000 AXNT20 KNHC 151811 AAA TWDAT TROPICAL WEATHER DISCUSSION...UPDATED NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 15 2008 ...UPDATED INFORMATION ON TROPICAL CYCLONES... 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... AT 15/1800 UTC...HURRICANE OMAR IS LOCATED BY AN AIR FORCE RESERVE UNIT HURRICANE HUNTER AIRCRAFT NEAR 15.3N 66.6W AT 15/1800 UTC OR ABOUT 205 NM...380 KM...SOUTHWEST OF ST. CROIX AND ABOUT 205 NM...375 KM...SOUTH-SOUTHWEST OF SAN JUAN PUERTO RICO MOVING E-NE AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 982 MB. MAXIMUM SUSTAINED WIND SPEED IS 75 KT WITH GUSTS TO 90 KT. PLEASE SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WITHIN 100 NM OF THE CENTER WITH OUTER RAINBANDS AFFECTING THE ABC ISLANDS AND THE NE CARIBBEAN. ONCE AGAIN...CURACAO REPORTED THIS MORNING 1.43 INCHES OF RAIN IN 24 HOURS. THE SAN JUAN DOPPLER RADAR IS ALREADY SHOWING THE EYE OF OMAR WITH NUMEROUS SHOWERS AND ISOLATED TSTMS OVER THE VIRGIN ISLANDS AND THE E AND SE PORTION OF PUERTO RICO. OMAR IS FORECAST TO MOVE THROUGH THE NORTHERN LEEWARD ISLANDS LATE TONIGHT AND EARLY THURSDAY LIKELY AS A CAT 2 HURRICANE ON THE SAFFIR-SIMPSON SCALE. IT ALSO ISN'T OUT OF THE QUESTION THAT OMAR COULD ACHIEVE MAJOR HURRICANE STATUS JUST BEFORE THE CYCLONE REACHES THE NORTHERN LEEWARD ISLANDS DUE TO THE CYCLONE IS IN A RELATIVELY LOW SHEAR ENVIRONMENT AND OVER 29C AND WARMER SEA SURFACE TEMPERATURES. STRONGER WINDS...ESPECIALLY IN GUSTS ARE LIKELY OVER ELEVATED TERRAIN. A HURRICANE WARNING COULD BE REQUIRED FOR PUERTO RICO LATER TODAY. LATEST VIS SATELLITE IMAGERY INDICATES THAT T.D. SIXTEEN HAS MADE LANDFALL OVER NE HONDURAS LATE THIS MORNING. TROPICAL DEPRESSION SIXTEEN IS CENTERED NEAR 15.6N AND 84.9W AT 15/1800 UTC OR ABOUT 35 NM...65 KM...EAST-SOUTHEAST OF LIMON HONDURAS AND ABOUT 210 NM...385 KM...EAST-SOUTHEAST OF MONKEY RIVER TOWN BELIZE MOVING W-SW AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. PLEASE SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE OVER THE SW AND NW CARIBBEAN FROM 10N-16N BETWEEN 77W-82W...AND FROM NORTHERN HONDURAS TO 19N WEST OF 80W TO BELIZE RESPECTIVELY. A TROPICAL STORM WARNING IS NOW IN EFFECT FOR THE ENTIRE HONDURAS COAST FROM THE HONDURAS/NICARAGUA BORDER WESTWARD TO THE GUATEMALA/HONDURAS BORDER AS WELL AS THE ENTIRE COAST OF BELIZE. THE DEPRESSION IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF 4 TO 8 INCHES OVER NORTHEASTERN NICARAGUA... NORTHERN HONDURAS...BELIZE...GUATEMALA...AND THE YUCATAN PENINSULA WITH MAXIMUM AMOUNTS UP TO 15 