Alert archive / Montana / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 45, NWS Great Falls, MT

July 19, 2010Glacier County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 19, 2010, 5:05 PM MDT for Glacier County, Montana. It was in force for 40 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, 2010, 5:05 PM MDT (23:05 UTC)
Expired
Jul 19, 2010, 5:45 PM MDT
In force
40 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon

County Glacier County, MT

The radar

The Great Falls radar (KTFX), 183 km from the middle of the area, began a volume at 23:09 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

Spokane, WA (KOTX), launched 12:00Z, 11.1 hours before the alert went out and 276 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, Spokane, WA at 12:00Z on 2010-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Spokane, WA at 12:00Z on 2010-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2094 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

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, 2:47 PM MDT, 2 hours 18 minutes earlier.

Area forecast discussion, Jul 19, 2:47 PM MDT, 2 hours 18 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
247 PM MDT MON JUL 19 2010

.DISCUSSION...

TONIGHT THROUGH WEDNESDAY...UPPER TROF MOVING ACROSS THE COUNTY
WARNING AREA WITH NUMEROUS THUNDERSTORMS CONTINUING TO DEVELOP.
MOST OF THE ACTIVITY IS OCCURRING ACROSS THE NORTHERN PORTION OF
THE COUNTY WARNING AREA. MOST STORMS ARE OF THE PULSE VARIETY WITH
SMALL HAIL BEING REPORTED AND BRIEF HEAVY RAIN. VERTICAL WIND
SHEAR REMAINS WEAK AND THUNDERSTORMS BECOMING SEVERE NOT LIKELY.
CONVECTIVE ACTIVITY SHOULD DIMINISH AFTER SUNDOWN AS THE TROF
PUSHES FURTHER TO THE EAST. ISOLATED SHOWERS WILL LINGER BEYOND
MIDNIGHT. HEIGHTS BEGIN TO RISE ON TUESDAY AS THE NEXT UPPER TROF
BEGINS TO DIG ALONG THE WEST COAST. CYCLONIC FLOW ALOFT OVER THE
NORTHEAST WILL ALLOW ISOLATED THUNDERSTORMS TO FORM AGAIN TUESDAY
AFTERNOON. DRY CONDITIONS TUESDAY NIGHT WILL YIELD TO AN
INCREASING THREAT OF THUNDERSTORMS AGAIN ON WEDNESDAY AS THE UPPER
TROF APPROACHES WESTERN MONTANA. THE AIRMASS WILL REMAIN COOL
THROUGH MIDWEEK WITH BELOW SEASONAL AVERAGE TEMPERATURES. EMANUEL

WEDNESDAY NIGHT THROUGH MONDAY...MEDIUM RANGE MODELS ARE KEEPING AN
UPPER LEVEL SHORTWAVE TROUGH OVER THE NORTHERN ROCKY MOUNTAIN REGION
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT OR FRIDAY. THIS SCENARIO IS
SLOWER THAN PREVIOUS MODEL RUNS WERE SHOWING AND SUGGESTS THAT THERE
WILL BE A GREATER CHANCE FOR SHOWERS AND THUNDERSTORMS EARLY IN THE
PERIOD. THE SHORTWAVE IS NOW EXPECTED TO EJECT BY FRIDAY EVENING
WITH A SHORTWAVE RIDGE BUILDING OVER THE REGION FOR MOSTLY DRY
CONDITIONS FRIDAY NIGHT AND SATURDAY. MODELS DEVELOP A CLOSED LOW
OVER CENTRAL/NORTHERN ALBERTA AND SASKATCHEWAN BY SUNDAY MORNING BUT
THEIR SOLUTIONS DIVERGE WITH REGARD TO HOW MUCH OF AN IMPACT THIS
WILL HAVE ON MONTANA. MOST LIKELY SCENARIO APPEARS TO BE THAT
MID-LEVEL SOUTHWESTERLY FLOW OVER THE GREAT BASIN WILL ALLOW
SUBTROPICAL MOISTURE TO ADVECT INTO THE SOUTHERN HALF OF MY FORECAST
AREA FOR ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORM
POSSIBILITIES ON SUNDAY AND MONDAY. MPJ

