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

 559 
 WTPA41 PHFO 281443
 TCDCP1
 
 TROPICAL DEPRESSION NIALA DISCUSSION NUMBER  15
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP062015
 500 AM HST MON SEP 28 2015
  
 THE LAST BURST OF DEEP CONVECTION THAT DEVELOPED JUST TO THE
 EAST OF THE LOW LEVEL CIRCULATION CENTER /LLCC/ OF NIALA SUNDAY
 EVENING HAS MOSTLY DISSIPATED. THERE ARE A FEW THUNDERSTORMS
 REMAINING JUST TO THE EAST OF THE EXPOSED LLCC. MORE IMPORTANTLY...
 INFRARED SATELLITE IMAGERY SHOWS A PATCH OF MID-LEVEL CLOUDS MOVING
 ACROSS THE LLCC DURING THE PAST FEW HOURS. THIS WOULD SUGGEST THAT
 NIALA IS JUST A SHALLOW SYSTEM AT THIS POINT...WITH NO ORGANIZED MID
 OR UPPER LEVEL STRUCTURE REMAINING. THE MOST RECENT SUBJECTIVE
 DVORAK SATELLITE INTENSITY ESTIMATES WERE 2.0/30 KT FROM JTWC...
 WHILE THE PHFO AND SAB ESTIMATES WERE 1.5/25 KT. THE MOST RECENT
 UW-CIMSS ADT ESTIMATE WAS 1.6/26 KT. AS A RESULT...WE HAVE WEAKENED
 NIALA TO A 30 KT TROPICAL DEPRESSION. 
  
 THE INITIAL MOTION HAS SLOWED SLIGHTLY...AND IT IS NOW 250/07 KT.
 THE MAIN STEERING MECHANISM FOR THE SHALLOW LLCC IS THE CIRCULATION
 AROUND A BROAD SUBTROPICAL HIGH CENTERED MORE THAN 1700 NM TO THE
 NORTH-NORTHEAST. HIGH PRESSURE TO THE NORTH OF NIALA WILL LIKELY 
 REMAIN THE PRIMARY DRIVER OF THE FUTURE TRACK DURING THE NEXT FEW 
 DAYS...UNTIL WHATEVER IS LEFT OF NIALA MOVES INTO AN AREA OF WEAK 
 STEERING DURING DAYS 4 AND 5. THE LATEST TRACK FORECAST IS SLIGHTLY 
 SLOWER...AND HAS BEEN NUDGED TO THE LEFT OF THE PREVIOUS 
 ADVISORY. THIS CLOSELY FOLLOWS THE LATEST GUIDANCE FROM THE TVCN 
 CONSENSUS OUTPUT...AS WELL AS THE INDIVIDUAL GFS AND HWRF MODELS.
  
 THE LATEST ESTIMATES OF ENVIRONMENTAL VERTICAL WIND SHEAR IN THE
 VICINITY OF NIALA INDICATE IT IS FROM THE WEST-SOUTHWEST AT 28 KT
 BASED ON SHIPS AND 33 KT BASED ON UW-CIMSS. THIS STRONG SHEAR IS
 FORECAST TO CONTINUE DURING THE NEXT FEW DAYS...SO IT IS VERY
 UNLIKELY THAT NIALA WILL REDEVELOP PERSISTENT DEEP CONVECTION
 NEAR ITS INNER CORE THROUGH DAY 3. THE CONVECTIVE FLARE UPS WE
 CONTINUE TO SEE WILL LIKELY BECOME LESS FREQUENT...AND WILL REMAIN
 DISPLACED TO THE EAST AND EAST-NORTHEAST OF THE LLCC. AS A RESULT...
 WE NOW WEAKEN THE DEPRESSION TO A REMNANT LOW LATER TODAY OR
 TONIGHT. AGAIN...AS IN PREVIOUS FORECAST CYCLES...WE DO NOT
 ANTICIPATE THAT NIALA WILL DISSIPATE COMPLETELY. ONCE IT TRAVELS 
 FAR ENOUGH SOUTH...IT WILL ENCOUNTER NOT ONLY MUCH WARMER OCEAN
 TEMPERATURES...IT MAY ALSO MOVE INTO A LESS HOSTILE SHEAR
 ENVIRONMENT.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  28/1500Z 15.0N 156.8W   30 KT  35 MPH
  12H  29/0000Z 14.7N 157.9W   25 KT  30 MPH
  24H  29/1200Z 14.5N 159.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
  36H  30/0000Z 14.3N 160.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
  48H  30/1200Z 14.1N 161.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
  72H  01/1200Z 13.5N 163.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
  96H  02/1200Z 13.0N 164.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 120H  03/1200Z 12.0N 165.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
  
 $$
 FORECASTER HOUSTON
 
Return to the Tropical Systems Page for NIALA

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