000 AXNT20 KNHC 192355 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUN 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 44W S OF 8N MOVING W NEAR 10 KT. THIS LOW AMPLITUDE WAVE REMAINS EMBEDDED WITHIN THE ITCZ AND SLIGHT CYCLONIC CURVATURE IS NOTED IN THE LOW-LEVEL CLOUD FIELD ALONG THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 5N-8N BETWEEN 42W-46W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N13W 6N30W 6N42W 5N46W AND INTO NE BRAZIL NEAR 4N52W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS OVER INTERIOR W AFRICA FROM 3N-15N BETWEEN 7W-13W. ISOLATED MODERATE CONVECTION IS FROM 4N-10N BETWEEN 16W-29W. ...DISCUSSION... GULF OF MEXICO... THE GULF REMAINS LARGELY UNDER THE AFFECTS OF TWO MAIN SYNOPTIC FEATURES...ONE ALOFT AND ONE AT THE SURFACE. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER NW LOUISIANA AND IS PROVIDING THE GULF WITH MOSTLY E-NE FLOW ALOFT. AT THE SURFACE...A 1017 MB HIGH IS CENTERED NEAR 28N90W AND REMAINS NEARLY STATIONARY. THESE TWO FEATURES ARE KEEPING FAIR CONDITIONS AND LIGHT WINDS ACROSS MUCH OF THE GULF WITH THE ONLY EXCEPTION BEING SELY WINDS TO 15 KT ACROSS THE FAR WRN GULF W OF 95W. AN ELONGATED UPPER LEVEL LOW CENTERED IN THE NW CARIBBEAN NEAR 20N85W IS GENERATING A FEW SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS CUBA...THE YUCATAN PENINSULA AND PORTIONS OF THE BAY OF CAMPECHE S OF 21N. THIS ACTIVITY SPREADS S OF 21N ACROSS SRN MEXICO...GUATEMALA AND BELIZE. LOOKING AHEAD...THE SURFACE HIGH IS FORECAST TO REMAIN ACROSS THE N/CENTRAL GULF THROUGH LATE SATURDAY GRADUALLY WEAKENING AS A COLD FRONT WILL BEGIN TO IMPACT THE NE GULF WATERS BY SUNDAY. CARIBBEAN SEA... AN UPPER LEVEL LOW IN THE NW CARIBBEAN CENTERED NEAR 20N85W IS SUPPORTING SCATTERED SHOWERS AND TSTMS ACROSS MAINLAND CUBA AND THE YUCATAN PENINSULA THIS EVENING. AN UPPER LEVEL DIFFLUENT PATTERN IS EVIDENT ON WATER VAPOR IMAGERY ACROSS THE REMAINDER OF THE WRN CARIBBEAN S OF 20N W OF 77W...INCLUDING THE GULF OF HONDURAS AND MUCH OF INTERIOR CENTRAL AMERICA WITH SCATTERED SHOWERS AND TSTMS W OF A LINE FROM THE GUAJIRA PENINSULA OF NRN COLOMBIA TO THE NERN TIP OF THE YUCATAN PENINSULA. THE MOST INTENSE SHOWER AND TSTM ACTIVITY IS LOCATED OVER THE SW CARIBBEAN S OF 16N W OF 77W AS THE ITCZ AXIS IS ANALYZED ACROSS PANAMA AND SRN COSTA RICA. UPPER LEVEL TROUGHING CONTROLS THE CENTRAL CARIBBEAN BETWEEN 67W-75W WITH MOIST SWLY UPPER LEVEL FLOW E OF THE UPPER TROUGH AXIS. LOW-LEVEL INSTABILITY E OF 67W ACROSS THE ERN CARIBBEAN IS GENERATING MIDDLE TO HIGH LEVEL CLOUDINESS WITH ISOLATED SHOWERS BEING USHERED IN ACROSS THE LESSER ANTILLES...THE VIRGIN ISLANDS AND PUERTO RICO ON MODERATE TO FRESH TRADE WINDS. ATLANTIC OCEAN... A DEEP LAYER CENTRAL ATLC TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N48W AND EXTENDS SW TO 31N51W CONTINUING AS A STATIONARY FRONT ALONG 31N60W AND INTO A 1013 MB LOW NEAR 32N65W. SCATTERED SHOWERS AND ISOLATED TSTMS ACCOMPANY THE LOW CENTER AND STATIONARY FRONT FROM 27N TO BEYOND 32N BETWEEN 55W-70W. THIS ACTIVITY IS FURTHER SUPPORTED BY UPPER LEVEL DIFFLUENCE E OF A SHORTWAVE TROUGH AXIS ALONG 32N67W TO 28N75W. THIS MIDDLE TO UPPER LEVEL TROUGHING IS SUPPORTING A WEAKNESS IN THE W ATLC SURFACE RIDGE THAT STRETCHES FROM BERMUDA ACROSS THE NW BAHAMAS TO NEAR BISCAYNE BAY AND IS GENERATING ISOLATED SHOWERS FROM 23N-28N BETWEEN 70W-79W. THE MAJORITY OF THE CENTRAL AND E ATLC ARE UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE PROVIDING NE TO ELY TRADES. HOWEVER...A DEEP LAYER LOW OVER THE NE ATLC IS ASSOCIATED WITH A 1016 MB SURFACE LOW W OF THE MADEIRA ISLANDS NEAR 32N19W. SCATTERED SHOWERS ASSOCIATED WITH THE SURFACE LOW REMAIN N OF THE DISCUSSION AREA. $$ HUFFMAN