&&

.AVIATION...
UPDATED 1750Z.
EXPECT GENERALLY VFR CONDITIONS WITH CONDITIONS RANGING FROM
NUMEROUS SHOWERS AND THUNDERSTORMS OVER NORTHCENTRAL MONTANA TO
ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST MONTANA. A FEW
THUNDERSTORMS OVER THE PLAINS AND ADJOINING MOUNTAINS WILL HAVE IFR
CONDITIONS IN HEAVY RAINFALL. THOUGHT THE POSSIBILITY OF THIS
HAPPENING WAS GREAT ENOUGH THAT MVFR/IFR CONDITIONS IN HEAVY RAIN
WERE MENTIONED AT KCTB..KHVR..AND KLWT. SHOWERS AND THUNDERSTORMS
WILL DISSIPATE DURING THE EARLY EVENING OVER SOUTHWEST MONTANA WHILE
THEY WILL GENERALLY DISSIPATE ELSEWHERE NEAR AND AFTER DARK. WOULD
NOT BE SURPRISED TO A FEW SHOWERS REDEVELOP LATE TONIGHT AT KHVR AND
POSSIBLY AT KLWT. ALTHOUGH EXPECT THE MAIN THREAT FROM THE
THUNDERSTORMS TODAY AND EARLY THIS EVENING TO BE HEAVY RAINFALL AND
SMALL HAIL..DO EXPECT LOCAL WIND GUSTS TO 40 KNOTS. BLANK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  76  49  78 /  40  10  10  20
CTB  45  73  48  75 /  40  20  20  20
HLN  51  81  51  81 /  20  10  10  20
BZN  48  86  49  84 /  10  10  10  20
WEY  37  76  38  80 /  20  10  10  20
DLN  44  81  46  81 /  10  10  10  10
HVR  49  75  51  81 /  40  30  10  20
LWT  46  74  47  75 /  30  20  10  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...EMANUEL
LONG TERM...MPJ
AVIATION...BLANK

WEATHER.GOV/GREATFALLS
Hazardous weather outlook, Jul 19, 3:26 AM MDT, 13 hours 39 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
326 AM MDT MON JUL 19 2010

MTZ008>015-044>055-200930-
BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-
CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-
TOOLE-LIBERTY-EASTERN PONDERA-BLAINE-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS-
JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
326 AM MDT MON JUL 19 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

In the hours before

Special weather statement, Jul 19, 1:12 PM MDT, 3 hours 53 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
112 PM MDT MON JUL 19 2010

MTZ048-049-191945-
EASTERN TETON MT-SOUTHERN ROCKY MOUNTAIN FRONT MT-
112 PM MDT MON JUL 19 2010

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL TETON COUNTY UNTIL 145 PM
MDT...

AT 105 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 17 MILES NORTHWEST OF CHOTEAU...MOVING SOUTHEAST
AT 25 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER IS EXPECTED WITH THIS
STORM...ALONG WITH BRIEF HEAVY RAIN OF UP TO A HALF-INCH IN A AN
HOUR. WIND GUSTS TO 30 MPH ARE ALSO POSSIBLE WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
   BYNUM...
   CHOTEAU...

LAT...LON 4799 11203 4768 11218 4788 11264 4804 11250
TIME...MOT...LOC 1911Z 300DEG 20KT 4791 11245
Special weather statement, Jul 19, 2:14 PM MDT, 2 hours 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
214 PM MDT MON JUL 19 2010

MTZ012-048-049-192045-
CASCADE MT-EASTERN TETON MT-SOUTHERN ROCKY MOUNTAIN FRONT MT-
214 PM MDT MON JUL 19 2010

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN LEWIS AND CLARK...
SOUTHERN TETON AND EXTREME NORTHWESTERN CASCADE COUNTIES UNTIL 245 PM
MDT...

AT 210 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 12 MILES NORTH OF AUGUSTA...OR 17 MILES SOUTHWEST
OF CHOTEAU...MOVING EAST AT 25 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER IS EXPECTED WITH THIS
STORM...ALONG WITH BRIEF HEAVY RAIN OF UP TO A HALF-INCH IN A AN
HOUR. WIND GUSTS TO 30 MPH ARE ALSO POSSIBLE WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
  RURAL SOUTHERN TETON COUNTY...
  RURAL NORTHERN LEWIS AND CLARK COUNTY...
  RURAL NORTHWESTERN CASCADE COUNTY...

