000 AXNT20 KNHC 121736 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUN 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 45W FROM 6N TO 19N MOVING W NEAR 25 KT. WHILE THIS WAVE CONTINUES TO HAVE A LARGE ENVELOPE OF CYCLONIC TURNING IN THE LOW LEVELS IT REMAINS ABSENT OF ANY DEEP CLOUDINESS OR SIGNIFICANT SHOWER ACTIVITY. A TROPICAL WAVE IS ALONG 54W S OF 11N MOVING W NEAR 15 KT. THIS WAVE HAS BECOME A BIT MORE CHALLENGING TO LOCATE IN THE LOW CLOUDS BUT STILL TRACKABLE FOLLOWING A WWD MOVING CLUSTER OF CONVECTION ON SATELLITE HOVMOLLER DIAGRAMS AND IN THE LOW TO MID LEVEL SATELLITE DERIVED WINDS. CURRENTLY...SCATTERED MODERATE CONVECTION IS WITHIN 90 NM W AND 150 NM E OF THE WAVE AXIS FROM 6N-9N. A TROPICAL WAVE IS IN THE WRN CARIB ALONG 78W S OF 17N MOVING W 10-15 KT. WHILE THE LOW LEVEL FLOW CLIMATOLOGICALLY FLOWS CYCLONICALLY AROUND THE OROGRAPHY OF NORTHERN S AMERICA...THERE APPEARS TO BE SOME ENHANCED TURNING ASSOCIATED WITH THIS FEATURE. PATCHES OF SCATTERED MODERATE CONVECTION...MOSTLY FUELED BY UPPER DIFFLUENCE...IS WITHIN 180 NM W OF THE AXIS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 6N26W 4N35W 6N43W 6N56W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 17W-21W. THIS ACTIVITY IS LIKELY ASSOCIATED WITH A TROPICAL WAVE AS REPRESENTED IN BAMAKO'S UPPER AIR TIME SECTION. THIS FEATURE WILL BE REVIEWED AND POSSIBLY ADDED TO THE 18Z ANALYSIS. ELSEWHERE SCATTERED MODERATE IS WITHIN 180 NM EITHER SIDE OF AXIS BETWEEN 30W-37W AND FROM 7N-9N BETWEEN 42W-44W. ...DISCUSSION... THE GULF OF MEXICO... MUCH OF THE GULF IS IN A N-NELY UPPER FLOW REGIME BETWEEN AN UPPER HIGH CENTERED OVER S TEXAS NEAR 28N98W...AN UPPER LOW SPINNING OVER THE NRN COAST OF THE YUCATAN AND A LARGE DIGGING TROUGH EXTENDING FROM THE N ATLC TO NRN FLORIDA. THIS CONFLUENT PATTERN CONTINUES TO ENHANCE SUBSIDENCE/SINKING AIR WHICH IS PROVIDING A STABLE AIRMASS ALLOWING FOR FAIR SKIES OVER THE GULF. HOWEVER...INSTABILITY ASSOCIATED WITH AN UPPER JET IS FUELING A SQUALL LINE ACROSS N CENTRAL FL WITH AN AREA OF SHOWERS AND TSTMS BEHIND IT...MORE ON THIS FEATURE IN THE ATLANTIC SECTION. AT THE SFC...THE PRES PATTERN REMAINS WEAK WITH A PAIR OF WEAK HIGHS AND A DISSIPATING TROUGH ALONG 95W. THE NET EFFECT IS LIGHT AND VARIABLE WINDS...WHICH ARE ANTICIPATED TO PERSIST FOR ANOTHER DAY OR TWO AS THE WEAK PRES PATTERN REMAINS IN PLACE. THE CARIBBEAN SEA... THE ACTIVE WEATHER IN THE REGION IS ACROSS THE WRN PORTION WHERE PATCHES OF SCATTERED MODERATE CONVECTION ARE GENERALLY BETWEEN 80W-85W S OF 21N. THIS ACTIVITY IS ASSOCIATED WITH DIFFLUENCE ALOFT BETWEEN AN UPPER LOW SPINNING JUST N OF THE YUCATAN PENINSULA AND A SPRAWLING RIDGE CENTERED NEAR 14N77W. AN EXTENDED IR LOOP SHOWS THIS CONVECTIVE ACTIVITY GENERALLY DECREASING WITH LITTLE FOCUS OF ORGANIZED CLUSTERS...THAT WHERE EVIDENT YESTERDAY AT THIS TIME. ELSEWHERE...A PLUME OF MID-HIGH LEVEL CLOUDINESS AND POSSIBLE SHOWERS ARE STREAMING ACROSS THE NRN CARIB...N OF 16N...AS DEBRIS MOISTURE IS PULLED AROUND THE NRN BRANCH OF THE ANTICYCLONE. THE REMAINDER OF THE CARIB WATERS IS FREE OF SIGNIFICANT MOISTURE...ALTHOUGH TYPICAL TRADE WIND SHOWERS ARE POSSIBLE AT ANY GIVEN LOCATION. THE ATLANTIC OCEAN... EXTENSIVE STRONG UPPER ZONAL FLOW...TO THE S OF A LARGE AND PERSISTENT OCCLUDED LOW PRES SYSTEM 200 NM OFF THE NEW ENGLAND COASTLINE...COVERS THE DISCUSSION AREA W OF 60W. THE ASSOCIATED JET AXIS RUNS FROM NEAR THE FL/GA BORDER TO JUST S OF BERMUDA THEN NEWD INTO THE N CENTRAL ATLC. SHOWERS AND TSTMS HAVE IGNITED TODAY IN THE RIGHT ENTRANCE REGION OF THE JET ENHANCED BY A WEAKENING STALLED FRONTAL BOUNDARY. DOPPLER RADAR DEPICTS A SQUALL LINE PUSHING S ACROSS N CENTRAL FL WITH SCATTERED SHOWERS AND TSTMS N AND E OF THE SQUALL. IR IMAGERY AND LIGHTNING DATA INDICATE THAT SOMEWHAT SIMILAR TSTM ACTIVITY MAY BE OCCURRING OVER PORTIONS OF THE BAHAMAS AND FROM 28N-30N BETWEEN 76W-78W. LESS ACTIVE ISOLATED TO SCATTERED PRECIP IS FURTHER E BETWEEN 60W-72W. FARTHER E...WV IMAGERY SHOWS A WEAK RIDGE EXTENDING NEWD ALONG 20N53W 32N43W. MUCH MORE EXTENSIVE RIDGING STRETCHES W FROM AFRICA ALONG 22N TO ABOUT 35W. A WEAK SHEARED UPPER TROUGH LIES BETWEEN THESE RIDGES EXTENDING FROM 32N32W TO AN UPPER LOW NEAR 22N42W CONTINUING TO 16N51W. THE ASSOCIATED COLD FRONT HAS NOW PULLED N OF THE REGION. THESE UPPER FEATURES ARE ONLY PRODUCING PATCHES OF CIRRUS EXCEPT FOR POSSIBLE ISOLATED SHOWERS WITHIN 90 NM E OF THE UPPER LOW. ELSEWHERE....HIGH PRES DOMINATES THE AREA ANCHORED BY A NEARLY STATIONARY 1026 MB CENTER NEAR 29N39W. 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 45W. $$ CANGIALOSI