000 AXNT20 KNHC 111033 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI JUL 11 2014 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS WEST OF THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 22N26W TO 9N31W MOVING W AT 15 KT. THE WAVE CONTINUES EMBEDDED IN THE DRY SAHARAN AIR LAYER...THEREFORE NO CONVECTION IS ASSOCIATED WITH IT. TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 19N62W TO 10N66W MOVING W AT 20-25 KT. DEEP LAYER MOISTURE IS ASSOCIATED WITH THE WAVE WHICH IS ENHANCING SCATTERED SHOWERS E-SE OF A LINE FROM 18N64W TO 11N70W. TROPICAL WAVE IS LOCATED OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 20N73W TO 10N75W MOVING W AT 20 KT. DRY AIR FROM A SAHARAN AIRMASS IS MOVING ACROSS THE CENTRAL WAVE ENVIRONMENT WHICH ALONG STRONG DEEP LAYER ENVIRONMENTAL SHEAR IN THE CARIBBEAN HINDER CONVECTION AT THE TIME. HOWEVER...LIFTING OF MOIST AIR IS BEING SUPPORTED BY AN UPPER-LEVEL LOW CENTERED IN THE WINDWARD PASSAGE...THUS ENHANCING SHOWERS AND TSTMS AHEAD OF THE AXIS FROM 18N-20N BETWEEN 73W-77W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 13N16W TO 10N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 10N22W AND CONTINUES ALONG 7N37W TO THE SOUTH AMERICAN COAST NEAR 5N53W. IN ADDITION TO THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS LOCATED FROM 8N-12N BETWEEN 21W-29W...FROM 5N-10N BETWEEN 34W-39W AND FROM 5N-9N W OF 51W. ...DISCUSSION... GULF OF MEXICO... THE NORTH ATLC SUBTROPICAL HIGH CONTINUES TO EXTEND A RIDGE AXIS SW INTO THE GULF THUS SUSTAINING HIGH PRESSURE ACROSS THE ENTIRE BASIN. THE SURFACE RIDGE IN THE GULF IS BEING ANCHORED BY A 1019 MB HIGH OVER THE NE WATERS NEAR 28N87W AND PROVIDES E-SE WIND FLOW OF 5-20 KT ACROSS MUCH OF THE GULF...BEING THE STRONGEST WINDS AT THE BAY OF CAMPECHE. EXCEPT FOR THE W-NW GULF AT THE LOWER-LEVELS...DEEP LAYER MOIST AIR IS PRESENT ACROSS THE REMAINDER BASIN. IN THE W GULF...BOTH DRY AIR AND DEEP LAYER STRONG ENVIRONMENTAL WIND SHEAR INHIBIT CONVECTION. THE SW AND E BASIN ARE ALSO DEVOID OF CONVECTION AS ENVIRONMENTAL CONDITIONS ARE NOT FAVORING AIR LIFTING. THE CENTER OF HIGH PRESSURE IS FORECAST TO PERSIST ACROSS THE N-NE GULF THROUGH SUN NIGHT. CARIBBEAN SEA... THE NORTH ATLC SUBTROPICAL HIGH CONTINUES TO EXTEND A RIDGE AXIS SW INTO THE NORTHERN CARIBBEAN WATERS. THIS CONTINUES TO SUPPORT A TIGHT PRESSURE GRADIENT IN THE CENTRAL AND EASTERN BASIN...THUS SUPPORTING A MODERATE TO FRESH BREEZE BETWEEN 64W- 80W. EXCEPT FOR PORTIONS OF THE NORTH CENTRAL BASIN WHERE DRY AIR FROM A SAHARAN AIRMASS LINGERS...THE REMAINDER BASIN SHOW A MOISTURE INCREASE. HOWEVER...STRONG DEEP LAYER ENVIRONMENTAL SHEAR OVER THE THE SW AND CENTRAL BASIN HINDERS THE DEVELOPMENT OF CONVECTION AT THE TIME. TWO TROPICAL WAVES ARE MOVING ACROSS THE CARIBBEAN. SEE THE TROPICAL WAVES SECTION ABOVE FOR DETAILS. OTHERWISE...AN UPPER-LEVEL CYCLONIC CIRCULATION CENTERED OVER THE WINDWARD PASSAGE SUPPORT SHOWERS AND TSTMS BETWEEN CUBA...JAMAICA AND HISPANIOLA FROM 18N-21N BETWEEN 74W-77W. SIMILAR CONVECTION IS OVER COASTAL WATERS OF SE CUBA. ...HISPANIOLA... A BROAD UPPER-LEVEL CYCLONIC CIRCULATION CENTERED OVER THE WINDWARD PASSAGE EXTENDS A TROUGH TO NORTHERN COLOMBIA. THIS IS SUPPORTING ISOLATED SHOWERS/TSTMS OVER THE WINDWARD PASSAGE AS WELL AS HAITI COASTAL WATERS. SHOWERS ARE EXPECTED TO CONTINUE THROUGH SAT MORNING AS THE UPPER LOW MOVES SLOWLY NW TO EASTERN CUBA. ATLANTIC OCEAN... NO SIGNIFICANT WEATHER HAPPENING IN THE BASIN. THIS IS DUE TO THE PRESENCE OF VERY DRY AIR ACROSS THE CENTRAL AND EASTERN ATLC AS WELL AS THE NORTH ATLC SUBTROPICAL HIGH. OVER THE TROPICAL ATLC...A WAVE IS WEST OF THE CAPE VERDE ISLANDS WITH NO CONVECTION ASSOCIATED WITH IT. SEE THE TROPICAL SECTION ABOVE FOR MORE MORE INFORMATION. OTHERWISE...BESIDES A SURFACE TROUGH FOR THE SW N ATLC...NO SIGNIFICANT CHANGES ARE EXPECTED DURING THE NEXT COUPLE OF DAYS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR