Alert archive / Montana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 73, NWS Great Falls, MT

August 14, 1999Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 14, 1999, 6:22 PM MDT for Fergus County, Montana. It was in force for 53 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 14, 1999, 6:22 PM MDT (00:22 UTC)
Expired: Aug 14, 1999, 7:15 PM MDT
In force: 53 min
Issued by: NWS Great Falls, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Fergus County, MT

The radar

The Billings radar (KBLX), 164 km from the middle of the area, began a volume at 00:24 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 14, 7:15 PM MDT	Hail 2	Grassrange, 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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 14, 4:15 PM MDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 0.4 hours before the alert went out and 106 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: 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

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 14, 2:45 PM MDT, 3 hours 37 minutes earlier.

Area forecast discussion, Aug 14, 2:45 PM MDT, 3 hours 37 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.

Issued	Product	Office	Counties	Lasted
Aug 14, 6:17 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	43 min
Aug 14, 6:37 PM MDT	Tornado Warning	TFX	Fergus	33 min
Aug 14, 6:55 PM MDT	Severe Thunderstorm Warning	TFX	Judith Basin	50 min
Aug 14, 7:12 PM MDT	Tornado Warning	TFX	Judith Basin	33 min
Aug 14, 7:17 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	28 min
Aug 14, 7:35 PM MDT	Tornado Warning	TFX	Fergus, Judith Basin	25 min
Aug 14, 7:54 PM MDT	Tornado Warning	TFX	Fergus	66 min
Aug 14, 10:22 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	38 min

Nearby

Severe Thunderstorm Warnings in Montana, 1999 Every severe thunderstorm warning 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.