1. LAPS Hurricane Analysis and Forecasting of Dennis and Katrina
Steve Albers, Isidora Jankov, John McGinley, Yuanfu Xie, J-Y Kim,
S. G. Gopalakrishnan, John Gamache and Sim Aberson
The 2005 Atlantic hurricane season is notable for having the most named storms in a single season. Five storms, including three hurricanes (Cindy, Dennis, and Emily), were active in July. Dennis was chosen for study because radar data was collected.
According to the reports from the Tropical Prediction Center (information online at Dennis formed from a vigorous tropical wave and 1 1 1

2. LAPS
Aimed at fine scale analysis where error covariances are not well known
Analysis is data dominated: detailed where data exists, smooth where data is sparse; blended to background where data is absent
Multi-step procedure

3. LAPS III Configuration
Slide 0
LAPS III Configuration
Data
Data Ingest
Intermediate
data files
variances
Error
Covariance
covariances
Trans
LAPS
GSI
STMAS3D
Trans
Post proc1
Post proc2
Post proc3
Model prep
WRF-ARW
MM5
WRF-NMM
Probabilistic
Post
Processing
Ensemble
Forecast 3

4. ANALYSIS QUESTIONS Dennis:
Can data, such as, aircraft measured doppler winds adjust the
3D winds and height with appropriate weights on observations
and constraints.
Katrina:
How much can an analysis benefit from drop sonde and radar
data?

5. GFS 850mb
wind 5

6. fdfdfd GOES/POES Soundings Cloud-Drift Winds ACARS Temperature
ACARS/Radar Wind

7. pre-balanced
850mb
wind with obs.
5 July 2005
2100 UTC 7

8. Balanced 850
wind
and heights. 8

9. AOML 0.5 - 3.0km doppler radar winds July 5, 2005 2100 UTC9

10. AOML 3km radar & dropsonde winds July 5, 2005 2200UTC10

11. Analysis with Radar
and Dropsondes
750mb
July 5, 2005
2200UTC 11

12. ANALYSIS CONSIDERATIONS
Increased time window to bring in more radar data with the dropsondes
Decreased minimum radius of influence to capture smaller scale wind maxima?
Increase vertical radius of influence - particularly if we bring in flight level winds

13. Balanced-GFS
temperature
W-E Xsect
through Dennis 13

14. Dennis
Height
Perturb.
X-sect 14

15. Dennis
Balanced
W-E wind and
omega Xsect. 15

16. ADDITIONAL DEVELOPMENTS
* Cyclostrophic term is being reweighted in the balance
package to strengthen height/temperature
perturbation in accordance with gradient wind relationship.
- Important for tight circulations in tropics.
* Improved cloud analysis contribution to the balance
package.
- Parameter adjustments to improve low cloud
depiction.

17. 11n satellite with
850mb wind
overlay 17

18. Aircraft radar reflectivity utilized in the analysis
Katrina
18 UTC 27 August
MSLP and drop sondes
Aircraft radar reflectivity
utilized in the analysis

19. Balance package testing (higher/lower weights on wind/heights)
Katrina
Balance package testing
(higher/lower weights on
wind/heights)
Favoring wind analysis
Favoring height analysis
950 mb pre-balanced (green) and
balanced (orange) heights (dm).

20. Katrina
Pre-balanced 950-mb wind speed
and height.
Balanced 950-mb wind speed
and height.

21. QUESTIONS?!?!?!?!?!?