SEMINAR: REMINDER- HRD/NHC CHART Seminar Series - February 14th, 2012 - 10:30 a.m - Dr. Mike Brennan - The Impact of Supplemental Dropwindsonde and Rawinsonde \,Observations on Model Track Forecasts of Hurricane Irene (2011)

[Aoml.Receptionist <aoml.receptionist@noaa.gov>]

HRD/NHC CHART 

Seminar Series

Date:           Tuesday, February 14th, 2012

Time:          10:30 a.m. - refreshments at 10:15 a.m.

Location:     AOML First-floor Conference Room

Speaker:      Dr. Mike Brennan

                    Senior Hurricane Specialist, National Hurricane Center

Title:          “The Impact of Supplemental Dropwindsonde and Rawinsonde \
Observations on Model Track Forecasts of Hurricane Irene (2011)”

Abstract: As Hurricane Irene approached the east coast of the United States the NOAA G-IV jet flew 10 synoptic surveillance 
missions from 23-27 August, along with one surveillance mission flown by an Air Force Reserve C-130 aircraft on 23 August.  
Additionally, supplemental 0600 and 1800 UTC rawinsondes were launched beginning at 1800 UTC 22 August from upper-air stations 
in the southeastern United States, and expanded to include all of the continental United States from the Rocky Mountains 
eastward beginning at 0600 UTC 25 August.

Data denial studies were performed for the supplemental observations using the National Centers for Environmental Prediction (NCEP) 
Gridpoint Statistical Interpolation (GSI) data assimilation scheme.  The NCEP Global Forecast System (GFS) and Hurricane Weather 
Research and Forecasting (HWRF) models were then run using the analyses that excluded the supplemental observations.  Differences 
between the operational GFS and HWRF forecasts and the “data-denial” forecasts were used to quantify the impact of the supplemental 
observations on the track forecast of Irene in both models. 

Preliminary results suggest a small but overall positive improvement due to both the dropwindsonde and supplementary radiosonde 
observations on the track of Irene in the GFS through 5 days.  The dropwindsonde data showed the largest improvement in 2 to 3 day 
forecasts, while the supplemental rawinsondes showed the largest improvement at days 4 and 5. The supplemental data resulted in little 
change to the track of Irene in the HWRF model through day 3 and some degradation to the track at days 4 and 5.

 1.  Please join my meeting: https://www2.gotomeeting.com/join/246745810

2.  Use your microphone and speakers (VoIP), a headset is recommended or, call in using your telephone.

  Dial 773-897-3001

  Access Code: 246-745-810

  Audio PIN: Shown after joining the meeting

  Meeting ID: 246-745-810