Alert archive / Montana / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 239, NWS Billings, MT
NWS Billings, MT issued this severe thunderstorm warning at Jul 23, 2001, 8:30 PM MDT for Carbon County, Yellowstone County, Montana. It was in force for 60 min. 5 reports 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
- Jul 23, 2001, 8:30 PM MDT (02:30 UTC)
- Expired
- Jul 23, 2001, 9:30 PM MDT
- In force
- 60 min
- Issued by
- NWS Billings, MT
- Area
- Whole counties
Counties Carbon County, MT, Yellowstone County, MT
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 23, 8:30 PM MDT | Hail 0.75 | Joliet, MT | |
| Jul 23, 8:35 PM MDT | Hail 0.88 | Laurel, MT | Hail covered the ground |
| Jul 23, 8:45 PM MDT | Hail 0.75 | Billings, MT | |
| Jul 23, 9:00 PM MDT | Hail 0.75 | Boyd, MT | |
| Jul 23, 9:30 PM MDT | Hail 0.75 | Silesia, 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 00:00Z, 2.5 hours before the alert went out and 257 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.
- Mixed-layer CAPE
- 455 J/kg
- Mixed-layer CIN
- -4 J/kg
- Mixed-layer LCL
- 2006 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 30 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
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 Billings, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 23, 1:59 PM MDT, 6 hours 31 minutes earlier.
Area forecast discussion, Jul 23, 1:59 PM MDT, 6 hours 31 minutes before
SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
159 PM MDT MON JUL 23 2001
.TUE AND WED...
AVN SEEMS TO HAVE A BETTER HANDLE ON THE SHORT WAVE GOING INTO WESTERN
MONTANA...KICKING OFF SHOWERS AND THUNDERSTORMS...LOOKING HOW BOTH
MODELS LINED UP WITH THE 18Z WATER VAPOR IMAGERY. DIFFICULT TO TELL ON
THEIR ALIGNMENT WITH THE SURFACE FEATURES AT 18Z. BOTH MODELS BASICALLY
TELL THE SAME STORY...NAMELY THE SLOW EAST PROGRESSION OF THE UPPER
TROUGH. THEY DIFFER IN STRENGTH AND TIMING OF THE SHORT WAVES.
THE MAIN THETA E MAXIMA REMAINS SOUTH OF MONTANA IN WYOMING THROUGHOUT
THE PERIOD. AVN AND ETA DIFFER IN PUSHING UP RIDGES INTO MONTANA...BUT
BOTH SOLUTIONS POINT TO A CONTINUING CHANCE OF THUNDERSTORMS WITH THE
BETTER POSSIBILITIES BEING OVER WYOMING INTO SOUTHEAST MONTANA. CAPES
NOT THAT BAD FOR THE REST OF TODAY...BUT THEY LOOK PROMISING FOR
TUESDAY OVER ABOUT THE EAST HALF OF THE COUNTY WARNING AREA. THEY ALSO
BECOME RATHER HIGH WEDNESDAY OVER EXTREME SOUTHEAST MONTANA AND
SHERIDAN COUNTY. AS THE UPPER TROUGH ADVANCES...MOISTURE BEGINS
DROPPING. IT SEEMS REASONABLE TO LOWER POPS TO ISOLATED ON WEDNESDAY
OVER MOST AREAS...BUT TO KEEP SCATTERED POPS GOING FOR EXTREME SOUTHEAST
MONTANA INTO SHERIDAN COUNTY WYOMING. AM HAVING PROBLEMS WITH AVN ON
WEDNESDAY WITH A VERY STRONG DIVERGENCE PATTERN DEVELOPING OVER ROUGHLY
CENTRAL MONTANA. THIS WOULD AID IN THUNDERSTORM DEVELOPMENT AND THE
SITUATION WILL HAVE TO BE WATCHED. WILL SEE WHAT OTHER MODEL RUNS
INDICATE. CHB
.THU...FRI...SAT...SUN...MON...
