000 AXNT20 KNHC 062357 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST TUE NOV 06 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... A LOW AMPLITUDE TROPICAL WAVE IS LOCATED ALONG 47W SOUTH OF 13N...MOVING W NEAR 10 KT. THE WAVE IS BEGINNING TO INTERACT WITH AN UPPER-LEVEL LOW THAT REMAINS NEAR 18N55W. THIS FEATURE PAIRED WITH UPPER DIFFLUENCE BETWEEN THE ABOVE MENTIONED LOW AND AN UPPER HIGH THAT ALSO REMAINS NEAR THE GUYANAS IS GENERATING BROKEN TO OVERCAST MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS FROM 5N-10N BETWEEN 40W-48W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 7N30W 7N45W 7N60W. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS WITHIN 150 NM N OF AXIS BETWEEN 28W-32W. SIMILAR CONVECTION IS WITHIN 200 NM SOUTH OF AXIS BETWEEN 23W-29W. DISCUSSION... GULF OF MEXICO... A NEW COLD FRONT IS MOVING ACROSS THE NORTHERN GULF WATERS. IT ENTERED THE REGION DURING THE AFTERNOON HOURS. AS OF 2100 UTC... THE FRONT EXTENDS FROM THE FLORIDA PANHANDLE TO THE DEEP SOUTH THEN ACROSS THE STATES OF COAHUILA AND CHIHUAHUA IN MEXICO. A NARROW BAND OF LOW/MID CLOUDS WITH SCATTERED SHOWERS IS RELATED TO THE FRONT. STRONG HIGH PRES WILL BUILD IN BEHIND THE FRONT BRINGING AN INCREASE IN WINDS AND SEAS TONIGHT THROUGH WED NIGHT. FAIRLY UNIFORM UPPER NW FLOW IS OVER THE GULF THIS EVENING BETWEEN A LONGWAVE TROUGH OVER THE ERN UNITED STATES AND RIDGING OVER MEXICO. DRY MID/UPPER AIR DOMINATES MOST OF THE REGION. THE FRONT IS FORECAST TO MOVE RAPIDLY S AND EXTEND FROM THE STRAITS OF FLORIDA TO NE MEXICO BY LATE WED. CARIBBEAN SEA... A STATIONARY FRONT PERSISTS OVER THE WRN CARIBBEAN AND EXTENDS FROM NEAR THE COAST NE HONDURAS TO THE ERN TIP OF CUBA...THEN CONTINUES ACROSS THE TURKS AND CAICOS ISLANDS INTO THE W ATLC. THE TAIL END OF THE FRONT IS GENERATING SCATTERED SHOWERS AND TSTMS...PARTICULARLY OVER NE HONDURAS AND ADJACENT WATERS S OF 19N BETWEEN 79W-85W. THIS FRONT WILL GRADUALLY BECOME DIFFUSE BY WED NIGHT. AN EARLIER QUIKSCAT PASS SHOWED NELY WINDS OF 20 KT BEHIND THE FRONT OVER THE NW CARIBBEAN. TYPICAL ISOLATED TSTMS ARE ALSO NOTED OVER PANAMA AND COSTA RICA...ASSOCIATED WITH LOW LEVEL CONVERGENCE. SCATTERED MODERATE CONVECTION IS NEAR THE CARIBBEAN PLAINS OF NICARAGUA. A DIFFLUENT PATTERN ALOFT... ASSOCIATED WITH A BROAD UPPER RIDGE THAT COVERS MOST OF THE BASIN...IS ENHANCING THIS CONVECTIVE ACTIVITY. AN UPPER LOW REMAINS JUST E OF THE LESSER ANTILLES IN THE TROPICAL ATLC. NLY FLOW AND DRY AIR BETWEEN THESE TWO UPPER FEATURES IS KEEPING THE E CARIBBEAN MOSTLY TRANQUIL. A WEAK SFC TROUGH IS MOVING ACROSS PUERTO RICO HELPING TO INDUCE SOME CONVECTIVE ACTIVITY MAINLY OVER THE W AND NW PORTION OF THE ISLAND WHERE DOPPLER RADAR DEPICTS SCATTERED SHOWERS AND A FEW TSTMS. THE LAST FEW VIS SAT IMAGERY SHOWED A SWIRL OF LOW CLOUDS ASSOCIATED WITH THE TROUGH NEAR 21N66W. THIS TROUGH IS EXPECTED TO MOVE AWAY FROM PUERTO RICO TOMORROW. ATLANTIC OCEAN... A WEAKENING RIDGE DOMINATES THE W ATLC AND THE NW/CENTRAL BAHAMAS. AHEAD OF THIS RIDGE...THERE IS A STATIONARY FRONT THAT ENTERS THE FORECAST AREA NEAR 31N58W...THEN CONTINUES TO THE TURKS AND CAICOS ISLANDS INTO THE CARIBBEAN SEA. THE FRONTAL BOUNDARY HAS FRACTIONED...PARTICULARLY OVER THE SE BAHAMAS WITH THE SHOWER ACTIVITY NOW MORE CONCENTRATED N OF 25N BETWEEN 60W AND 70W. EARLIER SCATTEROMETER DATA SHOWED NE WINDS OF NEAR 20 KT WITHIN 120NM BEHIND THE FRONT. THE NEXT COLD FRONT IS EXPECTED TO MOVE OFF THE NE FL COAST TONIGHT. AN INCREASE IN WINDS AND SEAS WILL FOLLOW THE FRONT. THE NEXT WEATHER FEATURE OF INTEREST IS THE OCCLUDED 1000 MB SFC LOW THAT IS JUST ENTERING THE FORECAST AREA. SHOWERS AND TSTMS REMAIN POORLY ORGANIZED IN ASSOCIATION WITH THIS NON-TROPICAL LOW PRESSURE AREA CENTERED ABOUT 630 NM SOUTHWEST OF THE AZORES. TROPICAL OR SUBTROPICAL DEVELOPMENT OF THIS SYSTEM IS NOT EXPECTED AS THE LOW MOVES TOWARD THE SOUTHEAST AT 5 TO 10 MPH. THE ASSOCIATED COLD FRONT ENTERS THE AREA NEAR 31N26W AND CONTINUES SW TO 23N35W...THEN W AND NW TO 27N48W. SCATTERED MODERATE CONVECTION IS WITHIN 50 NM EITHER SIDE OF FRONT EAST OF 30W. A PRE-FRONTAL TROUGH EXTENDS ALONG 28N24W 21N30W 16N41W. THE TAIL END OF THE TROUGH IS GENERATING CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION NEAR 17N38W AND 15N42W. WEAK SFC RIDGING DOMINATES THE REMAINDER OF THE E ATLC...EXTENDING S THROUGH THE CANARY ISLANDS. SCATTERED SHOWERS/TSTMS ALSO NOTED OVER THE TROPICAL ATLC FROM 14N-18N BETWEEN 27W-34W...ASSOCIATED WITH DIFFLUENT FLOW ALOFT. ANOTHER SFC TROUGH...WHICH APPEARS TO BE PART OF AN OLD FRONT RUNS ALONG 30N54W 25N55W 22N50W. THIS TROUGH IS ALSO ENHANCING THE DEVELOPMENT OF SCATTERED SHOWERS MAINLY N OF 24N. ALOFT...A TROUGH/RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE DISCUSSION AREA. $$ GR