000 AXNT20 KNHC 311048 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN MAY 31 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 02N41W TO 10N38W MOVING W AT 15-20 KT. THE WAVE REMAINS LARGELY EMBEDDED WITHIN THE ITCZ AXIS AND COINCIDES WITH VERY SUBTLE GLOBAL MODEL INDICATED 700 MB TROUGHING BETWEEN 32W-47W. NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 08N75W TO 17N75W MOVING W AT 15-20 KT. THE WAVE CONTINUES TO MOVE WITHIN THE SOUTHWESTERN PERIPHERY OF A 700 MB RIDGE CENTERED OVER THE WESTERN ATLC. A MIDDLE TO UPPER LEVEL TROUGH NOTED ON WATER VAPOR IMAGERY OVER THE WESTERN CARIBBEAN SEA IS PRODUCING SOUTHWESTERLY SHEAR OVER THE WAVE WITH UPPER LEVEL DIFFLUENCE OCCURRING IN THE VICINITY OF THE WAVE AXIS. NO SIGNIFICANT CONVECTION WAS NOTED IN ASSOCIATION WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 07N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N19W TO 05N25W TO 06N29W TO 03N41W TO 04N48W TO 02N51W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N- 06N BETWEEN THE PRIME MERIDIAN AND 05W...AND FROM 02N-20N BETWEEN 18W-23W. SCATTERED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 25W-34W...AND FROM 02N-07N BETWEEN 42W-55W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE WAS NOTED OVER THE GULF ALONG 91W. WEST- NORTHWESTERLY FLOW ALOFT WAS INDICATED OVER MUCH OF THE BASIN BETWEEN THE RIDGE AND A DOWNSTREAM BROAD UPPER LEVEL TROUGH EXTENDING FROM THE SOUTHEASTERN FLORIDA PENINSULA SOUTHWARD OVER THE WESTERN CARIBBEAN ALONG 78W. A SHARP UPPER TROUGH IS ALSO OVER THE CENTRAL AND SOUTHERN U.S. PLAINS THAT CONTINUES TO EJECT SHORTWAVE ENERGY AROUND THE BASE OF THE TROUGH OVER EASTERN TEXAS AND THE SOUTHERN MISSISSIPPI RIVER VALLEY REGION. CONVECTION ASSOCIATED WITH A STATIONARY FRONT ACROSS THIS AREA IS OCCURRING GENERALLY NW OF A LINE FROM 30N93W TO THE MEXICO COAST NEAR 23N98W. FARTHER EAST...A WEAK SURFACE TROUGH IS ANALYZED ALONG THE WESTERN COAST OF THE FLORIDA PENINSULA DIURNALLY DRIVEN BY DAYTIME HEATING. PREVIOUS TSTM ACTIVITY HAS ALL BUT DIMINISHED THIS MORNING WITH ONLY A FEW ISOLATED SHOWERS REMAINING OCCURRING WITHIN 30 NM EITHER SIDE OF THE BOUNDARY FROM THE MIDDLE FLORIDA KEYS TO THE FLORIDA BIG BEND REGION. ELSEWHERE...GENTLE TO MODERATE BREEZE ANTICYCLONIC WINDS ARE NOTED ACROSS THE GULF THIS MORNING ON THE SOUTHWESTERN PERIPHERY OF A RIDGE ANCHORED ACROSS THE SE CONUS. THE UPPER LEVEL TROUGH OVER THE PLAINS WILL CONTINUE TO DIG SOUTHEASTWARD WHICH WILL RESULT IN INCREASED CHANCE FOR CONVECTION ACROSS THE NW AND NORTH-CENTRAL GULF THROUGH SUNDAY. CARIBBEAN SEA... A BROAD UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE WESTERN CARIBBEAN WITH AXIS ALONG 78W/79W. WEAK UPPER LEVEL DIFFLUENCE IS SUPPORTING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS MUCH OF THE BASIN S OF 20N E OF 83W. DEEP MOISTURE IS ADVECTING EAST OF THE BROAD TROUGH AXIS IN SOUTHWESTERLY FLOW ALOFT FROM THE SOUTHWESTERN CARIBBEAN...OVER THE CENTRAL AND EASTERN CARIBBEAN...INTO THE TROPICAL ATLC. A TROPICAL WAVE IS ACROSS THE WESTERN CARIBBEAN ALONG 75W/76W AND CONTINUES TO PROVIDE FOCUS FOR PORTIONS OF THE ISOLATED SHOWER ACTIVITY ACROSS THE CENTRAL AND WESTERN CARIBBEAN. EAST-SOUTHEAST TRADES ARE EXPECTED TO INCREASE FROM FRESH BREEZE CONDITIONS TO A RANGE OF FRESH TO STRONG BREEZE CONDITIONS BY MONDAY AS STRONG HIGH PRESSURE ANCHORED TO THE NORTHEAST OVER THE CENTRAL ATLC CREATES A STRENGTHENED PRESSURE GRADIENT ACROSS THE CENTRAL CARIBBEAN. ...HISPANIOLA... MIDDLE TO UPPER LEVEL MOISTURE IS BEING DRAWN OVER THE ISLAND IN MODERATE SOUTHWESTERLY FLOW ALOFT. A WESTWARD MOVING TROPICAL WAVE IS PASSING TO THE SOUTHWEST OF THE ISLAND. THESE CONDITIONS ARE EXPECTED TO SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS THROUGH SUNDAY. ATLANTIC OCEAN... A BROAD QUASI-STATIONARY MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE SW NORTH ATLC NEAR 32N65W THAT SUPPORTS A 1015 MB LOW CENTERED NEAR 28N70W WITH SURFACE TROUGH EXTENDING N-NE FROM THE LOW TO 30N69W AND S-SW FROM THE LOW TO 25N72W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM OF THE LOW CENTER. SCATTERED MODERATE CONVECTION WAS NOTED OVER THE ATLC FROM 17N-25N BETWEEN 56W-69W FOCUSED IN THE VICINITY OF A SURFACE TROUGH ANALYZED FROM NE OF HISPANIOLA NEAR 20N68W TO 23N64W. 1030 MB AND 1031 MB HIGH CENTERS ARE LOCATED NORTH OF THE DISCUSSION AREA IN THE VICINITY OF 37N42W THAT DOMINATE THE REMAINDER OF THE SUBTROPICAL ATLC WITH GENERALLY FAIR WEATHER. EXPECT CONVECTION ASSOCIATED WITH THE UPPER LOW AND SURFACE LOW TO GRADUALLY WEAKEN OVER THE NEXT 24 HOURS AS THESE FEATURES DISSIPATE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN