Status:Ongoing analysis Material from: Linus, Rebecca


 

1. Impact


2. Description of the event

The plots below show analyses of MSLP and 6 hour rainfall from 27 September 00UTC to 30 September 00UTC, every 12th hour.


Radar loops can be found here:  https://bmcnoldy.rsmas.miami.edu/tropics/radar/



3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The plots below show observations from SYNOP (first plot), concatenated 6-hour forecasts (2nd plot) and HRES forecasts of 24-hour precipitation valid 28 September 12UTC - 29 September 12UTC, from different initial dates.


3.3 ENS

The plots below show the tropical cyclone track for the operational ECMWF forecasts from 28 September 00UTC (first plot) to 19 September 00UTC (last plot). The symbols shows the position on 28 September 18UTC. HRES (red), ENS CF (blue), ENS PF (grey) and BestTrack (black).

The plots below show time-series of central pressure (top), maximum wind (middle) and propagation speed (bottom) for HRES (red), ENS CF (blue), ENS PF (grey).


The plots below show EFI for 24-hour maximum wind gusts valid for 28 September.


The plot below shows the forecast evolution plot for 24-hour maximum wind gusts valid  28 September at Fort Myers. Concatenated 6-hour forecasts - green dot, HRES –red, ENS control - purple and ENS blue box-and-whisker.

3.4 Monthly forecasts


3.5 Comparison with other centres


4. Experience from general performance/other cases


5. Good and bad aspects of the forecasts for the event


6. Additional material

Evaluation from NCEP: https://www.emc.ncep.noaa.gov/users/meg/webinars/2022-10-06_Ian_Guidance.pdf


ERA5 maps of precipitation, and comparison with other Florida-landfall TCs in the past, plus a tweet from Brian McNoldy comparing the wind fields:


The plot below shows a map of GPM IMERG 24-hour total precipitation on 28th September 2022, the day of landfall:

The plots below show maps of HRES 24-hour precipitation totals on 28th September 2022, at different lead times ahead of 28th Sept:

The plots below show the difference between HRES and IMERG 24-hour precipitation totals on 28th September 2022, at different lead times:

The plot below show IMERG 24-hour rainfall for 29th September 2022:

The plots below show HRES 24-hour rainfall forecasts valid on 29th September, at different lead times:


The plots below show the difference between HRES and IMERG 24-hour precipitation totals on 29th September 2022, at different lead times:



The plots below show the 4-day rainfall from IMERG, and 4-day rainfall from observations (note 12-hour difference in period covered)

IMERG missing rainfall in central Florida/Orlando area? (unlikely this was in the last 12 hours of the observation period?)