE NW CARIBBEAN SUPPORTS SCATTERED MODERATE CONVECTION FROM 16N TO 18N BETWEEN 83W AND 88W. THE CENTRAL AND EASTERN CARIBBEAN UNDER STRONG SHEAR IS VOID OF DEEP CONVECTION. FRESH TO STRONG TRADE WINDS BETWEEN HIGH PRESSURE OVER THE WESTERN ATLC AND LOWER PRESSURE OVER S AMERICA COVER THE MAJORITY OF THE CARIBBEAN WITH WINDS UP TO 25 KT N OF THE COAST OF COLOMBIA...AND WINDS OF 10 KT OVER THE NW CARIBBEAN. EXPECT ENHANCED CONVECTION TO CONTINUE OVER THE SW CARIBBEAN OVER THE NEXT 24 HOURS WITH LITTLE CHANGE ELSEWHERE. ...HISPANIOLA... SHALLOW MOISTURE WILL SUPPORT ISOLATED THUNDERSTORMS OVER THE ISLAND MAINLY DURING THE AFTERNOON AND EVENING TODAY. DRY AIR MOVING OVER THE ISLAND TONIGHT WILL FURTHER INHIBIT SHOWER AND THUNDERSTORM ACTIVITY ON THURSDAY. ATLANTIC OCEAN... A SURFACE TROUGH ALONG THE SE FL COAST FROM 28N80W TO 24N81W WAS SUPPORTING SCATTERED THUNDERSTORMS WITHIN 30 NM OF THE TROUGH AXIS THIS MORNING. THIS FEATURE AND ASSOCIATED CONVECTION HAS SINCE DISSIPATED. AN UPPER LOW CENTERED NEAR 25N73W SUPPORTS SCATTERED THUNDERSTORMS FROM 23N TO 28N BETWEEN 70W AND 78W. A 1024 MB HIGH IS CENTERED NEAR 31N68W WITH AN AXIS EXTENDING ACROSS N FL. FARTHER EAST...A STATIONARY FRONT EXTENDS INTO THE AREA OF DISCUSSION NEAR 31N59W TO 31N47W. SCATTERED MODERATE CONVECTION IS WITHIN 50 NM OF THE FRONT BETWEEN 53W AND 58W. HIGH PRESSURE CENTERED N OF THE AREA OF DISCUSSION DOMINATES THE CENTRAL AND EASTERN SUBTROPICAL ATLC. A TROPICAL WAVE IS OVER THE FAR EASTERN ATLC. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. EXPECT THUNDERSTORMS TO CONTINUE NEAR THE UPPER LOW FOR THE NEXT 2 DAYS AS IT SLOWLY DRIFTS SW. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO