Alert archive / Indiana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 102, NWS Northern Indiana

July 21, 1999LaPorte County, Indiana

NWS Northern Indiana issued this severe thunderstorm warning at Jul 21, 1999, 8:38 PM CDT for LaPorte County, Indiana. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 21, 1999, 8:38 PM CDT (01:38 UTC)
Expired
Jul 21, 1999, 9:25 PM CDT
In force
47 min
Issued by
NWS Northern Indiana
Area
Whole counties

County LaPorte County, IN

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 1.6 hours before the alert went out and 303 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-pSkew-T log-p diagram, Detroit, MI at 00:00Z on 1999-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 429 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 00:00Z on 1999-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
429 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
867 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
157 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.8

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 Northern Indiana wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 1:29 PM CDT, 7 hours 9 minutes earlier.

Area forecast discussion, Jul 21, 1:29 PM CDT, 7 hours 9 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
129 PM EST WED JUL 21 1999

WDLY SCTD CONVECTION DVLPG THIS AFTN ALG WELL DEFINED OUTFLOW
BNDRIES ACRS IND INTO PTNS NW OHIO. MOST DISTINCT BNDRY EXTNDD FROM
AROUND PAULDING OH WSW TO NEAR PERU IN...AND CONTD NW INTO N CNTRL
IL. THIS BNDRY SHWED UP NICELY ON KLOT 88D ALG WITH A DISTINCT LAKE
BREEZE ACRS XTRM NE IL. THESE BNDRIES WILL BE FOCUS OF WDLY SCTD
CONVECTION THRU THIS EVNG.

MAIN QUESTION IS WHAT POPS TO GO WITH FOR THIS EVNG AND TNGT.
STILL NOT OUT OF QUESTION THAT MCC COULD DVLP IN MDT LOW LVL
WAA PTTN N AND W OF CWA... SRN WI/XTRM NRN IL WITH SOME HELP FM S/W
TOPPING RIDGE. ANY DVLPMT WOULD MOVE ESE ACRS XTRM NE IND INTO NW
OH. NEGATIVE FACTOR IS THAT SFC FNT HAS PUSHED NE OF CWA... CLOSE
TO A COLDWATER MI-TOL LINE AS OF 18Z. BEST CHC FOR PCPN SHD BE ALG
THIS BNDRY.

OTHER CONSIDERATION IS WHETHER HEAT ADVISORIES WILL BE NEEDED ACRS
AREA THIS WEEK INTO WEEKEND. HAVE DECIDED AGAINST HEADLINE FOR THIS
ISSUANCE AS REACHING OVERNIGHT CRITERIA WILL BE MARGINAL. NW SFC FLOW
TMRW MAY DROP DEWPOINTS A CPL OF DEGREES WHICH WOULD KEEP AREA OUT OF
ADVISORY CRITERIA AGAIN.

FWC GUIDANCE TEMPS HAVE BEEN GOOD AND SEE NO REASON TO DEVIATE.

SBN GG 073/092 070/093 071 08200
FWA GG 072/093 070/094 071 08200
AOH GG 072/092 069/093 070 08300

.IWX...NONE.

JAH

The office that day

Everything else NWS Northern Indiana issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 9:37 PM CDTSevere Thunderstorm WarningIWXElkhart, LaGrange48 min
Jul 21, 8:52 PM CDTSevere Thunderstorm WarningIWXCass, Saint Joseph33 min

Nearby

Severe Thunderstorm Warnings in Indiana, 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; the sounding from the Mesonet's radiosonde archive.