000 AXNT20 KNHC 190002 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT AUG 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE... AS OF 19/0000 UTC THE EYE OF EXTREMELY DANGEROUS HURRICANE DEAN WAS LOCATED NEAR 16.0 NORTH...LONGITUDE 71.0 WEST OR ABOUT 405 MILES EAST-SOUTHEAST OF KINGSTON JAMAICA AND ABOUT 165 MILES SOUTH OF SANTO DOMINGO IN THE DOMINICAN REPUBLIC. DEAN IS MOVING TOWARD THE WEST NEAR 15 KT. ON THIS TRACK...THE CORE OF THE HURRICANE WILL PASS JUST SOUTH OF THE SOUTHERN COAST OF HAITI TONIGHT AND WILL BE NEAR JAMAICA ON SUNDAY. MAXIMUM SUSTAINED WINDS REMAIN NEAR 130 KT WITH GUSTS TO 160 KT...THIS MAKES DEAN A STRONG CATEGORY FOUR HURRICANE. THE MINIMUM CENTRAL PRESSURE JUST REPORTED BY AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT WAS 920 MB. SOME FLUCTUATIONS IN INTENSITY ARE LIKELY DURING THE NEXT 24 HOURS. ALL INTERESTS IN THE CARIBBEAN SEA AND THE GULF OF MEXICO SHOULD CLOSELY MONITOR THE PROGRESS OF THIS POWERFUL HURRICANE. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE LATEST PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR THE MOST RECENT WATCH AND WARNING INFORMATION. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS ...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL WEATHER OFFICE. DEAN REMAINS VERY IMPRESSIVE ON SATELLITE IMAGERY WITH A WELL-DEFINED EYE AND SYMMETRIC SIGNATURE TO IT'S EYEWALL ...RAINBANDS AND OUTFLOW. NUMEROUS MODERATE TO STRONG IS WITHIN 90 NM OF THE CENTER. SCATTERED MODERATE TO STRONG...IN SPIRAL BANDS...IS ELSEWHERE WITHIN 14N-20N BETWEEN 68W-73W. ...TROPICAL WAVES... A LARGE TROPICAL WAVE IS ALONG 37W/38W S OF 19N MOVING W 20 KT. MET-9 SATELLITE HOVMOLLER DIAGRAMS CLEARLY SHOW A RATHER QUICK WWD MOVING AREA OF CLOUDINESS ASSOCIATED WITH THIS FEATURE. CURRENTLY...THE WAVE APPEARS EMBEDDED WITHIN A VERY BROAD ELONGATED AREA OF LOW TO MID LEVEL CYCLONIC TURNING ASSOCIATED WITH THIS WAVE AND THE ONE TO IT'S W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE IS ALONG 50W/51W S OF 20N MOVING W 15-20 KT. SIMILARLY TO THE WAVE TO IT'S E...SATELLITE HOVMOLLER DIAGRAMS INDICATE A CONTINUOUS HISTORY OF THIS WAVE SINCE MOVING OFF THE AFRICAN COAST. SHIP/BUOY OBS IN THE REGION SHOW A FAIR BIT OF TURNING AT THE SFC...WHICH HELPED IN LOCATING THE AXIS. SCATTERED SHOWERS AND TSTMS ARE CONFINED TO THE INTERSECTION OF THE ITCZ FROM 9-12N WITHIN 180 NM OF THE AXIS. ON A SIDE NOTE...LATEST SATELLITE IMAGERY SHOWS A BROAD CYCLONIC GYRE COVERING A REGION OF ABOUT 30 DEG LONGITUDE ASSOCIATED WITH THIS WAVE AND THE ONE ALONG 37W/38W. IT'S DIFFICULT TO PIN POINT AN AXIS IN THIS BROAD GYRE. TROPICAL WAVE IS OVER CENTRAL AMERICA AND THE W CARIB ALONG 87W S OF 21N MOVING W 15-20 KT. THE WAVE WAS ADJUSTED ON THE PREVIOUS MAP TO MATCH UP WITH A WEAK INVERTED V-SHAPE SEEN ON VIS IMAGES. SINCE THEN...THE SATELLITE SIGNATURE HAS BECOME QUITE BLURRY BUT THE WAVE APPEARS TO BE IN THE CORRECT PSN BASED ON AN ANIMATION OF THE UW-CIMSS TPW LOOP WHICH SHOWS A WEAK NARROW N-S MOISTURE SURGE APPROACHING THE YUCATAN. SCATTERED SHOWERS AND TSTMS ARE SCATTERED NEAR THE INTERSECTION OF THE ITCZ OVER COSTA RICA AND NICARAGUA FROM 10N-13N W OF 82W AND ISOLATED WITHIN 120 NM OF THE AXIS N OF 18N DUE TO THE INTERACTION WITH AN UPPER LOW. