Monday, August 20, 2007

Late Monday night look at Dean


Dean is poised to make landfall on the Yucatan Peninsula. Sustained winds were 160 mph with gusts to 195 mph. The minimum central pressure measured by the Air Force reconnaissance aircraft was 914mb or 26.99 inches.

From the NHC Discussion:
HURRICANE DEAN DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007
1100 PM EDT MON AUG 20 2007

DEAN HAS TAPPED INTO ENERGY PROVIDED BY THE DEEP WARM WATERS OF THE
NORTHWESTERN CARIBBEAN SEA THIS EVENING...AND HAS REACHED CATEGORY
FIVE STATUS WITH AN INTENSITY OF 140 KT. DURING THE LAST
PENETRATION BY THE AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT
AT 00Z...A CENTRAL PRESSURE OF 914 MB WAS MEASURED. THE PEAK
FLIGHT-LEVEL WIND WAS 162 KT...WHICH CORRESPONDS TO ABOUT 145 KT AT
THE SURFACE. DUE TO COMMUNICATIONS PROBLEMS...WE HAVE NOT RECEIVED
ALL OF THE DROPSONDE AND SFMR DATA IN REAL-TIME. THE ADVISORY
INTENSITY IS SET TO A POSSIBLY CONSERVATIVE 140 KT...PENDING A MORE
THOROUGH EXAMINATION OF ALL OF THE AIRCRAFT DATA. ANOTHER AIRCRAFT
WILL ARRIVE IN THE EYE OF DEAN IN A FEW HOURS...PRIOR TO LANDFALL
ALONG THE EAST COAST OF THE YUCATAN PENINSULA. THE EVOLVING
SATELLITE PRESENTATION OF DEAN REVEALS AN INCREASINGLY SYMMETRIC
CONVECTIVE PATTERN...AND A VERY WELL-DEFINED AND GRADUALLY
CONTRACTING EYE WITH A DIAMETER OF ABOUT 20 N MI. REPORTS FROM THE
AIRCRAFT...AND RECENT MICROWAVE SATELLITE IMAGERY...PROVIDE NO
INDICATIONS OF ANY INNER-CORE STRUCTURAL CHANGES THAT WOULD LEAD TO
WEAKENING PRIOR TO LANDFALL. THE OFFICIAL INTENSITY FORECAST IS
ESSENTIALLY UNCHANGED. DEAN IS EXPECTED TO MAINTAIN HURRICANE
STATUS DURING ITS ENTIRE STAY OVER YUCATAN...AND IT COULD STILL
REGAIN MAJOR HURRICANE STATUS OVER THE BAY OF CAMPECHE BEFORE FINAL
LANDFALL IN ABOUT 36 HOURS.

THE HURRICANE GENERALLY REMAINS ON TRACK WITH AN INITIAL MOTION OF
275/17. A STRENGTHENING RIDGE OVER THE SOUTHEASTERN UNITED STATES
SHOULD CONTINUE TO PUSH DEAN ROUGHLY ALONG THIS SAME HEADING AND
SPEED FOR THE NEXT COUPLE OF DAYS UNTIL DISSIPATION OVER MAINLAND
MEXICO. THE NEW OFFICIAL FORECAST IS AGAIN ADJUSTED TO THE SOUTH
IN ORDER TO MAINTAIN THE CURRENT WELL-ESTABLISHED HEADING...AND TO
BE IN BETTER AGREEMENT WITH A CONSENSUS OF THE GFDL...GFS...AND
NOGAPS MODELS. ALONG THE NEW TRACK...DEAN WILL SPEND A LITTLE LESS
TIME OVER THE BAY OF CAMPECHE...AND WILL PASS A LITTLE CLOSER TO
THE NORTHERN COAST OF THE ISTHMUS OF TEHUANTEPEC DURING THE 24-36
HOUR PERIOD. AS A RESULT...NEW WATCHES AND WARNINGS HAVE BEEN
ISSUED ALONG THE COAST OF MAINLAND MEXICO.

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