Image Department Meteorology
Meteorology_Home Weather_Server News/Seminars
People
Research
Academics Application Contact_Us

Hawaiian_Weather
US_Mainland_Weather
Tropical_Weather
Satellite_Imagery
Radar_Imagery
Marine
Numerical_Models
LAPS
Forecasts
Observations
Archive
Links Disclaimer
Space
SOEST_Home
University_of_Hawaii_Home

 477 
 WTPZ44 KNHC 280853
 TCDEP4
  
 HURRICANE HILARY DISCUSSION NUMBER  29
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092011
 200 AM PDT WED SEP 28 2011
  
 HILARY CONTINUES TO STEADILY WEAKEN. THOUGH RECENT MICROWAVE IMAGERY
 INDICATES THAT THE EYEWALL IS STILL IN TACT...THE ORGANIZATION OF
 THE CLOUD PATTERN HAS DECREASED FURTHER DURING THE LAST FEW HOURS.
 THE CENTRAL DENSE OVERCAST HAS BECOME MORE RAGGED IN APPEARANCE AND
 THE COVERAGE OF DEEP CONVECTION IS GRADUALLY DECREASING. A BLEND OF
 THE LATEST DVORAK T AND CI NUMBERS SUPPORT LOWERING THE INTENSITY
 TO 80 KT. ALTHOUGH THE VERTICAL SHEAR IS STILL NEGLIGIBLY
 LOW...HILARY IS MOVING ALONG A SHARP GRADIENT OF DECREASING SEA
 SURFACE TEMPERATURES AND SHOULD CROSS THE 26C-ISOTHERM WITHIN ABOUT
 18 HOURS. THIS SHOULD PROMOTE A CONTINUED...STEADY WEAKENING. THE
 RATE OF DECAY SHOULD ACCELERATE AFTER 24 HOURS AS SOUTHWESTERLY
 SHEAR IS FORECAST TO SUDDENLY INCREASE AND THE CYCLONE INGESTS AN
 INCREASINGLY COOLER AND MORE STABLE LOW-LEVEL AIR MASS. THE NHC
 INTENSITY FORECAST IS A LITTLE LOWER THAN THE PREVIOUS ONE AND IS
 IN GOOD AGREEMENT WITH THE SHIPS/LGEM MODELS THROUGH 24 HOURS AND
 THE FSSE GUIDANCE BEYOND THAT TIME.
 
 THE EYE OF HILARY APPEARS TO HAVE JOGGED A BIT TO THE LEFT IN RECENT
 HOURS...WITH A LONGER-TERM AVERAGE OF RECENT CENTER FIXES YIELDING
 AN INITIAL MOTION ESTIMATE OF 305/06. THE MODEL GUIDANCE IS IN GOOD
 AGREEMENT WITH THE SYNOPTIC STEERING PATTERN. HILARY SHOULD TURN
 TOWARD THE NORTH-NORTHWEST AND THEN THE NORTH VERY SOON AS IT MOVES
 FARTHER INTO A WEAKNESS IN THE SUBTROPICAL RIDGE OVER MEXICO...
 CREATED BY A MID-LEVEL TROUGH EXTENDING SOUTHWESTWARD FROM BAJA
 CALIFORNIA. THE APPROACH OF AN UPPER-LEVEL LOW CURRENTLY NEAR
 27N128W SHOULD THEN CAUSE THE TRACK TO BEND CYCLONICALLY DURING THE
 NEXT 24-72 HOURS. AFTER BECOMING A REMNANT LOW...GLOBAL MODELS SHOW
 POST-TROPICAL HILARY TURNING WESTWARD OR EVEN SOUTHWESTWARD IN THE
 LOW-LEVEL FLOW. THE NEW NHC TRACK FORECAST IS NUDGED SLIGHTLY TO
 THE LEFT AND IS A BIT FASTER THAN THE PREVIOUS ONE...BUT REMAINS
 CLOSE TO THE MULTI-MODEL AND HFIP CONSENSUS AIDS.
 
 A SIGNIFICANT ADJUSTMENT HAS BEEN MADE TO THE WIND RADII BASED UPON
 DATA FROM A 0528 UTC ASCAT OVERPASS.
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  28/0900Z 17.7N 118.1W   80 KT  90 MPH
  12H  28/1800Z 18.4N 118.4W   70 KT  80 MPH
  24H  29/0600Z 19.6N 118.7W   60 KT  70 MPH
  36H  29/1800Z 20.8N 118.8W   45 KT  50 MPH
  48H  30/0600Z 22.0N 119.1W   30 KT  35 MPH
  72H  01/0600Z 24.0N 120.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
  96H  02/0600Z 25.0N 120.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 120H  03/0600Z 25.0N 121.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
  
 $$
 FORECASTER KIMBERLAIN
  
 
Return to the Tropical Systems Page for HILARY

Back to main Tropical Weather page




This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students.
It was last modified on: Thu, Jul 23 2020 - 2003 UTC
Send comments to: Ryan Lyman