000 AXNT20 KNHC 100020 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT JUN 09 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 2315 UTC. ...TROPICAL WAVES... STRONG WELL DEFINED TROPICAL WAVE FOR EARLY JUNE WHICH WAS ADDED TO THE 12Z SFC ANALYSIS IS CURRENTLY ALONG 16W S OF 15N. THE LAST VISIBLE SATELLITE IMAGES AND A 1942 UTC QUIKSCAT PASS SUGGESTS A LOW PRES CENTER ALONG THE WAVE AXIS AT 8N WITH AN ESTIMATED CENTRAL PRESSURE OF 1009 MB. IN ADDITION...SURFACE OBSERVATIONS FROM SENEGAL AND GUINEA INDICATE A SECOND LOW CENTER...1008 MB AT THE NORTHERN END OF THE WAVE NEAR DAKAR. BASED ON THE LAST 6-12 HOURS OF MOTION THE WAVE APPEARS TO BE MOVING W NEAR 20 KT. THE WAVE CONSISTS OF WELL DEFINED LOW TO MID LEVEL CYCLONIC TURNING WITH SCATTERED MODERATE ISOLATED STRONG BANDED DEEP CONVECTION MAINTAINING ITSELF NEAR THE ESTIMATED LOW LEVEL CENTER. A WEAK LOW AMPLITUDE TROPICAL WAVE IS ALONG 39W S OF 10N MOVING W 10-15 KT. THIS WAVE IS NOT DISCERNIBLE IN OBS OR SAT IMAGES...THEREFORE THE PSN REMAINS BASED ON CONTINUITY. ASSOCIATED SHOWER ACTIVITY IS ISOLATED AT BEST. A TROPICAL WAVE HAS MOVED INTO THE E CARIBBEAN ALONG 63W S OF 16N MOVING W NEAR 15 KT. WIDELY SCATTERED SHOWER AND TSTM ACTIVITY APPEARS SOMEWHAT ORGANIZED FROM 12N-17N BETWEEN 55W-62W. NEARLY ALL OF THE ASSOCIATED CLOUDINESS LIES TO THE E OF THE WAVE AXIS...SHEARED BY STRONG UPPER WESTERLIES. A TROPICAL WAVE IS IN THE S CENTRAL CARIB ALONG 74W/75W S OF 15N MOVING W NEAR 15 KT. CYCLONIC TURNING IN THE LOWER CLOUDS APPEARS TO BE ASSOCIATED WITH THE NORMAL BACKGROUND FLOW AROUND THE N COAST OF COLOMBIA. ISOLATED SHOWERS/TSTMS ARE WITHIN 120 NM EITHER SIDE OF THE AXIS OVER THE CARIB PORTION. HOWEVER...A MORE SIGNIFICANT AREA OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LOCATED OVER THE SW CARIB S OF 14N W OF 77W TIED TO THE ITCZ AND ALSO BEING ENHANCED BY DIFLUENT SWLY FLOW SE OF AN UPPER LOW OVER W CUBA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 5N17W 3N21W 4N30W 2N45W 8N58W. EXCEPT AS NOTED WITH THE STRONG TROPICAL WAVE DESCRIBED ABOVE ...ISOLATED MODERATE IS WITHIN 90-120 NM N OF THE ITCZ BETWEEN 30W-38W. SIMILAR ACTIVITY IS FROM 8N-11N BETWEEN 54W-56W. ...DISCUSSION... GULF OF MEXICO... THE GULF IS RATHER TRANQUIL THIS EVENING WITH A 1020 MB HIGH SETTLING IN THE N CENTRAL GULF NEAR 28N91W. THIS PSN OF THE HIGH HAS ALLOWED SFC WINDS TO RELAX OVER THE GULF INCLUDING THE BAY OF CAMPECHE AS WELL. IN THE MID AND UPPER LEVELS...THE PATTERN REMAINS CONFLUENT BETWEEN AN UPPER HIGH OVER S