Alert archive / Michigan / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 21, NWS Grand Rapids, MI
NWS Grand Rapids, MI issued this severe thunderstorm warning at May 17, 1999, 4:50 PM EDT for Eaton County, Jackson County, Michigan. It was in force for 55 min. 2 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- May 17, 1999, 4:50 PM EDT (20:50 UTC)
- Expired
- May 17, 1999, 5:45 PM EDT
- In force
- 55 min
- Issued by
- NWS Grand Rapids, MI
- Area
- Whole counties
Counties Eaton County, MI, Jackson County, MI
The radar
The Grand Rapids radar (KGRR), 91 km from the middle of the area, began a volume at 20:51 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 17, 5:00 PM EDT | Thunderstorm Wind | Countywide, MI | Numerous trees and power lines were downed across the county. A small plane at the Fitch Beach Airport in Charlotte was flipped over by strong winds. |
| May 17, 5:00 PM EDT | Hail 0.75 | Parma, MI | 0.75" hail was reported in Parma. Numerous trees and power lines were also brought down in the Napoleon and Clark Lake areas. |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 17, 2:35 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 8.8 hours before the alert went out and 104 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 653 J/kg
- Mixed-layer CIN
- -27 J/kg
- Mixed-layer LCL
- 730 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 92 m²/s²
- 0-3 km storm-relative helicity
- 128 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
The office that day
Everything else NWS Grand Rapids, MI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 16, 10:56 PM EDT | Severe Thunderstorm Warning | GRR | Allegan, Kent, Ottawa | 34 min |
| May 17, 2:13 PM EDT | Severe Thunderstorm Warning | GRR | Kent | 32 min |
| May 17, 3:53 PM EDT | Severe Thunderstorm Warning | GRR | Van Buren | 22 min |
| May 17, 4:40 PM EDT | Severe Thunderstorm Warning | GRR | Allegan, Barry, Calhoun | 45 min |
| May 17, 4:40 PM EDT | Severe Thunderstorm Warning | GRR | Ottawa | 45 min |
| May 17, 4:50 PM EDT | Severe Thunderstorm Warning | GRR | Eaton, Jackson | 25 min |
| May 17, 4:50 PM EDT | Severe Thunderstorm Warning | GRR | Ionia, Kent | 25 min |
| May 17, 4:50 PM EDT | Severe Thunderstorm Warning | GRR | Ionia, Kent | 55 min |
| May 17, 5:13 PM EDT | Severe Thunderstorm Warning | GRR | Clinton, Ingham, Montcalm | 62 min |
| May 17, 5:38 PM EDT | Severe Thunderstorm Warning | GRR | Isabella, Mecosta | 52 min |
| May 17, 5:38 PM EDT | Severe Thunderstorm Warning | GRR | Gratiot | 52 min |
| May 17, 5:41 PM EDT | Severe Thunderstorm Warning | GRR | Van Buren | 49 min |
| May 17, 5:45 PM EDT | Severe Thunderstorm Warning | GRR | Calhoun, Jackson | 45 min |
| May 17, 5:59 PM EDT | Severe Thunderstorm Warning | GRR | Clare, Osceola | 61 min |
| May 17, 6:20 PM EDT | Severe Thunderstorm Warning | GRR | Ingham | 40 min |
| May 17, 6:26 PM EDT | Tornado Warning | GRR | Kalamazoo | 49 min |
| May 17, 7:05 PM EDT | Severe Thunderstorm Warning | GRR | Barry, Eaton | 40 min |
Nearby
Severe Thunderstorm Warnings in Michigan, 1999Every severe thunderstorm warning in 1999
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.