000 AXNT20 KNHC 071145 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU OCT 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURE... AT 0900 UTC...SUBTROPICAL STORM OTTO IS CENTERED NEAR 23.6N 68.2W OR ABOUT 235 MI...380 KM NE OF GRAND TURK ISLAND...OR ABOUT 635 MI...1025 KM SSW OF BERMUDA MOVING N AT 2 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS 60 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. LATEST SATELLITE IMAGERY SHOWS THAT THE LOW LEVEL CENTER CONTINUES TO BE EXPOSED WITH DEEP CONVECTION WRAPPING AROUND THE EAST AND SOUTH QUADRANTS OF THE CYCLONE. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 20N-25N BETWEEN 65W-71W. THIS SYSTEM CONTINUES TO DRAG DEEP LAYER MONSOONAL MOISTURE FROM NORTHERN S AMERICA ACROSS THE S CENTRAL AND EASTERN CARIBBEAN AS SEEN ON TOTAL PRECIPITABLE WATER IMAGERY AND SATELLITE DERIVED WINDS. HENCE...MULTIPLE ACTIVE BANDS SSE OF THE CENTER EXTEND ACROSS THE EASTERN CARIBBEAN SEA AND NE OF THE LEEWARD ISLANDS...WITH THE HEAVIEST ACTIVITY ACROSS THE MONA PASSAGE...PUERTO RICO...AND THE US/UK VIRGIN ISLANDS. WINDS IN THESE AREAS ARE NOTED FORM THE SSW AT 15-20 KT. FLASH FLOOD AND MUD SLIDES ARE LIKELY TO OCCUR OVER THESE AREAS...ESPECIALLY OVER SATURATED TERRAIN FROM PREVIOUS RAINFALLS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS ANALYZED FROM 11N40W TO 3N48W MOVING W AT 8 KT. THE WAVE IS EMBEDDED WITHIN AN AREA OF ELEVATED VALUES OF MOISTURE AS SEEN IN THE TOTAL PRECIPITABLE WATER IMAGERY. LOW LEVEL SATELLITE DERIVED WIND DATA SHOWS A SHARP CYCLONIC TURNING ALONG THE WAVE AXIS. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION HAS BECOME MORE PRONOUNCED TODAY IN THE LAST 6 TO 9 HOURS IN ASSOCIATION WITH THE WAVE FROM 7N-12N BETWEEN 40W-50W. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE COAST OF GUINEA-BISSAU NEAR 14N17W WESTWARD ALONG 10N20W 5N27W 6N34W 10N40W. SCATTERED MODERATE CONVECTION IS OCCURRING WITHIN 140 NM OF THE AXIS BETWEEN 19W AND 29W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY SHOWS A VERY DRY AND STABLE AIR MASS ALOFT MOVING ACROSS THE GULF. FURTHERMORE...A 1023 MB HIGH IS CENTERED OVER CENTRAL TEXAS NEAR 31N99W PRODUCING NE SURFACE FLOW AND FAIR WEATHER OVER THE GULF OF MEXICO. PATCHES OF FAIR WEATHER STRATOCUMULUS CLOUDS DOT THE AREA SOUTH OF 27N. 10-15 KT NE SURFACE WINDS ARE NOTED OVER THE GULF WITH THE EXCEPTION OF 15-20 KT NE WINDS E OF 85W AND OVER THE FLORIDA KEYS AND STRAITS OF FLORIDA. IN THE UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE GULF OF MEXICO AND STRONG SUBSIDENCE PREVAILS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS QUITE DRY CONDITIONS OVER THE ENTIRE GULF. EXPECT...SOME WEAKENING OF THE SURFACE WINDS OVER THE NEXT 24 HOURS. CARIBBEAN SEA... THE LARGE SCALE CYCLONIC SFC CIRCULATION ASSOCIATED WITH SUBTROPICAL STORM OTTO CONTINUES TO DRAG DEEP LAYER MONSOONAL MOISTURE FROM NORTHERN S AMERICA ACROSS THE S CENTRAL AND EASTERN CARIBBEAN AS SEEN ON TOTAL PRECIPITABLE WATER IMAGERY AND SATELLITE DERIVED WINDS. SCATTERED MODERATE TO STRONG BANDS OF CONVECTION COVER THE EASTERN CARIBBEAN E OF 72W...WITH THE HEAVIEST ACTIVITY OVER THE MONA PASSAGE...THE COASTAL WATERS OF PUERTO RICO...ACROSS THE US/UK VIRGIN ISLANDS. WINDS IN THESE AREAS ARE NOTED FORM THE SSW AT 15-20 KT. SCATTERED MODERATE CONVECTION IS ALSO OVER THE S CENTRAL CARIBBEAN AFFECTING THE COASTAL WATERS OF COLOMBIA AND VENEZUELA S OF 15N BETWEEN 65W AND 73W. SIMILAR CONVECTION IS OVER THE FAR SW BASIN S OF 12N BETWEEN 75W AND 82W. ELSEWHERE...A WEAK STATIONARY FRONT FROM THE W ATLANTIC REACHES ACROSS CUBA AND CONTINUES SOUTHWARD AS A SURFACE TROUGH TO THE SW CARIBBEAN ALONG 21N78W 16N79W 10N79W. ISOLATED STRONG CONVECTION IS OCCURRING WITHIN 200 NM W OF THE TROUGH AXIS FORM 13N TO 20N. IN THE UPPER LEVELS...AN UPPER LEVEL LOW...WHICH IS PART OF THE SUBTROPICAL STORM...IS CENTERED N OF HISPANIOLA NEAR 22N68W AND IS PRODUCING UPPER LEVEL DIVERGENCE OVER THE E CARIBBEAN ENHANCING CONVECTION. EXPECT LITTLE CHANGE DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... A DEEP LAYERED TROUGH MOVES OFF THE EASTERN US SEABOARD. THIS SYSTEM SUPPORTS A FRONTAL BOUNDARY THAT ENTERS OUR AREA OF DISCUSSION AS A STATIONARY FRONT ACROSS THE W ATLANTIC FROM 32N71W TO THE BAHAMAS NEAR 25N76W AND TO CENTRAL CUBA AT 22N78W. SCATTERED SHOWERS ARE WITHIN 80 NM ON EITHER SIDE OF THE FRONT AXIS. SURFACE WINDS ON BOTH SIDES OF THE FRONT ARE 15-20 KT OUT OF THE NORTH-NORTHEAST. SUB-TROPICAL STORM OTTO IS TO THE EAST OF THIS FRONTAL SYSTEM ENHANCING A BROAD AREA OF CONVECTION OVER THE SW ATLC AND EASTERN CARIBBEAN. SEE SPECIAL FEATURE ABOVE FOR MORE DETAILS. ELSEWHERE E OF 50W N OF 12N...A 1020 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 32N47W. OF NOTE IN THE UPPER LEVELS...TWO UPPER LEVEL LOWS ARE OVER THE ATLANTIC AT 23N67W AND 25N52W. THE FORMER LOW IS ENTWINED WITHIN THE CIRCULATION OF THE SUBTROPICAL STORM. EACH UPPER CYCLONE IS CAUSING UPPER LEVEL DIVERGENCE ENHANCING CONVECTION. AN AREA OF SAHARAN DUST IS NOTED OVER THE ATLANTIC E OF 45W FROM 10N-25N. IN THE NEXT DAY...THE FRONTAL BOUNDARY SHOULD FADE WHILE THE AREA OF BRISK TO STRONG WINDS ASSOCIATED WITH THE SUBTROPICAL STORM SHOULD GROW. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA