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

 285 
 WTNT44 KNHC 130253
 TCDAT4
  
 HURRICANE HUMBERTO DISCUSSION NUMBER  18
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092013
 1100 PM AST THU SEP 12 2013
  
 MICROWAVE IMAGERY...FROM METOP AND SSMIS...INDICATE THAT THE DEEP
 CONVECTION IS BECOMING DISLOCATED FROM THE LOW-LEVEL CENTER OF
 HUMBERTO. SO WHILE THE HURRICANE IS STILL PRODUCTING QUITE COLD
 CLOUD TOPS...WEAKENING OF THE SYSTEM HAS APPARENTLY BEGUN. THE
 INTENSITY OF 70 KT IS A BLEND OF THE HIGHER SUBJECTIVE DVORAK
 CURRENT INTENSITY NUMBERS FROM TAFB AND SAB WITH THE LOWER ADT. A
 RECENT ASCAT SCATTEROMETER PASS ALSO INDICATED THAT THE CYCLONE
 CONTINUES TO GROW LARGER...WITH TROPICAL STORM FORCE WINDS
 EXTENDING OUT ALMOST 200 NM FROM THE CENTER IN THE EASTERN
 SEMICIRCLE.
 
 THE AFOREMENTIONED DISPLACEMENT OF THE CONVECTION IS BEING CAUSED BY
 STRONG SOUTHWESTERLY VERTICAL WIND SHEAR OF OVER 30 KT...PRIMARILY
 DUE TO A RATHER ROBUST TROPICAL UPPER TROPOSPHERIC TROUGH TO THE
 WEST OF HUMBERTO.  THIS STRONG SHEAR SHOULD CONTINUE FOR AT LEAST A
 COUPLE OF DAYS...WHICH...IN COMBINATION WITH MARGINAL
 THERMODYNAMICS...SHOULD LEAD TO STEADY WEAKENING.  AT THE LONGER
 TIME RANGE...THE SHEAR IS PREDICTED TO LESSEN DUE TO THE FILLING OF
 THE UPPER TROUGH WHILE HUMBERTO ALSO REACHES WARMER WATERS.  THE
 GFS MODEL SUGGESTS THIS REDUCTION IN SHEAR WILL OCCUR IN ABOUT
 THREE DAYS...WHILE THE ECMWF MODEL WAITS UNTIL FOUR OR EVEN FIVE
 DAYS FOR THIS TO OCCUR.  THIS DIFFERENCE LEADS TO SUBSTANTIAL
 UNCERTAINTY IN HOW MUCH OF A CYCLONE WILL REMAIN AND WHETHER IT
 WILL SIGNIFICANTLY RE-INTENSIFY LATE IN THE PERIOD.  THE INTENSITY
 FORECAST IS VERY SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO
 THE CONSENSUS IN THE FIRST THREE DAYS AND BELOW IT THEREAFTER.
 
 HUMBERTO HAS BEEN MOVING AT 10 KT TOWARD THE NORTH-NORTHWEST...AS IT
 IS PROGRESSING THROUGH A BREAK IN THE MID-LEVEL RIDGE.  IN ABOUT A
 DAY...A STRONG DEEP-LAYER RIDGE REBUILDS NEAR THE AZORES AND
 SHOULD ABRUPTLY TURN HUMBERTO TOWARD THE WEST-NORTHWEST.  BY DAY
 FIVE...HUMBERTO SHOULD BE ROUNDING THIS RIDGE AND BEGINNING
 RECURVATURE.  THE TRACK MODELS ARE TIGHTLY CLUSTERED...BUT ARE
 SOMEWHAT FASTER AND FARTHER NORTH THAN THE PREVIOUS CYCLE.  THE
 TRACK FORECAST IS A BLEND OF THE LAST ADVISORY AND AN AVERAGE OF
 THE GFS/ECMWF/FIM GLOBAL MODELS.
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  13/0300Z 23.4N  29.7W   70 KT  80 MPH
  12H  13/1200Z 24.4N  30.7W   65 KT  75 MPH
  24H  14/0000Z 25.3N  32.8W   60 KT  70 MPH
  36H  14/1200Z 26.2N  35.3W   50 KT  60 MPH
  48H  15/0000Z 27.4N  37.6W   45 KT  50 MPH
  72H  16/0000Z 29.5N  41.5W   45 KT  50 MPH
  96H  17/0000Z 31.5N  44.0W   45 KT  50 MPH
 120H  18/0000Z 34.5N  45.0W   50 KT  60 MPH
  
 $$
 FORECASTER LANDSEA
  
 
Return to the Tropical Systems Page for HUMBERTO

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