000 AXNT20 KNHC 280551 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUL 28 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 20W S OF 20N MOVING W NEAR 20 KT. THIS WAVE COINCIDES WITH A BROAD MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. W OF THE WAVE AXIS A 1010 MB SURFACE LOW...LIKELY THE NORTHERN VORTICITY MAXIMUM ASSOCIATED WITH THE TROPICAL WAVE...IS CENTERED N OF THE CAPE VERDE ISLANDS NEAR 18N24W. WHILE THE SURFACE LOW ASSOCIATED WITH THE WAVE LACKS ANY SIGNIFICANT DEEP CONVECTION DUE TO THE PRESENCE OF SAHARAN DUST...SCATTERED SHOWERS ARE WITHIN 300 NM EITHER SIDE OF THE WAVE AXIS. A TROPICAL WAVE IS ALONG 47W S OF 16N MOVING W NEAR 18 KT. THIS WAVE COINCIDES WITH A BROAD MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. ALSO...AN EARLIER SCATTEROMETER PASS AROUND 27/2100 UTC DEPICTED CYCLONIC CURVATURE IN THE LOW-LEVELS NEAR THE WAVE AXIS. SCATTERED SHOWERS ARE FROM 9N-15N BETWEEN 42W-50W. A TROPICAL WAVE IS ALONG 72W S OF 20N MOVING W NEAR 25 KT. THIS WAVE COINCIDES WITH A WELL-DEFINED MAXIMUM IN DEEP LAYER MOISTURE ACROSS THE CENTRAL CARIBBEAN BASED ON THE TPW IMAGERY FROM CIMSS. SATELLITE IMAGERY INDICATES AN INVERTED-V PATTERN IN THE COVERAGE OF LOW LEVEL CLOUDS NEAR THIS WAVE. DRY AND STABLE ATMOSPHERIC CONDITIONS ASSOCIATED WITH AN UPPER LEVEL RIDGE ARE INHIBITING DEEP CONVECTION NEAR THIS WAVE. HOWEVER...SCATTERED SHOWERS ARE FROM 15N-19N BETWEEN 64W-70W...INCLUDING THE MONA PASSAGE...PUERTO RICO AND NEARBY ADJACENT COASTAL WATERS. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N16W 10N45W 10N49W 9N60W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF A LINE FROM 12N22W TO 7N40W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS OVER THE ERN GULF WITH AN AXIS EXTENDING ACROSS THE BIG BEND REGION OF FLORIDA TO 24N90W AND CONTINUING WWD TO AN UPPER LEVEL LOW NEAR 23N95W. ATMOSPHERIC LIFT IN MOIST SWLY FLOW ALOFT AND ATMOSPHERIC INSTABILITY TO THE E OF THE UPPER LEVEL TROUGH AXIS ARE SUPPORTING ISOLATED SHOWERS OVER THE SE GULF S OF 26N E OF 90W. ADDITIONALLY...THE UPPER LEVEL LOW ACROSS THE SW GULF IS GENERATING SCATTERED SHOWERS S OF 26N BETWEEN 90W-97W. ACROSS THE NRN GULF WATERS...UPPER LEVEL MOISTURE STREAMING SOUTHWARD W OF THE UPPER LEVEL TROUGH IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE N/CENTRAL GULF N OF 28N BETWEEN 86W-92W. SELY WINDS ARE FORECAST TO INCREASE OVER THE W GULF BY TUESDAY...AS A SURFACE RIDGE ACROSS THE N GULF MOVES NWD DURING THE NEXT FEW DAYS AND SURFACE LOW PRESSURE DEVELOPS OVER W TEXAS. CARIBBEAN SEA... AN UPPER LEVEL HIGH OVER THE NW CARIBBEAN IS CENTERED NEAR 21N84W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS UPPER LEVEL RIDGE IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 20N-22N BETWEEN 78W-85W. ACROSS THE SW CARIBBEAN...UPPER LEVEL RIDGING EXTENDS FROM THE E PACIFIC REGION AND IS LIMITING ISOLATED SHOWERS AND TSTMS S OF 9N ACROSS NW COLOMBIA AND FAR ERN PANAMA. ACROSS MUCH OF THE CENTRAL AND E CARIBBEAN...DEEP LAYER DRY IS SUPPORTING GENERALLY FAIR WEATHER. HOWEVER... CONVERGENT LOW-LEVEL ELY WINDS E OF THE TROPICAL WAVE ALONG 72W AND UPPER LEVEL DIFFLUENCE ASSOCIATED TO THE SW OF AN UPPER LEVEL RIDGE OVER THE CENTRAL ATLC IS SUPPORTING SCATTERED SHOWERS FROM 15N-19N BETWEEN 64W-70W ACROSS THE NE CARIBBEAN AND PORTIONS OF PUERTO RICO AND ADJACENT COASTAL WATERS. FRESH TO STRONG TRADE WINDS ARE OCCURRING ACROSS THE E AND CENTRAL CARIBBEAN S OF A SURFACE RIDGE OVER THE CENTRAL ATLC. THE STRONGEST WINDS ARE FOUND NEAR THE COAST OF COLOMBIA...WHERE E WINDS OF 25 TO 30 KT ARE OCCURRING. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS PRESENT OVER THE ERN U.S. AND ALONG THE ERN SEABOARD EXTENDING ACROSS NRN FLORIDA AND THE NE GULF OF MEXICO. ATMOSPHERIC LIFT IN MOIST SWLY FLOW ALOFT BETWEEN THIS UPPER LEVEL TROUGH AND AN UPPER LEVEL RIDGE FARTHER TO THE E OVER THE SW NORTH ATLC IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 23N BETWEEN 73W-79W INCLUDING PORTIONS OF THE NW BAHAMAS. TO THE E...AN UPPER LEVEL LOW IS CENTERED NEAR 31N56W. ATMOSPHERIC INSTABILITY IN THE VICINITY OF THIS UPPER LEVEL LOW...AND UPPER LEVEL DIFFLUENCE LOCATED E OF THE LOW...ARE SUPPORTING ISOLATED SHOWERS FROM 28N-32N BETWEEN 51W-58W. THE REMAINDER OF THE CENTRAL AND ERN ATLC ARE DOMINATED BY A SURFACE RIDGE ANCHORED ON A 1028 MB HIGH CENTERED NEAR 34N55W THAT IS PROVIDING GENERALLY FAIR WEATHER N OF 20N E OF 73W. $$ HUFFMAN