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

 145 
 WTNT44 KNHC 272034
 TCDAT4
  
 TROPICAL STORM NADINE DISCUSSION NUMBER  61
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
 500 PM AST THU SEP 27 2012
 
 THE CONVECTION ASSOCIATED WITH NADINE HAS CHANGED FROM RAGGED TO
 WRAPPED-UP THIS AFTERNOON...WITH FORMATION OF A WELL-DEFINED
 CENTRAL DENSE OVERCAST AND AN EARLIER ATTEMPT AT EYE FORMATION. 
 SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE INCREASED TO
 55 KT...AND THAT IS THE INITIAL INTENSITY.  THIS COULD BE A LITTLE
 CONSERVATIVE...AS RECENT AMSU INTENSITY ESTIMATES FROM CIMSS AND
 CIRA HAVE BEEN 55-65 KT.  THE CIRRUS OUTFLOW IS FAIR IN THE
 NORTHEASTERN SEMICIRCLE...BUT IT IS RESTRICTED IN THE SOUTHWESTERN
 SEMICIRCLE WHERE THERE ARE SIGNS OF INCREASING VERTICAL WIND SHEAR.
  
 THE INITIAL MOTION IS NOW 255/6.  NADINE IS ON THE SOUTH SIDE
 OF A DEEP-LAYER RIDGE...WHICH IS FORECAST TO MOVE EASTWARD DURING
 THE NEXT 48-72 HR.  THIS WILL ALLOW NADINE TO TURN NORTHWESTWARD
 AND NORTHWARD AS IT MOVES BETWEEN THE RIDGE AND A MID/UPPER-LEVEL
 LOW SEEN IN WATER VAPOR IMAGERY NEAR 30N48W.  AFTER 72 HR...THE
 TRACK GUIDANCE REMAINS CONSISTENT IN ITS DIVERGENCE.  THE GFS...GFS
 ENSEMBLE MEAN...GFDL...AND HWRF FORECAST NADINE TO MOVE SLOWLY
 EASTWARD TO NORTHEASTWARD ALONG THE SOUTHERN EDGE OF THE WESTERLIES
 AS A TROUGH PASSES NORTH OF THE STORM.  THE UKMET...ECMWF...
 CANADIAN...AND NOGAPS FORECAST A RIDGE TO BUILD NORTH AND NORTHWEST
 OF NADINE IN THE WAKE OF THE WESTERLY TROUGH...WHICH WOULD STEER
 THE STORM BACK TOWARD THE SOUTH OR SOUTHWEST.  SINCE THERE IS
 LITTLE CHANGE TO THE TRACK GUIDANCE SINCE THE LAST ADVISORY...THE
 NEW FORECAST TRACK IS AN UPDATE OF THE PREVIOUS FORECAST...WITH A
 FORECAST SLOW MOTION AFTER 72 HR.
  
 THE GLOBAL MODELS FORECAST NADINE TO INTERACT WITH THE
 MID/UPPER-LEVEL LOW NEAR 30N48W DURING THE FORECAST PERIOD...WITH
 THE TWO SYSTEMS POSSIBLY MERGING BY 96-120 HR.  IN ADDITION...SMALL
 SHORTWAVE TROUGHS ROTATING AROUND THE LOW COULD ALSO INTERACT WITH
 THE STORM.  WHILE IT IS EXPECTED THAT NADINE WILL ENCOUNTER
 INCREASING SHEAR...IT IS POSSIBLE THAT THE SHORTWAVE TROUGHS COULD
 PARTLY SHIELD THE STORM...AS WELL AS PROVIDE UPPER-LEVEL DIVERGENCE
 THAT COULD ALLOW STRENGTHENING.  THE INTENSITY GUIDANCE IS IN FAIR
 AGREEMENT ON FORECASTING A LITTLE MORE INTENSIFICATION BEFORE
 NADINE REACHES COOLER SEA SURFACE TEMPERATURES IN ABOUT 36 HR.  THE
 NEW INTENSITY FORECAST DOES LIKEWISE AND IS NOW CLOSE TO THE
 SHIPS...LGEM...AND INTENSITY CONSENSUS MODELS.  HOWEVER...THIS IS A
 LOW CONFIDENCE FORECAST DUE TO THE UNCERTAINTY IN HOW MUCH SHEAR
 NADINE COULD ENCOUNTER.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  27/2100Z 28.6N  32.8W   55 KT  65 MPH
  12H  28/0600Z 28.8N  33.8W   60 KT  70 MPH
  24H  28/1800Z 29.7N  34.8W   60 KT  70 MPH
  36H  29/0600Z 31.2N  35.5W   60 KT  70 MPH
  48H  29/1800Z 32.9N  36.1W   60 KT  70 MPH
  72H  30/1800Z 35.5N  37.0W   55 KT  65 MPH
  96H  01/1800Z 36.0N  37.0W   50 KT  60 MPH
 120H  02/1800Z 36.5N  37.0W   45 KT  50 MPH
  
 $$
 FORECASTER BEVEN
  
 
Return to the Tropical Systems Page for NADINE

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