000 AXNT20 KNHC 281803 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAY 28 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS OVER THE EASTERN TROPICAL ATLC WITH AXIS ALONG 28W...JUST IN THE WESTERN PERIPHERY OF A SAHARAN DUST OUTBREAK NOTED ON METEOSAT PSEUDO NATURAL COLOR IMAGERY. THE SOUTHERN PORTION OF THE WAVE IS EMBEDDED WITHIN THE ITCZ AXIS MOIST ENVIRONMENT WHERE SCATTERED MODERATE CONVECTION IS OBSERVED FROM 1N-4N BETWEEN 25W-33W. THE REMAINDER WAVE ENVIRONMENT IS DEVOID OF CONVECTION DUE TO THE PRESENCE OF DEEP LAYER DRY AIR. A SECOND TROPICAL WAVE IS EMBEDDED WITHIN THE ITCZ WITH AXIS NEAR 40W/41W...MOVING W ABOUT 15 KT DURING THE LAST 24 HOURS. EVEN THAT THE WAVE SIGNAL IN MODEL GUIDANCE IS VERY SUBTLE AT 700 HPA...AN INVERTED-V CLOUD PATTERN ASSOCIATED WITH THIS WAVE IS DISCERNIBLE ON SATELLITE IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 1N-5N W OF 39W. A TROPICAL WAVE IS MOVING ACROSS THE SOUTHERN CARIBBEAN BASIN WITH AXIS EXTENDING FROM 13N66W TO INLAND VENEZUELA NEAR 6N68W. THE WAVE LIES JUST IN A CONFLUENCE ZONE IN THE MIDDLE TO UPPER LEVELS AND HAS BEEN MOVING W NEAR 20 KT DURING THE LAST 24 HOURS. STRONG SW DEEP LAYER WIND SHEAR OVER THE EASTERN CARIBBEAN IS LIMITING THE CONVECTION TO SCATTERED/ISOLATED SHOWERS WITHIN 200 NM OF THE WAVE AXIS. A TROPICAL WAVE IS OVER THE SW CARIBBEAN BASIN WITH AXIS ALONG 76W. THE WAVE HAS BEEN MOVING NEAR 15 KT DURING THE LAST 24 HOURS. ISOLATED SHOWERS ARE S OF 10N WITHIN 20 NM EITHER SIDE OF THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 6N10W TO 3N17W WHERE THE ITCZ AXIS CONTINUES ALONG 3N25W. THE ITCZ RESUMES W OF A TROPICAL WAVE FROM 2N30W TO 3N39W...THEN AGAIN W OF A SECOND TROPICAL WAVE FROM 2N42W TO 1N49W. SCATTERED MODERATE CONVECTION IS FROM 0N-5N E OF 16W...FROM 1N-4N BETWEEN 24W- 32W AND FROM 1N-5N W OF 39W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW ON THE BORDER BETWEEN THE SOUTHERN PLAINS AND THE LOWER MISSISSIPPI IS SUPPORTING A 1011 MB LOW OVER SOUTHERN LOUISIANA AND A SQUALL LINE EXTENDING FROM SOUTHERN MISSISSIPPI SW TO 29N92W TO 28N96W. HEAVY SHOWERS AND TSTMS ARE OVER THE NW GULF N OF 27N W OF 91W. THIS CONVECTION IS BEING FUELED BY MOISTURE BEING ADVECTED FROM THE CARIBBEAN AND WESTERN ATLC BY SE WIND FLOW. THE MIDDLE LEVEL LOW EXTENDS A TROUGH TO THE WESTERN GULF TO SUPPORT A SURFACE TROUGH OVER THE BAY OF CAMPECHE ALONG 22N94W TO 17N93W...HOWEVER THERE IS NO CONVECTION ASSOCIATED WITH IT. THE AZORES HIGH EXTENDS A RIDGE AXIS SW TO COVER THE EASTERN GULF...THUS SUPPORTING RETURN FLOW OF 10-15 KT ACROSS THE BASIN. OTHERWISE...DIFFLUENCE ALOFT NEAR THE STRAITS REGION IS SUPPORTING SCATTERED/ISOLATED HEAVY SHOWERS AND TSTMS ACROSS PORTIONS OF SOUTHERN FLORIDA AND ADJACENT WATERS. RAINSHOWERS ARE EXPECTED TO CONTINUE TO AFFECT THE NORTHER GULF WITHIN THE NEXT DAY OR TWO. CARIBBEAN SEA... MIDDLE TO UPPER LEVEL RIDGING COVERS THE FAR WESTERN AND EASTERN CARIBBEAN WHILE A SHORT WAVE TROUGH DOMINATES ACROSS THE CENTRAL BASIN. TWO TROPICAL WAVES ARE MOVING ACROSS THE SOUTHERN CARIBBEAN WATERS...SEE THE WAVES SECTION ABOVE. DEEP LAYER MOISTURE ACROSS CUBA ALONG WITH DIFFLUENCE ALOFT IS SUPPORTING SCATTERED/ISOLATED HEAVY SHOWERS AND TSTMS OVER CUBA AND ADJACENT WATERS. LIGHTING DATA INDICATE ISOLATED TSTMS OVER HISPANIOLA AS WELL. A MIDDLE TO UPPER LEVEL CONFLUENCE ZONE IS OVER THE EASTERN CARIBBEAN WHERE DEEP LAYER MOISTURE IS NOTED...THIS IS SUPPORTING A SWATH OF SCATTERED/ISOLATED MODERATE CONVECTION E OF A LINE FROM 18N67W TO 11N74W. A NEW TROPICAL WAVE IS EXPECTED TO ENTER THE EASTERN CARIBBEAN FRIDAY NIGHT SUPPORTING MORE SHOWERS FOR THIS REGION. ...HISPANIOLA... A SHORT WAVE MIDDLE TO UPPER LEVEL TROUGH IS OVER THE CENTRAL CARIBBEAN WITH ASSOCIATED MOISTURE REMAINING MINIMAL ACROSS THE ISLAND TO SUPPORT ONLY ISOLATED SHOWERS AND TSTMS. OTHERWISE...LITTLE CHANGE IS EXPECTED THROUGH WED. DEEP MOISTURE OVER THE EASTERN CARIBBEAN AHEAD OF THE TROUGH...AND ALSO ASSOCIATED WITH THE TROPICAL WAVE IN THAT AREA AS DESCRIBED ABOVE MAY APPROACH THE SE PART OF THE ISLAND LATE WED. ATLANTIC OCEAN... A NARROW UPPER LEVEL RIDGE OVER THE FAR SW N ATLC IS JUST N OF THE SHORT WAVE TROUGH COVERING THE CENTRAL CARIBBEAN THUS GENERATING DIFFLUENT FLOW ALOFT TO SUPPORT SCATTERED/ISOLATED HEAVY SHOWERS AND TSTMS OVER THE STRAITS OF FLORIDA AND THE GREAT BAHAMAS BANK. FARTHER EAST...A CONFLUENCE ZONE BETWEEN A NARROW TROUGH ALOFT BETWEEN 60W-70W AND A BROAD RIDGE COVERING THE CENTRAL ATLC SUPPORTS SCATTERED MODERATE CONVECTION S OF 30N BETWEEN 40W-66W. OTHERWISE...BESIDES THE TROPICAL WAVES ALREADY DISCUSSED...THE AZORES HIGH EXTENDS A RIDGE ACROSS THE BASIN N OF 11N THUS SUPPORTING FAIR WEATHER ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR