# Presentation: 709343

## Using The Short Fuse Composite to Forecast Severe Convection:

- Part II – “The Next Generation,” Updating the Technique

- By Jim Johnson & Mike Umscheid
- NWS Dodge City, KS

## “Next generation” Short Fuse Composite (SFC)

- _Objective analysis routines_
- NWS AWIPS MSAS and LAPS
- _Gridded display software_
- NWS-FSL Graphical Forecast Editor (GFE)
- _Updated techniques_
- Low-level Lapse Rate replaces “Cap” parameter as convective initiation tool

## Components of the SFC 

- _Surface Moisture Flux Convergence_
- Calculated from hourly MSAS grids  **(g/kg/hr * 100)**** **
- _Potential Temperature Advection_
- Native pot. temp. adv. grid from hourly LAPS **(K/hr * 100)**** **
- _CAPE and ThetaE_
- CAPE-  Native grid from hourly LAPS **(J/kg)**
- ThetaE- Native grid from hourly LAPS **(K)**
- _Low Level Lapse Rate (0 to 2.5km AGL)_
- Calculated from hourly LAPS grids **(C/km * 10)**

## The Charts

***weather.gov/ddc/short.html***

## “Threat Area” Components

- axis of highest
- moisture flux
- convergence

- Downwind of
- positive pot.
- temp. axis

- within axis of
- greatest surface
- based instability

## Threat Area: 19 Aug 2005 @ 2000 UTC

- 3 components from Chart 1

- SB Conv. Inhib component from Chart 2

## 19 Aug 2005:  Great Bend Tornadoes

- SFC Threat Area Analysis 2000 UTC

**2004**

**2104**

**2159**

***© Henry Diehl***
*with permission*

- Just northeast of
- Great Bend around
- 2120 UTC

## A few more 2005 cases. . .

- _April 10_ *(local tornado outbreak)*
- “cold core” upper low setup with advancing dry intrusion
- _June 9_ *(local tornado outbreak)*
- Traditional southwest flow setup ahead of broad upper trough
- _July 3_ *(long-lived monster supercell)*
- Elevated supercell transitioning to surface based supercell

## Threat Area: 10 Apr 2005 @ 1800 UTC

- Radar imagery 1904 UTC

- 1900 UTC
- weak tornado west of  Scott State Lake

- 3 components from Chart 1

## Threat Area: 10 Apr 2005 @ 2000 UTC

- 3 components from Chart 1

- Radar imagery 2059 UTC

- Multiple tornadoes from 2 storms in Trego County from 2135 to 2205 UTC

## Threat Area: 10 Apr 2005 @ 2200 UTC

- Radar imagery 2259 UTC

- 3 components from Chart 1

- Gorham-Russell Tornadic Supercell (large tornado at 2308 UTC)

- Toulon-Catherine Tornadic Supercell (large tornado crosses I-70 at 2252 UTC)

## Threat Area: 9 Jun 2005 @ 1800 UTC

- Satellite imagery 1932 UTC

- 3 components from Chart 1

- Convective Initiation

## Threat Area: 9 Jun 2005 @ 2000 UTC

- Large Tornadic Supercell – “Hill City” tornado 2120 to 2148 UTC rated F2

- 3 components from Chart 1

- Radar imagery 2101 UTC

***© Eric Nguyen***
*with permission*

## Threat Area: 9 Jun 2005 @ 2100 UTC

- Large Tornadic Supercell – “Zurich-Stockton” tornadoes 2225 to 2240 UTC

- New Supercells
- Developing

- Radar imagery 2201 UTC

- 3 components from Chart 1

***© Eric Nguyen***
*with permission*

## Threat Area: 9 Jun 2005 @ 2200 UTC

- Large Tornadic Supercell – “Stockton” tornado 2257 to 2306 UTC rated ***F1***

- Radar imagery 2301 UTC

- Tornadic Supercell – “Trego Center” tornado 2300 to 2310 UTC rated ***F3***

- Tornadic Supercell – several tornadoes between 2330 and 2400 UTC

- 3 components from Chart 1

***© Amos Magliocco***
*with permission*

## Threat Area: 3 Jul 2005 @ 1700 UTC

- Radar imagery 1803 UTC

- Chart 1

- Chart 2

- Baseball size hail @ 1830 and 1855 UTC in Rush County... no wind reports

## Threat Area: 3 Jul 2005 @ 1900 UTC

- Radar imagery 2002 UTC

- Chart 1

- Chart 2

- Golfball size hail numerous reports + 70mph winds 1925 to 2015 UTC in Barton-Rice Counties.

## Threat Area: 3 Jul 2005 @ 2100 UTC

- Radar imagery 2230 UTC

- Chart 1

- Chart 2

- 3 tornado rpts, 2 golfball or larger hail rpts, and numerous wind damage rpts from est. 80 to 90mph winds.
- 2220 to 2330 UTC

## Future Work	

- Network of local office SFC
- Operational version 1.0 on AWIPS LAD
- NWS Goodland, KS first office outside of DDC to implement
- http://weather.gov/gld/short
- Improvements
- Web-based looping feature
- Chart 3:  Empirical “Threat Area” development?

- NWS DDC Short Fuse Composite website –
- http://weather.gov/ddc/short.html

## Questions & Comments?

**Questions & Comments?**

- Thank You!

***© Mike Umscheid***