INCHES. THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES ...TROPICAL WAVES... ON AVERAGE...SIXTY TROPICAL WAVES MOVE OUT OF THE AFRICAN COAST EVERY YEAR. TODAY...THE 57TH TROPICAL WAVE THAT WE HAS TRACKED THIS TROPICAL SEASON HAS JUST EMERGED FROM AFRICA...AND IS ADDED TO THE 1200 UTC SURFACE MAP ALONG 18W/19W BASED ON SATELLITE PICTURES AND SURFACE DATA. AN ASCAT PASS FROM AROUND 1130 UTC CONFIRMS THE PRESENCE OF THE WAVE SHOWING ALSO SOME CYCLONIC TURNING NEAR 11N. IN ADDITION...THE HOVMOLLER DIAGRAM INDICATES THE WWD PROPAGATION OF THIS SYSTEM WHILE THE TPW PRODUCT FROM CIMSS REVEALS A NORTH-SOUTH MOISTURE MAXIMUM BETWEEN THE AFRICAN COAST AND 20W. SCATTERED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 16W-20W. A LOW AMPLITUDE TROPICAL WAVE IS ALONG 40W/41W SOUTH OF 14N MOVING WEST NEAR 10 KT. THE WAVE SHOWS UP VERY WELL ON THE SSMI TPW PRODUCT FROM CIMSS. AN EARLIER QSCAT PASS SHOWED THE WIND SHIFT ASSOCIATED WITH THIS FEATURE WITH NE WINDS JUST AHEAD OF THE WAVE AXIS...AND E TO SE WINDS BEHIND THE WAVE LINE. VIS SATELLITE IMAGERY SHOWS AN INVERTED-V SIGNATURE. AN AREA OF MODERATE/ISOLATED STRONG CONVECTION IS AHEAD OF THE WAVE AXIS AND JUST NORTH OF THE ITCZ FROM 7.5N-11N BETWEEN 41W-44W. SIMILAR CONVECTION IS WITHIN 140 NM EAST OF THE SOUTH END OF THE WAVE AXIS. A WEAK TROPICAL WAVE IS ALONG 58W S OF 18N MOVING W NEAR 10 KT. THE WAVE IS ALREADY EMBEDDED IN THE CYCLONIC CIRCULATION OF HURRICANE OMAR WITH MOSTLY SLY WINDS EITHER SIDE OF THE WAVE AXIS. THIS WAVE IS EXPECTED TO BECOME ABSORBED INTO THE LARGE CIRCULATION OF OMAR AS IT TRACKS WWD...AND PROBABLY BE DROPPED FROM THE 18Z SFC MAP. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N14W 7N25W 8N38W 8N50W 9N57W. IN ADDITION TO CONVECTION ASSOCIATED WITH THE TROPICAL WAVES... SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-10N BETWEEN 45W-52W. ...DISCUSSION... GULF OF MEXICO... AN UPPER-LEVEL LOW LOCATED OVER CENTRAL MEXICO NEAR 20N100W IS PRODUCING A MOIST SLY WIND FLOW OVER THE GULF REGION WEST OF 93W INCLUDING ALSO THE BAY OF CAMPECHE. THESE UPPER-LEVEL WINDS ARE HELPING TO INDUCE SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE WRN GULF MAINLY BETWEEN 93W AND 96W. A SURFACE TROUGH... LIKELY A REFLECTION OF THIS UPPER FEATURE REMAINS OVER THE WEST GULF AND NOW EXTENDS FROM THE DEEP SOUTH TEXAS TO THE BAY OF CAMPECHE. SHIP AND BUOY OBSERVATIONS AS WELL AS A QSCAT PASS FROM AROUND 12Z CONFIRM THE WIND SHIFT ASSOCIATED WITH THIS SURFACE TROUGH. AN UPPER-LEVEL RIDGE ANCHORED ON A HIGH OVER THE SE CONUS COVERS THE REMAINDER OF THE GULF AND THE