Official VUSIT Chase Log:

04/11/01 – Day Chase

Synopsis:

The team started off the morning with a meeting at 7:30 AM. It was decided to wait longer and discuss again at 9:00. At the second briefing, conditions were looking favorable, although there was still some question since the majority of the shear was speed shear with some directional shear, and Illinois was completely clouded over. The decision was made to shift from code yellow to code red however, with a departure time of 11 AM for the Western Illinois / Eastern Iowa region.

Chase Log:

12:55    Crossed Fox River; now in high risk area

1:00     PDS Tornado Watch issued for Nern MO, Ern IA, and Nwrn IL. Expecting explosive Supercell development.

1:30      Stop in Princeton.  Rain starts.

1:38      Back on the road following a gas and food stop at Wendy’s.

1:56      Des Moines 1040 am radio talk show host finally "takes off his weather man hat" as

tornado warnings in Polk County area expire.

2:30      Cross Mississippi River into Iowa on I-280

2:38      Back on I-80, having exited the Quad Cities area

3:28      Stopped at a rest area just west of Iowa City to check DTN radar.  Line of relatively weak echoes from near Des Moines arching southeastward toward extreme Nrn MO. Cells moving very rapidly northward.

3:00      Back on I-80, heading west

3-3:10   Tornado warnings around Des Moines in Boone, Lucas, and Marian counties.  Storms are moving N at 60 mph…!

3:25      Stopped at a rest area just west of Iowa City to once again, look at radar on the DTN

3:34      Back on I-80

3:37      Just east of Oxford, IA. Pass a Semi-truck with a wide load that had recently blown off the road due to very strong S to S-SE synoptic winds.

3:40      We get off I-80 at exit 230 and parked at a pig farm south of I-80 just to the south of Oxford.  We record peak wind gusts at 43 knots.

4:00     PDS Tornado watch until 10:00 PM for Wrn Iowa, SWrn Wisconsin, and Wrn Illinois.

4:05      Departed from Oxford.  Back on I-80, heading back to the east.  Heading for U.S. 218 south at Iowa City in an attempt to intercept the south end of the arching line of severe storms along the dryline.  Storms moving rapidly N to N-NE.

4:06      Severe T-storm warning for Poweshiok County, IA.

4:14     Tornado reported on ground NE of Ottumwa, IA. Turning south on I-380/U.S. 218 to head south toward the area.

4:21     Tornado Warning for Keokuk Co.  Decide to head west on IA 22 upon arriving in Riverside.  Valid until 4:45 PM.  Issued for a storm 4 miles SE of Ollie with a developing tornado, moving Newd at 55mph.

4:29      Turned west on IA 22 at Riverside. Clearing appears to the west.

4:35      Damage and Injuries reported in Wapello Co. Anvil and darkening west of Riverside

4:38      Arrive in Kolona, IA. Tornado reported 9 miles NNE of Ollie, IA, or only about 10 miles SW of Kolona! Continue west on IA 22.  Now just west of Kalona.

4:40      Tornado warning for Nwrn Washington County, IA near Kalona.  Right where we are!

4:42      See dark skies, rain shaft, and possible wall cloud to our west.  Turned around about 2 miles west of Kolona to head back east for safety and better visibility.

4:44      Pulled into someone's driveway about 1.5 miles west of Kolona. Everyone gets out of cars to watch.

4:45     Wall cloud spotted several miles to west (by Eric Muller and several others) just south of precip core.  No lightning is observed at all.

4:46     Saw tornado slowly form out of the center of the wall cloud! Textbook formation with small funnel extending toward ground.  Classic RFD notch wrapping around the SE edge of the mesocyclone.  Sunlight backlights the funnel as it touches the ground for just a moment…!  What a beautiful sight…!  No debris cloud (as far as we can see). Rain begins to wrap around in front of it, making it hard to see.  The tornado begins to rope out horizontally before becoming totally concealed in rain or dissipating.  Report from weather center: relatively weak echos, only 50 DBZ.  No lightning!  Most likely, it was the same storm that produced the tornado N-NE of Ollie.  Eric Muller, along with others, suggest it was probably a cyclic Supercell with a regenerating mesocyclone.

4:55      Tornado warning until 5:15pm for SErn Iowa and Johnson counties, IA.

5:05      T/Td:  75/63

5:15      Heading back east of Kalona on 22

5:24      Heading north on U.S. 218

Bart:     “I sure hope those pigs are ok.  I hope they didn’t ham it up”

·                     News on the Radio is reporting that the storm dropped another tornado further south.  Its being reported that the tornado killed 1 and injured 8 at a community center in the town of Agency, located just to the east of Ottumwa, IA.

5:46      Re-issuance of tornado warning for Linne county, IA until 6:50 PM

5:59      We cross the flooded Cedar River

6:01      Stop at rest area, just west of exit 267

6:08      Back on I-80, then exited at exit 271

6:11      We park just south of I-80

6:13      T/Td:  69/63

6:24      Leaving to head back east on I-80

6:31      Anvil and Towering Cu Spotted to ESE near exit 280. Weather center reports we are seeing the back edge of a large MCS in IL.

6:40      Back on I-280

·                     Toilet falls off as we are driving 80 mph, with sustained winds already likely between 30-45 mph.  Threshold of the magnet thus has been established at around 110 knots!

6:50      We cross Mississippi River back into Illinois on I-280

7:00      Cross Mississippi back into IL. The large MCS is now to our E and NE. After seeing limited convection to north and northwest, we decide to call it a day.

7:42      1 mile west of Princeton, IL. Drive under nice roll cloud from MCS outflow coming out of the east. Stop at Wendy's in Princeton.

Bart:     "If the White Sox win and no one's around do they make a sound?"

10:35    Arrive back at the VU weather center to take down equipment

Final mileage:  626 miles

This is the first tornado interception of the year for VUSIT coming on the third official chase of the year.  This came on the fifth code yellow issued within the week.  The high risk did not seem to have held up very well, as essentially absolutely nothing happened in Illinois.  Most of the storms for the day occurred in Iowa, including many tornadoes.  A few storms also occurred within Michigan.  The interesting feature with the Iowa storms that we noticed was that the Supercells were not all that big, were low-topped, and that there was very little if any lightning all day!  The forward movement of the storms was also amazing.  These storms were reportedly moving 50 to 60 mph to the North-Northeast.  We want to send a special thank you to base support and to all of those who participated today!  We all worked very well together today folks!  We were not only able to see a Tornado today, but we were also able to forecast where one would strike…  Congrats to everyone actively involved in today’s chase!  We stayed safe and were still able to see a gorgeous storm…