000 AXNT20 KNHC 221801 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 22 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 1745 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM RICHARD AT 22/1800 UTC IS NEAR 15.8N 81.3W. RICHARD IS MOVING WEST AT 3 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. THE STORM IS ABOUT 140 MI...225 KM ENE OF CABO GRACIAS A DIOS ON THE NICARAGUA AND HONDURAS BORDER. PLEASE READ THE FORECAST/ADVISORY LISTED UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 KNHC...AND THE INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. MODERATE TO STRONG CONVECTION FROM 14N-19N BETWEEN 78W-83W. ANOTHER AREA OF MODERATE TO STRONG CONVECTION IS OVER THE FAR SOUTHWEST BASIN FROM 10N-14N WEST OF 80W... ASSOCIATED WITH THE LARGE CYCLONIC FLOW FROM RICHARD DRAWING DEEP MOISTURE FORM THE FAR EAST TROPICAL PACIFIC ITCZ TO THE SOUTHWEST CARIBBEAN. ENVIRONMENTAL CONDITIONS ARE BECOMING MORE CONDUCTIVE TO STRENGTHENING OVER THE NEXT 24 TO 36 HOURS. A VIGOROUS TROPICAL WAVE IS OVER THE FAR EAST TROPICAL ATLANTIC AFFECTING THE CAPE VERDE ISLANDS. THE WAVE AXIS IS ANALYZED ALONG 17N21W TO A SURFACE LOW NEAR 13N25W TO 7N27W MOVING NW AT ABOUT 8-13 KT. THIS SYSTEM IS EMBEDDED IN A SURGE OF DEEP LAYER MOISTURE NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. A BROAD AREA OF WEAK CYCLONIC CURVATURE IS OBSERVED ALONG THE AXIS. SCATTERED MODERATE TO ISOLATE STRONG CONVECTION IS FROM 11N-18N BETWEEN 20W-26W. SIMILAR CONVECTION IS IN THE SOUTHERN EXTENT OF THE WAVE AXIS FROM 8N-10N BETWEEN 24W-28W. ENVIRONMENTAL CONDITIONS ARE ONLY MARGINALLY CONDUCIVE FOR SOME DEVELOPMENT OF THIS DISTURBANCE DURING THE NEXT 24 HOURS...AND A LESS FAVORABLE ENVIRONMENT IS EXPECTED AFTER THAT TIME. THERE IS A MEDIUM CHANCE...30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. HOWEVER...LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS WILL BE POSSIBLE OVER THE CAPE VERDE ISLANDS THROUGH SATURDAY AS THE LOW MOVES TOWARD THE NORTHWEST OR NORTH-NORTHWEST AT 8-13 KT. ...THE ITCZ... THE CONVENTIONAL CONFLUENCE OF WINDS ASSOCIATED WITH THE ITCZ IS BEING INTERRUPTED BY THE LARGE SCALE SFC CYCLONIC FLOW GENERATED BY THE TROPICAL WAVE CURRENTLY SW OF THE CAPE VERDE ISLANDS AND A WEAK LOW PRESSURE SYSTEM OVER THE TROPICAL CENTRAL ATLC NEAR 13N45W. THIS SCENARIO ONLY ALLOWS FOR A SMALL PART OF THE ITCZ TO DEVELOP...ANALYZED ALONG 12N28W 13N35W 14N40W. SCATTERED WEAK TO MODERATE CONVECTION IS FROM 2N-15N BETWEEN 28W-33W. THIS AREA OF CONVECTION IS ALSO RELATED TO THE TROPICAL WAVE...GENERATING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER THE CAPE VERDE ISLANDS. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ...DISCUSSION... THE GULF OF MEXICO... A BROAD MID-UPPER RIDGE OF HIGH PRESSURE IS CENTERED OVER THE FAR SOUTHWEST GULF CONTINUES TO DOMINATE THE AREA OF DISCUSSION THIS AFTERNOON...GIVING MOSTLY CLEAR SKIES WITH FEW AREAS OF SCATTER LOW LEVEL STRATOCUMULUS CLOUDS EMBEDDED IN THE LIGHT ANTICYCLONIC SFC FLOW...EXCEPT THE FAR NW BASIN...WHERE 15 KT TO 20 KT RETURN FLOW IS OBSERVED FROM THE COASTAL WATERS NEAR MATAMOROS MEXICO TO THE CENTRAL COAST OF TEXAS. STRONG SUBSIDENCE AND DRY AIR ALOFT WILL CONTINUE OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... TROPICAL STORM RICHARD IS OVER THE WESTERN CARIBBEAN PRODUCING MODERATE TO STRONG CONVECTION FROM 14N-19N BETWEEN 78W-83W. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ANOTHER AREA OF MODERATE TO STRONG CONVECTION IS OVER THE FAR SOUTHWEST BASIN FROM 10N-14N W OF 80W...ASSOCIATED WITH THE LARGE CYCLONIC FLOW FROM RICHARD DRAWING DEEP MOISTURE FORM THE FAR EAST TROPICAL PACIFIC ITCZ. ELSEWHERE OUTSIDE THE AREAS OF CONVECTION ASSOCIATED TO RICHARD...AN ELONGATED UPPER LEVEL LOW ACROSS THE OVER THE SOUTH CENTRAL CARIBBEAN. SE FLOW ALOFT EAST OF THIS FEATURE IS DRAWING SOME LIMITED MID-UPPER LEVEL MOISTURE FROM NORTHERN S AMERICA...ENHANCING A FEW AREAS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EMBEDDED IN THE TRADE WINDS E OF 74W. THE ATLANTIC OCEAN... A BROAD MID-UPPER LEVEL TROUGH MOVES OFF THE NORTH AMERICA SEABOARD SUPPORTING A FRONTAL SYSTEM THAT ENTERS OUR AREA OF DISCUSSION AS A SURFACE TROUGH NEAR 31N62W TO 26N72W. AN AREA OF BROAD UPPER LEVEL ANTI-CYCLONIC CIRCULATION IS CENTERED NE OF THE LESSER ANTILLES NEAR 22N60W. THIS FEATURE COMBINED WITH THE UPPER TROUGH IN THE WESTERN ATLC IS DRAWING DEEP MOISTURE FROM THE WESTERN CARIBBEAN ACROSS THE WESTERN ATLC...INTO THE NORTH CENTRAL ATLC...GENERATING AN AREA OF DEEP LAYER CONFLUENCE ZONE MARKED BY THE FRONTAL SYSTEM MENTIONED ABOVE. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 110 NM ON EITHER SIDE OF THE SFC TROUGH AXIS. AN UPPER LEVEL LOW IS OVER THE CENTRAL/EAST ATLC SPINNING NEAR 23N37W. THIS UPPER FEATURE IS PRODUCING AN AREA OF ISOLATED CONVECTION FROM 20N-26N BETWEEN 30W-40W. THE REST OF THE AREA OF DISCUSSION N OF 20N REMAINS UNDER FAIR WEATHER CONDITIONS SUPPORTED BY A DRY AND STABLE UPPER ATMOSPHERE SEEN ON WATER VAPOR IMAGERY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA