1. Intensity change and possible unusual eye wall replacement cycle of Edouard between 14 – 15 September 2014 Ed Zipser Department of Atmospheric Sciences University of Utah, Salt Lake City, UT, USA ed.zipser@utah.edu Acknowledgments: Trey Alvey, Rob Rogers, Jon Zawislak, SSEC team, and so many, many others who made HS3 possible HS3 Science Meeting Tuesday May 5, 2015

2. At least 2 drops ~ 21 UTC with sfc pressure 40 m/s

3. re GPM Overpass of Edouard

4. GPM Cross-Section through Edouard’s eye (Ku dBZ and Tb at 37, 85, 183+/-7 GHz) [Eye radius ~ 25 km at low levels] From Chuntao Liu’s PF database

5. P3 Lower Fuselage Images 14 Sept. Inner circle is estimated RMW (25 km) from tail radar Outer black line Is 50 km. 850-200 hPa shear vector N

6. P3 Lower Fuselage Images 15 Sept. Circle is estimated RMW (45 km) from tail radar Box (1 X 1°) is same scale as on 14 Sept. N 850-200 hPa shear vector

7. 15 th 15 UTC 14 th 16 UTC 16 th 20 UTC 16 th 19 UTC 14 th 15 UTC 15 th 16 UTC

8. 85-91 GHz PCT 85-91 GHz P3 exit GH enter EWRC?

9. So, what can the GH Flight of 14-15 September tell us about Edouard’s intensity change and possible eyewall replacement cycle? Interesting changes in distribution of deep convection started during the 3 hours between departure of the P-3 and the arrival of the GH. Convective bursts close to the center left of shear evolved quickly into more symmetric coverage, and at a larger radius. Dropsondes should reveal both large scale humidity distribution and small scale changes in the inner core. S-HIS may supplement occasional satellite coverage and give profiles in the eye center that the dropsondes just missed.

10. Passive Microwave Tb at time of first GH eye crossing (N-S) Deep convection at r=25 km (west), 60 km (east). Start of EWRC? 91 GHz PCT37 GHz (H) 100 km 200 km

18. Location and trajectory of AVAPS drops near Edouard N-S eye crossing at 2102 Z on 14 Sept (Note: SHIS shows GH over eye at 2102 Z; also at 0034 Z) IR Tb < 200K

19. 2100 Z release N of eye, gets into N wall2103 Z release SE of eye. enters eye -48° -45° -2° +2° COOL!WARM!

20. Brief Summary In spite of a great deal of data from 2 P-3 flights and an excellent GH flight, Edouard’s inner core evolution between 14-15 Sept. is complex and not easily understood. The RMW expands from 25 – 45 km during the GH flight but there is little indication of a conventional EWRC. A quick look at the dropsondes indicates both high and low theta-e air in different portions of the eyewall. (Why?) Challenge: Can numerical simulations shed light on the reasons for the convective evolution, eyewall radius and intensity changes between 14-16 September?

22. Upshear – Downshear cross section