000 AXNT20 KNHC 132350 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUN 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2245 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IMPACTING THE EASTERN CARIBBEAN EXTENDS FROM 19N62W TO 9N63W MOVING W AT 20 KT. THE WAVE LIES WITHIN A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 11N-16N BETWEEN 60W-63W. SCATTERED MODERATE/STRONG CONVECTION IS INLAND OVER VENEZUELA FROM 6N-10N BETWEEN 61W-68W. A TROPICAL WAVE EXTENDS ACROSS CENTRAL AMERICA INTO THE EAST PACIFIC ALONG 16N84W TO 8N86W MOVING WEST TO NORTHWEST NEAR 10 KT. SCATTERED MODERATE/STRONG CONVECTION IS FROM 10N-16N BETWEEN 83W-88W. SCATTERED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 79W-83W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR 11N16W TO 6N23W. THE ITCZ BEGINS NEAR 6N23W AND CONTINUES ALONG 4N40W 5N50W 8N59W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-8N BETWEEN 19W-26W...AND FROM 6N-8N BETWEEN 31W-35W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-11N BETWEEN 51W-60W. ...DISCUSSION... THE GULF OF MEXICO... WEAK SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1019 MB HIGH NEAR 26N89W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE COVERING THE WESTERN GULF CENTERED OVER CENTRAL MEXICO NEAR 19N101W. LIGHT ANTI-CYCLONIC WINDS ARE AROUND THE HIGH CENTER INCREASING TO 10-15 KT OVER THE WESTERN GULF. AN UPPER LEVEL LOW IS SITTING OVER THE FLORIDA KEYS NEAR 25N82W. WHILE DRY AIR ALOFT AROUND THE WEST SIDE OF THE UPPER LOW IS KEEPING THE CENTRAL GULF CLEAR...DIFFLUENCE AROUND THE EAST SIDE IS PRODUCING SCATTERED SHOWERS/THUNDERSTORMS OVER THE SOUTHERN HALF OF THE FLORIDA PENINSULA CONTINUING INTO THE SE GULF NORTH OF CUBA AND INTO THE BAHAMAS. A FEW ISOLATED SHOWERS ARE ALSO OVER THE NW GULF AS MOIST AIR WRAPS AROUND THE NORTHERN PART OF THE UPPER RIDGE OVER MEXICO. SURFACE RIDGING WILL REMAIN THE DOMINANT FEATURE UNTIL A FRONTAL BOUNDARY MOVES IN TO THE NE GULF TOMORROW AFTERNOON. THE CARIBBEAN SEA... A TROPICAL WAVE OVER CENTRAL AMERICA IS SUPPORTING WIDESPREAD SHOWERS/THUNDERSTORMS OVER HONDURAS...NICARAGUA...COSTA RICA...AND PANAMA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO OVER WATER IN THE SW CARIBBEAN FROM 11N-14N BETWEEN 79W- 83W. A FEW ISOLATED SHOWERS ARE ALSO OVER THE NW CARIBBEAN. THE WAVE IS BEING ENHANCED BY AN UPPER TROUGH/LOW ALONG 83W. DAYTIME HEATING AND INSTABILITY ARE PRODUCING SCATTERED SHOWERS/THUNDERSTORMS ACROSS CUBA...JAMAICA...AND HISPANIOLA. THE UPPER LOW NEAR THE FLORIDA KEYS IS HELPING SUPPORT THIS ACTIVITY. THE CENTRAL CARIBBEAN IS FAIRLY CLEAR AT THIS TIME. A SECOND TROPICAL WAVE IS IMPACTING THE EASTERN CARIBBEAN SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM EAST OF 64W. ALOFT...A BROAD UPPER RIDGE COVERS THE MAJORITY OF THE BASIN EAST OF THE UPPER TROUGH. TRADEWIND FLOW OF 15-20 KT IS PRESENT THROUGHOUT MUCH OF THE AREA REACHING 25 KT NEAR THE COAST OF COLOMBIA. EXPECT THE WAVE IN THE SW CARIBBEAN TO DRIFT WESTWARD WITH MOISTURE LIKELY TO REMAIN NEAR CENTRAL AMERICA. THE TROPICAL WAVE IN THE EASTERN CARIBBEAN WILL CONTINUE WESTWARD AS WELL BRINGING MOISTURE INTO THE CENTRAL CARIBBEAN. HISPANIOLA... A CLUSTER OF HEAVY SHOWERS/THUNDERSTORMS IS CURRENTLY OVER HAITI FROM 18N-19N BETWEEN 71W-72W. THIS ACTIVITY IS MOSTLY TIED TO DAYTIME HEATING AND INSTABILITY PRESENT ON MOST AFTERNOONS. THERE IS AN UPPER TROUGH TO THE EAST...BUT IT LIKELY IS NOT INFLUENCING THE ACTIVITY OVER THE ISLAND YET. A TROPICAL WAVE IN THE EASTERN CARIBBEAN IS MOVING WEST AND WILL BEGIN TO BRING EXTRA MOISTURE TO HISPANIOLA TOMORROW AFTERNOON THROUGH THE WEEKEND. AT THE SAME TIME THE UPPER TROUGH TO THE WEST WILL MOVE EAST AND LIKELY ENHANCE ACTIVITY NEAR THE WAVE. THIS COMBINATION COULD MEAN MORE THAN AVERAGE RAINFALL OVER HISPANIOLA. THE ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE OVER THE BAHAMAS SOUTH OF 28N WEST OF 72W ASSOCIATED WITH AN UPPER LEVEL LOW OVER THE FLORIDA KEYS. THE REMAINDER OF THE AREA IS DOMINATED BY ONE LARGE AND BROAD SURFACE RIDGE ANCHORED BY A 1028 MB HIGH NEAR 30N41W. ALOFT...UPPER RIDGING COVERS THE WEST AND CENTRAL ATLC. AN UPPER LEVEL TROUGH IS ALONG 41W SUPPORTING A FEW UPPER LEVEL CLOUDS TO THE EAST. A SECOND UPPER RIDGE AXIS IS ALONG 30W FOLLOWED BY AN UPPER LEVEL TROUGH OVER NW AFRICAN. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE A LARGE AREA OF SAHARAN DUST EXTENDS OFF THE COAST OF AFRICA AND CONTINUES TO NEAR 53W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON