Alert archive / Montana / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 27, NWS Missoula, MT

August 6, 2003Granite County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 6, 2003, 4:27 PM MDT for Granite County, Montana. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 6, 2003, 4:27 PM MDT (22:27 UTC)
Expired: Aug 6, 2003, 5:15 PM MDT
In force: 48 min
Issued by: NWS Missoula, MT
Area: Counties, with a storm outline in the text

County Granite County, MT

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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 6, 2:10 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.5 hours before the alert went out and 268 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: 23 J/kg
Mixed-layer CIN: -474 J/kg
Mixed-layer LCL: 2186 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 42 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.

451 
WUUS55 KMSO 062227
SVRMSO
MTC039-062315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
425 PM MDT WED AUG 6 2003

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN GRANITE COUNTY IN WEST CENTRAL MONTANA

* UNTIL 515 PM MDT

* AT 425 PM MDT...RADAR INDICATED A SEVERE THUNDERSTORM 33 MILES
  SOUTHWEST OF PORTERS CORNER...OR 29 MILES SOUTHEAST OF HAMILTON...
  MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  8 MILES SOUTHEAST OF PORTERS CORNER AT 515 PM MDT

THIS STORM PRODUCED HAS HAD A HISTORY OF PRODUCING ONE-INCH DIAMETER 
HAIL AT 405 PM MDT.

DAMAGING WINDS IN EXCESS OF 55 MPH ARE LIKELY WITH THIS SEVERE
THUNDERSTORM. LARGE HAIL IS POSSIBLE...ALONG WITH FREQUENT LIGHTNING
AND HEAVY RAIN. FOR YOUR PROTECTION...GO INDOORS AND STAY AWAY FROM
WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL PROTECTED AREA.

&


LAT...LON 4596 11365 4601 11367 4603 11380 4610 11363
          4631 11324 4622 11315 4621 11327 4609 11327
          4600 11335 4595 11346 4593 11356

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 Missoula, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 6, 2:45 PM MDT, 1 hour 42 minutes earlier.

Area forecast discussion, Aug 6, 2:45 PM MDT, 1 hour 42 minutes before

WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MISSOULA MT
245 PM MDT WED AUG 6 2003

UPDATED TO ADD WATCH BELOW

.SHORT TERM...CUMULUS BEGINNING TO FIRE IN LEMHI COUNTY IDAHO...AS
EVIDENT ON VISIBLE SATELLITE IMAGERY. THIS CUMULUS IS EXPECTED TO
CONTINUE TO GROW AND DEVELOP INTO FULL BLOWN THUNDERSTORMS...A
SEVERE THUNDERSTORM WATCH IS ANTICIPATED SHORTLY. IN ADDITION...
LOCALLY HEAVY RAINFALL FROM THESE STORMS MAY LEAD TO LOCALIZED FLASH
FLOODING AND MUDSLIDES...ESPECIALLY IN DRAINAGES IN STEEP TERRAIN.
THE MAIN FOCUS ON THIS WILL BE IN THE GENERATION AREA OF THESE
STORMS. THIS WOULD BE THE CLEARWATER/BITTERROOT MOUNTAINS AND IN
LEMHI COUNTY IDAHO. A FLASH FLOOD WATCH WILL BE ISSUED FOR THESE
AREAS. SOUTHWEST FLOW HAS BROUGHT GOOD INSTABILITY ACROSS THE
NORTHERN ROCKIES. A SHORTWAVE TROUGH OF ENERGY IS CURRENTLY ENTERING
CENTRAL IDAHO AND IS SERVING AS THE TRIGGER FOR THE CONVECTION. THESE
STORMS WILL TRACK NORTHEAST ACROSS CENTRAL IDAHO AND WESTERN
MONTANA...AND FOR THE MOST PART BE EAST OF THE DIVIDE BY MIDNIGHT.
LINGERING INSTABILITY WILL LIKELY KEEP SHOWERS AND ISOLATED
THUNDERSTORMS GOING THROUGH THE NIGHT OVER NORTHWEST MONTANA.
THURSDAY THE SOUTHWEST FLOW CONTINUES WITH SOME A DECENT PIECE OF
ENERGY SPINNING OVER WESTERN MONTANA AND NORTH CENTRAL IDAHO.
MOISTURE LOOKS TO BE MORE LIMITED WITH THIS SYSTEM WHEN COMPARED WITH
PREVIOUS DAYS. ONCE AGAIN INSTABILITY LOOKS TO LINGER OVER NORTHWEST
MONTANA ALLOWING ISOLATED SHOWERS TO CONTINUE THROUGH THE NIGHT.
FRIDAY INTO FRIDAY NIGHT SOUTHWEST FLOW CONTINUES WITH THE BEST
CHANCES FOR PRECIPITATION LOOKING TO BE IN SOUTHWEST MONTANA AS THE
LEFT EXIT REGION OF A 70KT JET NOSES INTO THE AREA. SATURDAY THE JET
MOVES NORTHWARD INCREASING SHOWER ACTIVITY ACROSS ALL OF WESTERN
MONTANA AND CENTRAL IDAHO. TEMPERATURES LOOK TO WARM THROUGH THE
PERIOD AS WARMER AIR SLOWLY BUILDS INTO THE AREA. GILCHRIST

.LONG TERM...A FEW CHANGES IN THE EXTENDED FORECAST FOR SATURDAY
NIGHT THROUGH WEDNESDAY. EURO AND GFS ARE BRINGING COOLER CONDITIONS
INTO WESTERN MONTANA AND NORTH CENTRAL IDAHO...HOWEVER THERE ARE SOME
TIMING DIFFERENCES. THE EURO MODEL IS MUCH QUICKER WITH THE UPPER LOW
AND COOLER TEMPERATURES...SETTLING THEM IN TUESDAY MORNING. WILL SHOW
THE COOLER AFTERNOON TEMPERATURES ARRIVING BY WEDNESDAY...WHICH WOULD
BE A COMPROMISE. CLIMATOLOGICALLY SPEAKING...WE HAVE 7 OUT OF 10
AUGUSTS THAT HAVE AN UPPER LOW PASSAGE. THEREFORE THE MODEL SOLUTIONS
TRENDING THIS DIRECTION ARE NOT NECESSARILY OFF. NEVERTHELESS...
COOLER AIR DOES LOOK TO CREEP INTO THE REGION OVER THE EXTENDED.
PATTERN WILL PROVIDE FOR CHANCES FOR SHOWERS AND THUNDERSTORMS...THEN
SHIFT INTO A MORE DOMINANT SHOWERY REGIME WITH ISOLATED
THUNDERSTORMS. DICKSON

.MSO...RED FLAG WARNING FOR WESTERN MONTANA ALONG THE DIVIDE THROUGH
       THIS EVENING. (FIRE WEATHER ZONES 110-111-109-108-105.)
    ...FLASH FLOOD WATCH FOR IDAHO AND LEMHI COUNTIES IN IDAHO AND
       RAVALLI COUNTY IN MONTANA THROUGH 10 PM MDT...
    ...SEVERE THUNDERSTORM WATCH FOR ALL OF WESTERN MONTANA AND
       NORTH CENTRAL IDAHO THROUGH 9 PM MDT...

...7-DAY SPOT TEMPS AND POPS...
LIB BBB 052/087 052/089 052/090 33222112
     BBBE 055/087 055/084 053/083 053/083 3722222233
FCA BBB 050/086 049/087 050/088 33322112
     BBBE 052/085 052/082 050/081 050/081 3722222333
POL BBB 055/087 054/088 055/089 33322222
     BBBE 055/086 055/083 053/082 053/082 3722222333
MSO BBB 052/088 051/090 051/090 33422111
     BBBB 054/087 054/084 052/083 052/083 3713333333
HMM BBB 051/089 052/091 052/091 33411111
     BBBB 055/088 055/085 053/084 053/084 3713333333
BTM BBB 047/086 046/088 046/089 33422222
     BBBB 049/086 049/083 047/082 047/082 3722222332
ORO BBB 061/092 061/094 060/092 33322112
     BBBE 060/089 060/086 058/085 058/085 3722211233
GRV BBB 057/086 055/088 054/087 33322112
     BBBB 054/084 054/081 052/080 052/080 3722222333
SMN BBB 051/087 049/090 050/091 33311221
     BBBB 054/088 054/085 052/084 052/084 3712222222

Hazardous weather outlook, Aug 6, 10:02 AM MDT, 6 hours 25 minutes before

MTZ001>007-043-IDZ005>010-071200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MISSOULA MT
600 AM MDT WED AUG 6 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MONTANA AND NORTH
CENTRAL IDAHO

.DAY ONE... TODAY

SCATTERED THUNDERSTORMS CAN BE EXPECTED ACROSS NORTH-CENTRAL IDAHO
AND WEST-CENTRAL MONTANA TODAY THROUGH THIS EVENING. THE ATMOSPHERE
REMAINS UNSTABLE TO SUPPORT THUNDERSTORM DEVELOPMENT WITH SOME
POTENTIALLY GUSTY WINDS...HAIL AND HEAVY RAIN.

.DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 5, 6:39 PM MDT	Severe Thunderstorm Warning	MSO	Flathead	36 min
Aug 6, 3:45 PM MDT	Severe Thunderstorm Warning	MSO	Ravalli	60 min
Aug 6, 3:49 PM MDT	Severe Thunderstorm Warning	MSO	Powell	26 min
Aug 6, 4:23 PM MDT	Severe Thunderstorm Warning	MSO	Powell	52 min

Nearby

Severe Thunderstorm Warnings in Montana, 2003 Every severe thunderstorm warning in 2003

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.