LAT...LON 4782 11188 4749 11190 4756 11261 4778 11260
TIME...MOT...LOC 2014Z 277DEG 21KT 4766 11244
Special weather statement, Jul 19, 2:32 PM MDT, 2 hours 33 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
232 PM MDT MON JUL 19 2010

MTZ009-046-048-049-192100-
EASTERN PONDERA MT-EASTERN TETON MT-NORTHERN ROCKY MOUNTAIN FRONT
MT-SOUTHERN ROCKY MOUNTAIN FRONT MT-
232 PM MDT MON JUL 19 2010

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN TETON AND CENTRAL
PONDERA COUNTIES UNTIL 300 PM MDT...

AT 228 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 18 MILES SOUTHEAST OF HEART BUTTE...OR 27 MILES
NORTHWEST OF CHOTEAU...MOVING EAST AT 25 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER IS EXPECTED WITH THIS
STORM...ALONG WITH BRIEF HEAVY RAIN OF UP TO A HALF-INCH IN A AN
HOUR. WIND GUSTS TO 30 MPH ARE ALSO POSSIBLE WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
   PENDROY AND  BYNUM...

LAT...LON 4814 11198 4790 11202 4799 11275 4817 11271
TIME...MOT...LOC 2031Z 277DEG 22KT 4807 11260
Special weather statement, Jul 19, 3:11 PM MDT, 1 hour 54 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
311 PM MDT MON JUL 19 2010

MTZ012-014-048-049-192200-
CASCADE MT-CENTRAL AND SOUTHERN LEWIS AND CLARK MT-EASTERN TETON
MT-SOUTHERN ROCKY MOUNTAIN FRONT MT-
311 PM MDT MON JUL 19 2010

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN LEWIS AND CLARK...
EXTREME SOUTHERN TETON AND WESTERN CASCADE COUNTIES UNTIL 400 PM
MDT...

AT 306 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 11 MILES SOUTHWEST OF FAIRFIELD...OR 23 MILES
NORTHWEST OF CASCADE...MOVING SOUTHEAST AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 30 MPH ARE
POSSIBLE WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...CASCADE...FORT SHAW
AND SIMMS.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4740 11152 4714 11178 4741 11228 4760 11210
TIME...MOT...LOC 2111Z 304DEG 16KT 4745 11206

GUSTAFSON
Special weather statement, Jul 19, 3:12 PM MDT, 1 hour 53 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
312 PM MDT MON JUL 19 2010

MTZ046-048-049-192200-
EASTERN PONDERA MT-EASTERN TETON MT-SOUTHERN ROCKY MOUNTAIN FRONT MT-
312 PM MDT MON JUL 19 2010

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL TETON AND EXTREME
SOUTHERN PONDERA COUNTIES UNTIL 400 PM MDT...

AT 312 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 7 MILES NORTHWEST OF CHOTEAU...MOVING SOUTHEAST
AT 25 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 30 MPH ARE
POSSIBLE WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...CHOTEAU...FAIRFIELD
AND DUTTON.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4783 11156 4751 11215 4782 11257 4807 11216
TIME...MOT...LOC 2112Z 314DEG 21KT 4789 11229

GUSTAFSON
Special weather statement, Jul 19, 4:17 PM MDT, 48 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 9:52 AM MDTSpecial Weather StatementTFX53 min
Jul 19, 1:08 PM MDTSpecial Weather StatementTFXLewis and Clark22 min
Jul 19, 1:12 PM MDTSpecial Weather StatementTFXTeton33 min
Jul 19, 2:14 PM MDTSpecial Weather StatementTFXTeton31 min
Jul 19, 2:32 PM MDTSpecial Weather StatementTFXPondera28 min
Jul 19, 3:11 PM MDTSpecial Weather StatementTFXCascade49 min
Jul 19, 3:12 PM MDTSpecial Weather StatementTFXTeton48 min
Jul 19, 3:36 PM MDTSevere Thunderstorm WarningTFXCascade, Lewis and Clark, Teton39 min
Jul 19, 4:17 PM MDTSpecial Weather StatementTFXCascade58 min
Jul 19, 4:54 PM MDTSevere Thunderstorm WarningTFXCascade, Meagher51 min
Jul 19, 5:21 PM MDTSevere Thunderstorm WarningTFXGlacier39 min
Jul 19, 5:53 PM MDTSevere Thunderstorm WarningTFXGlacier, Toole52 min

Nearby

Severe Thunderstorm Warnings in Montana, 2010Every severe thunderstorm warning in 2010

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.