Alert archive / Montana / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 106, NWS Great Falls, MT

August 18, 2000Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 18, 2000, 4:16 PM MDT for Gallatin County, Montana. It was in force for 29 min. 1 report 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
Aug 18, 2000, 4:16 PM MDT (22:16 UTC)
Expired
Aug 18, 2000, 4:45 PM MDT
In force
29 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Gallatin County, MT

The radar

The Billings radar (KBLX), 202 km from the middle of the area, began a volume at 22:20 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

TimeReportWhereRemark
Aug 18, 4:20 PM MDTHail 1.5Maudlow, MT

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

Great_falls, MT (KTFX), launched 12:00Z, 10.3 hours before the alert went out and 218 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 2000-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 2000-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.193958Sfc1 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
3 J/kg
Mixed-layer CIN
-482 J/kg
Mixed-layer LCL
2601 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

786 
WUUS55 KTFX 182218
SVRGTF
MTC031-182245-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
416 PM MDT FRI AUG 18 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN GALLATIN COUNTY IN SOUTHWEST MONTANA

* UNTIL 445 PM MDT

* AT 415 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER MAUDLOW...OR ABOUT 26 MILES NORTH OF
  BOZEMAN...MOVING NORTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE CONTINUE OVER...
RURAL NORTHERN GALLATIN COUNTY THROUGH 445 PM MDT

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN GREAT FALLS.

$$
LAT...LON 4606 11130 4593 11112 4610 11082 4619 11094

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 Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 18, 3:00 PM MDT, 1 hour 16 minutes earlier.

Area forecast discussion, Aug 18, 3:00 PM MDT, 1 hour 16 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT FRI AUG 18 2000

WEAK SHORT WAVE NORTHERN GREAT BASIN HAS FIRED OFF THUNDERSTORMS EAST OF
BOZEMAN...WHICH ARE WEAKENING ON RADAR. SATELLITE PICTURES SHOW MORE
MOISTURE WEST OF AREA...SO ISOLATED EVENING...MOSTLY DRY...THUNDERSTORMS
WITH GUSTY WINDS EXPECTED SOUTHWEST AND CENTRAL...ESPECIALLY OVER THE
MOUNTAINS SINCE SURFACE DEWPOINTS SO LOW. THERMAL TROUGH IN AREA AND TFX
VAD WIND PROFILE SHOWS SOUTHWEST WIND 15 KT JUST ABOVE SURFACE. EXPECT
SOUTHWEST WINDS TO DEVELOP ON SURFACE SOON...BROWNING ALREADY GUSTING TO
22KT FROM SOUTHWEST. WINDS ALOFT WILL BE INCREASING TONIGHT AND
SATURDAY...WHICH WILL BE A SERIOUS FIRE WEATHER THREAT. DUE TO DIURNAL
COOLING...EXPECT GUSTY WEST WINDS MAINLY HIGHER ELEVATIONS TONIGHT AND
ALL ELEVATIONS SATURDAY. FAIRLY VIGOROUS SHORT WAVE MOVING INTO AREA
SATURDAY NIGHT AND EASTWARD SUNDAY. FAIRLY GOOD RAIN OCCURRING WESTERN
WASHINGTON...SO EXPECT SLIGHT CHANCE OF THUNDERSTORMS SATURDAY THROUGH
SUNDAY IN AREA...EXCEPT SHOWERS MORE NUMEROUS NORTHERN ROCKIES. OARD

EXTENDED DISCUSSION...MODELS IN UNUSUALLY GOOD AGREEMENT WITH TRENDS
DURING THE PERIOD...ESPECIALLY THE ECMWF AND MRF. AS FAR AS THOSE TWO
MODELS ARE CONCERNED BOTH BRING IN A WEAK POSITIVELY TILTED SHORTWAVE ON
MON. UPPER RIDGE IS THEN FORECAST OVER AREA ON TUE BEFORE A ANOTHER WEAK
SHORTWAVE MOVES THROUGH FORECAST AREA ON WED. EVEN WITH SHORTWAVES MRF
LOOKS DRY. ABOUT ONLY THREAT OF A THUNDERSTORM MIGHT BE OVER THE FAR S
BUT WILL GO MOSTLY DRY THERE. ECMWF..MRF..CMC..AND NOGAPS ALL AGREE ON
RISING THICKNESSES THROUGH PERIOD FOR A WARMING TREND.

CCF NUMBERS
GTF NN 054/077 047/070 044 160122
CTB NN 050/073 043/066 040 160122
HLN NN 053/078 048/072 046 161222
BZN NN 050/082 047/073 043 161222
WEY KK 037/078 037/068 030 162222
DLN NN 052/078 047/070 044 161222
HVR NN 055/082 050/074 048 160122
LWT NN 052/078 046/068 042 161122

Nearby

Severe Thunderstorm Warnings in Montana, 2000Every severe thunderstorm warning in 2000

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.