000 AXNT20 KNHC 010004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE CONTINUES OVER THE CENTRAL TROPICAL ATLANTIC EXTENDING FROM 09N41W TO 01N42W...MOVING W AT AROUND 15 KT OVER THE PAST 24 HOURS. THE WAVE IS EMBEDDED ALONG THE ITCZ WITH SSMI TPW INDICATING DEEP MOISTURE SOUTH OF 08N ALONG THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 03N TO 06N BETWEEN 40W AND 45W. A TROPICAL WAVE CONTINUES ACROSS THE SOUTHWESTERN CARIBBEAN EXTENDING FROM 14N78W TO 07N78W...MOVING W AT AROUND 15 KT OVER THE PAST 24 HOURS. THIS WAVE IS EMBEDDED IN AN ENVIRONMENT WITH STRONG DEEP LAYER SHEAR...WHICH IS INHIBITING SIGNIFICANT CONVECTION ALONG THIS WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 07N20W...WHERE THE ITCZ BEGINS AND EXTENDS THROUGH 04N30W TO 04N40W THEN RESUMES W OF A TROPICAL WAVE NEAR 04N45W TO THE COAST OF BRAZIL NEAR 02N51W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 03N TO 07N BETWEEN 28W AND 40W...AND FROM 02N TO 06N BETWEEN 45W AND 49W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW OVER ARKANSAS SUPPORTS A COLD FRONT THAT ENTERS THE NORTHWESTERN GULF NEAR 30N93W TO 28N95W TO THE TEXAS COAST NEAR 27N98W. A PRE-FRONTAL TROUGH EXTENDS FROM NEAR THE LOUISIANA COAST AT 29N91W TO NEAR THE TEXAS/MEXICO BORDER NEAR 26N97W. SCATTERED MODERATE CONVECTION IS FROM 50 NM SOUTHEAST OF THE TROUGH TO THE COLD FRONT. UPPER LEVEL DIFFLUENCE AROUND THE BASE OF AN UPPER TROUGH THAT EXTENDS ACROSS THE WESTERN GULF FROM THE UPPER LOW SUPPORTS SCATTERED THUNDERSTORMS FROM 20N TO 26N BETWEEN 88W AND 95W...INCLUDING IN THE VICINITY OF A SURFACE TROUGH THAT EXTENDS FROM 24N92W TO 19N93W OVER THE SOUTHWESTERN GULF OF MEXICO. ACROSS THE EASTERN GULF...MAINLY DAYTIME CONVECTION FROM THE SURROUNDING LAND AREAS IS BEGINNING TO AFFECT NEAR SHORE WATERS FROM LOUISIANA TO THE WEST COAST OF FLORIDA AND ALSO THE YUCATAN PENINSULA. EXPECT CONVECTION TO REMAIN LIKELY ACROSS THE WESTERN GULF TONIGHT AS THE FRONT AND PRE-FRONTAL TROUGH REMAIN OVER THE NORTHWESTERN GULF AND THE UPPER TROUGH DEEPENS OVER THE WESTERN PORTION OF THE BASIN. THIS CONVECTION WILL SHIFT FOCUS TO THE CENTRAL GULF DURING THE DAY MONDAY. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE SOUTHWESTERN CARIBBEAN. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. IN THE UPPER LEVELS...ZONAL WESTERLIES DOMINATE THE CARIBBEAN WITH A WEAK UPPER TROUGH OVER THE SOUTHWESTERN CARIBBEAN. UPPER LEVEL DIFFLUENCE BETWEEN THE WESTERLIES AND UPPER TROUGH SUPPORTS WIDELY SCATTERED MODERATE CONVECTION OVER THE WESTERN CARIBBEAN FROM 11N TO 21N BETWEEN 80W AND 89W. DAYTIME CONVECTION OVER COLOMBIA IS ENCROACHING ON THE SOUTHERN CARIBBEAN S OF 12N BETWEEN 70W AND 75W. 15 TO 25 KT TRADE WINDS COVER THE CARIBBEAN WITH THE STRONGEST WINDS OVER THE SOUTH-CENTRAL CARIBBEAN ALONG THE NORTHERN COAST OF COLOMBIA. EXPECT CONVECTION TO CONTINUE OVER THE WESTERN CARIBBEAN THROUGH MONDAY AS A TROUGH DEEPENS OVER THE WESTERN GULF...INCREASING DYNAMIC LIFT ACROSS THAT PORTION OF THE CARIBBEAN. ...HISPANIOLA... NUMEROUS THUNDERSTORMS THIS AFTERNOON ARE DECREASING IN COVERAGE WITH THE LOSS OF DAYTIME HEATING. HOWEVER...THE PRESENCE OF A SURFACE TROUGH EXTENDING FROM THE NORTHWESTERN TIP OF HAITI TO THE TURKS AND CAICOS WILL COMBINE WITH A VERY MOIST AIRMASS TO PRODUCE ONGOING SHOWERS OVERNIGHT TONIGHT. THE TROUGH WILL MOVE NORTHWEST OVER THE BAHAMAS ON MONDAY...WITH SUFFICIENT MOISTURE LINGERING BEHIND TO GENERATE SCATTERED THUNDERSTORMS ACROSS THE ISLAND...ESPECIALLY DURING THE AFTERNOON. HEAVY RAINFALL WILL BE POSSIBLE WITH SOME OF THESE THUNDERSTORMS. ATLANTIC OCEAN... A PERSISTENT 1017 MB LOW IS CENTERED NEAR 29N71W WITH A SURFACE TROUGH EXTENDING FROM 32N71W THROUGH THE LOW CENTER TO 28N71W. ISOLATED THUNDERSTORMS ARE WITHIN 160 NM OF THE LOW CENTER. A NEWLY IDENTIFIED SURFACE TROUGH EXTENDS FROM 24N70W...ACROSS THE TURKS AND CAICOS...TO HAITI NEAR 20N73W. THIS TROUGH IS INTERACTING WITH A MODERATELY MOIST AIRMASS AND FAVORABLE SOUTHWESTERLY FLOW ON THE EASTERN PERIPHERY OF AN UPPER TROUGH TO SUPPORT WIDELY SCATTERED MODERATE CONVECTION FROM 19N TO 26N BETWEEN 60W AND 73W. SCATTERED THUNDERSTORMS FROM 26N TO 31N BETWEEN 60W AND 66W ARE ASSOCIATED WITH AN UPPER LOW JUST NORTH OF OUR AREA OF DISCUSSION. A 1032 MB HIGH CENTERED OVER THE NORTH CENTRAL ATLC SUPPORTS GENERALLY FAIR WEATHER ACROSS THE CENTRAL AND EASTERN SUBTROPICAL ATLC EAST OF 60W. CONVECTION WILL CONTINUE IN THE VICINITY OF THE SURFACE TROUGH AS IT MOVES OVER THE SOUTHERN BAHAMAS ON MONDAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO