476 
 WTNT41 KNHC 300851
 TCDAT1
 HURRICANE ALEX DISCUSSION NUMBER  19
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL012010
 400 AM CDT WED JUN 30 2010
  
 ALEX HAS BECOME MUCH BETTER ORGANIZED THIS MORNING BASED ON
 WELL-DEFINED BANDING FEATURES WRAPPING INTO THE CENTER AND THE
 APPEARANCE OF A SMALL EYE IN INFRARED IMAGERY. AN AIR FORCE RESERVE
 UNIT RECONNAISSANCE AIRCRAFT AT 0842Z MEASURED A CENTRAL PRESSURE
 961 MB AND 850 MB FLIGHT-LEVEL WINDS OF 82 KT IN THE NORTHEAST
 QUADRANT. THE SFMR ABOARD THE PLANE MEASURED A RELIABLE SURFACE
 WIND OF 62 KT AND A RAIN-CONTAMINATED PEAK WIND OF 71 KT. THE
 DVORAK INTENSITY ESTIMATE FROM BOTH TAFB AND SAB WAS T4.5/77 KT.
 THEREFORE...THE INITIAL INTENSITY IS CONSERVATIVELY INCREASED TO 70
 KT FOR THIS ADVISORY.
  
 ALEX HAS WOBBLED WEST-NORTHWESTWARD OVER THE PAST 6 HOURS...AND EVEN
 BRIEFLY STALLED. HOWEVER...TRENDING THROUGH THE SATELLITE AND RECON
 FIXES YIELDS AN AVERAGE MOTION OF 290/06. UPPER-AIR OBSERVATIONS AT
 00Z INDICATED MODEST 10-30 METER HEIGHT RISES FROM 700-400 MB
 ACROSS THE GULF COAST FROM LOUISIANA TO FLORIDA...BUT ALSO TO THE
 NORTHWEST AND WEST OF ALEX ACROSS TEXAS MEXICO TO THE WEST. THIS
 MEANS ALEX IS EMBEDDED BETWEEN TO RIDGES AND IN A WEAKER STEERING
 FLOW REGIME THAT NONE OF THE MODELS PICKED UP ON IN THE SHORT TERM.
 HOWEVER...ALL OF THE GLOBAL AND REGIONAL MODELS ARE CONSISTENT ON
 BRINGING A MID-LEVEL RIDGE FROM WESTERN NEBRASKA SOUTHEASTWARD TO
 THE TENNESSEE VALLEY DURING THE NEXT 48 HOURS...WHICH SHOULD ACT TO
 STEER ALEX ON WEST-NORTHWESTWARD TRACK FOR THE NEXT 24 HOURS AND
 THEN WESTWARD ACROSS NORTHERN MEXICO AFTER THAT. THERE HAS BEEN AN
 INTERESTING CHANGE IN THE 00Z AND 06 MODEL GUIDANCE WITH THE ECMWF
 SHIFTING FARTHER NORTHWARD...WHICH MEANS THIS MDOEL HAS GONE FROM
 BEING THE PERSISTENT LEFT-MOST OF THE MODELS TO THE RIGHT SIDE OF
 THE MODEL SUITE...AND IT NOW HAS A TRACK SIMILAR TO HWRF. THE
 OFFICIAL FORECAST TRACK HAS BEEN SHIFTED SLIGHTLY TO THE RIGHT OF
 THE PREVIOUS TRACK BASED ON THE MORE NORTHWARD INITIAL POSITION...
 AND REMAINS NEAR THE EXTREME RIGHT SIDE OF THE GUIDANCE ENVELOPE
 AND NORTH OF THE MODEL CONSENSUS.
 
 VERTICAL SHEAR IS FORECAST TO REMAIN LIGHT UP UNTIL LANDFALL OCCURS
 IN ABOUT 24 HOURS. GIVEN THAT ALEX IS ALSO MOVING SLOWLY OVER SOME
 OF THE WARMEST UPPER-OCEAN HEAT CONTENT IN THAT REGION OF THE GULF
 OF MEXICO...STEADY STRENGTHENING RIGHT UP UNTIL LANDFALL SEEMS
 REASONABLE.  HOWEVER...GIVEN THE RELATIVELY LOW CENTRAL PRESSURE
 RECENTLY MEASURED BY THE RECON AIRCRAFT...RAPID INTENSIFICATION OF
 AT LEAST 30 KT IN 24 HOURS IS A DISTINCT POSSIBILITY. THE OFFICIAL
 INTENSITY FORECAST IS A BLEND OF THE LGEM AND SHIPS MODELS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      30/0900Z 23.3N  95.1W    70 KT
  12HR VT     30/1800Z 23.8N  96.2W    80 KT
  24HR VT     01/0600Z 24.3N  97.7W    85 KT
  36HR VT     01/1800Z 24.5N  99.6W    35 KT...INLAND
  48HR VT     02/0600Z 24.4N 101.7W    20 KT...DISSIPATING INLAND
  72HR VT     03/0600Z...DISSIPATED INLAND
  
 $$
 FORECASTER STEWART