000 AXNT20 KNHC 120600 TWDAT TROPICAL WEATHER DISCUSSION...AMENDMENT NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST THU DEC 12 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0530 UTC ...SPECIAL FEATURE... TROPICAL STORM OLGA IS INLAND OVER HISPANIOLA NEAR 19.0N 71.4W AT 12/0600 UTC ABOUT 55 NM EAST-NORTHEAST OF PORT-AU-PRINCE HAITI AND ABOUT 170 NM EAST-SOUTHEAST OF THE EASTERN TIP OF CUBA MOVING W AT 14 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED HAS DECREASED TO 45 KT WITH GUSTS TO 55 KT. 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. SCATTERED MODERATE CONVECTION IS MOST ORGANIZED TO THE N OF THE STORM CENTER FROM 19N-23N BETWEEN 66W-72W. EVEN THOUGH THE COLDEST CLOUD TOPS ARE N OF PUERTO RICO AND HISPANIOLA ...BANDS OF HEAVY RAINS CONTINUE OVER THOSE ISLANDS. DOPPLER DERIVED RAINFALL TOTALS DEPICTED OVER 8 INCHES OF RAIN OVER MUCH OF THE PUERTO RICO MOUNTAIN CHAIN. ADDITIONAL RAIN ACCUMULATIONS OF 2 TO 4 INCHES ARE EXPECTED OVER PUERTO RICO AND THE SOUTHEASTERN BAHAMAS...WITH ISOLATED MAXIMUM STORM TOTAL AMOUNTS OF 12 INCHES OVER PUERTO RICO. RAINFALL AMOUNTS OF 4 TO 6 INCHES ARE POSSIBLE OVER HISPANIOLA WITH POSSIBLE ISOLATED MAXIMUM TOTALS OF 10 INCHES. THESE RAINS ARE EXPECTED TO PRODUCE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES IN PUERTO RICO AND HISPANIOLA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 5N23W 5N44W 3N51W. SCATTERED MODERATE CONVECTION IS FROM 4N-6N E OF 12W AND WITHIN 150 NM OF THE AXIS BETWEEN 27W-38W. ISOLATED MODERATE IS WITHIN 210 NM N OF THE AXIS BETWEEN 41W-46W. DISCUSSION... GULF OF MEXICO... MID TO UPPER LEVEL RIDGE REMAINS PARKED OVERHEAD WHILE AN UPPER LOW CONTINUES ITS SLOW W MOVEMENT OVER THE BAHAMAS. THIS PATTERN IS ENHANCING DRY STABLE AIR ALOFT SUPPRESSING THE FORMATION OF ANY DEEP CLOUDINESS. AT THE SFC...SIMILAR SETUP AS THE PAST COUPLE OF DAYS WITH RIDGING EXTENDING SW INTO THE AREA FROM A 1028 MB HIGH NEAR BERMUDA. THE SFC FLOW IS MAINLY MODERATE OUT OF THE E TO SE...EXCEPT SLY IN THE NW CORNER AHEAD OF A SLOW MOVING COLD FRONT OVER TEXAS. MILD AND RATHER HUMID WEATHER WITH THE CHANCE OF LIGHT ISOLATED SHOWERS IS THE RESULT OF THIS FLOW PATTERN. HOWEVER...THIS WILL BEGIN TO CHANGE AS THE FRONT OBTAINS FURTHER SUPPORT FROM UPPER TROUGHING CURRENTLY OVER THE ROCKIES AND ENTERS THE NW WATERS LATE TOMORROW/TOMORROW NIGHT. CARIBBEAN SEA... HEAVY RAIN IS OCCURRING OVER MUCH OF HISPANIOLA AND PUERTO RICO ASSOCIATED WITH TROPICAL STORM OLGA. THIS RAINFALL IS EXPECTED TO PRODUCE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES OVER THESE ISLANDS. FOR MORE DETAILS SEE ABOVE. ELSEWHERE...SCATTERED SHOWERS AND ISOLATED TSTMS ARE AFFECTING THE WINDWARD ISLANDS AND E CARIB WATERS S OF 15N E OF 64W ASSOCIATED WITH SLIGHT DIFFLUENCE ALOFT AND A LOW-LEVEL ELY SURGE. THE REMAINDER OF THE REGION IS EXPERIENCING MOSTLY FAIR WEATHER BENEATH MODERATE TO STRONG SUBSIDENCE ESPECIALLY N OF 17N W OF 77W WHERE THE UPPER FLOW IS CONFLUENT BETWEEN AN UPPER LOW IN THE BAHAMAS AND A RIDGE IN THE GULF. TRADE WIND FLOW IS WEAKER TODAY ACROSS MUCH OF THE S CENTRAL AND SE CARIB DUE TO THE WEAKNESS BROUGHT ABOUT BY OLGA. STRONG NELY WINDS PERSIST N OF 10N W OF 73W. ATLANTIC OCEAN... TROPICAL STORM OLGA IS THE WEATHER HIGHLIGHT ACROSS THE ATLC DISCUSSION AREA. SEE SPECIAL FEATURE SECTION FOR DETAILS. OTHERWISE...THE BASIN IS FAIRLY QUIET THIS EVENING/EARLY MORNING WITH MODERATE TO STRONG RIDGING DOMINATING THE SFC PATTERN SUPPORTED BY A 1028 MB HIGH NEAR BERMUDA AND A 1027 MB ABOUT 300 NM N OF THE MADEIRA ISLANDS NEAR 37N15W. THERE IS A SLIGHT WEAKNESS IN THE RIDGE BETWEEN 30W-45W DUE TO A COLD FRONT N OF THE AREA AND NEAR THE THE AFRICAN COAST N OF 18N DUE TO INVERTED TROUGHING ASSOCIATED WITH AN UPPER LOW. WINDS ARE STRONGEST NEAR OLGA AS TROPICAL STORM FORCE WINDS EXTEND WITHIN 210 NM IN THE N SEMICIRCLE. A LARGE AREA OF 20-30 KT NE TO E WINDS EXTEND NWD TO 27N BETWEEN 60W-78W DUE TO THE TIGHT PRES PATTERN BETWEEN THE BERMUDA HIGH AND OLGA. THE MID AND UPPER PATTERN CONSISTS OF A LONGWAVE RIDGE/TROUGH IN THE SUBTROPICS AND FAIRLY ZONAL FLOW ACROSS THE TROPICAL BELT. THE ONLY AREAS OF ORGANIZED MOISTURE IS NEAR THE N BORDER N OF 30N BETWEEN 34W-45W ASSOCIATED WITH A FAIRLY VIGOROUS SHORTWAVE AND S OF 13N AIDING BY THE STRONG ZONAL FLOW. $$ CANGIALOSI