000 AXNT20 KNHC 211748 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUN 21 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC IS ANALYZED ALONG 47W S OF 14N MOVING W NEAR 10 KT. THE WAVE COINCIDES WITH A SURGE OF MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SOME INVERTED V LOW LEVEL SIGNATURE IS ALSO NOTED ON VISIBLE SATELLITE IMAGERY WITH SOME SHOWER ACTIVITY EITHER SIDE OF THE WAVE AXIS. AN EARLIER WINDSAT PASS SHOWED NE WINDS OF 20-25 KT AHEAD OF THE WAVE. MOISTURE FROM THIS TROPICAL WAVE WILL REACH THE N TROPICAL ATLC EARLY WED. THIS WAVE WILL MOVE INTO THE E CARIBBEAN EARLY THU. TROPICAL WAVE IS INLAND OVER WESTERN VENEZUELA ALONG 70W S OF 13N MOVING W NEAR 10 KT. THE WAVE IS AFFECTING THE ABC ISLANDS. A FEW SHOWERS ARE SEEN OVER THE COASTAL WATERS OF THOSE ISLANDS. THIS WAVE WILL BECOME ABSORBED INTO THE EASTERN EXTENT OF THE MONSOON TROUGH OVER THE SW CARIBBEAN ONCE IT MOVES OFF THE WESTERN COAST OF S AMERICA TONIGHT. BASED ON THE HOVMOLLER DIAGRAM AND VISIBLE SATELLITE IMAGERY... A THIRD TROPICAL WAVE IS JUST MOVING OUT OF AFRICA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA CROSSING THE PRIME MERIDIAN AT 19N THEN ALONG 20N10W INTO THE E TROPICAL ATLC NEAR 14N17W TO 10N20W WHERE THE ITCZ AXIS CONTINUES ALONG 7N30W 6N40W TO INLAND OVER SOUTH AMERICA NEAR 5N54W. A COUPLE OF CYCLONIC VORTICES ARE NOTED ALONG THE MONSOON TROUGH OVER AFRICA. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE ITCZ AXIS FROM 26W-40W. SIMILAR CONVECTION IS ALSO OBSERVED WITHIN 60-70 NM EITHER SIDE OF THE MONSOON TROUGH E OF 21W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE COVERS THE GULF ANCHORED ALONG THE SW COAST OF MEXICO ASSOCIATED WITH HURRICANE BEATRIZ. THE AXIS OF THIS RIDGE EXTENDS NE FROM NEAR TAMPICO TO THE FLORIDA BIG BEND. HIGH CLOUDS ASSOCIATED WITH BEATRIZ'S OUTFLOW ARE OVER THE SW PORTION OF THE GULF. A FEW SHOWERS ARE CURRENTLY AFFECTING THE CENTRAL GULF LIKELY ASSOCIATED WITH A DIFFLUENT PATTERN ALOFT. DRY STABLE AIR ALOFT IS OBSERVED ACROSS THE GULF ON WATER VAPOR IMAGERY. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS FLORIDA INTO THE EASTERN HALF OF THE GULF REGION. PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER TEXAS AND NE MEXICO IS RESULTING IN SLY RETURN FLOW IN THE 20-25 KT RANGE ACROSS THE WESTERN HALF OF THE AREA. THE 1240 UTC WINDSAT PASS PROVIDED OBSERVATIONS OF THESE WINDS. THE RIDGE WILL BRIEFLY MOVE N OF THE AREA TONIGHT AND WED...AND WILL REESTABLISH ITSELF ACROSS THE N GULF WED NIGHT WHERE IT WILL PREVAIL THROUGH SAT. CARIBBEAN SEA... AN UPPER LEVEL TROUGH ENTERS THE CARIBBEAN SEA THROUGH EASTERN CUBA THEN CONTINUES SW TO NEAR 16N82W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE NOTED ON THE EAST SIDE OF THIS TROUGH OVER PARTS OF E CUBA AND HISPANIOLA. AN UPPER LEVEL RIDGE EXTENDS ACROSS THE TROPICAL N ATLC INTO THE SE CARIBBEAN. UPPER DIFFLUENCE ASSOCIATED WITH THIS FEATURE IS HELPING TO INDUCE SOME SHOWER ACTIVITY OVER THE WINDWARD ISLANDS AND THE SE CARIBBEAN. A SHORT WAVE TROUGH IS ALSO NOTED OVER THE VIRGIN ISLANDS AND THE NE CARIBBEAN. THE MONSOON TROF EXTENDS ACROSS THE SW CARIBBEAN FROM THE COLOMBIAN/PANAMANIAN LOW LOCATED NEAR 11N76W TO NEAR THE PANAMA/COSTA RICA BORDER. AN AREA OF SHOWERS WITH EMBEDDED TSTMS IS OVER THE SW CARIBBEAN WITHIN 150 NM N OF THE MONSOON TROUGH FROM 79W TO 83W. THE MOST RECENT WINDSAT PASS SHOWS TRADE WINDS OF 20-25 KT ACROSS THE CENTRAL CARIBBEAN MAINLY S OF 16N. BUOYS 42O58 AND 42059 ALSO CORROBORATED THESE WIND SPEEDS WHICH ARE THE RESULT OF THE PRES GRADIENT BETWEEN HIGH N OF THE AREA AND THE LOW PRES NEAR THE COAST OF COLOMBIA. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW WILL CONTINUE TO MOVE ACROSS THE BASIN PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. ATLANTIC OCEAN... AN UPPER TROUGH IS OVER THE FAR W ATLC EXTENDING FROM 30N72W TO EASTERN CUBA. AN UPPER-LEVEL LOW IS SPINNING NEAR 29N42W. IN BETWEEN...THERE IS A RIDGE WITH AXIS EXTENDING BEYOND 31N57W. SOME SHOWER AND TSTMS ACTIVITY CAN BE FOUND AHEAD OF THE THROUGH AXIS OVER THE SE BAHAMAS AND REGIONAL WATERS...AND OVER THE SW ATLC COVERING MAINLY THE AREA FROM 22N-28N BETWEEN 66W-74W. A SURFACE RIDGE DOMINATES THE ENTIRE ATLC EXTENDING FROM A 1026 MB HIGH PRES NEAR 29N42W TO FLORIDA. THIS HIGH PRES CENTER IS FORECAST TO DISSIPATE IN ABOUT 24 HOURS. THIS RIDGE IS GIVING THE REMAINDER OF THE ATLC MAINLY FAIR CONDITIONS. AS PREVIOUSLY MENTIONED...AN E/W UPPER LEVEL RIDGE EXTENDS ACROSS THE TROPICAL N ATLC ALONG 12W/13W INTO THE SE CARIBBEAN. AN UPPER LEVEL RIDGE DOMINATES THE EASTERN CARIBBEAN WITH AXIS EXTENDING N ACROSS THE CANARY/MADEIRAS ISLANDS. THE SAHARAN AIR LAYER PRODUCT FROM CIMMS SHOWS SOME OF THE USUAL SUMMERTIME AFRICAN DUST SPREADING WWD AND REACHING THE LESSER ANTILLES. BY THE WAY...TODAY MARKS THE BEGINNING OF THE SUMMER SOLSTICE IN THE NORTHERN HEMISPHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR