# Presentation: 398093

## 61st Interdepartmental Hurricane ConferenceCIMSS TC Intensity Satellite Consensus (SATCON)

- Derrick Herndon and Chris Velden

- Funding Supported by SPAWAR PEO C4I&Space/PMW
- 180 and the ONR Marine Meteorology program via NRL.

## Motivation

-  Remove some of the ambiguity associated with objective intensity estimates
-  Hurricane Lili 2002 current intensity estimates 5 hours prior to landfall varied from 83 - 125 kts
-  Hurricane Isabel 2003 intensity estimates varied from 77 -105 kts 17 hours  prior to landfall.
-  Hurricane Charley 2004 rapid intensification
-  Goal is to assist forecasters in determining current TC intensity by combining the best aspects of individual objective estimates into a single weighted consensus estimate

## The Problem:  2006 04W

- 09JUL 0030 UTC

- 09JUL 2100 UTC

- Estimated intensity at 00Z on 09JUL is 75 kts.  System
- is moving swiftly toward Korea with apparent weakening.

- IR image from NRL TC Page

- IR image from NRL TC Page

## The Problem:  2006 04W

- 09JUL 2100 UTC

- IR image from NRL TC Page

## How It Works

- Each member is weighted based on the members statistical performance in a given situation:
-  ADT is weighted according to scene type (Eye scenes get the most weight while shear scenes get the least)
-  CIMSS AMSU is weighted according to instrument resolution (well resolved storms get more weight than poorly resolved storms as determined by IR/ATCF RMW)
-  CIRA AMSU is weighted according to CLW.  Estimates with CLW values < 1.4 mm get more weight.

## 2005-2006 Stats (Pressure)

|  | CIMSS
AMSU | CIMSS
ADT | CIRA AMSU | SATCON
 |
| --- | --- | --- | --- | --- |
| BIAS | -2.5 | -2 | -4.9 | -3.2 |
| AVG ERROR | 6.7 | 10.2 | 8.1 | 6.3 |
| RMSE | 10.4 | 14.6 | 12.7 | 9.7 |
| N | 128 | 128 | 128 | 128 |

- Values in millibars.  Validation is aircraft recon pressure +/- 3 hours from estimate time
- - bias = method was too weak.

## 2005-2006 Stats (Pressure)

- Values in millibars.  Validation is aircraft recon pressure +/- 3 hours from estimate time
- - bias = method was too weak. Simple AVG is average of CIMSS AMSU/ADT and CIRA

## Katrina 2005

**Katrina 2005**

## Slide 9

## Slide 10

## Slide 11

## Slide 12

## All 3 algorithms recently updated

## 1999-2006 Stats (Pressure)

|  | CIMSS
AMSU | CIMSS
ADT | CIRA AMSU | SATCON
 |
| --- | --- | --- | --- | --- |
| BIAS | -3 | -1.1 | -3 | -1.5 |
| AVG ERROR | 6.7 | 10.8 | 6.7 | 4.7 |
| RMSE | 9.4 | 14.2 | 10.3 | 7 |
| N | 274 | 274 | 274 | 274 |

- Values in millibars.  Validation is aircraft recon (bouys) pressure +/- 3 hours from
- estimate time  - bias = method was too weak.

## 1999-2006 Stats (MSW)

|  | CIMSS
AMSU | CIMSS
ADT | CIRA AMSU | SATCON
 |
| --- | --- | --- | --- | --- |
| BIAS | -2.1 | - 4.7 | -7.8 | -3.7 |
| AVG ERROR | 8.5 | 12.1 | 11.2 | 7.8 |
| RMSE | 10.9 | 15.8 | 15.3 | 10.1 |
| N | 274 | 274 | 274 | 274 |

- Values in knots.  Validation is best track msw coincident with aircraft recon +/- 3 hours
- from estimate time.  A - bias = method was too weak.

## 1999-2006 Stats (MSW)

|  | SATCON
MSLP | SIMPLE
MSLP | SATCON MSW | SIMPLE
MSW |
| --- | --- | --- | --- | --- |
| BIAS | -1.5 | -2.3 | -3.7 | - 4.6 |
| AVG ERROR | 4.7 | 5.3 | 7.8 | 8.4 |
| RMSE | 7.0 | 7.8 | 10.1 | 10.8 |
| N | 274 | 274 | 274 | 274 |

- MSW validation in knots.  MSLP validation in millibars.  - bias = method was too weak.

## ADT MSLP Error Compared to AMSU Max Tb Anomaly

- ADT MSLP Error (mb)

- AMSU Tmax (k)

## CIRA MSLP Error vs AMSU 89 Ghz

- AMSU 89 Ghz Average (k) for AMSU-A FOV

- CIRA MSLP Error (mb)

## Future Work

- Re-derive weights for wind component using Best Track winds
- Address MW latency
- Add error bars for estimate confidence
- Continue cross-platform information sharing
- Add additional TC intensity methods                  (SSMI / TRMM ?)

## SATCON HOMEPAGE

**SATCON HOMEPAGE**

- http://cimss.ssec.wisc.edu/tropic/satcon/satcon.html