000
WTNT41 KNHC 010239
TCDAT1
HURRICANE ALEX DISCUSSION NUMBER  22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL012010
1000 PM CDT WED JUN 30 2010
 
OBSERVATIONS FROM THE BROWNSVILLE WSR-88D RADAR AND THE AIR FORCE
RESERVE UNIT HURRICANE HUNTERS INDICATE THAT THE EYE OF ALEX
CROSSED THE COAST IN A SPARSELY-POPULATED AREA OF NORTHEASTERN
MEXICO AROUND 0200 UTC.  JUST BEFORE LANDFALL...THE AIRCRAFT
MEASURED SURFACE WINDS OF 87 KT FROM THE SFMR INSTRUMENT AND A
MINIMUM CENTRAL PRESSURE OF 947 MB.  ASSUMING THAT THE PEAK WINDS
WERE NOT SAMPLED...AND OUT OF RESPECT FOR THE CONTINUED DROP IN
CENTRAL PRESSURE...THE LANDFALL INTENSITY WAS SET AT 90 KT.  THE
CURRENT INTENSITY ESTIMATE OF 85 KT IS BASED ON AN ASSUMED SLIGHT
DECREASE SINCE LANDFALL.  CONTINUED WEAKENING WILL OCCUR AS ALEX
MOVES OVER LAND...AND THE WEAKENING IS LIKELY TO BE RATHER RAPID
AFTER THE TROPICAL CYCLONE REACHES THE VERY HIGH AND RUGGED TERRAIN
ASSOCIATED WITH THE SIERRA MADRE ORIENTAL MOUNTAINS OF MEXICO. 
DISSIPATION IS LIKELY WITHIN 36 TO 48 HOURS...IF NOT SOONER.

INITIAL MOTION IS ABOUT 260/9...JUST A TAD SOUTH OF DUE WEST. 
MID-LEVEL RIDGING TO THE NORTH OF ALEX IS PREDICTED TO BE MORE OR
LESS MAINTAINED FOR THE NEXT 24 TO 48 HOURS.  THIS WOULD MOVE THE
CYCLONE ON A MAINLY WESTWARD TRACK UNTIL DISSIPATION.

AS THE WINDS DECREASE AND THE SURGE AND WAVES ALONG THE COAST
GRADUALLY DIMINISH...THE PRIMARY THREAT FROM ALEX WILL BE
TORRENTIAL RAINS TOTALING AS HIGH AS 20 INCHES...WHICH WOULD LIKELY
PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES OVER THE
MOUNTAINOUS REGIONS OF MEXICO.  ALSO...A FEW TORNADOES ARE POSSIBLE
OVERNIGHT WITHIN THE NORTHERN PORTION OF THE CIRCULATION OF ALEX.

IT MAY BE OF INTEREST THAT ALEX WAS THE FIRST CATEGORY TWO...AND THE
STRONGEST...HURRICANE TO OCCUR IN JUNE SINCE ALMA OF 1966.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/0300Z 24.3N  97.8W    85 KT
 12HR VT     01/1200Z 24.3N  99.4W    60 KT...INLAND
 24HR VT     02/0000Z 24.3N 101.6W    30 KT...INLAND
 36HR VT     02/1200Z 24.8N 103.8W    20 KT...INLAND
 48HR VT     03/0000Z...DISSIPATED INLAND
 
$$
FORECASTER PASCH/BERG