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

 883 
 WTNT42 KNHC 300831
 TCDAT2
 SUBTROPICAL STORM LAURA DISCUSSION NUMBER   5
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122008
 500 AM EDT TUE SEP 30 2008
  
 LAURA CONTINUES TO PRODUCE CONVECTIVE BANDS AROUND THE CENTER...WITH
 CLOUD TOPS COLDER THAN -60C TO THE NORTH AND NORTHEAST OF THE
 CENTER.  A RECENT AMSU OVERPASS SHOWS A WELL-DEFINED MID/UPPER-
 LEVEL WARM CORE...SUGGESTING THAT LAURA IS BECOMING MORE TROPICAL. 
 HOWEVER...WATER VAPOR IMAGERY SHOWS THAT THE SYSTEM IS STILL
 STRONGLY INVOLVED WITH AN UPPER-LEVEL LOW.  ALSO...THERE ARE NO
 SIGNS OF THE ANTICYCLONIC UPPER-LEVEL OUTFLOW CHARACTERISTIC OF A
 TROPICAL CYCLONE.  BASED ON THIS...THE SYSTEM IS STILL DESIGNATED A
 SUBTROPICAL STORM.  SATELLITE INTENSITY ESTIMATES ARE UNCHANGED
 SINCE 6 HR AGO...SO THE INITIAL INTENSITY REMAINS 50 KT.  
 
 LAURA HAS JOGGED TO THE LEFT AND ACCELERATED OVER THE PAST FEW
 HOURS...WITH THE INITIAL MOTION NOW 350/11.  OTHER THAN THAT...
 THERE IS LITTLE CHANGE IN THE FORECAST PHILOSOPHY FROM THE
 PREVIOUS ADVISORY.  A DEEP-LAYER RIDGE OVER THE NORTHEASTERN
 ATLANTIC AND A MID/UPPER-LEVEL TROUGH MOVING EASTWARD THROUGH NEW
 ENGLAND AND THE CANADIAN MARITIMES SHOULD STEER LAURA GENERALLY
 NORTH-NORTHEASTWARD FOR THE NEXT 48 HR OR SO...FOLLOWED BY A SHARP
 RIGHT TURN AS THE CYCLONE ENTERS THE WESTERLIES.  WHILE THERE IS
 THE NORMAL AMOUNT OF SPREAD IN THE GUIDANCE...IT ALL AGREES WITH
 THIS SCENARIO.  THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS
 ADVISORY...BUT NUDGED A LITTLE TO THE LEFT BASED ON THE CURRENT
 POSITION AND MOTION.
 
 LAURA WILL BE MOVING OVER STEADILY DECREASING SEA SURFACE
 TEMPERATURES DURING THE NEXT 36-48 HR...WITH THE SYSTEM LIKELY TO
 ENCOUNTER SSTS OF 12C BY 36 HR.  THIS SUGGESTS THE SYSTEM SHOULD
 GRADUALLY WEAKEN AS THE FALLING SSTS CAUSE THE CONVECTION TO
 DECREASE.  THE SYSTEM IS EXPECTED TO UNDERGO EXTRATROPICAL
 TRANSITION BETWEEN 24-48 HR...AND AFTER THIS IS COMPLETE THE
 LARGE-SCALE MODELS FORECAST SOME RE-INTENSIFICATION AS A BAROCLINIC
 LOW.  IT SHOULD BE NOTED THAT NONE OF THE LARGE-SCALE MODELS
 CURRENTLY FORECAST LAURA TO PRODUCE STORM-FORCE...50 KT...WINDS AS
 AN EXTRATROPICAL LOW.  BASED ON THIS...THE 120 HR FORECAST
 INTENSITY IS NUDGED DOWNWARD...AND ADDITIONAL ADJUSTMENTS TO THE
 FORECAST INTENSITY MAY BE NECESSARY IF THE CURRENT MODEL INTENSITY
 FORECASTS PERSIST.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      30/0900Z 40.3N  49.0W    50 KT
  12HR VT     30/1800Z 42.0N  48.5W    50 KT
  24HR VT     01/0600Z 44.6N  47.7W    50 KT
  36HR VT     01/1800Z 47.5N  46.5W    45 KT...EXTRATROPICAL
  48HR VT     02/0600Z 50.6N  44.5W    40 KT...EXTRATROPICAL
  72HR VT     03/0600Z 55.0N  37.0W    45 KT...EXTRATROPICAL
  96HR VT     04/0600Z 56.0N  25.0W    50 KT...EXTRATROPICAL
 120HR VT     05/0600Z 56.0N  10.0W    50 KT...EXTRATROPICAL
  
 $$
 FORECASTER BEVEN
  
 
Return to the Tropical Systems Page for LAURA

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