STATE OF FLORIDA GENERATING STRONG SUBSIDENCE AND THE IMPLIED DRY AND STABLE ATMOSPHERE. ANOTHER UPPER-LEVEL HIGH IS OVER THE YUCATAN PENINSULA ASSOCIATED WITH T.D. SIXTEEN IN THE WRN CARIBBEAN. AT THE SURFACE...HIGH PRESSURE CENTER OVER THE SE CONUS DOMINATES MUCH OF THE GULF E OF 90W...INCLUDING THE FLORIDA PENINSULA AND STRAITS OF FLORIDA. THE PRESSURE GRADIENT BETWEEN THIS HIGH AND T.D. SIXTEEN CONTINUES TO GENERATE MODERATE TO STRONG ELY WINDS OVER THE CENTRAL AND ERN GULF. AN EARLIER QSCAT PASS SHOWED 20 TO 25 KT ELY WINDS OVER THE EASTERN GULF SOUTH OF 27N AND THE YUCATAN CHANNEL. CARIBBEAN SEA... TWO TROPICAL CYCLONES ARE IN THE CARIBBEAN SEA...ONE IS HURRICANE OMAR AND THE SECOND ONE IS T.D. SIXTEEN. SEE THE SPECIAL FEATURES FOR MORE DETAILS. THE UPPER-LEVEL HIGH OVER THE YUCATAN PENINSULA EXTENDS A RIDGE OVER MUCH OF THE CARIBBEAN SEA AND CENTRAL AMERICA...AND IS ENHANCING CONVECTION ASSOCIATED WITH T.D. SIXTEEN. WATER VAPOR IMAGERY REVEALS A DEEP LAYERED TROUGH ACROSS THE W ATLC DIGGING SWD INTO THE NRN CARIBBEAN. THIS TROUGH WILL PLAY A ROLE IN TRACKING OMAR TO THE NE OVER THE NEXT FEW DAYS. UPPER DIFFLUENCE E OF THE UPPER TROUGH ACROSS THE ERN CARIBBEAN IS PROVIDING AMPLE OUTFLOW FOR THE CONVECTIVE ACTIVITY ASSOCIATED WITH OMAR. PATCHES OF LOW LEVEL CLOUDS WITH POSSIBLE SHOWERS ARE REACHING PART OF THE CENTRAL AND EAST CUBA UNDER A NE WIND FLOW. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE IS ACROSS THE SE CONUS EXTENDING ACROSS THE W ATLC WATERS AND THE BAHAMAS W OF 71W. MODERATE TO STRONG SUBSIDENCE IS ASSOCIATED WITH THIS UPPER RIDGE BRINGING DRY AIR ACROSS THE FLORIDA PENINSULA...NRN CUBA AND THE BAHAMAS. A DEEP LAYERED TROUGH EXTENDING FROM AN UPPER-LEVEL LOW LOCATED NEAR 31N62W ENTERS THE CARIBBEAN SEA THROUGH HISPANIOLA AND EXTENDS MAINLY WWD SOUTH OF CUBA. THIS UPPER TROUGH SUPPORTS A SURFACE TROUGH THAT EXTENDS INTO THE DISCUSSION AREA NEAR 31N55W SW TO 20N65W. A LARGE AREA OF DEEP-LAYERED MOISTURE WITH EMBEDDED SHOWERS IS AHEAD OF THE TROUGH. THE UPPER-LOW MENTIONED ABOVE IS GENERATING SOME SHOWER ACTIVITY. A 1012 MB LOW...REMNANTS OF NANA...CENTERED NEAR 22N48W IS DRIFTING N-NW INTO THE DEEP LAYERED TROUGH ACROSS THE CENTRAL ATLC. SCATTERED SHOWERS AND TSTMS ARE WITHIN 70 NM NE QUADRANT. TO THE SE...ANOTHER 1012 MB LOW IS GENERATING SCATTRED SHOWERS. THE E ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED ON A 1029 MB HIGH CENTERED NEAR THE AZORES. AN UPPER-LEVEL HIGH CENTERED NEAR 17N48W IS SUPPORTING CONVECTION ALONG THE ITCZ MAINLY WEST OF 40W. ANOTHER CELL IS NEAR 9N30W. $$ GR