000 AXNT20 KNHC 021042 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU OCT 02 2008 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 41W/42W S OF 19N MOVING W 10-15 KT. WAVE REMAINS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE AS INDICATED BY THE MIMIC TPW ANIMATION WITH A BROAD MID LEVEL ROTATION COVERING THE AREA FROM 7N-18N BETWEEN 36W-46W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 9N-12N BETWEEN 42W-46W WITH CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 60/75 NM OF LINE FROM 15N31W-18N37W. TROPICAL WAVE IS TILTED ALONG 21N50W TO 12N53W MOVING W NEAR 10 KT. THIS IS AT THE LEADING EDGE OF DEEP LAYERED MOISTURE AS INDICATED BY THE MIMIC TPW ANIMATION WITH THE INVERTED-V LOW CLOUD PATTERN OBSERVED ON SATELLITE IMAGERY. ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE IS ALONG 69W S OF 16N MOVING W NEAR 15 KT. WEAK WAVE WITH NO CLEAR INDICATION ON SATELLITE IMAGERY. POSITION IS BASED ON CONTINUITY WITH NO ASSOCIATED SHOWERS/CONVECTION. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 13N16W 11N26W 15N43W 12N56W 11N63W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 120 NM OF THE AXIS E OF 25W TO INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 3N-10N E OF 18W TO THE COAST OF SW AFRICA...WITHIN 150 NM N OF THE ITCZ FROM 25W-30W...AND WITHIN 60 NM OF THE ITCZ FROM 37W-40W. ...DISCUSSION... GULF OF MEXICO... DEEP UPPER TROUGH OVER THE E US DOMINATES THE ENTIRE GULF WITH THE ASSOCIATED COLD FRONT ENTERING THE GULF ACROSS CENTRAL FLORIDA NEAR FORT MYERS EXTENDING W TO 24N90W THEN DISSIPATING TO 24N94W. SCATTERED LOW CLOUDS MARK THE FRONTAL BOUNDARY AS NORTHERLY WINDS DOMINATE THE ENTIRE GULF. STRONG SUBSIDENCE AND DRY STABLE AIR COVER ALL OF THE GULF EXCEPT IN THE FLORIDA STRAITS SE OF THE FLORIDA KEYS. LOW LEVEL CONVERGENCE IS PILING LOW CLOUDS WITH POSSIBLE ISOLATED SHOWERS OVER THE BAY OF CAMPECHE. OTHERWISE THE GULF REMAINS REMARKABLY CLEAR THIS MORNING WITH DEW POINTS AT OR BELOW 60 DEG ACROSS THE N GULF COAST STATES. CARIBBEAN SEA... AN INDUCED NARROW UPPER RIDGE EXTENDS FROM NE HONDURAS TO CENTRAL CUBA SANDWICHED BETWEEN THE DEEP LAYERED TROUGH OVER THE GULF OF MEXICO AND THE UPPER LOW THAT COVERS THE CENTRAL CARIBBEAN CENTERED NEAR 14N74W. A SURFACE TROUGH EXTENDS ACROSS W/CENTRAL CUBA NEAR 22N81W TO THE YUCATAN AND CENTRAL BELIZE. DIFFLUENCE ALOFT COVERS THE NW CARIBBEAN AND COUPLED WITH AN ABUNDANCE OF TROPICAL MOISTURE ARE GENERATING CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG TO SCATTERED STRONG CONVECTION W OF 70W. THE BROAD UPPER RIDGE IS OVER THE W/CENTRAL ATLC AND DIPS ACROSS THE NE CARIBBEAN N OF 16N E OF 70W BRINGING DRIER AIR TO THE LEEWARD/VIRGIN ISLANDS AND PUERTO RICO. A SHORT RIDGE AXIS EXTENDS FROM INLAND OVER VENEZUELA ALONG 69W TO 15N COVERING THE SE CARIBBEAN. AN ABUNDANCE OF MOIST TROPICAL AIR ALSO COVERS THE SE CARIBBEAN GENERATING SCATTERED SHOWERS S OF 16N E OF 70W TO OVER THE WINDWARD ISLANDS. ATLANTIC OCEAN... DEEP TROUGH OVER THE E US AND THE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF 74W WITH THE ASSOCIATED COLD FRONT ENTERING THE REGION THROUGH 32N76W S OVER CENTRAL FLORIDA NEAR BETWEEN VERO BEACH AND WEST PALM BEACH INTO THE GULF OF MEXICO. SCATTERED LOW CLOUDS MARK THE FRONTAL BOUNDARY. A LINGERING STATIONARY BOUNDARY EXTENDS THROUGH 32N69W ALONG 30N72W TO A WEAK 1010 MB LOW OVER THE N BAHAMA ISLANDS NEAR 27N76W WITH A SURFACE TROUGH CONTINUING S INTO THE CARIBBEAN ACROSS W/CENTRAL CUBA. A NARROWING UPPER RIDGE DOMINATES THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC ANCHORED NEAR 25N66W EXTENDING A RIDGE AXIS NE TO BEYOND 32N58W AND S OVER THE NE CARIBBEAN. DIFFLUENCE ALOFT IS GENERATING A BAND OF MULTILAYERED CLOUDS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150/175 NM OF LINE FROM ACROSS CUBA NEAR 23N77W TO BEYOND 32N69W. THIS UPPER RIDGE IS TILTED AND BEGINNING TO NARROW FROM THE NE TO SW WITH THE APPROACH OF THE DEEP LAYERED TROUGH TO THE W. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR COVER THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC BRINGING FAIR WEATHER TO THAT AREA. A NARROW UPPER TROUGH IS OVER THE CENTRAL ATLC N AND AN EQUALLY NARROW UPPER RIDGE JUST TO THE E ENHANCING SCATTERED MODERATE CONVECTION WITHIN 120 NM OF LINE FROM 25N42W TO BEYOND 32N38W. A CUT-OFF UPPER LOW REMAINS IN THE W TROPICAL ATLC COVERING THE AREA FROM 13N-22N BETWEEN 49W-56W CENTERED NEAR 18N53W AND ENHANCING THE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE JUST TO THE E. AN ELONGATED E/W UPPER LOW IS CENTERED ALONG THE CENTRAL COAST OF MOROCCO COVERING THE NE ATLC FROM THE CANARY ISLANDS NORTHWARD E OF 23W. BROAD E/W UPPER RIDGE EXTENDS FROM AFRICA ALONG 15N TO 45W DOMINATING THE E TROPICAL ATLC. THE FIRST VISIBLE SATELLITE IMAGES SHOW A CONCENTRATION OF AFRICAN DUST FROM 8N-20N E OF 31W. $$ WALLACE