# Presentation: 533502

## Developing an Inner-Core SST Algorithm for use in SHIPS

**Principal Investigator**: Joseph J. Cione
- NOAA’s Hurricane Research Division
**Co-Investigators:** John Kaplan (HRD); Chelle Gentemann (Remote Sensing Systems); Mark Demaria (NESDIS)
*IHC 2005 *
*Joint Hurricane Testbed*
*March 9, 2005*

## Developing an Inner-Core SST Algorithm for use in SHIPS

**	****The Goal of this JHT  project is to...**
**  ****	**
**	****Improve SHIPS intensity forecasts ****by incorporating realistic ****SST estimates in the TC high wind inner core.**

## Developing an Inner-Core SST Algorithm for use in SHIPS

**	**** ****Background/Project motivation... **
**	****+ Currently, SHIPS uses ‘pre-storm’, ambient SSTs obtained from weekly 100km resolution Reynolds analyses.**
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**	****+ As such, SHIPS is unable to account for any storm-induced ocean cooling that occurs within the high wind inner core environment.**
**	**
**	****+ Furthermore....The ‘potential term’,  PI, is defined in SHIPS as:**
**	****	****	****PI = MPI*****(fn of SST only)***** - TC intensity**
**	****   ****and is a **_**highly significant predictor**_** in the statistical model...**
**	****+ Therefore....****even modest improvements to SST may result in significant improvements in SHIPS**** intensity forecasts...**

## Developing an Inner-Core SST Algorithm for use in SHIPS

**	**** ****The Problem...**
**	****Routine observation of the inner core hurricane ocean environment is often impractical and in many cases impossible...**
**	**
**	****+ However... recent multi-hurricane  observations (1975-2002) from Cione and Uhlhorn (2003), have provided an improved representation of inner core (<60km) SST conditions...**
**	**
**	****+ Using storm-specific information in conjunction with ambient and inner core SST observations from the 33 TC events documented in Cione and Uhlhorn (2003)....**
**an algorithm **_***to predict***_** hurricane inner core SST was developed....**

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## Developing an Inner-Core SST Algorithm for use in SHIPS

**“****Dependent  Sample” Testing in SHIPS...**
**	****+ ****The ****Inner-Core SST Algorithm**** was recently tested on **_**thousands**_** of individual SHIPS forecast events between ****1989-2002****...**
**	****...****For the Inner-core SHIPS re-runs, Reynolds SST was replaced with the algorithm-derived....**
_**Inner-Core SST**_

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**	****Some major highlights from the dependent SHIPS analysis:**
**** ZER0 degradation in mean SHIPS forecast skill was found***** **
**when the inner core SST algorithm was used,  regardless of sample stratification...**
*** The algorithm is very stable...****Analysis used 1000s of individual forecast events from the 1989-2002 SHIPS storm database**
*** Biggest improvement in skill was ****found **_***later***_** in the forecast period **
**(48h-96h)**
**Specifics....**
**For **_**All Hurricanes **_** (N=4528)**
** ****an average ****1.5-3.5%**** ****improvement in skill ****over the 12-120h period **
**For all **_**Major Hurricanes**_**  (N=1011)**
** ****an average ****2.7-7.0%**** ****improvement in skill**** over the 12-120h period **
**For the **_**Top 10% “Rapid Intensifiers”**_
** ****an average ****4.5-8.0%**** ****improvement in skill**** over the 12-120h period**
**For the **_**Bottom 10% “Rapid Fillers”**_** **
** ****an average ****2.0-13.5%**** ****improvement in skill**** over the 12-120h period**

- Inner-Core SST Algorithm:Dependent Sample Summary...

## Developing an Inner-Core SST Algorithm for use in SHIPS

**	****...****. Independent Sample Testing in SHIPS...**
**	****+  Investigate the ****impact**** of the ****TC Inner-Core SST Algorithm**** ****on SHIPS 2003/04 Atlantic hurricane season forecasts...**
**	****...****For the Inner-Core SHIPS re-runs, Reynolds SST was replaced with the algorithm-derived....**
_**Inner-Core SST**_**	****	**

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*	**Highlights from the 2003/04 independent sample SHIPS analysis:*
**When the  SST inner core algorithm was used in SHIPS....**** **
**	****+ No mean degradation of forecast skill was found ****over any **
**	****forecast interval for Hurricane events**
**	****+ A significant increase in forecast skill was found ****for 2003/04 Rapid Intensifiers**
**	****+ The largest increase in absolute skill was found over the 72-120h forecast interval, ****regardless of sample stratification *****(similar to the dependent analysis)***
**Specifics....**
**For **_**All Hurricane Cases**_** (N=147-207)**
** ****an average ****7%**** ****improvement in skill ****over the 72-120h period ****(2kts)**
**For **_**All Rapid Intensifiers**_**  (N=27-33)**
** ****an average ****33%**** ****improvement in skill**** over the 72-120h period ****(5kts)**

- Inner-Core SST Algorithm:Independent Sample Summary...

**	****+**** ****Run a parallel version of SHIPS that uses the Inner-Core SST Algorithm **_***in real-time***_** during the 2005 N. Atlantic Hurricane Season**** ***(Planned activity...Coordination with M Demaria)*
**	****+**** Test the impact of high resolution (time and space) SSTs on SHIPS forecasts ***(Recently completed..2003 N. Atlantic hurricane season)*
**	****+**** Investigate the possibility of incorporating a sub-surface ocean predictor into the algorithm ***(Ongoing...near completion)*
**	****+****  Given the algorithm’s success with RI events, investigate the feasibility of using a version of the algorithm in the Atlantic RI Index ***(Preliminary work recently started with J. Kaplan)*
**	****+****  Use hurricane inner core air-sea composite analyses from Cione et al 2000 to help develop a bulk enthalpy flux predictor for possible future use in SHIPS ***(Future...begin late 2005)*

*Ongoing/Future work...*