000 AXNT20 KNHC 021807 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 02 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 41W S OF 15N MOVING W NEAR 15 KT. WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE AS INDICATED IN TOTAL PRECIPITABLE WATER IMAGERY BUT REMAINS AT A LOW AMPLITUDE. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 9N-16N BETWEEN 38W-44W. TROPICAL WAVE THAT WAS ALONG 55W IS NOW A SURFACE TROUGH EXTENDING FROM 20N51W THROUGH A 1014 MB LOW NEAR 16N52W TO 13N53W MOVING W 5-10 KT. A DISTINCT LOW LEVEL SWIRL IS OBSERVED ON VISIBLE SATELLITE IMAGERY AND IS TO THE E OF THE PREVIOUS ANALYSIS...THUS THE CONVERSION TO A SURFACE TROUGH. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 14N15W 9N28W 10N43W 9N55W 10N62W. SCATTERED CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 4N-14N E OF 35W TO THE COAST OF W AFRICA. ...DISCUSSION... GULF OF MEXICO... A STRONG COLD FRONT HAS MOVED INTO THE GULF ENTERING THE AREA OVER CENTRAL LOUISIANA NEAR 30N92W SW TO ACROSS S TEXAS NEAR CORPUS CHRISTI. THE FRONT IS SUPPORTED BY A LARGE UPPER LEVEL TROUGH THAT DIPS ACROSS THE N GULF COAST. A BROAD UPPER RIDGE ANCHORED OVER CENTRAL MEXICO EXTENDS ACROSS THE GULF FROM TAMPICO TO S FLORIDA PROVIDING DIFFLUENCE ALOFT TO ENHANCE SCATTERED/NUMEROUS SHOWERS/THUNDERSTORMS SE OF THE FRONT WITHIN 90 NM OF LINE FROM 28N89W 26N92W TO JUST OFF THE TEXAS COAST NEAR 27N97W. ISOLATED/SCATTERED SHOWERS ARE WITHIN 90 NM OF LINE FROM 28N89W TO INLAND OVER THE N GULF COAST BETWEEN PANAMA CITY FLORIDA AND SE COAST OF LOUISIANA. THE REMNANTS OF A STATIONARY FRONT EXTENDS ACROSS EXTREME S FLORIDA PENINSULA S OF MIAMI JUST N OF THE FLORIDA KEYS TO 25N84W. DRY STABLE CONDITIONS DOMINATE THE S AND E GULF GIVING THE REMAINDER OF THE GULF RELATIVELY CLEAR SKIES THIS AFTERNOON. HOWEVER CONDITIONS WILL DETERIORATE ACROSS THE N GULF AS THE FRONT PUSHES EASTWARD. CARIBBEAN SEA... AN UPPER LEVEL TROUGH EXTENDS FROM AN UPPER LOW OVER THE BAHAMAS ACROSS CENTRAL CUBA INTO THE CARIBBEAN TO JUST S OF JAMAICA. THIS COMBINED WITH THE UPPER RIDGE OVER THE GULF OF MEXICO IS USHERING IN DRY STABLE AIR TO 14N W OF 79W INCLUDING PORTIONS OF CENTRAL AMERICA AND THE YUCATAN PENINSULA. THE UPPER TROUGH IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 17N FROM 72W-76W. AN UPPER RIDGE IN THE SE PACIFIC EXTENDS FROM COLOMBIA TO S OF CENTRAL AMERICA DRAWING UPPER LEVEL MOISTURE ACROSS PANAMA AND COSTA RICA AND COUPLED WITH THE ITCZ THAT EXTENDS ACROSS COLOMBIA N OF PANAMA INTO THE E PACIFIC OVER E COSTA RICA ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF A LINE FROM THE TIP OF HONDURAS/NICARAGUA TO COLOMBIA NEAR 11N74W. A WEAK SURFACE TROUGH IS OVER THE NE CARIBBEAN EXTENDING FROM 20N65W ACROSS THE VIRGIN ISLANDS TO 16N64W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90 N M EITHER SIDE OF THE TROUGH AXIS. MOSTLY CLEAR SKIES PREVAIL ACROSS THE CENTRAL CARIBBEAN FROM E TO W WITH THE EXCEPTION OF A FEW ISOLATED SHOWERS BEING USHERED IN ON MODERATE TO FRESH EASTERLY TRADE WINDS. ATLANTIC OCEAN... A COLD FRONT ENTERS THE REGION NEAR 32N61W EXTENDING SW TO 28N67W WHERE IT BECOMES STATIONARY OVER THE N BAHAMA ISLANDS NEAR 27N77W THEN DISSIPATING ACROSS EXTREME S FLORIDA INTO THE SE GULF OF MEXICO S OF MIAMI SUPPORTED BY AN UPPER TROUGH WHICH COVERS THE ATLC N OF 30N W OF 60W. ISOLATED/SCATTERED SHOWERS ARE WITHIN 60 NM E OF THE COLD FRONT. AN UPPER TROUGH IS OVER THE W ATLC EXTENDING FROM AN UPPER LOW OVER THE N BAHAMA ISLANDS NEAR 26N77W S ACROSS CENTRAL CUBA INTO THE NW CARIBBEAN. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 30N TO OVER THE GREATER ANTILLES BETWEEN 70W-80W. A BROAD UPPER RIDGE COVERS THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC ANCHORED NEAR 21N58W EXTENDING N TO BEYOND 32N52W. DIFFLUENCE ALOFT IS ENHANCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER AN AREA FROM 25N-30N BETWEEN 43W-56W. A SURFACE TROUGH...PREVIOUSLY A TROPICAL WAVE...EXTENDS FROM 20N51W THROUGH A 1014 MB LOW NEAR 16N52W TO 13N53W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 14N-18N BETWEEN 50W-56W. AN UPPER TROUGH IS IN THE E/CENTRAL ATLC EXTENDING FROM AN UPPER LOW WELL N OF THE REGION NARROWING S OF 29N ALONG 29N38W INTO THE TROPICS TO 16N51W. A SURFACE TROUGH EXTENDS FROM A DISSIPATING COLD FRONT ENTERING THE REGION NEAR 32N21W SW ALONG 28N30W TO 27N40W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT/TROUGH. THE TYPICAL E/W UPPER RIDGE DOMINATES MUCH OF THE TROPICS WITH THE AXIS EXTENDING ALONG 10N/11N TO 42W ENHANCING THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE AND THE ITCZ. WEAK SURFACE RIDGE CUTS A SWATH ACROSS THE REGION BETWEEN 20N-30N WITH A WEAK 1018 MB HIGH NEAR 26N59W. $$ WALLACE