Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 99, NWS Billings, MT

July 27, 2002Sweet Grass County, Montana

NWS Billings, MT issued this severe thunderstorm warning at Jul 27, 2002, 1:43 PM MDT for Sweet Grass County, Montana. It was in force for 62 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 27, 2002, 1:43 PM MDT (19:43 UTC)
Expired
Jul 27, 2002, 2:45 PM MDT
In force
62 min
Issued by
NWS Billings, MT
Area
Whole counties

County Sweet Grass County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 7.7 hours before the alert went out and 190 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, Great_falls, MT at 12:00Z on 2002-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 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, Great_falls, MT at 12:00Z on 2002-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.1939Sfc1 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
9 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1136 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

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 Billings, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 27, 8:56 AM MDT, 4 hours 47 minutes earlier.

Area forecast discussion, Jul 27, 8:56 AM MDT, 4 hours 47 minutes before
SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
856 AM MDT SAT JUL 27 2002

.SHORT TERM...VALID FOR TDY...SUN...MON...
UPDATES PLANNED TO ZONES THIS MORNING. UNSETTLED WEATHER CONTINUES TO
DEVELOP WEST OF BILLINGS COUNTY WARNING AREA AND IS MOVING EAST. AREA OF
SHOWERS/THUNDERSTORMS PROGRESSIVELY MOVING TOWARD THE BILLINGS AREA AND
WILL UPDATE POPS TO LIKELY CATEGORY. 8AM TEMPS IN THE 60S TO LOWER 70S
ACROSS SC/SE MT AND SHR CO WY. FORECAST HIGHS IN THE LOWER TO MID 80S
REASONABLE GIVEN PRESENT CLOUD COVER AND EXPECTED PRECIPITATION TODAY IN
THE EAST. WILL TWEAK TEMPS DOWN A COUPLE DEGREES FOR LOCATIONS WEST OF
BIL WHERE CLOUD COVER IS THICKER AND PRECIPITATION ALREADY OCCURRING.
WINDS PRIMARILY W/NW AS FORECAST AND WILL ONLY MAKE SLIGHT ADJUSTMENTS
TO SHR WHERE WINDS HAVE YET TO SHIFT. SPRINGER

.LONG TERM...VALID FOR TUE...WED...THU...FRI...
UPPER LEVEL LOW ACROSS BRITISH COLUMBIA DROPS SOUTH ALONG THE COAST
TUESDAY...WITH NORTHWEST FLOW TRANSITIONING TO SOUTHWEST FLOW BY
WEDNESDAY. LATEST AVIATION RUN DEVIATES FROM THIS SOLUTION...PRODUCING
STRONGER ZONAL FLOW ACROSS THE AREA. HAVE LOW CONFIDENCE IN LATEST
AVIATION SOLUTION...SINCE PREVIOUS EXTENDED AVIATION...ECMWF...AND
NOGAPS RUNS SHOWED GOOD AGREEMENT. LATEST UKMET DOES NOT DROP THE UPPER
LOW SOUTH ALONG THE COAST UNTIL WEDNESDAY...BUT EVENTUALLY DOES
TRANSITION TO SOUTHWEST FLOW ACROSS THE CWA BY EARLY THURSDAY. GOING
FORECAST LOOKS GOOD WITH SCATTERED POPS FOR THURSDAY AND FRIDAY AS UPPER
LEVEL SHORTWAVE ENERGY AND ASSOCIATED SURFACE COLD FRONT WORK ACROSS THE
CWA. FRIDAY HIGH TEMPERATURES MAY BE TOO COOL AS EXTENDED AVIATION
INDICATES SLIGHT WARMING AT 850MB AND 700MB...BUT WILL NOT MAKE CHANGES
THIS PACKAGE. CARPENTER

    TDY SUN     MON     TUE     WED     THU     FRI
-------------------------------------------------------
BIL 079 054/080 054/085 059/085 058/087 056/083 056/078
    6/T 40/B    00/B    00/B    00/B    03/T    33/T
LVM 077 048/079 048/083 055/083 054/085 052/078 052/073
    6/T 40/B    00/B    00/B    00/B    03/T    33/T
HDN 081 052/082 052/087 057/087 056/088 054/085 054/080
    6/T 42/W    00/B    00/B    00/B    03/T    33/T
MLS 083 055/080 052/087 059/087 058/089 056/084 056/079
    4/T 42/W    20/B    00/B    00/B    03/T    33/T
4BQ 084 055/081 053/086 058/086 058/088 056/083 056/078
    4/T 42/W    00/B    00/B    00/B    03/T    33/T
BHK 082 053/079 050/085 055/085 056/087 054/080 054/075
    4/T 42/W    20/B    00/B    00/B    03/T    33/T
SHR 083 053/081 051/086 055/086 055/087 053/081 053/076
    4/T 42/W    00/B    00/B    00/B    03/T    33/T

.BYZ...
MT...NONE.
WY...NONE.

The office that day

Everything else NWS Billings, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 27, 1:52 PM MDTSevere Thunderstorm WarningBYZStillwater53 min
Jul 27, 3:23 PM MDTSevere Thunderstorm WarningBYZMusselshell67 min

Nearby

Severe Thunderstorm Warnings in Montana, 2002Every severe thunderstorm warning in 2002

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.