Alert archive / Michigan / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 57, NWS Grand Rapids, MI

July 9, 1999Kent County, Ottawa County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Jul 9, 1999, 1:57 AM EDT for Kent County, Ottawa County, Michigan. It was in force for 63 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: Jul 9, 1999, 1:57 AM EDT (05:57 UTC)
Expired: Jul 9, 1999, 3:00 AM EDT
In force: 63 min
Issued by: NWS Grand Rapids, MI
Area: Whole counties

Counties Kent County, MI, Ottawa County, MI

The radar

The Grand Rapids radar (KGRR), 29 km from the middle of the area, began a volume at 05:58 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
Jul 9, 2:30 AM EDT	Thunderstorm Wind 53	Zeeland, MI	Numerous trees were downed in Zeeland.
Jul 9, 2:41 AM EDT	Thunderstorm Wind 53	Kentwood, MI	Several large tree limbs were downed in Kentwood.

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 nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 6.0 hours before the alert went out and 201 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 4 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1655 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 129 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Rapids, MI wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 8, 10:35 PM EDT, 3 hours 22 minutes earlier.

Area forecast discussion, Jul 8, 10:35 PM EDT, 3 hours 22 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1035 PM EDT THU JUL 8 1999

...BEST CONVECTION WILL STAY NORTH OF GRR CWA BUT SOME ACTION STILL
POSSIBLE...

TWO MAIN FOCUS AREAS FOR THUNDERSTORMS TONIGHT.  THE FIRST IS THE
LIFT OVER THE WARM FRONT.  RUC ANAL SHOWS 40 TO 50 KNOT 850 WINDS
BRINGING  16 TO 18C DWPT AIR OVER THE WARM FRONT.  THE BEST 850 THTE
CONVERGENCE IS OVER NRN WI AND LATER TONIGHT OVER NRN LWR MI.  IS
OVER THE NRN PART OF MI WHERE THE BEST DPVA WILL BE... WHERE THE
BEST WIND SHERE WITH HEIGHT WILL BE/ GRB SOUNDING AT 00Z HAD
HELICITY VALUES OVER 700  MEANWHILE... NEAR SW LWR MI... 850 ANAL
AT 00Z SHOWS STRONG DRY ADVECTION AS ILX SOUNDING HAD 49C BETWEEN
THE TEMP AND DWPT.  THIS WILL KEEP THE STORMS OVER THE NRN MOST PART
OF OUR CWA THROUGH 06Z AT LEAST.

THIS BRINGS ME TO THE SECOND REASON FOR TSTSMS... THAT IS THE COLD
FRONT CURRENTLY MVG THROUGH WRN WI.  THE 00Z RUC IS FASTER THEN THE
12Z MODELS ON BRINGING THE FRNT INTO SW MI AND MY 12HR CONTINUITY ON
THE FRONT SIDES WITH THE RUC... SO AFTER 06Z... THERE WILL BE AN
INCREASE IN MOISTURE THROUGH THE SOUNDING AS THE FRONT MOVES INTO
THE AREA.  ON THE OTHER HAND... 700 TEMPS RISE TO OVER 10C... AND
500 TEMPS RISE TO NEAR 6C... SO SOME CAPING AT THOSE LEVELS.  EVEN
SO... RUC SOUNDING AT 12Z SHOWS NEARLY 1000 J/KG WITH STORM TOPS
NEAR 50000 FT... ABOUT 5000 FEET ABOVE THE TROP.  ADD TO THIS THE 40
TO 50 KNOTS OF WIND ABOVE 2000 FT... AND IT IS NOT OUT OF THE
QUESTION SOME GUSTY WINDS ARE POSSIBLE... MAYBE EVEN TO SEVERE
LEVELS. HAIL THREAT MINIMAL SINCE WET BULB ZERO FCST TO BE ABOVE
13000 FT TONIGHT.

SO... WILL KEEP OCCASSIONAL SHOWERS/TSTMS WITH LOCALLY HEAVY RAIN IN
FCST OVER NRN PART OF CWA AND WILL INCREASE POP TO LIKELY OVR CTNL
PART OF CWA AND STILL CARRY CHANCE OVER SE PART OF CWA OVERNIGHT.

.GRR...NONE.

WDM

The office that day

Everything else NWS Grand Rapids, MI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 9, 1:14 AM EDT	Severe Thunderstorm Warning	GRR	Muskegon, Ottawa	46 min
Jul 9, 2:11 AM EDT	Severe Thunderstorm Warning	GRR	Allegan	49 min
Jul 9, 2:30 AM EDT	Tornado Warning	GRR	Allegan	30 min
Jul 9, 2:37 AM EDT	Tornado Warning	GRR	Barry	40 min
Jul 9, 2:46 AM EDT	Severe Thunderstorm Warning	GRR	Ionia	44 min

Nearby

Severe Thunderstorm Warnings in Michigan, 1999 Every 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.