000 AXNT20 KNHC 121157 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN JUN 12 2011 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 1115 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 38W S OF 10N MOVING W AT 10 KT. THIS WAVE IS SUBTLE AND NOT WELL DEFINED IN THE OBSERVATIONS OR IN THE TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE...HOWEVER...CAN BE IDENTIFIED IN THE GFS AND ECMWF MODEL ANALYSES AND IT IS ALSO ASSOCIATED WITH ENHANCED CONVECTION ALONG THE ITCZ. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM OF THE WAVE AXIS BETWEEN 4N AND 8N. TROPICAL WAVE EXTENDS FROM 16N46W TO 4N49W MOVING WNW 10-12 KT. THE SYSTEM SHOWS A CLASSIC INVERTED-V STRUCTURE IN THE SHORT-WAVE INFRARED IMAGERY. THE TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES A WELL-DEFINED MAXIMUM OF MOISTURE ON THE EASTERN FLANK OF THE WAVE AXIS. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THIS TROPICAL WAVE AT THIS TIME. TROPICAL WAVE IS ALONG 80W S OF 12N MOVING W AT 10 KT. THIS WAVE WAS NEWLY INTRODUCED BASED UPON PANAMA RAWINSONDE TIME SERIES...SATELLITE HOVMOLLER DIAGRAMS...AND GFS-ECMWF MODEL DIAGNOSTICS. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 240 NM W OF AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM INLAND WEST AFRICA AT 16N00W TO 15N10W TO THE COAST AT 14N16W TO 6N21W. THE ITCZ THEN CONTINUES FROM THERE TO 4N30W TO SOUTH AMERICA AT 7N58W. A SEPARATE MONSOON TROUGH EXTENDS FROM THE EAST COAST OF COSTA RICA AT 10N83W EASTWARD INTO THE SW CARIBBEAN AND INTO COLUMBIA AT 10N76W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE ITCZ AXIS BETWEEN 30W AND 40W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE MONSOON TROUGH AXIS FROM COSTA RICA TO 80W. ...DISCUSSION... GULF OF MEXICO... A 1015 MB HIGH IS CENTERED OVER THE N GULF OF MEXICO AT 29N88W...WHICH IS HELPING TO PRODUCE GENERALLY FAIR WEATHER WITH LIGHT WINDS AND VERY LITTLE CLOUDINESS. THE ONLY SIGNIFICANT RAINFALL IS SOME SHOWERS AND THUNDERSTORMS JUST OFF OF THE COAST OF WEST CENTRAL FLORIDA AND IN THE STRAITS OF FLORIDA. THE SHOWERS IN THE STRAITS OF FLORIDA ARE ASSOCIATED WITH A SURFACE TROUGH THAT BEGINS NORTH OF THE BAHAMAS...GOES THROUGH THE FLORIDA STRAITS...TO CUBA...AND OVER THE YUCATAN PENINSULA. IN THE UPPER LEVELS...NE TO SW ORIENTED TROUGHING IS SEEN ACROSS THE GULF OF MEXICO AND STRONG SUBSIDENCE COVERS THE AREA. LITTLE CHANGE IN THE THESE CONDITIONS ARE ANTICIPATED DURING THE NEXT DAY. CARIBBEAN SEA... THE AFOREMENTIONED SURFACE TROUGH EXTENDS SOUTHWESTWARD TO THE YUCATAN PENINSULA OF MEXICO AND GUATEMALA AT 17N91W. DEEP CONVECTION HAS DIMINISHED DURING THE EVENING...BUT SHOWERS CONTINUE OVER THE YUCATAN...BELIZE...AND GUATEMALA. AS MENTIONED ABOVE...A MONSOON TROUGH EXTENDS INTO THE SW CARIBBEAN AND IS ASSOCIATED WITH CONVECTION OVER COSTA RICA AND PANAMA. SHOWERS ARE ALSO OCCURRING OVER WESTERN CUBA AS SEEN FROM THE CASABLANCA RADAR IN ASSOCIATION WITH THE SURFACE TROUGH. A MODERATE SURFACE PRESSURE GRADIENT IS PRODUCING EASTERLY WINDS ACROSS THE CARIBBEAN OF GENERALLY 10 TO 20 KT...THOUGH NORTH OF NE COLUMBIA THE TRADEWINDS REACH UP TO 25 KT. IN THE UPPER LEVELS...AN UPPER HIGH IS CENTERED OVER HISPANIOLA AND IS PROMOTING GENERALLY FAIR WEATHER ACROSS MOST OF THE CARIBBEAN. A SUBTROPICAL JET OF SW WINDS TO 50 KT OCCURS OVER THE NW CARIBBEAN AND IS A RESULT OF THE UPPER HIGH AND THE UPPER TROUGH OVER THE GULF OF MEXICO. LITTLE CHANGE IN THE WINDS ARE EXPECTED DURING THE NEXT DAY...WITH LIKELY LESS RAIN OVER CUBA BUT CONTINUED RAINFALL OVER CENTRAL AMERICA. ATLANTIC OCEAN... A 1010 MB LOW IS CENTERED N OF THE BAHAMAS AT 27N78W. A SURFACE TROUGH EXTENDS FROM 31N71W TO THE LOW CENTER TO THE STRAITS OF FLORIDA AND CONTINUES TO THE CARIBBEAN. DEEP CONVECTION HAS CEASED OVER THE BAHAMAS THIS EVENING...BUT SHOWERS LIKELY HAVE BEEN CONTINUING FOR THE NORTHERN AND CENTRAL BAHAMAS. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 23N-28N BETWEEN 66W-71W. A DISSIPATING COLD FRONT IS OVER THE CENTRAL ATLANTIC FROM 32N38W TO 27N43W. ISOLATED MODERATE CONVECTION IS FROM 20N-24N BETWEEN 46W-55W IN ASSOCIATION WITH A WEAK 1013 MB SURFACE LOW AT 23N57W WITH A TRAILING TROUGH TO ITS SOUTHWEST TO 18N60W AND ANOTHER TROUGH TO ITS EAST TO 23N49W. A 1024 MB HIGH IS OVER THE E ATLANTIC NEAR 31N26W PRODUCING FAIR WEATHER. ALL OF THE ATLANTIC OCEAN IN OUR AREA OF RESPONSIBILITY HAS WINDS 20 KT OR LESS. MOST OF THE REGION WILL SEE LITTLE CHANGE IN THE NEXT DAY...THOUGH THE BAHAMAS WILL LIKELY HAVE LESS RAIN AS THE LOW N OF THE BAHAMAS PULLS NORTHWARD AND WEAKENS. F0R ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LANDSEA