MEXICO NEAR 21N102W AND AN UPPER LOW IN THE VICINITY OF HAVANA CUBA. STRONGLY CONFLUENT FLOW AND ASSOCIATED SUBSIDENCE ALOFT IS RESPONSIBLE FOR THE FAIR WEATHER. WHILE THE MAJORITY OF THE GULF IS CURRENTLY CLEAR THERE IS SOME SIGNIFICANT CONVECTION NEAR THE EDGES. SCATTERED STRONG CONVECTION IS EMERGING OFF THE COAST BETWEEN THE FLORIDA PANHANDLE AND E-CENTRAL LOUISIANA. WSR-88D DATA INDICATED THE STRONGEST ACTIVITY WAS CENTERED FROM 55 NM S OF MOBILE ALABAMA WWD THROUGH THE CHANDELEUR ISLANDS OFF LOUISIANA TO NEAR GRAND ISLE. THE ACTIVITY WAS PRESSING SWD AT 20-25 KT. ADDITIONAL BUT WEAKER SCATTERED SHOWER ACTIVITY IS PUSHING ACROSS THE UPPER FLORIDA KEYS AND THE STRAITS ASSOCIATED WITH INSTABILITY NEAR THE UPPER LOW OVER CUBA. CARIBBEAN SEA... THE MOST ACTIVE WEATHER IS IN THE SW CARIB FROM THE N COAST OF PANAMA/COSTA RICA TO 14N BETWEEN 77W-82W. THIS ACTIVITY IS APPARENTLY SUPPORTED BY THE ITCZ AND ENHANCED IN A PRONOUNCED UPPER DIFFLUENT ZONE. AN UPPER LOW WHICH WAS OVER FLORIDA YESTERDAY HAS BEEN DRIFTING TO THE SW AND IS NOW CENTERED IN THE VICINITY OF HAVANA CUBA. INSTABILITY NEAR THIS UPPER SYSTEM AND OROGRAPHIC LIFT IS GENERATING SCATTERED SHOWER AND TSTM ACTIVITY OVER CUBA. SURFACE OBSERVATIONS OVER THE WRN CARIBBEAN INDICATED PRESSURES OF 1008-1010 MB AS FAR N AS THE CAYMAN ISLANDS AND JAMAICA. THESE PRESSURES ARE ABOUT 2-3 MB BELOW CLIMATOLOGICAL VALUES EVEN FACTORING IN DIURNAL OSCILLATIONS. THE COMBINATION OF LOW PRESSURES...UPPER DIFFLUENCE SE OF THE UPPER LOW AND THE APPROACHING TROPICAL WAVE ALONG 74W/75W SUGGESTS THE POSSIBILITY OF MORE ORGANIZED CONVECTION IN THE SAME AREA TOMORROW. ATLANTIC OCEAN... SHOWERS AND TSTMS OVER THE BAHAMAS ASSOCIATED WITH THE UPPER LOW THAT IS DRIFTING TO THE SW OVER WRN CUBA HAVE DIMINISHED. OTHERWISE...A WEAK SFC HIGH PRES RIDGE RULES THE WRN ATLC. FARTHER NE...A LARGE STATIONARY VERTICALLY STACKED LOW PRES AREA IS LOCATED NEAR 37N61W. THIS SYSTEM IS PROVIDING SOME SUPPORT FOR A FRONTAL TROUGH WHICH ENTERS THE AREA NEAR 32N53W AND EXTENDS SW TO 23N65W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM E OF THIS BOUNDARY. MUCH OF THE CENTRAL AND EASTERN ATLC DISCUSSION AREA IS UNDER THE INFLUENCE OF SFC HIGH PRES ANCHORED BY A 1022 MB CENTER NEAR 27N33W RESULTING IN LIGHT TO MODERATE WINDS. WV IMAGERY SHOWS AN UPPER TROUGH EXTENDING ALONG 32N40W TO 12N44W AND A SPRAWLING RIDGE COVERING THE E ATLC WITH THE HIGH CENTERED OVER MAURITANIA. THESE UPPER SYSTEMS ARE NOT PRODUCING MUCH MORE THAN SCATTERED PATCHES OF CIRRUS. $$ COBB