1. Frantic About Frances Richard H. Grumm and John LaCorte
National Weather Service
State College, PA 16803

2. Introduction Significant Hurricane as approached Florida
Had a big impact on Florida
Raised issues of impacts as it moved north
Would the track and timing be better than with…Charlie?
Big issue was the transition stage
Heavy rains, tornadoes, and winds
Frances was a large storm lots of anomalies in wind, moisture and pressure fields
And timing of heavy rain, tornadoes, and wind
Timing was in doubt due to model differences in the speed of movement
Heavy rains on north and west side of the storm in Pennsylvania, New York, and Ohio
Cold conveyor rains (heavy) in western New York, PA, and OH.

3. Frances…the hurricane …not the mule…

4. MODUS Image as CAT-3 Storm 3 Sept 2004

5. 4 Sept GOES-12

6. Track through transition based on TPC and John LaCorte’s analyses

7. Florida and beyond Big impact of Big Storm Florida’s East Coast
Winds and rain
Tornadoes
Expectations of storm as it moved northward
Charlie had a bad “track” record (more on this later!)
Where would it rain and would there be significant winds etc.
Tornadoes were a problem too
Mainly in the feeder bands within the warm tropical air mass.
Okay, Ivan, terrible as it was…produced more tornadoes.

8. Tornadoes on the 6th

9. 54 Tornadoes on the 7th

10. 26 Tornadoes on the 8th

11. Eta 00-hour 850 hPa wind anomalies 0000 UTC 8 September
Extremely anomalous southerly winds ahead of the system
5-6 Standard Deviation above normal winds
Strong shear produced tornadoes
The strong wind anomalies persisted, though weakened as the storm moved northward
Note evolving easterly jet north of the cyclone…focus for heavy rains

12. 850 Winds 9 September 0000 UTC
Still had anomalously strong low-level winds in the warm sector east of the surface low center
Last day of tornadoes in Mid-Atlantic region
Tornadoes in the feeder bands and in the warm tropical air
The easterly jet was now well-developed north and west of the main low
Cold conveyor belt area of heavy rainfall
Well north of the cyclone center and removed from the tropical air at low-levels

13. 0000 UTC 9 September Low up western slopes Appalachians
Anomalous precipitable water
Even in the cool air in western PA and OH
Strong LLJ into Mid-Atlantic
Strong northeasterly jet
Cold conveyor

14. KCCX Storm Total Estimated Rainfall
Heaviest rains were well to the west
Western PA and Ohio hard hit
Not nearly as much rainfall in the warmer air to the east
The cold conveyor rain effect dominated in this event.

15. KPBZ estimated Rainfall real rainfall shown later
More reliance on tropical Z-R
There was some very heavy rain in eastern Ohio
Same overall pattern as KCCX though this extends farther west

16. GFS Forecasts For Frances

17. Eta Forecasts For Frances Eta taken it slowly?

18. 0000 UTC 09 September L Heavy rains in cold conveyor belt region
Note temperatures in the 60s. L

19. 0000 UTC 09 September L Heavy rains in cold conveyor belt region
Note temperatures in the 60s. L
Tropical air

20. Cold conveyor rain
Rain shield heavy rain north and west of surface low
Strongly baroclinic
Northern ageostrophic winds
Strong low- and mid-level forcing (Frontogensis)
Not most common concept heavy rain in tropical systems but big in Mid-Atlantic /northeastern US

21. Frontogenetic Rains 0000 UTC 9 Sept 850 FGEN/OBS/AGE 1000 hPa

22. ETA 0600 UTC 9 Sep

23. 1200 UTC 9 Sept

24. RUC FGEN and OBS

25. 0500 UTC RUC

26. 0800 UTC rain/FGEN anchored in cold airmoving north

27. 1200 UTC 9 Sept rain about over in PA!L

28. 1800 UTC 9 September L

29. Eta Forecasts For Frances Eta got faster with time but initially missed Oswego area locaiton!

30. The Eta and Tropical Storm Tracks
The Eta was too slow with Frances
The GFS did a better job and was more consistent
SREFS were good too….
This lead to rainfall forecasts and flood products talking about rainfall into the day of the 9th in PA
The rain ended in most locations before 1200 UTC
Lets look at the woeful Eta forecasts for Charlie

31. Eta Tracks with Charlie all valid 12Z 15 August initialized different times

32. GFS Tracks of Charlie all valid 12Z 15 August initialized different times

33. Hard to make good rainfall analyses

34. Central Appalachian Zoomed in view power of databases and arcview

35. Central Pennsylvania

36. New York

37. A word about rainfall Not very standardized data
We need better means/methods to share data
Post analysis is not so easy with such sporadic data
We could put together most but not all of the picture
We really need to improve sharing
Snowfall and rainfall data for good case reviews
This needs to be done in near real-time

38. Conclusions Frances wreaked some havoc Track of the storm
In Florida as a hurricane
In the southeast-Mid-Atlantic as
Rain and tornado machine
Central PA had mainly a cold rain
Remained in cool low-level air when the heavy rains arrived
Track of the storm
The GFS was faster with storm progression and better than the track of the Eta
The Eta has this slow bias with moving tropical storms….what's up with that?
Ensembles (not shown) are a better way to go.