000 AXNT20 KNHC 052349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUL 05 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... ...GALE IN THE CARIBBEAN... A GALE WARNING IS IN EFFECT FOR THE SW CARIBBEAN FROM 11N TO 13.5N BETWEEN 73W AND 78W THROUGH MONDAY MORNING. THESE WINDS ARE GENERATED BY A TIGHT PRESSURE GRADIENT BETWEEN THE STRONG SURFACE RIDGE OVER THE ATLANTIC AND LOWER PRESSURES OVER SOUTH AMERICA. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS EXTENDING FROM 14N47W TO 06N48W. THIS WAVE HAS MOVED W AT AROUND 25 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN SURGE OF MODERATE MOISTURE S OF 10N. ENHANCED METEOSAT IMAGERY SHOWS SAHARAN DUST ACROSS THE NORTHERN PORTION OF THE WAVE MAINLY N OF 10N WHICH IS INHIBITING CONVECTION. SCATTERED MODERATE CONVECTION PREVAILS S OF 10N BETWEEN 46W-52W. THIS CONVECTION IS PARTIALLY ASSOCIATED ALSO WITH THE PROXIMITY OF THE ITCZ. A TROPICAL WAVE IS AT ABOUT 200 NM E OF THE LESSER ANTILLES WITH AXIS EXTENDING FROM 17N56W TO 08N58W. THIS WAVE IS MOVING W NEAR 20 KT. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN DEEP HIGH MOISTURE MAINLY S OF 11N. A DRY SAHARAN AIRMASS PREVAILS N OF 12N INHIBITING CONVECTION. SCATTERED LIGHT TO MODERATE CONVECTION IS S OF 10N BETWEEN 54W- 62W. LIKE THE PREVIOUS WAVE DISCUSSED...THIS CONVECTION IS PARTIALLY ASSOCIATED WITH THE PROXIMITY OF THE ITCZ. A TROPICAL WAVE IS CURRENTLY OVER CENTRAL AMERICA WITH AXIS EXTENDING FROM 18N84W TO 11N84W. THIS WAVE IS MOVING W AT AROUND 20 KT. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE MOISTURE. ISOLATED CONVECTION IS ALONG 15N BETWEEN 82W-86W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL ATLANTIC NEAR 18N16W TO 10N23W TO 08N26W WHERE THE ITCZ BEGINS AND CONTINUES TO 07N46W...THEN RESUMES W OF A TROPICAL WAVE NEAR 07N49W TO 07N57W. SCATTERED MODERATE CONVECTION IS WITHIN 50 NM N OF THE ITCZ AXIS BETWEEN 42W-56W. ...DISCUSSION... GULF OF MEXICO... AN UPPER-LEVEL LOW IS CENTERED OVER THE SOUTHERN GULF NEAR 23N88W AND EXTENDING ACROSS THE BASIN. WITH THIS...UPPER-LEVEL DIFFLUENCE PREVAILS ACROSS THE E GULF SUPPORTING SCATTERED MODERATE CONVECTION MAINLY E OF 88W. ANOTHER AREA OF UPPER-LEVEL DIFFLUENCE IS SUPPORTING SCATTERED MODERATE CONVECTION ACROSS THE GULF COAST STATES E OF TEXAS AND THE N GULF WATERS N OF 29N. AT THE SURFACE...THE RIDGE THAT PREVAILS ACROSS THE ATLANTIC EXTENDS W ACROSS THE NORTHERN GULF WATERS. AN ANTICYCLONIC LIGHT TO GENTLE FLOW PREVAILS ACROSS THE BASIN. OVER THE NEXT 24 HOURS...EXPECT CONVECTION TO DECREASE OVER THE NE GULF TONIGHT WITH MAINLY ISOLATED TO SCATTERED WEAK CONVECTION OVER THE EASTERN GULF ON MONDAY. CARIBBEAN SEA... THE UPPER-LEVEL DIFFLUENCE THAT PREVAILS ACROSS THE E GULF ALSO EXTENDS ACROSS THE W CARIBBEAN AND W CUBA SUPPORTING ISOLATED CONVECTION MAINLY W OF 80W. A TROPICAL WAVE IS OVER THE SW CARIBBEAN...PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. ENHANCED METEOSAT IMAGERY DEPICTS A SAHARAN AIRMASS DOMINATING THE CENTRAL AND E CARIBBEAN INHIBITING SIGNIFICANT CONVECTION. A STRONG PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE OVER THE SUBTROPICAL NORTHERN ATLANTIC AND LOWER PRESSURES OVER S AMERICA SUPPORTS MODERATE TO FRESH WINDS S OF 18N BETWEEN 70W- 80W WITH GALE FORCE WINDS OVER A PORTION OF THE SW CARIBBEAN. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. THE PRESSURE GRADIENT IS EXPECTED TO WEAKEN SLIGHTLY ON MONDAY AS THE HIGH PRESSURE OVER THE ATLANTIC ERODES FROM THE W WITH THE APPROACH OF AN UPPER-LEVEL TROUGH. THIS WILL BE SUFFICIENT TO BRING WINDS BELOW GALE FORCE OVER THE SW CARIBBEAN BY LATE MONDAY MORNING. A TROPICAL WAVE WILL MOVE OVER THE LEEWARD ISLANDS OVER THE NEXT 24 HOURS. ...HISPANIOLA... DRY AIR AND SAHARAN DUST PREVAIL OVER THE ISLAND AND THE CARIBBEAN BASIN. EXPECT THIS CONDITIONS TO CONTINUE OVER THE NEXT 24 HOURS. A TROPICAL WAVE CURRENTLY APPROACHING THE WINDWARD/LEEWARD ISLANDS MAY BRING AN INCREASE IN MOISTURE ACROSS THE AREA SUPPORTING SHOWER AND THUNDERSTORM ACTIVITY BY LATE MONDAY. ATLANTIC OCEAN... AN UPPER-LEVEL LOW IS CENTERED NEAR 27N69W. THIS FEATURE... COMBINED WITH THE UPPER-LEVEL LOW OVER THE SOUTHERN GULF OF MEXICO...IS SUPPORTING A DIFFLUENT FLOW BETWEEN THESE CENTERS WHICH IS GENERATING SCATTERED CONVECTION ACROSS THE FLORIDA PENINSULA AND W ATLANTIC MAINLY W OF 75W. AT THE SURFACE...A BROAD AREA OF HIGH PRESSURE EXTENDS ACROSS THE WHOLE BASIN CENTERED NEAR 34N42W. A SAHARAN AIRMASS ALSO EXTENDS ACROSS THE BASIN INHIBITING ANY SIGNIFICANT CONVECTION...WITH HIGHER CONCENTRATION E OF 50W. TWO TROPICAL WAVES ARE OVER THE TROPICAL NORTHERN ATLANTIC. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA