000 AXNT20 KNHC 221714 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUL 22 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 1615 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE EASTERN TROPICAL ATLANTIC EXTENDS ALONG ABOUT 28W FROM 10N-19N MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. THE WAVE HAS A NEGLIGIBLE SURFACE COMPONENT AND IS ONLY DETECTABLE VIA THE GFS-BASED TROUGH DIAGNOSTICS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS NORTH OF SIGNIFICANT MOISTURE...AS THE WAVE REMAINS EMBEDDED WITHIN A DUSTY SAHARAN AIR LAYER LIMITING ANY ASSOCIATED CONVECTION. TROPICAL WAVE IN THE EASTERN CARIBBEAN EXTENDS ALONG ABOUT 66W SOUTH OF 20N TO INLAND OVER SOUTH AMERICA MOVING W-NW NEAR 20 KT OVER THE PAST 24 HOURS. THE WAVE HAS A DISTINCT SURFACE TROUGH AS SHOWN BY THE ASCAT AND WINDSAT WIND VECTORS. THE WAVE IS ALSO EVIDENT IN THE LESSER ANTILLES RAWINDSONDES AND THE TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS INTERACTING WITH A TROPICAL UPPER TROPOSPHERIC TROUGH NORTH OF THE CARIBBEAN. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE FROM 13N- 20 N BETWEEN 60W-67W. TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS ALONG ABOUT 78W SOUTH OF 18N TO INLAND OVER PANAMA MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THE WAVE HAS A NEGLIGIBLE SURFACE COMPONENT...BUT IS OBSERVABLE VIA THE TOTAL PRECIPITABLE WATER IMAGERY AND CARIBBEAN RAWINDSONDES. THERE IS NO SIGNIFICANT CONVECTION ASSOCIATED WITH THE WAVE AT THIS TIME. TROPICAL WAVE IN THE WESTERN CARIBBEAN EXTENDS ALONG ABOUT 84W SOUTH OF 20N TO OVER CENTRAL AMERICA MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THE WAVE IS BECOMING INDISTINCT WITH ALL METHODS OF DETECTION AND MAY BE MERGING WITH THE WAVE TO ITS EAST OVER THE CENTRAL CARIBBEAN. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE SOUTH OF 15N WITHIN 120 NM OF THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE EASTERN TROPICAL ATLANTIC NEAR 12N16W TO NEAR 10N27W. THE ITCZ BEGINS AT 10N27W AND CONTINUES TO SOUTH AMERICA AT 05N53W. SCATTERED MODERATE CONVECTION IS LOCATED FROM 06N TO 10N BETWEEN 13W AND 26W. ...DISCUSSION... GULF OF MEXICO... A WEAK SURFACE RIDGE EXTENDS FROM THE STRAITS OF FLORIDA TO THE TEXAS COAST. SOUTH OF THE RIDGE LINE WINDS ARE 5-15 KT OUT OF THE EAST AND NORTH OF THE RIDGE WINDS ARE 5-15 KT OUT OF THE WEST. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION IS OCCURRING NORTH OF 28N EAST OF 90W. LITTLE CHANGE IS EXPECTED DURING THE NEXT TWO DAYS. CARIBBEAN SEA... A MODERATE PRESSURE GRADIENT PRODUCED BY THE BERMUDA HIGH OVER THE SUBTROPICAL ATLANTIC AND LOW PRESSURE OVER SOUTHERN CENTRAL AMERICA AND COLOMBIA IS FORCING EASTERLY TRADEWINDS OF GENERALLY 10-20 KT WITH SOME 25 KT WINDS JUST NORTH OF COLOMBIA. SOME CONVECTION IS OCCURRING IN ASSOCIATION WITH THE TROPICAL WAVES...AS DESCRIBED ABOVE. THE REMAINDER OF THE CARIBBEAN HAS MOSTLY CLEAR SKIES CURRENTLY. THE PRESSURE GRADIENT WILL TIGHTEN SLIGHTLY BY FRIDAY...BOOSTING SOMEWHAT THE WINDS ACROSS THE CARIBBEAN. ...HISPANIOLA... NO SIGNIFICANT SHOWER ACTIVITY IS OCCURRING CURRENTLY OVER HISPANIOLA. HOWEVER...AS THE TROPICAL WAVE OVER THE EASTERN CARIBBEAN APPROACHES THE ISLAND INCREASED MOISTURE AND INSTABILITY SHOULD ENHANCE CHANCES FOR SHOWERS AND DEEP CONVECTION LATER TODAY AND AGAIN ON THURSDAY AFTERNOON. BY FRIDAY...THE TROPICAL WAVE AND THE ADDITIONAL MOISTURE SHOULD BE WEST OF HISPANIOLA...REDUCING PRECIPITATION POTENTIAL THEN. ATLANTIC OCEAN... A 1023 MB BERMUDA HIGH CENTERED NEAR 29N47W AND A 1025 MB AZORES HIGH CENTERED NEAR 32N32W ARE DOMINATING CONDITIONS ACROSS THE SUBTROPICAL NORTH ATLANTIC. THE MODERATE PRESSURE GRADIENT SOUTH OF THE HIGHS ARE PRODUCING NORTHEAST TRADEWINDS OF 10-15 KT EAST OF ABOUT 55W AND SOUTHEAST TRADEWINDS OF 10-15 KT FROM ABOUT 55W-70W. A WEAK TROUGH OF LOW PRESSURE IS EAST OF FLORIDA EXTENDING FROM 26N80W TO 30N76W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION EXISTS WITHIN 60 NM OF THE TROUGH NORTH OF 27N. SURFACE WINDS WEST OF 70W ARE GENERALLY SW AT 10- 20 KT. ISOLATED MODERATE CONVECTION EXISTS FROM 24N-27N BETWEEN 45W-48W DUE TO AN UPPER LEVEL LOW. NO SIGNIFICANT CHANGES ARE EXPECTED TO THE WINDS DURING THE NEXT TWO DAYS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LANDSEA