Alert archive / Montana / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 91, NWS Great Falls, MT

July 19, 2000Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 19, 2000, 8:32 PM MDT for Fergus County, Montana. It was in force for 28 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 19, 2000, 8:32 PM MDT (02:32 UTC)
Expired
Jul 19, 2000, 9:00 PM MDT
In force
28 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Fergus County, MT

The radar

The Billings radar (KBLX), 164 km from the middle of the area, began a volume at 02:36 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 nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 2.5 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-pSkew-T log-p diagram, Great_falls, MT at 00:00Z on 2000-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 291 joules per kilogram.LCLEL10008507005003002001001 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 2000-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
291 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
2863 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
37 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 
WUUS55 KTFX 200233
SVRGTF
MTC027-200300-
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
832 PM MDT WED JUL 19 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL FERGUS COUNTY IN MONTANA

* UNTIL 900 PM MDT

* AT 823 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER SOUTH CENTRAL FERGUS COUNTY...OR ABOUT 5
  MILES SOUTHEAST OF LEWISTOWN...MOVING SOUTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
RURAL SOUTHERN FERGUS COUNTY AT 850 PM MDT

HEAVY RAIN ALONG WITH MINOR FLOODING AND HAIL UP TO NICKEL SIZE HAVE 
BEEN REPORTED WITH THIS STORM.

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 4710 10930 4698 10949 4678 10921 4677 10884

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 Jul 19, 3:00 PM MDT, 5 hours 32 minutes earlier.

Area forecast discussion, Jul 19, 3:00 PM MDT, 5 hours 32 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT WED JUL 19 2000

ALL THE INGREDIENTS TODAY FOR DEEP CONVECTION EXCEPT FOR SHEAR AND
FORCING ALOFT.  MESOANALYSIS SHOWS A GOOD CONVERGENCE ZONE BOUNDARY
ALONG A HAVRE TO MILES CITY LINE...HIGH DEW POINTS AND LOTS OF
INSOLATION THIS AFTERNOON.  THIS MORNINGS SOUNDING SHOWS WEAK WINDS
THROUGHOUT DEPTH OF TROP SO THREAT OF BRIEF HEAVY RAINS WITH ANY TSTMS
THAT FORM. ETA AND AVN NOT IN AGREEMENT ON PATTERN EVOLUTION NEXT 48
HRS.  AVN MORE PESSIMISTIC IN HOLDING RIDGE TO THE WEST AND IN BRINGING
SHORT WAVES THROUGH THE AREA INTO FRIDAY.  WILL HOLD AT LEAST ISOLATED
SHWRS/TSTMS THROUGH FRIDAY.  CROSS SECTIONS ALSO SUGGEST AT LEAST A
MODERATE AMOUNT OF MID AND UPPER LEVEL MOISTURE WITH DECENT VERTICAL
MOTION FIELDS...PEAKING AROUND 00Z NEXT TWO DAYS.  MIELKE

EXTENDED OUTLOOK...MODELS IN CLOSER AGREEMENT TODAY THAN
YESTERDAY...HOWEVER SIGNIFICANT DIFFERENCES STILL REMAIN FOR DAYS 4 AND
5. LAST PERIOD OF AVN/UKMET HAVE UPPER LEVEL RIDGE AXIS OVER WESTERN
MONTANA WITH SHORTWAVE TROUGH JUST OFF PACIFIC NORTHWEST COAST...WITH
ECMWF IN GOOD AGREEMENT. FOR SAME TIME PERIOD...NOGAPS HAS SHORTWAVE
OVER PACIFIC NORTHWEST AND MRF SLOWER WITH SHORTWAVE PROGRESS THAN
ECMWF. THESE TRENDS CONTINUE THROUGH MONDAY...WITH MRF SLOWEST...NOGAPS
QUICKEST...AND ECMWF IN BETWEEN. ECMWF/MRF BRING SHORTWAVE FARTHER NORTH
OVER RIDGE THAN NOGAPS FOR SUNDAY AND MONDAY...KEEPING BEST CHANCE OF
PRECIPITATION ACROSS NORTHERN ZONES. WILL GENERALLY GO WITH SLOWER
ECMWF/MRF IDEA...AS MODELS IN GENERAL HAVE BEEN SLOWING THINGS DOWN EACH
RUN. AT SURFACE...COLD FRONT DEVELOPS OVER MONTANA ON SATURDAY AND
MODELS PROGRESS IT EASTWARD AT SPEEDS SIMILAR TO SHORTWAVE MOVEMENTS.
LOOKS LIKE WESTERLY WINDS SHOULD DEVELOP BEHIND FRONT REGARDLESS. BOTTOM
LINE...MOSTLY DRY AND WARM SATURDAY WITH RIDGE OVERHEAD...THEN ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY WITH COOLER
TEMPERATURES.  COULSTON

CCF NUMBERS
GTF BB 053/085 055/088 057 013222
CTB BB 051/083 053/086 055 013222
HLN BB 055/088 056/092 057 013222
BZN CB 050/085 052/090 05I4 014232
WEY CB 042/077 044/082 045 015332
DLN BB 050/083 050/085 050 013222
HVR CB 055/086 057/090 058 014332
LWT CB 052/082 052/088 052 014332

In the hours before

Local storm report, Jul 19, 7:16 PM MDT, 1 hour 16 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
716 PM MDT WED JUL 19 2000

TIME(MDT)  .....EVENT  LOCATION..... ST   ...EVENT/REMARKS...........
           .....COUNTY LOCATION.....

0320 PM    22 N CHINOOK              MT   0.25 INCH HAIL
07/19/00   BLAINE

0320 PM    22 N CHINOOK              MT   70 MPH TSTM GUST
07/19/00   BLAINE

0415 PM    2 SE ZURICH               MT   0.50 INCH HAIL
07/19/00   BLAINE

0520 PM    25 S HARLEM               MT   0.88 INCH HAIL
07/19/00   BLAINE

0535 PM    33 S LLOYD                MT   0.88 INCH HAIL
07/19/00   BLAINE

0535 PM    33 S LLOYD                MT   65 MPH TSTM GUST
07/19/00   BLAINE

0543 PM    LODGEPOLE                 MT   0.75 INCH HAIL
07/19/00   BLAINE                       \  VERY STRONG WINDS

NNNN

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.