000 AXNT20 KNHC 251755 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON OCT 25 2010 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. ...SPECIAL FEATURES... TROPICAL DEPRESSION RICHARD IS CENTERED NEAR 17.8N 90.2W AT 25/1500 UTC OR ABOUT 125 NM S OF CAMPECHE MEXICO MOVING W-NW AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SATELLITE IMAGERY SHOWS VERY LITTLE DEEP CONVECTION LEFT IN THE VICINITY OF RICHARD AS IT CONTINUES TO WEAKEN OVER NORTHERN GUATEMALA AND THE SOUTHERN YUCATAN PENINSULA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 150 NM IN THE NE QUADRANT AND 120 NM OF CENTER ALL OTHER QUADRANTS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 02N31W TO 10N24W MOVING W AT 10-15 KT. THE WAVE REMAINS AS A BROAD CYCLONIC PERTURBATION WITHIN THE ITCZ REGION BETWEEN 21W AND 32W. AN EARLIER MORNING ASCAT PASS AROUND 25/1110 UTC CONFIRMED NE WINDS TO 20 KT NORTHWEST OF THE WAVE AXIS. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS OCCURRING FROM 01N-11N BETWEEN 23W-32W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 13N17W 12N21W THEN RESUMES NEAR 04N32W 09N49W 09N61W. A SURFACE TROUGH IS ANALYZED FROM THE ITCZ REGION NEAR 08N49W NE TO NEAR 16N44W. WHILE LOCATED BENEATH VERY DRY AIR ALOFT DUE TO UPPER LEVEL W-NW WINDS...NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE SURFACE TROUGH. ELSEWHERE... SCATTERED MODERATE CONVECTION IS FROM 04N-11N BETWEEN 17W-23W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL SHORTWAVE TROUGH LOCATES OVER THE SE CONUS WITH AXIS EXTENDING ACROSS THE NW GULF FROM 30N87W TO 25N97W THEN SW ACROSS CENTRAL MEXICO. WHILE THE WEAKENING SURFACE BOUNDARY CONTINUES MOVING ACROSS NORTHERN GEORGIA AND THE CAROLINAS THIS AFTERNOON...LOW-LEVEL SOUTHERLY CONVERGENCE ACROSS THE NE GULF IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 29N W OF 87W..INCLUDING INLAND PORTIONS OF SOUTHERN ALABAMA AND THE FLORIDA PANHANDLE. BETWEEN THE UPPER LEVEL TROUGH AXIS AND AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE NW CARIBBEAN NEAR 18N81W...DRY AND SUBSIDENT SOUTHWESTERLY FLOW ALOFT COVERS THE REMAINDER OF THE GULF. THIS UPPER LEVEL ENVIRONMENT IN TURN IS SUPPORTING A SURFACE RIDGE ACROSS MUCH OF THE GULF NORTH AND NORTHWEST OF T.D. RICHARD AS IT WEAKENS OVER THE YUCATAN PENINSULA. THE SURFACE RIDGE AXIS EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA ALONG 28N83W TO 26N91W TO A WEAK 1015 MB HIGH CENTERED OVER EAST-CENTRAL MEXICO NEAR 20N97W. MOSTLY FAIR CONDITIONS ACCOMPANY THIS SURFACE RIDGE WITH MAINLY HIGH LEVEL CIRRUS OUTFLOW FROM RICHARD STREAMING OVER THE SE GULF. CARIBBEAN SEA... A BROAD UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE NW CARIBBEAN NEAR 18N81W AND EXTENDS ITS INFLUENCE BETWEEN 66W TO BEYOND 95W AND INTO THE E PACIFIC REGION. T.D. RICHARD IS LOCATED ON THE NORTHWESTERN PERIPHERY OF THE UPPER LEVEL CIRCULATION PROVIDING MARGINAL OUTFLOW ALOFT...HOWEVER THE SYSTEM CONTINUES TO WEAKEN DUE TO INCREASING DEEP LAYER SHEAR LOCATED TO THE NW OVER THE GULF OF MEXICO AND FRICTION OVER LAND. WITH AN UPPER LEVEL DIFFLUENT PATTERN IN PLACE OVER THE NW CARIBBEAN AND CONVERGENT LOW-LEVEL E-SE TRADEWINDS...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 14N-20N BETWEEN 80W-86W. ANOTHER AREA OF WEAKENING CONVECTION IS EMERGING OFF THE NE PORTION OF THE YUCATAN PENINSULA MOVING INTO THE YUCATAN CHANNEL. ELSEWHERE OVER THE REMAINDER OF THE CARIBBEAN...A WESTERN ATLC SURFACE RIDGE EXTENDS TO SOUTHWARD TO 15N PROVIDING THE BASIN WITH MODERATE TO FRESH TRADES THAT ARE FORECAST TO PERSIST THROUGH TUESDAY. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE NW CARIBBEAN SEA ACROSS CENTRAL CUBA TO BEYOND 32N74W AND SUPPORTS A 1026 MB SURFACE HIGH CENTERED NEAR 34N64W. WHILE MOST OF THE W ATLC IS INFLUENCED BY THIS SURFACE HIGH...A SHEAR LINE ENTERS THE DISCUSSION AREA NEAR 31N46W AND EXTENDS SW ALONG 26N55W TO 24N70W. AN EARLIER MORNING ASCAT PASS AROUND 25/1246 UTC DEPICTED STRONGER NE WINDS WITHIN 120 NM NORTH OF THE SHEAR LINE AXIS BETWEEN 49W-67W. LOW-LEVEL SPEED CONVERGENCE ALONG WITH A WEAK UPPER LEVEL SHORTWAVE TROUGH ALONG 28N60W TO 24N66W IS GENERATING AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 90 NM EITHER SIDE OF THE SHEAR LINE BETWEEN 52W-63W. ELSEWHERE ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE SHEAR LINE. FARTHER EAST...A 1010 MB LOW IS CENTERED NEAR 23N39W AND EXTENDS A SURFACE TROUGH SOUTH ALONG 21N39W TO 17N41W. THIS SURFACE LOW COLLOCATES WITH AN UPPER LEVEL LOW CENTERED NEAR 21N39W AND CONTINUES TO GENERATE AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS FROM 24N-30N BETWEEN 30W-43W. AN UPPER LEVEL DIFFLUENT ZONE LOCATED N AND NE OF THE UPPER LEVEL LOW IS CONTINUING TO SUSTAIN AND ENHANCE THE ONGOING CONVECTION. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE AXIS ALONG 23W DIPPING SOUTHWARD TO THE CAPE VERDE ISLANDS AND ANCHORED BY A QUASI-STATIONARY 1031 MB HIGH CENTERED EAST OF THE AZORES NEAR 38N21W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN