Alert archive / Montana / Flash Flood Watches in 2010

Flash Flood Watch 1, NWS Missoula, MT

June 20, 2010Deer Lodge County, Granite County, Silver Bow County, Montana

NWS Missoula, MT issued this flash flood watch at Jun 20, 2010, 1:40 PM MDT for Deer Lodge County, Granite County, Silver Bow County, Montana. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Jun 20, 2010, 1:40 PM MDT (19:40 UTC)
Expired
Jun 20, 2010, 7:01 PM MDT
In force
5 hr
Issued by
NWS Missoula, MT
Flood severity
None

Counties Deer Lodge County, MT, Granite County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 125 km from the middle of the area, began a volume at 19:43 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 12:00Z, 7.7 hours before the alert went out and 239 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 12:00Z on 2010-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2010-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 square meters per square second.193958Sfc1 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
9 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1121 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
32 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 flash flood watch 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 flash flood watch went out at Jun 20, 3:25 AM MDT, 10 hours 15 minutes earlier.

Area forecast discussion, Jun 20, 3:25 AM MDT, 10 hours 15 minutes before
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Hazardous weather outlook, Jun 20, 12:19 AM MDT, 13 hours 21 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MISSOULA MT
1219 AM MDT SUN JUN 20 2010

IDZ009-010-MTZ005>007-043-202100-
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-
MISSOULA/BITTERROOT VALLEYS-BITTERROOT/SAPPHIRE MOUNTAINS-
BUTTE/BLACKFOOT REGION-POTOMAC/SEELEY LAKE REGION-
1219 AM MDT SUN JUN 20 2010

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

.DAY ONE...TODAY AND TONIGHT

STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA THIS
AFTERNOON AND EVENING. THE MAIN THREAT WILL BE WITH HEAVY RAIN AND
LARGE HAIL...BUT STRONG WIND GUSTS ARE ALSO POSSIBLE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SMALL STREAMS COULD RUN VERY HIGH MONDAY AND TUESDAY DUE TO THE
HEAVY RAIN SHOWERS. OTHERWISE THERE IS NO HAZARDOUS WEATHER
EXPECTED THROUGH THE COMING WEEK.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Special weather statement, Jun 20, 1:01 PM MDT, 39 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
101 PM MDT SUN JUN 20 2010

MTZ007-201945-
BUTTE/BLACKFOOT REGION-
101 PM MDT SUN JUN 20 2010

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN GRANITE AND NORTHERN
DEER LODGE COUNTIES UNTIL 145 PM MDT...

AT 1255 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A STRONG THUNDERSTORM 14 MILES WEST OF ANACONDA...MOVING EAST AT 15
MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...WEST VALLEY AND LOST
CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

&&

LAT...LON 4626 11291 4615 11288 4606 11329 4624 11336
TIME...MOT...LOC 1901Z 255DEG 12KT 4617 11320

ZUMPFE

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 19, 8:12 PM MDTSpecial Weather StatementMSOSanders63 min
Jun 19, 8:34 PM MDTSevere Thunderstorm WarningMSOSanders27 min
Jun 20, 1:20 AM MDTFlood WatchMSOFlathead, Lake, Lincoln, Mineral, Missoula, Powell and 1 more37 hr
Jun 20, 1:01 PM MDTSpecial Weather StatementMSODeer Lodge44 min
Jun 20, 2:08 PM MDTSpecial Weather StatementMSOSilver Bow52 min
Jun 20, 2:31 PM MDTFlash Flood WarningMSOSilver Bow60 min
Jun 20, 2:42 PM MDTAreal Flood AdvisoryMSOGranite3 hr
Jun 20, 2:52 PM MDTSevere Thunderstorm WarningMSOPowell38 min
Jun 20, 3:15 PM MDTAreal Flood AdvisoryMSOGranite, Missoula69 min
Jun 20, 3:43 PM MDTSpecial Weather StatementMSOMissoula47 min
Jun 20, 3:53 PM MDTSpecial Weather StatementMSOPowell37 min
Jun 20, 5:32 PM MDTSpecial Weather StatementMSOFlathead43 min
Jun 19, 8:06 PM MDTSpecial Weather StatementMSOClearwater39 min
Jun 19, 8:08 PM MDTSpecial Weather StatementMSOClearwater67 min

Nearby

Flash Flood Watches in Montana, 2010Every flash flood watch 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.