Alert archive / Idaho / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 20, NWS Spokane, WA

June 17, 1997Lewis County, Idaho

NWS Spokane, WA issued this severe thunderstorm warning at Jun 17, 1997, 6:41 PM PDT for Lewis County, Idaho. It was in force for 64 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: Jun 17, 1997, 6:41 PM PDT (01:41 UTC)
Expired: Jun 17, 1997, 7:45 PM PDT
In force: 64 min
Issued by: NWS Spokane, WA
Area: Whole counties

County Lewis County, ID

The radar

The Spokane radar (KOTX), 185 km from the middle of the area, began a volume at 01:43 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.

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 1.7 hours before the alert went out and 163 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: 184 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1405 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 231 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KGEG 180141 RRA
SVRGEG
IDC061-180245-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SPOKANE WA
641 PM PDT TUE JUN 17 1997
 
THE NATIONAL WEATHER SERVICE IN SPOKANE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  745 PM PDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH IDAHO
 
   ...LEWIS COUNTY
 
AT 640 PM A SEVERE THUNDERSTORM WAS LOCATED OVER SOUTHERN NEZ PERCE
COUNTY AROUND 30 MILES SOUTH OF LEWISTON. THIS STORM WAS MOVING TO THE
NORTHEAST AT 35 MPH.
 
THIS SEVERE THUNDERSTORM WILL MOVE OVER SOUTHWEST LEWIS COUNTY NEAR THE
COMMUNITIES OF MORROW AND FOREST BY 650 PM AND TO NEAR CRAIGMONT BY 710
PM.
 
REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING.  REMAIN CALM BUT BE
ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS.

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 Spokane, WA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 17, 1:48 PM PDT, 4 hours 53 minutes earlier.

Area forecast discussion, Jun 17, 1:48 PM PDT, 4 hours 53 minutes before

EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WASHINGTON
130 PM PDT TUE JUN 17 1997

WAVE DVLPG ON THE BACK OF CURRENT SHORT WAVE... NOW CROSSING OVER COL
RIVER GORGE. WILL TAKE UNTIL MID EVENING TO REACH ERN WA AND AROUND
06Z TO CLEAR THE ID PANHANDLE. 15Z MESO ETA SHOWS GOOD INSTABILITY
OVER ERN WA BY 00Z WITH OVER 1000 J/KG OF CAPE. WILL FCST TSRA INTO
THE EVENING HOURS... THEN TAPERING OFF. ZONAL FLOW THEN FORECAST TO
BECOME ESTABLISHED WED MORNING THRU THURS WITH WK RDG AND 70 TO 90 KT
JET RIGHT ACROSS THE AREA. LOW LVL WESTERLY FLOW UNFAVORABLE FOR
MEASURABLE PCPN AT GEG... BUT WILL FORECAST SHRA OVER THE HIGHER
TERRAIN THRU THURS. MOISTURE AND INSTABILITY CONFINED TO THE LOWER
LAYERS AFTER TONIGHT. DEFINITELY COOLER WITH WED MOS MAX TEMP FOR GEG
COOLER THAN PREVIOUSLY FCST. WILL FOLLOW DOWNWARD TREND AND STAY NR
MOS TEMPS FOR REMAINDER OF THE FCST PD. JL

...PRODUCTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...
...PLEASE SEE SEACCFSEA AND ZONE FORECAST PRODUCTS...

GEG 053/070/048/072 4222
CQV 053/076/047/078 4222
S86 051/071/046/072 4222
COE 052/070/047/071 4222
WWP 051/068/044/070 4222

.GEG...FLOOD WARNING FOR PEND OREILLE RIVER
       FLOOD WARNING FOR LAKE PEND OREILLE

Nearby

Severe Thunderstorm Warnings in Idaho, 1997 Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.