000 AXNT20 KNHC 160605 RRA TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN AUG 16 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE E ATLC ASSOCIATED WITH A 1012 MB LOW NEAR 10N24W THAT MOVES W AT 10-15 KT. CIRA LAYER PRECIPITABLE WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE WAVE IS ASSOCIATED WITH A BROAD AREA OF MAINLY MODERATE MOISTURE THAT ALONG WITH A DIFFLUENT WIND ENVIRONMENT ALOFT SUPPORT SCATTERED MODERATE CONVECTION FROM 07N TO 12N BETWEEN 22W AND 28W. SAHARAN DRY AIR AND DUST ARE N OF THE LOW...THUS SUPPRESSING CONVECTION. A TROPICAL WAVE IS IN THE CENTRAL ATLC WITH AXIS NEAR 42W ...MOVING W AT 10 KT OVER THE PAST 24 HOURS. CIRA LAYER PRECIPITABLE WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE WAVE IS WITHIN A MODERATE MOIST ENVIRONMENT. HOWEVER...ENHANCED METEOSAT IMAGERY SHOW SAHARAN DRY AIR AND DUST COVERING MOST OF THE WAVE...THUS LIMITING THE CONVECTION TO ISOLATED SHOWERS AND TSTMS FROM 06N TO 11N BETWEEN 40W AND 45W. A TROPICAL WAVE IS IN THE CARIBBEAN WITH AXIS NEAR 68W...MOVING W AT 15-20 KT OVER THE PAST 24 HOURS. THE WAVE IS ASSOCIATED WITH A MODERATE MOIST ENVIRONMENT FROM THE SURFACE TO 850 MB ACCORDING TO CIRA LAYER PRECIPITABLE WATER IMAGERY. A DIFFLUENT WIND ENVIRONMENT AT THE UPPER LEVELS IN THE NE CARIBBEAN AND ADJACENT ATLC WATERS ALONG WITH THE MOISTURE SUPPORT SCATTERED TO ISOLATED SHOWERS OVER PUERTO RICO...VIRGIN ISLANDS AND NORTHERN LEEWARD ISLANDS. STRONG DEEP LAYER WIND SHEAR HINDER CONVECTION ACROSS THE E-SE CARIBBEAN BASIN. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 19N16W TO A 1012 MB LOW NEAR 10N24W TO 07N37W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N37W TO 08N42W...THEN RESUMES W OF A TROPICAL WAVE NEAR 07N44W TO THE COAST OF SURINAME NEAR 05N54W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVE NEAR THE CAPE VERDE ISLANDS...SCATTERED MODERATE CONVECTION IS FROM 07N-10N E OF 19W AND FROM 05N TO 08N BETWEEN 47W AND 52W. ...DISCUSSION... GULF OF MEXICO... AN ELONGATED UPPER TROUGH EXTENDS FROM THE NE CONUS SW TO TENNESSEE TO A BASE OVER THE NW GULF...THUS SUPPORTING A 1012 MB LOW NEAR 25N94W FROM WHICH A SURFACE TROUGH EXTENDS N-NE TO 24N91W TO MISSISSIPPI COASTAL WATERS NEAR 30N88W. SOUTHWESTERLY WIND FLOW AROUND THE NW PERIPHERY OF AN UPPER RIDGE CENTERED OVER THE CARIBBEAN AND SOUTHERLY WIND FLOW OVER THE CENTRAL GULF GENERATE A DIFFLUENT WIND ENVIRONMENT E OF 92W...WHICH ALONG WITH SHALLOW MOISTURE ADVECTING FROM THE CARIBBEAN SUPPORT SCATTERED SHOWERS AND TSTMS FROM 22N TO 30N BETWEEN 82W AND 92W. BROAD SURFACE HIGH PRESSURE OVER THE ATLC EXTENDS A RIDGE AXIS SW ACROSS THE FLORIDA PENINSULA TO E OF 89W AND PROVIDES MAINLY SE TO E WIND FLOW OF LESS THAN 15 KT ACROSS THE GULF. THE LOW PRESSURE CENTER IS FORECAST TO DISSIPATE BY TOMORROW NIGHT LEAVING JUST A TROUGH OF LOW PRESSURE ALONG THE NW BASIN. RIDGING WILL BE THE DOMINANT FEATURE ELSEWHERE. CARIBBEAN SEA... A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 12N68W AND COVERS THE BASIN TONIGHT. EVEN THAT SHALLOW MOISTURE DOMINATES ACROSS THE BASIN...DRY AIR SUBSIDENCE FROM ALOFT ALONG WITH STRONG DEEP LAYER WIND SHEAR PROVIDE STABILITY...SUPPORTING MAINLY FAIR WEATHER BASIN-WIDE. SCATTERED SHOWERS AND TSTMS ARE OVER THE NE CARIBBEAN ASSOCIATED WITH A TROPICAL WAVE WITH AXIS CURRENTLY MOVING OVER THE MONA PASSAGE TOWARDS HISPANIOLA. SIMILAR CONVECTION IS OVER THE SW BASIN S OF 11N BETWEEN NORTHERN COLOMBIA AND COSTA RICA BEING ENHANCED BY THE EPAC MONSOON TROUGH. NE TO E WINDS OF 20 TO 25 KT ARE FROM 11N TO 13.5N BETWEEN 70W AND 76W WITH SEAS TO 9 FT. THESE CONDITIONS ARE EXPECTED TO PREVAIL IN THIS REGION FOR THE NEXT TWO DAYS. THE WAVE WILL MOVE ACROSS THE CENTRAL BASIN SUNDAY THROUGH MONDAY ENHANCING SHOWERS ACROSS HISPANIOLA AND ADJACENT WATERS. ...HISPANIOLA... CLOUDY SKIES WITH POSSIBLE ISOLATED SHOWERS COVER THE ISLAND...HOWEVER CONVECTIVE ACTIVITY IS EXPECTED TO INCREASE DURING THE NEXT 24 TO 36 HOURS WITH THE APPROACH OF A TROPICAL WAVE IMPACTING PUERTO RICO THIS MORNING. THE INCREASED PROBABILITY OF PRECIPITATION...LOCALLY HEAVY AT TIMES ON SUNDAY...WILL INCREASE THE RISK OF FLASH FLOODING AND MUDSLIDES THROUGH THROUGH MONDAY. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS NEAR 30N60W AND EXTENDS A TROUGH SW TO A BASE E-NE OF THE SOUTHERN BAHAMAS. THIS IS SUPPORTING A 1018 MB LOW NEAR 29N57W FROM WHICH A SURFACE TROUGH EXTENDS SW TO 26N64W. ISOLATED SHOWERS ARE POSSIBLE IN THE VICINITY OF THE LOW. SCATTERED SHOWERS ARE S OF 23N BETWEEN 60W AND 68W ASSOCIATED WITH THE PASSAGE OF A TROPICAL WAVE ACROSS THE EASTERN CARIBBEAN. A BROAD SURFACE RIDGE COVERS THE REMAINDER BASIN AND SUPPORTS FAIR WEATHER. FOR TROPICAL WAVES SEE SECTION ABOVE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR