000 AXNT20 KNHC 281721 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUL 28 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. ...SPECIAL FEATURES... A STRONG PRESSURE GRADIENT PREVAILS ACROSS THE CENTRAL CARIBBEAN SUPPORTING GALE FORCE WINDS FROM 11N-13N BETWEEN 74W-78W. THESE CONDITIONS ARE VERIFIED BY SCATTEROMETER DATA. EXPECT WINDS TO DIMINISH BY THIS AFTERNOON. PLEASE REFER TO THE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E TROPICAL ATLANTIC WITH AXIS EXTENDING FROM 19N29W TO 13N34W...MOVING W AT 15 KT. THE WAVE COINCIDES WITH BROAD AND VERY SUBTLE 700 MB TROUGHING BETWEEN 26W-32W WITH 700 MB RELATIVE VORTICITY FOCUSED NEAR THE SOUTHERN EXTENT OF THE WAVE AXIS. NO CONVECTION IS RELATED TO THE WAVE AT THIS TIME. A TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 18N48W TO 09N50W...MOVING W AT 15 KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 48W-55W. NO SIGNIFICANT CONVECTION IS OBSERVED AT THIS TIME DUE TO A BROAD AREA OF SAHARAN DUST PREVAILING IN THE ENVIRONMENT OF THE WAVE. A TROPICAL WAVE IS MOVING OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 18N71W TO 08N74W...MOVING W AT 15-20 KT. THIS WAVE COINCIDES WITH 700 MB TROUGHING BETWEEN 70W-80W WITH NO SIGNIFICANT CONVECTION AT THIS TIME DUE TO SAHARAN DUST PREVAILING IN THE ENVIRONMENT OF THE WAVE. A TROPICAL WAVE IS MOVING OVER CENTRAL AMERICA WITH AXIS EXTENDING FROM 20N85W INTO THE EPAC NEAR 10N87W. THIS WAVE IS MOVING W AT 15-20 KT. A BROAD 700 MB TROUGHING IS OBSERVED BETWEEN 80W-88W. ISOLATED MODERATE CONVECTION PREVAILS S OF 18N AND W OF 85W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 16N17W TO 11N28W THEN RESUMES W OF A TROPICAL WAVE NEAR 11N31W TO 10N41W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM THAT POINT TO 10N49 THEN RESUMES W OF A TROPICAL WAVE NEAR 09N51W TO 07N53W. SCATTERED MODERATE CONVECTION IS FROM 08N-14N AND W 28W. ...DISCUSSION... GULF OF MEXICO... THE PERIPHERY OF AN UPPER-LEVEL HIGH CENTERED OVER NE TEXAS EXTENDS ACROSS THE BASIN. AT THE SURFACE...THE RIDGE THAT PREVAILS ACROSS THE ATLANTIC EXTENDS W REACHING THE E GULF ANCHORED BY A 1018 MB SURFACE HIGH CENTERED NEAR 24N83W. TO THE N...A 1013 MB SURFACE LOW PREVAILS ACROSS THE NE GULF WATERS CENTERED NEAR 29N83W. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO 27N83W. SCATTERED MODERATE CONVECTION IS OBSERVED IN THE VICINITY OF THE LOW/TROUGH MAINLY N OF 25N AND E OF 88W. FAIR WEATHER PREVAILS ACROSS THE REMAINDER OF THE BASIN. SCATTEROMETER DATA DEPICTS A LIGHT ANTICYCLONIC FLOW ACROSS THE BASIN BECOMING VARIABLE NEAR THE CONVECTION OVER THE NE PORTION. OVER THE NEXT 24 HOURS...EXPECT FOR THE LOW OVER THE NE GULF TO MOVE ACROSS NORTHERN FLORIDA THEN INTO THE W ATLANTIC WITH CONVECTION. SURFACE RIDGE WILL PREVAIL ACROSS THE BASIN. CARIBBEAN SEA... FAIR WEATHER PREVAILS ACROSS MOST OF THE BASIN A SAHARAN AIRMASS PREVAILS AND STRONG DEEP-LAYER WIND SHEAR DOMINATES THE AREA. ASIDE FROM THE ISOLATED CONVECTION OBSERVED OVER THE FAR W CARIBBEAN RELATED TO A TROPICAL WAVE...A SMALL AREA WITH A FEW SHOWERS IS OBSERVED NEAR THE LEEWARD ISLANDS AND PUERTO RICO SUPPORTED BY AN UPPER-LEVEL LOW CENTERED NEAR 20N64W. A GALE WARNING IS IN EFFECT FROM THE S CENTRAL CARIBBEAN MAINLY N OF COLOMBIA. FOR MORE DETAILS...PLEASE REFER TO THE SPECIAL FEATURES SECTION ABOVE. NO SIGNIFICANT CHANGES ARE EXPECTED OVER THE NEXT 24 HOURS. ...HISPANIOLA... MOSTLY CLEAR SKIES AND FAIR WEATHER PREVAIL ACROSS THE ISLAND. THESE CONDITIONS WILL CONTINUE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH EXTENDS ACROSS THE W ATLANTIC SUPPORTING A STATIONARY FRONT CURRENTLY LOCATED FROM 33N67W TO 31N80W. WITH THIS...A BROAD AREA OF SCATTERED MODERATE CONVECTION PREVAILS IN THE VICINITY OF THIS FRONT MAINLY N OF 28N BETWEEN 68W-79W. ISOLATED CONVECTION IS ALSO SPREADING ACROSS THE NORTHERN BAHAMAS FROM 25N-27N BETWEEN 77W-80W. TO THE E...A SURFACE RIDGE PREVAILS ACROSS THE REMAINDER OF THE BASIN ANCHORED BY A PAIR OF SURFACE HIGHS...ONE NEAR 26N60W AND THE OTHER NEAR 35N30W. NO SIGNIFICANT CONVECTION IS OBSERVED ACROSS THIS AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA