September 22, 2005 Severe Storms

Photos

The following are still captures taken from video shot by Kurt Hulst. The top picture is from near Kinderhook, Michigan in southern Branch County. The bottom picture is just over the border in Indiana about 6 miles east of Angola. The pictures show a nice lowering from beneath the thunderstorm which is called  a wall cloud. Also note on the right side of the second photo a feature sometimes referred to as a beavertail, which forms along the channel of air flowing into the base of the thunderstorm as it becomes ingested by the intense updraft. Hail size often increases when a storm forms a mesocyclone (rotation), since mesocyclones enhance the upward vertical motions within the thunderstorm and intensify the updraft. All else being equal, the stronger the updraft, the bigger the hail. This rotating storm was not able to produce a funnel cloud or tornado on this day, most likely due to the environmental conditions in the low levels of the atmosphere, which were not favorable for tornadoes.
If you have pictures of damage or storms from this event that you want us to see, send it to our email account (nws.northernindiana@noaa.gov) or post it on our Twitter (@NWSIWX) or Facebook. Remember to use the TEL method when you submit your report, including the Time, Event, & Location.

Near Kinderhook, Michigan

6 E Angola

Radar

Radar trends and observations
Many of the warned storms were very tall and had impressive elevated cores. Several impressive cross sections were taken including a 65-70dBz core to nearly 30 thousand feet on a storm over Fremont in Steuben County which produced golf ball size hail. A threshold of more than 4 pixels of 80+ DVIL (Digital Vertically Integrated Liquid) for 2 or more radar volume scans was used very successfully for warning decision making along with other tools, such as cross sections, legacy VIL, all tilts, and storm top divergence.

The image on the left below is Digital Vertically Integrated Liquid (DVIL) of the storm which produced golf ball size hail in Fremont, IN. This was a new radar product at the time that NWS forecasters here at the Northern Indiana Forecast Office evaluated and incorporated into the warning decision making process for large hail producing severe storms. The image in the middle is a reflectivity cross section of this same storm. Radar operators at the NWS can cut cross sections of storms, which are produced by putting together images from all of the elevation angles that the radar scans for that particular volume coverage pattern (>a href="https://training.weather.gov/wdtd/courses/rac/documentation/rac20-introduction.pdf" target="_blank">VCP). This image shows several storm features including an elevated core, which marks the location of developing hail stones within the storm, and also a Bounded Weak Echo Region (BWER). The BWER marks the location of the intense thunderstorm updraft. In this image the BWER is the area of weaker reflectivity below the elevated core. The presence of the BWER is a strong indication of an intense storm with supercell characteristics. The image on the right shows a 3-D view of this supercell at the same time. White arrow denotes air parcel flow into and through this intense supercell storm.

National Weather Service Doppler radar produces over 100 radar products designed to assist in warning decision making. These products however are only tools, and the decision to issue warnings is made by National Weather Service meteorologists who are constantly interrogating radar, satellite, observational, and spotter data.

Digital vertical integrated liquid (VIL) product.	2-D reflectivity cross-section. White circle denotes large hail core aloft.	3-D refectivity cube. White arrow denotes air parcel trajectory.

Storm Reports

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1024 PM EST THU SEP 22 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0426 PM     HAIL             THREE RIVERS            41.94N 85.63W 
09/22/2005  0.50 INCH        ST. JOSEPH         MI   LAW ENFORCEMENT 

0430 PM     TSTM WND DMG     MENDON                  42.01N 85.45W 
09/22/2005                   ST. JOSEPH         MI   LAW ENFORCEMENT 

            1 TREE BLOWN DOWN

0505 PM     HAIL             CENTREVILLE             41.92N 85.53W 
09/22/2005  0.75 INCH        ST. JOSEPH         MI   AMATEUR RADIO   

0522 PM     HAIL             BRONSON                 41.87N 85.19W 
09/22/2005  0.75 INCH        BRANCH             MI   AMATEUR RADIO   

0552 PM     HAIL             9 SSE COLDWATER         41.82N 84.94W 
09/22/2005  0.75 INCH        BRANCH             MI   AMATEUR RADIO   

0605 PM     HAIL             MONTGOMERY              41.78N 84.81W 
09/22/2005  0.88 INCH        HILLSDALE          MI   EMERGENCY MNGR  

0610 PM     HAIL             5 N ANGOLA              41.72N 85.00W 
09/22/2005  0.88 INCH        STEUBEN            IN   AMATEUR RADIO   

0610 PM     TSTM WND DMG     FREMONT                 41.73N 84.93W 
09/22/2005                   STEUBEN            IN   AMATEUR RADIO   

            NUMEROUS 3 INCH LIMBS DOWN. DEAD TREE BLOWN OVER.

0619 PM     HAIL             4 N ANGOLA              41.70N 85.00W 
09/22/2005  0.75 INCH        STEUBEN            IN   AMATEUR RADIO   

0623 PM     HAIL             FREMONT                 41.73N 84.93W 
09/22/2005  1.75 INCH        STEUBEN            IN   AMATEUR RADIO   

0625 PM     HAIL             6 E FREMONT             41.73N 84.82W 
09/22/2005  1.75 INCH        STEUBEN            IN   AMATEUR RADIO   

0633 PM     HAIL             6 SE MONTGOMERY         41.72N 84.72W 
09/22/2005  0.88 INCH        HILLSDALE          MI   TRAINED SPOTTER 

0640 PM     HAIL             MONTGOMERY              41.78N 84.81W 
09/22/2005  0.88 INCH        HILLSDALE          MI   EMERGENCY MNGR  

0648 PM     HAIL             FREMONT                 41.73N 84.93W 
09/22/2005  0.75 INCH        STEUBEN            IN   AMATEUR RADIO   

0648 PM     HAIL             FREMONT                 41.73N 84.93W 
09/22/2005  0.88 INCH        STEUBEN            IN   AMATEUR RADIO   

            FIRESTATION DOWNTOWN

0650 PM     HAIL             3 N MONTPELIER          41.62N 84.60W 
09/22/2005  0.75 INCH        WILLIAMS           OH   LAW ENFORCEMENT 

0650 PM     TSTM WND DMG     WEST UNITY              41.59N 84.43W 
09/22/2005                   WILLIAMS           OH   LAW ENFORCEMENT 

            NUMEROUS TREES DOWN IN NORTHEAST WILLIAMS COUNTY.

0700 PM     TSTM WND DMG     FREMONT                 41.73N 84.93W 
09/22/2005                   STEUBEN            IN   AMATEUR RADIO   

            TWO 12 INCH DIAMETER TREES DOWN. ALL POWER IS OUT IN 
            FREMONT AND ALL LAND PHONES NOT WORKING.

0705 PM     HAIL             EDON                    41.56N 84.77W 
09/22/2005  1.00 INCH        WILLIAMS           OH   LAW ENFORCEMENT 

0705 PM     HAIL             4 NW WEST UNITY         41.63N 84.49W 
09/22/2005  1.00 INCH        WILLIAMS           OH   LAW ENFORCEMENT 

0710 PM     HAIL             1 W ANGOLA              41.64N 85.02W 
09/22/2005  1.00 INCH        STEUBEN            IN   AMATEUR RADIO   

0713 PM     TSTM WND DMG     4 S FAYETTE             41.61N 84.33W 
09/22/2005                   FULTON             OH   LAW ENFORCEMENT 

            TREE DOWN

0732 PM     TSTM WND DMG     4 N ARCHBOLD            41.57N 84.30W 
09/22/2005                   FULTON             OH   LAW ENFORCEMENT 

            POWER POLE DOWN

0838 PM     HAIL             10 NE HICKSVILLE        41.40N 84.63W 
09/22/2005  0.75 INCH        DEFIANCE           OH   TRAINED SPOTTER 

0910 PM     HAIL             ANTWERP                 41.18N 84.74W 
09/22/2005  0.75 INCH        PAULDING           OH   LAW ENFORCEMENT 


&&

$$

Environment

Mesoscale/Stormscale conditions
A decaying MCS (Mesoscale Convective System) moved through southern lower Michigan during the morning hours. This along with ongoing convection over central lower Michigan lead to a differential heating boundary over far southern lower Michigan between rain cooled air to the north and warm and sunny conditions to the south. An Elevated Mixed Layer (EML) plume emanating off the high plains advected over the region and provided a strong cap over the warm sector. The only location where this cap was overcome was immediately along the main surface cold front where mass convergence was maximized and the cap was sufficiently weakened. Storms initiated over Cass County Michigan and continued to build slowly southeast. There was a tendency for back-building of new storms over the same areas. Once the strong cap was overcome storm updrafts were able to take advantage of steep mid level lapse rates within the EML plume of 7.5C/km in the 700mb-500mb layer. This resulted in vigorous and very tall updrafts which were very efficient in producing large hail. Several storms took on HP (High Precipitation) supercell characteristics with well developed mid level mesocyclones. High LCL heights and unfavorable low level helicity profiles prevented these mesocyclones from descending.
The image below on the left shows 500mb heights and vorticity. The dashed red line shows the location of the mid level shortwave trough. Large scale lift in the atmosphere, which promotes storm development, occurs just ahead of these mid level shortwaves. The image at center is a surface map depicting the location of the surface cold front at 23Z, or 6pm EST. The image on the right is a map of Convective Available Potential Energy (CAPE). CAPE is a measure of the potential energy for storm growth if a thunderstorm updraft initiates.

500 mb Heights and Vorticity	SFC map at 23Z/6pm EST	Convective Available Energy (CAPE)