000 AXNT20 KNHC 291719 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUL 29 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 IS NOTED ACROSS THE CENTRAL CARIBBEAN SUPPORTING GALE FORCE WINDS FROM 11N-13N BETWEEN 74W-78W. THESE CONDITIONS ARE FORECAST TO DIMINISH BY 29/1800 UTC AND RE- INTENSIFY ONCE AGAIN BY 30/0600 UTC. FOR MORE DETAILS PLEASE REFER TO THE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC. ...TROPICAL WAVES... A TROPICAL WAVE IS MOVING OVER THE E ATLANTIC WITH AXIS EXTENDING FROM 19N31W TO 10N30W...MOVING W AT AROUND 15 KT. THE WAVE COINCIDES WITH 700 MB TROUGHING BETWEEN 25W-35W AND A LOW- LEVEL MONSOONAL GYRE EMBEDDED WITHIN THE MONSOON TROUGH AXIS NEAR THE SOUTHERN PORTION OF THE WAVE. ISOLATED MODERATE CONVECTION IS OBSERVED FROM 09N-11N BETWEEN 29W-31W. A LOW AMPLITUDE TROPICAL WAVE IS MOVING OVER THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 16N46W TO 10N45W...MOVING W AT 20-25 KT. THE WAVE REMAINS EMBEDDED WITHIN VERY SUBTLE 700 MB TROUGHING BETWEEN 37W-45W AND MODERATE MOISTURE CONTENT SURROUNDS THE WAVE. NO SIGNIFICANT CONVECTION IS OCCURRING AT THIS TIME DUE TO A LARGE AND DRY SAHARAN AIRMASS PREVAILING ACROSS THE ATLANTIC. A TROPICAL WAVE IS CURRENTLY OVER THE WINDWARD ISLANDS WITH AXIS EXTENDING FROM 19N60W TO 11N61W...MOVING W AT 20-25 KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 55W-65W. NO SIGNIFICANT CONVECTION IS OCCURRING WITH THE WAVE AT THIS TIME DUE TO A LARGE AND DRY SAHARAN AIRMASS PREVAILING ACROSS THE ATLANTIC. A TROPICAL WAVE IS MOVING OVER THE W CARIBBEAN WITH AXIS EXTENDING FROM 20N82W TO 09N82W...MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 80W-90W. ISOLATED MODERATE CONVECTION IS OBSERVED ALONG THE SOUTHERN PORTION OF THE WAVE...MAINLY S OF 12N. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 19N16W TO A 1010 MB LOW NEAR 12N21W TO 11N29W...THEN RESUMES W OF A TROPICAL WAVE NEAR 10N31W TO 10N38W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N38W TO 12N44W...THEN RESUMES W OF A TROPICAL WAVE NEAR 11N48W TO 10N59W. SCATTERED MODERATE CONVECTION IS OBSERVED SURROUNDING THE SURFACE LOW FROM 09N-14N BETWEEN 19W-28W. ...DISCUSSION... GULF OF MEXICO... A NE TO E FLOW ALOFT PREVAILS ACROSS THE BASIN ON THE SOUTHERN PERIPHERY OF AN UPPER-LEVEL HIGH CENTERED OVER NE TEXAS. WATER VAPOR IMAGERY INDICATES MOST ATMOSPHERIC MOISTURE IS NOTED ACROSS THE EASTERN HALF OF THE GULF MAINLY E OF 90W. A SURFACE TROUGH EXTENDS ACROSS THE FLORIDA PENINSULA FROM A 1012 MB LOW CENTERED OVER THE W ATLANTIC ENHANCING SCATTERED MODERATE CONVECTION FROM 25N-27N AND BETWEEN 82W-89W. A SURFACE RIDGE ANCHORED BY A 1017 MB HIGH CENTERED NEAR 24N86W IS PROVIDING THE BASIN WITH GENTLE TO MODERATE ANTICYCLONIC BREEZE CONDITIONS. OVER THE NEXT 24 HOURS...THE SURFACE HIGH WILL PREVAIL ACROSS THE BASIN DRIFTING NW. BY THE WEEKEND...A WEAK FRONTAL TROUGHING IS EXPECTED TO EXTEND ALONG THE NORTHERN GULF WATERS. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE W CARIBBEAN. PLEASE REFER TO THE SECTION ABOVE FOR MORE DETAILS. FAIR WEATHER PREVAILS ACROSS MOST OF THE BASIN AS A BROAD SAHARAN AIRMASS DOMINATES THE AREA. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE TRADES ACROSS MOST OF THE BASIN EXCEPT S OF 14N BETWEEN 74W-78W WHERE STRONG TO GALE FORCE WINDS PREVAIL. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS. SIMILAR WEATHER CONDITIONS WILL ARE EXPECTED OVER THE NEXT 24 HOURS. ...HISPANIOLA... MOSTLY CLEAR SKIES AND FAIR WEATHER PREVAIL ACROSS THE ISLAND AS A SAHARAN AIRMASS DOMINATES THE CARIBBEAN. THIS PATTERN WILL PREVAIL OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE W ATLANTIC SUPPORTING A PAIR OF SURFACE LOWS...ONE CENTERED NEAR 31N79W AND THE OTHER NEAR 33N75W. A SURFACE TROUGH EXTENDS FROM THE FLORIDA PENINSULA INTO THE W ATLANTIC CONNECTED TO THE LOW ALONG 79W AND SUPPORTING SCATTERED MODERATE CONVECTION FROM 27N- 30N BETWEEN 76W-80W. A FRONTAL SYSTEM PREVAILS N OF 31N CONTINUES TO ENHANCE ISOLATED CONVECTION MAINLY N OF 29N BETWEEN 68W-73W. A SURFACE RIDGE PREVAILS ACROSS THE REMAINDER OF THE BASIN ANCHORED BY A 1020 MB SURFACE HIGH NEAR 28N67W AND A 1026 MB SURFACE HIGH NEAR 35N31W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA