Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 101, NWS Glasgow, MT

July 24, 2002Richland County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Jul 24, 2002, 4:18 PM MDT for Richland County, Montana. It was in force for 57 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 24, 2002, 4:18 PM MDT (22:18 UTC)
Expired: Jul 24, 2002, 5:15 PM MDT
In force: 57 min
Issued by: NWS Glasgow, MT
Area: Counties, with a storm outline in the text

County Richland County, MT

The radar

The Glasgow radar (KGGW), 155 km from the middle of the area, began a volume at 22:22 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
Jul 24, 5:08 PM MDT	Hail 0.75	Sidney, 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 10.3 hours before the alert went out and 154 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: 260 J/kg
Mixed-layer CIN: -228 J/kg
Mixed-layer LCL: 1204 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

199 
WUUS55 KGGW 242218
SVRGGW
MTC083-242315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GLASGOW MT
418 PM MDT WED JUL 24 2002

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN RICHLAND COUNTY IN NORTHEAST MONTANA

* UNTIL 515 PM MDT

* AT 412 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 42 MILES NORTHWEST OF SIDNEY...OR ABOUT 19
  MILES WEST OF CULBERTSON...MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER...
  RURAL NORTHERN RICHLAND COUNTY
  
LARGE HAIL...DAMAGING WINDS...AND HEAVY RAINFALL ARE LIKELY WITH THIS
STORM. TAKE COVER IN A STURDY BUILDING UNTIL THE STORM HAS PASSED.

LAT...LON 4805 10504 4774 10515 4760 10411 4781 10407
          4799 10412 4810 10459

.END
77

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 Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 24, 2:10 PM MDT, 2 hours 8 minutes earlier.

Area forecast discussion, Jul 24, 2:10 PM MDT, 2 hours 8 minutes before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
210 PM MDT WED JUL 24 2002

.SHORT TERM...THUNDERSTORMS CONTINUE TO TRACK ALONG THE
SASKATCHEWAN/MONTANA BORDER. THESE STORMS HAVE FORMED ALONG A
SURFACE TROUGH AND JUST AHEAD OF THE UPPER LEVEL WAVE MOVING
ACROSS SOUTHERN SASKATCHEWAN. VISIBLE SATELLITE IMAGERY SHOWS AREAS
OF CUMULUS DEVELOPING ELSEWHERE TO THE WEST AND SOUTH. BELIEVE
INSTABILITY WILL CONTINUE TO INCREASE AS THE AFTERNOON WEARS ON AND
CAP IS PROGGED TO WEAKEN AS WELL. EXPECT THUNDERSTORMS TO CONTINUE
DEVELOP ACROSS THE CWA AND THEN PROGRESS EASTWARD INTO NORTH DAKOTA
LATER TONIGHT. CURRENT FORECAST HANDLES THIS SCENARIO WELL WITH
EVENING THUNDERSTORMS.

MAIN AREA OF INSTABILITY THEN SHIFTS EAST FOR TOMORROW WITH A WEAK
AREA OF HIGH PRESSURE BUILDING IN OVER THE AREA. UPPER LEVEL RIDGE
ALSO AMPLIFIES...A REFLECTION OF THE WAA OCCURRING AHEAD OF THE NEXT
H5 SHORTWAVE TROUGH. RIDGE BREAKS DOWN AS ANOTHER SHORTWAVE
PROGRESSES EAST FROM THE PACNW THURSDAY NIGHT AND FRIDAY. THIS WAVE
WILL BEGIN TO SPREAD SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
EASTERN MONTANA THURSDAY NIGHT. THUNDERSTORM ACTIVITY WILL CONTINUE
INTO FRIDAY BUT MAINLY AFFECT THE EASTERN ZONES AS THE WAVE EXITS
INTO NORTH DAKOTA.

A MUCH STRONGER UPPER LEVEL TROUGH WILL THEN DIG SOUTHEAST ACROSS
ALBERTA AND SASKATCHEWAN STARTING. ACCOMPANYING THIS TROUGH WILL BE
A STRONG COLD FRONT CROSSING THE CWA FRIDAY NIGHT. WILL KEEP CHANCE
POPS IN FOR THIS FRONT FOR PERIOD 5. TROUGH FOLLOWS DURING THE DAY
SATURDAY CONTINUING THE CHANCE FOR PRECIPITATION. A MUCH COOLER AIR
MASS MOVES IN ACROSS THE AREA BEHIND THE FRONT FOR
SATURDAY...DROPPING TEMPERATURES 10 TO 15 DEGREES INTO THE UPPER 70S
TO NEAR 80.  BERDES

.LONG TERM...SOMEWHAT OF A ZONAL FLOW DEVELOPS OVER MT...WITH WEAK
RIPPLES MOVING THROUGH JET. MRF PLACES A SMALL TROUGH OVER MT WITH
NW FLOW ALOFT FOR SUNDAY INTO MONDAY. TOWARD THE END OF THE EXTENDED
MRF BUILDS A RIDGE IN THE WEST...KEEPING FLOW NW OVER MT. THE ECMWF
KEEPS THE FLOW MORE ZONAL SUNDAY THROUGH TUESDAY...WITH WEAK
SHORTWAVES PIVOTING THROUGH FROM THE NORTHWEST. SINCE BOTH MODELS
SEEM TO AGREE ON WEAK DISTURBANCES EMBEDDED IN MOSTLY ZONAL
FLOW...IT WILL BE A DRIER...COOLER PATTERN. KIMBALL

KGGW BTT 061/091 062/092 059/078 77203333
     BBBB 052/076 053/081 056/083 057/087 7722222222
KGDV TTT 061/091 063/092 061/080 77312333
     BBBB 052/073 051/081 056/084 060/088 7722222222

.GGW...NONE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 24, 2:45 PM MDT	Severe Thunderstorm Warning	GGW	Daniels	30 min
Jul 24, 2:54 PM MDT	Severe Thunderstorm Warning	GGW	Garfield, Valley	66 min
Jul 24, 3:15 PM MDT	Severe Thunderstorm Warning	GGW	Roosevelt, Sheridan	60 min
Jul 24, 3:59 PM MDT	Severe Thunderstorm Warning	GGW	McCone	61 min
Jul 24, 4:07 PM MDT	Severe Thunderstorm Warning	GGW	Garfield, Valley	53 min
Jul 24, 4:09 PM MDT	Severe Thunderstorm Warning	GGW	Garfield, Valley	51 min
Jul 24, 4:16 PM MDT	Severe Thunderstorm Warning	GGW	Roosevelt	44 min
Jul 24, 4:53 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, McCone, Prairie	52 min
Jul 24, 5:16 PM MDT	Severe Thunderstorm Warning	GGW	Richland	29 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.