AFTER WAVE PASSES WEDNESDAY MORE OF A WESTERLY FLOW BUILDS INTO AREA...
HOWEVER FLOW CONTINUES TO HAVE SOMEWHAT A CYCLONIC FLOW TO IT THURSDAY
AND FRIDAY. WOULD EXPECT A FEW WAVES TO MOVE ACROSS AREA THURSDAY AND
FRIDAY IN THIS FLOW. WESTERLY FLOW...SHOULD...DRY LOWER ATMOSPHERE TO
KEEP CONVECTION THAT DOES OCCUR LESS WIDE SPREAD...BUT ENOUGH TO KEEP
MENTION OF THUNDERSTORMS IN THURSDAY AND FRIDAY. SATURDAY...MODELS BEGIN
TO DIVERGE A BIT. MRF/UKMET DRIVE ENERGY SOUTH FROM GULF OF ALASKA INTO
PACIFIC NORTHWEST WITH DEEPENING SOUTHWEST FLOW OVER MONTANA...THEN
MOVE TROUGH ACROSS AREA...WITH WESTERLY FLOW BY MONDAY. ECMWF MORE
PROGRESSIVE WITH THIS ENERGY SLIDING IT ACROSS MONTANA SATURDAY WITH
RIDGING BY LATE SUNDAY. NEW AVN ON THE OTHER HAND HAS TROUGH MUCH DEEPER
ON WEST COAST THAN 00Z MRF...WHICH COULD OPEN US UP TO DEEPER MOISTURE
AGAIN SATURDAY AND SUNDAY...THUS WILL CONTINUE CHANCE OF THUNDERSTORMS
SATURDAY AND SUNDAY. RASCH
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 056/088 057/088 060/088 062/090 063/090 059/087 057/084
33/T 32/T 33/T 33/T 33/T 33/T 11/B
LVM 049/084 048/084 055/085 057/086 058/087 055/085 053/080
32/T 22/T 33/T 33/T 33/T 33/T 11/B
HDN 053/092 054/092 058/090 060/092 061/092 057/089 055/086
43/T 42/T 33/T 33/T 33/T 33/T 11/B
MLS 058/088 059/092 062/087 063/088 064/090 060/088 057/085
33/T 32/T 33/T 33/T 33/T 33/T 11/B
4BQ 059/086 058/091 060/086 061/087 062/089 058/087 055/084
44/T 43/T 33/T 33/T 33/T 33/T 11/B
BHK 056/084 057/089 059/085 060/086 060/088 056/086 054/083
33/T 32/T 33/T 33/T 33/T 33/T 11/B
SHR 055/087 055/090 057/088 058/090 058/090 -056/087 054/084
44/T 43/T 33/T 33/T 33/T 33/T 11/BThe office that day
Everything else NWS Billings, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 6:12 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Rosebud | 63 min |
| Jul 23, 6:44 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Powder River | 61 min |
| Jul 23, 6:49 PM MDT | Severe Thunderstorm Warning | BYZ | Rosebud, Treasure, Yellowstone | 56 min |
| Jul 23, 7:42 PM MDT | Severe Thunderstorm Warning | BYZ | Rosebud | 63 min |
| Jul 23, 7:54 PM MDT | Severe Thunderstorm Warning | BYZ | Powder River | 51 min |
| Jul 23, 8:05 PM MDT | Severe Thunderstorm Warning | BYZ | Carbon, Stillwater | 40 min |
| Jul 23, 9:03 PM MDT | Severe Thunderstorm Warning | BYZ | Carbon | 57 min |
| Jul 23, 9:56 PM MDT | Severe Thunderstorm Warning | BYZ | Yellowstone | 64 min |
| Jul 23, 10:04 PM MDT | Severe Thunderstorm Warning | BYZ | Carbon, Stillwater | 56 min |
Nearby
Severe Thunderstorm Warnings in Montana, 2001Every severe thunderstorm warning in 2001
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.