000 AXNT20 KNHC 111756 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST TUE DEC 11 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 FEATURE... SUBTROPICAL STORM OLGA CONTINUES MOVING WWD ACROSS THE MONA PASSAGE. AT 15Z...OLGA WAS CENTERED NEAR 18.1N 68.0W OR ABOUT 110 NM EAST-SOUTHEAST OF SANTO DOMINGO IN THE DOMINICAN REPUBLIC MOVING JUST SOUTH OF WEST AT 13 KT. MAXIMUM SUSTAINED WIND SPEED HAS INCREASED TO 40 KT WITH GUSTS TO 50 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. SCATTERED MODERATE CONVECTION IS CONFINED TO THE NORTH AND NORTHEAST OF THE CENTER FROM 18N-22N BETWEEN 63W-70W. AS OF 12Z...SAN JUAN PUERTO RICO REPORTED RAINFALL ACCUMULATION OF 1.45 IN. ADDITIONAL RAINFALL OF 2-4 IN IS EXPECTED OVER PUERTO RICO AND THE VIRGIN ISLANDS WITH MAXIMUM AMOUNTS OF 12 IN POSSIBLE. RAINFALL ACCUMULATIONS OF 4 TO 6 IN WITH ISOLATED MAXIMUM TOTALS OF 10 INCHES ARE POSSIBLE OVER HISPANIOLA. HEAVY RAINFALL REMAINS A HIGH CONCERN WITH LIFE-THREATENING FLASH FLOODS AND MUDSLIDES POSSIBLE OVER THE ISLANDS OF PUERTO RICO AND HISPANIOLA. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 5N25W 7N35W 7N45W AND INTO SOUTH AMERICA NEAR 54N53W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 27W-38W. A CLUSTER OF MODERATE TO STRONG CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE AXIS BETWEEN 43W-48W. DISCUSSION... GULF OF MEXICO... SFC RIDGING EXTENDS THROUGH THE GULF FROM A 1027 MB HIGH IN THE W ATLC USHERING IN PATCHES OF LOW TO MID LEVEL CLOUDS. WINDS THROUGHOUT THE REGION ARE PRIMARILY E TO SE 15-20 KTS WITH 25 KT IN THE STRAIGHTS OF FLORIDA. LIGHT ISOLATED SHOWERS CONTINUE TO MOVE THROUGH THE STRAIGHTS. ALOFT...AN UPPER RIDGE REMAINS OVER THE EASTERN HALF OF THE GULF KEEPING THE ATMOSPHERE FAIRLY STABLE. CARIBBEAN SEA... NUMEROUS SQUALLS OF SHOWERS AND TSTMS ASSOCIATED WITH SUBTROPICAL STORM OLGA ARE ROTATING THROUGH THE DOMINICAN REPUBLIC...PUERTO RICO AND THE VIRGIN ISLANDS AS NOTED IN SAN JUAN DOPPLER RADAR AND SATELLITE IMAGERY. THE HEAVIEST SHOWERS ARE CURRENTLY OVER THE WESTERN HALF OF PUERTO RICO. DOPPLER RADAR INDICATES STORM TOTAL PRECIP UP TO 8 INCHES OVER CENTRAL PUERTO RICO. THESE HEAVY RAINS MAY CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. SEE THE SPECIAL FEATURE SECTION FOR MORE DETAILS. THE REMAINDER OF THE REGION IS EXPERIENCING MOSTLY FAIR WEATHER BENEATH MODERATE TO STRONG SUBSIDENCE PARTICULARLY N OF 17N AND W OF 74W. UPPER LEVEL MOISTURE IS BEING TRANSPORTED OVER THE SW CARIBBEAN NEAR PANAMA FROM CONVECTION ASSOCIATED WITH THE E PAC ITCZ. TROPICAL STORM FORCE WINDS ARE IN THE NE CARIBBEAN N OF 18N E OF 73W. OTHERWISE MODERATE TO STRONG TRADE WINDS PERSIST THROUGHOUT THE CARIBBEAN. ATLANTIC OCEAN... WEATHER ACTIVITY ACROSS THE REGION IS CONFINED TO SUBTROPICAL STORM OLGA...SEE ABOVE FOR DETAILS...EXCEPT FOR CONVECTION ASSOCIATED WITH THE ITCZ. STACKED SFC AND MID LEVEL RIDGING CONTROLS THE PATTERN IN THE W ATLC. THE TIGHT PRES GRADIENT BETWEEN THE SFC RIDGE ALONG 32N AND OLGA IS PRODUCING TROPICAL STORM FORCE WINDS THAT EXTEND UP TO 240 NM FROM THE CENTER OF CIRCULATION. LOW TO MID LEVEL CLOUDINESS IS BEING ADVECTED ACROSS THE W ATLC BY THE STRONG LOW-LEVEL FLOW. SLY FLOW ON THE E SIDE OF OLGA IS SPREADING HIGH LEVEL MOISTURE WELL TO THE N AND NE OF THE SYSTEM. THE CENTRAL AND E ATLC REMAIN TRANQUIL WITH SFC RIDGING AROUND A 1026 MB HIGH NEAR 30N46W DOMINATING THE PATTERN. BETWEEN 9N-24N...THE MID AND UPPER FLOW IS FAIRLY ZONAL ACROSS THIS PORTION OF THE ATLC AIDING IN THE TRANQUILITY. $$ WADDINGTON