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 14N17W 12N31W 11N48W 7N56W 10N63W. BESIDES FOR THE ACTIVITY MENTIONED ABOVE...NO SIGNIFICANT CONVECTION. DISCUSSION... THE GULF OF MEXICO... THE MAIN FEATURE TONIGHT IS A WWD MOVING UPPER LOW CENTERED ABOVE THE SE GULF NEAR 25N84W. LIGHTNING DATA SHOWS SOME SCATTERED TSTM ACTIVITY IN THE VICINITY OF THE UPPER CIRCULATION AND WSW OF IT S OF 24N BETWEEN 86W-91W IN AN DIFFLUENT ZONE ALOFT AND NEAR THE NRN EXTENSION OF A TROPICAL WAVE. THE REMAINDER OF THE GULF IS FAIRLY QUIET WITH ONLY PATCHY HIGH LEVEL CLOUDS DRIVEN QUICKLY SWWD ON THE PERIPHERY OF A LARGE UPPER HIGH CENTERED ABOVE THE S CENTRAL U.S. AT THE SFC...THE WRN EXTENT OF THE SUBTROPICAL ATLC RIDGE STRETCHES ACROSS THE REGION. THIS IS KEEPING WINDS FAIRLY LIGHT ACROSS THE AREA EXCEPT THE SW PART WHERE SE WINDS ARE NEAR 15 KT BASED ON AN EARLIER QSCAT PASS. ALL EYES ARE ON HURRICANE DEAN WHICH IS EXPECTED TO MOVE INTO THE W/SW PORTION OF THE AREA IN A FEW DAYS. THE CARIBBEAN SEA... ALL THE ATTENTION REMAINS FOCUSED ON POWERFUL CATEGORY FOUR HURRICANE DEAN. DEAN WILL CONTINUE TO HAVE SIGNIFICANT IMPACTS ON THE CARIBBEAN OVER THE NEXT FEW DAYS. FOR DETAILS REFER TO THE SPECIAL FEATURE SECTION ABOVE. ELSEWHERE...SCATTERED SHOWERS AND TSTMS ARE OVER COSTA RICA AND NICARAGUA ASSOCIATED WITH THE ITCZ AND A TROPICAL WAVE. FOR MORE DETAILS ON THIS REFER TO THE TROPICAL WAVES SECTION ABOVE. THE ATLANTIC OCEAN... WELL WITH ALL THE ABOVE SAID...MOST OF THE ATLC DISCUSSION AREA IS QUIET THIS EVENING. NONE OF THE TROPICAL WAVES ARE SHOWING IMPRESSIVE ORGANIZATION AND THERE ARE NOT ANY LARGE AREAS OF CONVECTIVE ACTIVITY. THE SFC PATTERN REMAINS DOMINATED BY A STRONG BERMUDA-AZORES RIDGE WHICH IS PRODUCING LIGHT TO MODERATE TRADES ACROSS THE BULK OF THE AREA...EXCEPT STRONG WINDS NEAR THE CARIB ISLANDS WHERE THERE ARE EFFECTS FROM DEAN AND NEAR THE COAST OF AFRICA WHERE THE GRADIENT IS TYPICALLY TIGHTER DUE TO LOWER PRES OVER THE CONTINENT. A COLD FRONT REMAINS N OF THE AREA ALONG 33N/34N W OF 70W...THIS LIKELY WILL PRESS TO OUR NRN BORDER LATER TONIGHT/TOMORROW. IN THE MID AND UPPER LEVELS...A LARGE RIDGE...WHICH HAS BEEN STEERING DEAN...IS CENTERED IN THE SW ATLC. AN UPPER LOW IS LOCATED IN THE CENTRAL ATLC NEAR 29N54W PRODUCING AN AREA OF STRONG WINDS ALOFT AND CIRRUS. ANOTHER ELONGATED UPPER LOW IS LOCATED ABOVE THE E ATLC NEAR 31N28W. STRONG RIDGING LIES FURTHER S ALONG 23N E OF 45W COVERING MUCH OF THE TROPICAL ATLC. $$ CANGIALOSI