Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 84, NWS Great Falls, MT

August 4, 2002Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 4, 2002, 4:14 PM MDT for Gallatin County, Montana. It was in force for 46 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 4, 2002, 4:14 PM MDT (22:14 UTC)
Expired: Aug 4, 2002, 5:00 PM MDT
In force: 46 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 22:16 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
Aug 4, 4:40 PM MDT	Hail 0.75	Three Forks, MT	A severe thunderstorm produced 0.75 inch hail in Three Forks.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 4, 2:40 PM MDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.2 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-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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 863 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 106 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.

050 
WUUS55 KTFX 042214
SVRTFX
MTC031-042300-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
414 PM MDT SUN AUG 4 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL GALLATIN COUNTY IN SOUTHWEST MONTANA

* UNTIL 500 PM MDT

* AT 411 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 12 MILES SOUTHWEST OF THREE FORKS...OR ABOUT 31
  MILES NORTHEAST OF SHERIDAN...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  THREE FORKS AT 430 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM MDT SUNDAY
EVENING FOR WESTERN MONTANA.

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 4, 3:00 PM MDT, 1 hour 14 minutes earlier.

Area forecast discussion, Aug 4, 3:00 PM MDT, 1 hour 14 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT SUN AUG 4 2002

.SHORT TERM...MORNING CONVECTIVE ACTIVITY CONTINUES OVER NORTH
CENTRAL MONTANA WITH THE SOUTHWEST CLEARING OUT. MODELS INDICATE
DECENT CAPES AND LIS DEVELOP THIS AFTERNOON OVER THE SOUTHWEST WHERE
THE NEXT ROUND SHOULD BEGIN FIRING UP EARLY THIS AFTERNOON.
ELEVATED CAPES AND FAVORABLE SHEAR PROFILES OVER THE PLAINS SHOULD
ALLOW STORMS OVER THE SOUTHWEST TO MAINTAIN STRENGTH AND
ORGANIZE AS THEY PROGRESS NORTHEAST.  SPC OUTLOOK FOR SEVERE
LOOKS GOOD AND WILL KEEP SEVERE WORDING OVER ALL OF CWA.

DROPPED TEMPS AND UPPED POPS FOR MONDAY THROUGH WEDNESDAY AS
UPPER TROUGH OVER PACNW WILL KEEP US MOIST AND UNSTABLE.  DITTMANN

.EXTENDED...ON SAT MODEL SOLUTIONS FELL IN TWO CAMPS WITH THE
ECMWF/AVN TAKING AN UPPER TROUGH OVER THE PAC NW AT MIDWEEK NE INTO
SRN CAN LATE THIS WEEK. CMC AND UKMET TOOK THE TROUGH E. TODAY THE
AVN HAS JOINED THE CMC AND UKMET SOLUTIONS IN TAKING THE UPPER TROUGH
E. ECMWF IS TRENDING TOWARDS THE CMC AND UKMET SOLUTIONS OF SAT BUT
NOT AS MUCH AS THE AVN. WHAT THIS MEANS IS WILL BE UPPING THE CHANCES
FOR PRECIPITATION FOR LATER THIS WEEK AND LOWERING FORECAST HIGH
TEMPERATURES. FOR SAT AND SUN LOOKS LIKE DRIER NW OR W FLOW ALOFT
WILL BE OVER THE AREA. WILL GO DRY AND WARMER FOR THE WEEKEND. BLANK

.CCF NUMBERS
GTF BB 048/076 052/077 052 02433
    BEBBB 076/050 075/052 075/050 083/053 084 33223441111
CTB BB 047/072 048/072 048 02433
    BBBBB 072/045 072/048 076/048 080/050 080 32212221111
HLN BB 051/080 052/078 052 02433
    BEWBB 077/052 076/052 076/050 084/053 086 32224551111
BZN BB 050/082 048/082 048 02433
    BEWBB 080/048 078/050 074/045 082/048 084 32244542111
WEY BB 043/078 040/076 040 02333
    BEWBB 075/040 074/042 068/038 075/038 076 32245662111
DLN BB 049/082 048/080 048 02333
    BBWBB 078/048 077/048 075/044 080/047 084 32224451111
HVR BB 052/078 053/082 053 02434
    BBEBB 080/050 079/052 078/050 085/054 086 32222222111
LWT BB 051/078 052/080 050 02634
    BEWBB 078/048 074/050 070/045 079/050 081 32233452111=

.TFX...

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 2:10 PM MDT	Severe Thunderstorm Warning	TFX	Beaverhead	35 min
Aug 4, 4:39 PM MDT	Severe Thunderstorm Warning	TFX	Broadwater	36 min
Aug 4, 4:49 PM MDT	Severe Thunderstorm Warning	TFX	Lewis and Clark	56 min
Aug 4, 5:49 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	41 min

Nearby

Severe Thunderstorm Warnings in Montana, 2002 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.