000 AXNT20 KNHC 010533 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT NOV 01 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...THE ITCZ... ITCZ AXIS IS ANALYZED ALONG 10N14W 9N20W 10N35W 9N52W 10N63W. TWO SURFACE TROUGHS REMAIN EMBEDDED WITHIN THE ITCZ. ONE TROUGH EXTENDS FROM E OF THE CANARY ISLANDS NEAR 16N22W TO 13N24W TO 8N25W. THIS TROUGH COINCIDES WITH A WESTWARD-MOVING SURGE IN DEEP LAYER MOISTURE BASED ON TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE TROUGH FROM 10N-14N...WHICH IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE. THE SECOND TROUGH EXTENDS FROM 18N46W TO 14N46W TO 10N46W AND COINCIDES WITH ANOTHER WESTWARD-MOVING SURGE IN DEEP LAYER MOISTURE. THIS TROUGH IS SUPPORTING SCATTERED MODERATE CONVECTION FROM 9N-16N BETWEEN 38W-48W... WHICH IS ALSO BEING ENHANCED BY UPPER LEVEL DIVERGENCE. ELSEWHERE...ISOLATED MODERATE CONVECTION IS FROM 4N-12N BETWEEN 13W-21W...AFFECTING W PORTIONS OF GUINEA AND W GUINEA-BISSAU. ALSO...SCATTERED MODERATE CONVECTION IS FROM 9N-16N BETWEEN 27W-38W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE OF HIGH PRESSURE IS AFFECTING MUCH OF THE GULF REGION. THIS SURFACE RIDGE IS ANCHORED BY A 1033 MB SURFACE HIGH NEAR THE E COAST OF N CAROLINA. SUBSIDENCE IN THE VICINITY OF THE RIDGE IS RESULTING IN FAIR WEATHER CONDITIONS ACROSS MUCH OF THE GULF REGION. ALOFT...UPPER LEVEL MOISTURE EMBEDDED WITHIN THE BASE OF AN UPPER LEVEL TROUGH OVER THE W GULF CONTINUES TO RESULT IN HIGH CLOUDINESS OVER THE SW GULF. ACROSS THE N AND E GULF...DEEP LAYER DRY AIR AND STRONG MID/UPPER-LEVEL WESTERLY FLOW ARE PRESENT. THE UPPER LEVEL PATTERN IS FORECAST TO CHANGE OVER THE NEXT DAY AS A CLOSED UPPER LEVEL LOW AND ASSOCIATED UPPER TROUGH AND UPPER MOISTURE...CURRENTLY OVER W TENNESSEE... APPROACH THE N GULF. HOWEVER...COMPUTER MODEL GUIDANCE INDICATES THAT THESE FEATURES COULD WEAKEN AS THEY POTENTIALLY BECOME OVERTAKEN BY AN EASTWARD-MOVING UPPER RIDGE CURRENTLY OVER THE PLAINS OF THE CONUS. ADDITIONALLY...STRONG N TO NE SURFACE WINDS ARE BLOWING THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN GALE FORCE WINDS IN THE E PACIFIC REGION. CARIBBEAN SEA... ANTICYCLONIC FLOW AROUND AN UPPER HIGH CENTERED NEAR 15N76W COVERS MUCH OF THE CARIBBEAN...WITH DEEP MOISTURE OVER THE W CARIBBEAN. UPPER LEVEL DIVERGENCE SW OF THE UPPER HIGH IS SUPPORTING SCATTERED MODERATE/ISOLATED STRONG CONVECTION OVER THE W CARIBBEAN FROM 9N-18N BETWEEN 76W-85W...AFFECTING PORTIONS OF PANAMA AND COSTA RICA WHERE LOW LEVEL CONVERGENCE NEAR THE E PACIFIC ITCZ IS ENHANCING THE CONVECTION. ADDITIONALLY...A SURFACE TROUGH EXTENDS FROM W OF HAITI NEAR 20N73W TO 18N79W TO E NICARAGUA NEAR 14N83W. A RECENT QUIKSCAT PASS DEPICTS NE WINDS OF 20 TO 25 KT NW OF THE SURFACE TROUGH...AND NE WINDS NEAR 15 KT SE OF THE SURFACE TROUGH. THE CORRESPONDING LOW LEVEL CONVERGENCE NEAR THIS TROUGH...COMBINED WITH DEEP MOISTURE...IS SUPPORTING SCATTERED MODERATE CONVECTION WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH. DEEP LAYER DRY AIR E OF THE UPPER HIGH IS RESULTING IN MAINLY FAIR WEATHER ACROSS THE E CARIBBEAN. ATLANTIC OCEAN... DEEP LAYER DRY AIR EMBEDDED WITHIN A BROAD UPPER LEVEL TROUGH COVERS THE W ATLC...WHERE GENERALLY FAIR WEATHER IS PRESENT. AT THE SAME TIME...A SURFACE RIDGE OF HIGH PRESSURE...ANCHORED BY A 1033 MB SURFACE HIGH NEAR THE E COAST OF N CAROLINA...IS RESULTING IN SUBSIDENCE ACROSS MUCH OF THE W ATLC. FARTHER TO THE E...A SURFACE STATIONARY FRONT EXTENDS FROM 32N53W TO 27N59W TO 24N65W...AND A SURFACE TROUGH EXTENDS FROM 24N65W TO 21N71W TO W HAITI NEAR 20N73W. ATMOSPHERIC LIFT IN MOIST SOUTHWESTERLY FLOW ALOFT IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE SURFACE STATIONARY FRONT AND SURFACE TROUGH N OF 22N...WHICH ARE BEING SUPPORTED BY UPPER DIFFLUENCE NEAR AN UPPER RIDGE FROM 24N-30N BETWEEN 51W-60W. FARTHER TO THE E...A COMPACT UPPER LEVEL TROUGH IS PRESENT WITH AN AXIS THAT EXTENDS FROM 30N45W TO 31N47W TO 12N49W. ALSO...A DEEP LAYER TROUGH IS N OF 24N E OF 42W...WHICH IS SUPPORTING A SURFACE COLD FRONT EXTENDING FROM 32N11W TO 30N20W TO 32N28W THAT IS APPROACHING THE CANARY ISLANDS FROM THE NORTH. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE COLD FRONT E OF 15W. OVER THE TROPICAL ATLC...AN EAST-TO-WEST UPPER RIDGE IS ALONG 11N BETWEEN THE AFRICAN COAST AND 42W. UPPER LEVEL DIVERGENCE NEAR THIS RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE SURFACE TROUGHS THAT ARE EMBEDDED WITHIN THE ITCZ. OF NOTE...NOVEMBER IS THE LAST MONTH OF THE ATLANTIC HURRICANE SEASON. SO FAR...FIFTEEN NAMED STORMS HAVE DEVELOPED...OF WHICH SEVEN BECAME HURRICANES...WITH FOUR OF THE HURRICANES ATTAINING MAJOR HURRICANE STATUS. IN ADDITION...A SHORT-LIVED TROPICAL DEPRESSION FORMED IN OCTOBER. THE MOST POWERFUL HURRICANES SEEN THIS SEASON ARE GUSTAV AND IKE...BOTH CAT 4 ON THE SAFFIR SIMPSON SCALE. $$ COHEN/GR