000 AXNT20 KNHC 112356 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUN 11 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 2345 UTC. ...TROPICAL WAVES... A LARGE TROPICAL WAVE IS ALONG 382/39W FROM 6N TO 20N MOVING QUICKLY WNW NEAR 25 KT. WHILE THIS WAVE STILL HAS AN IMPRESSIVE SHIELD OF LOW CLOUDS...WHICH HAS MADE TRACKING IT EASY SINCE EMERGING OFF THE W COAST OF AFRICA 2 DAYS AGO...IT LACKS ANY DEEP SHOWER OR TSTM ACTIVITY. A TROPICAL WAVE ALONG 47W S OF 11N MOVING W 10-15 KT. WAVE IS NOTED BY MID-LEVEL TURNING AND A WEAK INVERTED V-SHAPE SEEN ON SATELLITE IMAGES. 24 HOUR LOOP OF THESE SATELLITE IMAGERY INDICATES CLEAR WWD CONTINUITY OF THIS STRUCTURE. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 120-150 NM EITHER SIDE OF THE WAVE AXIS. A TROPICAL WAVE IS IN THE CENTRAL CARIB ALONG 74W/75W S OF 17N MOVING W 10-15 KT. THERE IS A BROAD AREA OF LOW LEVEL TURNING IN THE VICINITY OF THE WAVE...HOWEVER THIS IS LIKELY ASSOCIATED WITH CLIMATOLOGICAL FLOW AROUND THE OROGRAPHY OF NORTHERN S AMERICA. LITTLE IN THE WAY OF CONVECTION IS ASSOCIATED WITH THIS FEATURE. A TROPICAL WAVE WHICH WAS IN THE WESTERN CARIB ALONG 84W EARLIER HAS BEEN ADJUSTED WWD TO ALONG 89W/90W AND IS NOW W OF THE DISCUSSION AREA. NONETHELESS THE INTERACTION BETWEEN THIS WAVE...OR SOME ASSOCIATED ENERGY THAT BROKE OFF OVER THE NW CARIBBEAN...AND PRONOUNCED UPPER DIFFLUENCE E OF AN UPPER LOW OVER THE YUCATAN CHANNEL IS FUELING SCATTERED MODERATE CONVECTION FROM 15N-20N BETWEEN 75W-82W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 6N20W 5N26W 6N35W 6N45W 4N52W. EXCEPT AS NOTED ABOVE ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE AXIS E OF 17W...AND WITHIN 60-90 NM EITHER SIDE OF THE AXIS BETWEEN 26W-28W...AND BETWEEN 39W-47W. ...DISCUSSION... THE GULF OF MEXICO... MUCH OF THE GULF IS IN A N-NELY UPPER FLOW REGIME BETWEEN RIDGE/ANTICYCLONE CENTERED OVER THE RIO GRANDE VALLEY/S TEXAS NEAR 28N98W AND AN UPPER LOW NEAR THE YUCATAN CHANNEL. CONFLUENCE BETWEEN THE 2 FEATURES HAS MANIFESTED ITSELF IN A BROAD AREA OF MID TO UPPER LEVEL SUBSIDENCE/SINKING AIR WHICH IS PROVIDING A STABLE AIRMASS ALLOWING FOR FAIR SKIES OVER THE GULF. VERY WEAK SFC PRES PATTERN IS NOTED WITH A 1013 MB FRONTAL LOW OVER THE FLA PANHANDLE NEAR TALLAHASSEE AND A 1016 MB HIGH CENTER NEAR 27N90W. ADDITIONALLY...A WEAK SFC TROUGH IS ANALYZED ALONG 90W/91W S OF 25N. NET EFFECT IS LIGHT AND AND VARIABLE WINDS OVER MUCH OF THE GULF. THE LOW OVER FLORIDA AND ASSOCIATED FRONTAL BOUNDARIES ARE RATHER ILL DEFINED AND NOTED ONLY BY A WEAK WIND SHIFT AND SLIGHTLY LOWER PRESSURES. THE SFC TROUGH IS SOMEWHAT BETTER