Alert archive / Montana / Tornado Warnings in 1999

Tornado Warning 4, NWS Great Falls, MT

August 14, 1999Fergus County, Montana

NWS Great Falls, MT issued this tornado warning at Aug 14, 1999, 6:37 PM MDT for Fergus County, Montana. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Aug 14, 1999, 6:37 PM MDT (00:37 UTC)
Expired
Aug 14, 1999, 7:10 PM MDT
In force
33 min
Issued by
NWS Great Falls, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Fergus County, MT

The radar

The Great Falls radar (KTFX), 144 km from the middle of the area, began a volume at 00:39 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 14, 4:15 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 0.6 hours before the alert went out and 86 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 00:00Z on 1999-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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 00:00Z on 1999-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
13 J/kg
Mixed-layer CIN
-177 J/kg
Mixed-layer LCL
1802 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
225 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.

000 
TTAA00 KTFX 150039 RRA
TORGTF
MTC027-150110-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
637 PM MDT SAT AUG 14 1999

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL FERGUS COUNTY IN MONTANA

* UNTIL 710 PM MDT

* AT 636 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH A POSSIBLE TORNADO OVER WEST CENTRAL FERGUS
  COUNTY...OR ABOUT 20 MILES NORTHWEST OF LEWISTOWN...MOVING EAST    
  AT 25 MPH.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN 2THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM MDT
SATURDAY EVENING FOR MONTANA.

LAT...LON 4737 10984 4719 10985 4712 10899 4735 10896

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Aug 14, 2:45 PM MDT, 3 hours 52 minutes earlier.

Area forecast discussion, Aug 14, 2:45 PM MDT, 3 hours 52 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
245 PM MDT SAT AUG 14 1999

12Z MDL DATA SLOW TO ARRIVE. NGM AND AVN FAIRLY SIMILAR WITH MOST
DETAILS OF UPR TROF MOVG E. SAT IMAGERY INDICATES UPR LOW OVR XTRM ERN
WA ATTM WITH A FAIRLY WELL DEFINED MSTR PLUME THRU N-CNTRL ID AND WRN
MT. SOME CNVTV ACTVTY ALRDY KICKING OFF OVR SW MT BUT TSTMS HAVE BEEN
WEAK. WL LEAVE HIGHEST POPS TGNT FOR SW AND NW PORTION OF CWA AND THEN
GO WITH HIGH POPS ACRS N-CNTRL MT SUN. AVN HAS WLY FLOW OVR CWA BY SUN
NGT WITH ANOTHER S/WV DROPPING INTO NW MT MON. COOLER AIR FOR SUN WITH A
SLGT WRMG MON. EMANUEL
GTF 5512 HLN 6423 HVR 5632

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 14, 6:17 PM MDTSevere Thunderstorm WarningTFXFergus43 min
Aug 14, 6:22 PM MDTSevere Thunderstorm WarningTFXFergus53 min
Aug 14, 6:55 PM MDTSevere Thunderstorm WarningTFXJudith Basin50 min
Aug 14, 7:12 PM MDTTornado WarningTFXJudith Basin33 min
Aug 14, 7:17 PM MDTSevere Thunderstorm WarningTFXFergus28 min
Aug 14, 7:35 PM MDTTornado WarningTFXFergus, Judith Basin25 min
Aug 14, 7:54 PM MDTTornado WarningTFXFergus66 min
Aug 14, 10:22 PM MDTSevere Thunderstorm WarningTFXFergus38 min

Nearby

Tornado Warnings in Montana, 1999Every tornado warning in 1999Tornadoes 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; radar from the NEXRAD Level II archive.