DEFINED WITH BROAD LOW-LEVEL TURNING...EVIDENT IN BUOY AND VISIBLE SATELLITE IMAGERY. SEABREEZE CONVERGENCE OVER THE YUCATAN PENINSULA HAS RESULTED IN STRONG TSTMS ALONG THE COAST FROM PROGRESO TO CAMPECHE. OVERALL WEAK PATTERN IS EXPECTED TO PERSIST THRU MID-WEEK THUS ENSURING LIGHT WINDS. LIGHT WINDS HAVE ALREADY ALLOWED SEA SURFACE TEMPERATURES TO RISE WITH SEVERAL NOAA BUOYS ALONG 28N REPORTING TEMPERATURES OF 83-85F...28-29C. THE CARIBBEAN SEA... SCATTERED MODERATE CONVECTION IN THE NW CARIB FROM 15N-20N BETWEEN 75W-82W IS THE ACTIVE REGION IN THIS BASIN TODAY. THIS ACTIVITY IS ASSOCIATED WITH DIFFLUENCE ALOFT TO THE E OF A FAIRLY VIGOROUS UPPER LOW SPINNING OVER THE YUCATAN CHANNEL. AIDING IN CONVECTIVE INITIATION IS SOME LOW-LEVEL LIFT FROM A TROPICAL WAVE...OR MORE LIKELY ENERGY THAT BROKE OFF FROM THE MAIN SYSTEM. ELSEWHERE...A PATCH OF WEAKENING SHOWERS LIES JUST TO THE E OF THE LESSER ANTILLES FROM 13N-18N BETWEEN 57W-61W. SIMILARLY...THIS MOISTURE IS ASSOCIATED WITH UPPER DIFFLUENCE BETWEEN AN UPPER RIDGE PARKED OVER THE CENTRAL CARIB NEAR 14N71W AND TROUGHING TO THE NE OF THE AREA. THE REMAINDER OF THE CARIB WATERS IS FREE OF DEEP MOISTURE...ALTHOUGH TYPICAL TRADE WIND SHOWERS ARE POSSIBLE AT ANY GIVEN LOCATION. THE ATLANTIC OCEAN... THE WRN PART OF THE DISCUSSION AREA LIES TO THE S OF A LARGE AND PERSISTENT OCCLUDED LOW PRES SYSTEM ABOUT 250 NM S OF NOVA SCOTIA. BROAD UPPER TROUGHING EXTENDS INTO THE AREA ALONG 65W N OF 24N WITH A LARGE AREA OF BROKEN TO OVERCAST CIRRUS WITH TRANSVERSE BANDING NOTED. THIS CIRRUS SHIELD IS ESSENTIALLY S OF AN UPPER JET AXIS SLICING INTO THE NW ATLC JUST N OF THE AREA. AN ASSOCIATED COLD FRONT IS ANALYZED TO THE E OF BERMUDA ALONG 32N62W 28N72W...WHICH BECOMES STATIONARY TO THE FLORIDA/GEORGIA BORDER. THE ONLY AREA OF SIGNIFICANT DEEP CONVECTION EXTENDS FROM 22N-25N BETWEEN 66W-71W. FARTHER E...WV IMAGERY SHOWS AN UPPER HIGH CENTERED NEAR 23N54W AND MUCH MORE EXTENSIVE RIDGING STRETCHING W FROM AFRICA ALONG 22N TO ABOUT 35W. A SHEARED UPPER TROUGH LIES BETWEEN THESE RIDGES EXTENDING FROM 32N34W TO AN UPPER LOW NEAR 22N46W CONTINUING TO 17N51W. AN ASSOCIATED DISSIPATING COLD FRONT ENTERS THE AREA NEAR 32N21W AND EXTENDS WWD ALONG 29N30W TO 31N35W. UPPER DIFFLUENCE IS PRODUCING PATCHES OF SCATTERED SHOWERS WITHIN 90-120 NM E OF THE UPPER LOW. ELSEWHERE....HIGH PRES DOMINATED THE AREA ANCHORED BY A 1027 MB CENTER NEAR 33N40W. THIS HIGH IS AIDING IN THE MOSTLY FAIR WEATHER AND PRODUCING A LARGE AREA OF MODERATE TRADES ACROSS THE TROPICAL ATLC...ESPECIALLY BETWEEN THE HIGH AND THE LARGE TROPICAL WAVE NOTED ALONG 38W/39W. $$ COBB