Alert archive / Montana / Heavy Snow Warnings in 2007

Heavy Snow Warning 3, NWS Missoula, MT

February 7, 2007Flathead County, Lake County, Montana

NWS Missoula, MT issued this heavy snow warning at Feb 7, 2007, 2:30 PM MST for Flathead County, Lake County, Montana. It took effect at Feb 8, 2007, 2:00 AM MST. It was in force for 12 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Feb 7, 2007, 2:30 PM MST (21:30 UTC)
In effect from
Feb 8, 2007, 2:00 AM MST
Expired
Feb 8, 2007, 2:22 PM MST
In force
12 hr
Issued by
NWS Missoula, MT

Counties Flathead County, MT, Lake County, MT

The radar

The Missoula radar (KMSX), 104 km from the middle of the area, began a volume at 21:32 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, 9.5 hours before the alert went out and 177 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 2007-02-07Temperature 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 2007-02-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.1939Sfc1 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
757 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
15 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 heavy snow 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 heavy snow warning went out at Feb 7, 2:29 PM MST, 1 minute earlier.

Area forecast discussion, Feb 7, 2:29 PM MST, 1 minute before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
229 PM MST WED FEB 7 2007

.DISCUSSION...A MOIST PACIFIC WEATHER SYSTEM WILL MOVE ACROSS
NORTH CENTRAL IDAHO AND WESTERN MONTANA LATER TONIGHT AND THURSDAY.
THIS WEATHER SYSTEM WILL DRAW SOME COLDER AIR ACROSS THE DIVIDE
AND INTO THE GLACIER PARK...FLATHEAD/MISSION VALLEYS...AND SEELEY
LAKE AREAS TONIGHT. ALTHOUGH THE PACIFIC WEATHER SYSTEM IS NOT
STRONG...GOOD SNOW PRODUCTION CONDITIONS SHOULD DEVELOP ACROSS
PORTIONS OF NORTHWEST MONTANA...WHERE THE COLD AIR IS IN PLACE.
FURTHER TO THE SOUTH...THE AIR MASS DOES NOT APPEAR TO COOL
SUFFICIENTLY TO SUPPORT SIGNIFICANT VALLEY SNOW. WEAK HIGH
PRESSURE IS EXPECTED TO RETURN THURSDAY NIGHT. THE GFS MODEL IS
THE PREFERRED SOLUTION FOR GENERAL REGIONAL FORECAST CONDITIONS.

FRIDAY AND FRIDAY NIGHT...LATEST MODELS AND SATELLITE IMAGERY ARE IN
AGREEMENT WITH AN AREA OF DEEP MOISTURE OFF THE CALIFORNIA COAST
PRESENTLY. DISAGREEMENT LIES IN HOW THIS MOISTURE IS TRANSFERED
OVER THE ROCKY MOUNTAINS. I HAVE TRENDED FRIDAYS FORECAST TO THE
NEWER SOLUTIONS THAT BRING MOISTURE AND PRECIPITATION INTO CENTRAL
IDAHO AND SOUTHWEST MONTANA...BUT CONFIDENCE IS LOW WITH THIS
SOLUTION.

SATURDAY THROUGH WEDNESDAY...THERE IS STILL A LOT OF INCONSISTENCIES
IN THE LONG TERM FORECASTS...BUT MORE MODELS ARE KEEPING MOISTURE
AND NORMAL TEMPERATURES OVER THE AREA. THIS WAS COVERED WELL IN THE
PREVIOUS FORECAST...SO LITTLE CHANGE WAS MADE AFTER FRIDAY NIGHT.
&&

.AVIATION...VALLEY INVERSIONS AND AREAS OF FOG AND LOW CLOUDS
ACROSS NORTHWEST MONTANA WILL GIVE WAY TO MORE GENERAL
PRECIPITATION TONIGHT AND THURSDAY. AS THE MORE GENERAL AREA OF
PRECIPITATION DEVELOPS OVERNIGHT...WIDESPREAD MOUNTAIN
OBSCURATIONS ARE LIKELY THROUGH MUCH OF THURSDAY. SEE APPROPRIATE
TAFS AND TWEBS.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...SNOW ADVISORY FROM 4 AM TO 5 PM MST THURSDAY ABOVE 4500 FEET FOR
     BITTERROOT/SAPPHIRE MOUNTAINS-LOWER CLARK FORK REGION.

     SNOW ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM MST THURSDAY FOR
     FLATHEAD/MISSION VALLEYS-KOOTENAI/CABINET REGION.

     HEAVY SNOW WARNING FROM MIDNIGHT TONIGHT TO 5 PM MST THURSDAY
     FOR WEST GLACIER REGION.

     SNOW ADVISORY FROM 4 AM TO 5 PM MST THURSDAY FOR POTOMAC/SEELEY
     LAKE REGION.

ID...SNOW ADVISORY FROM 3 AM TO 4 PM PST THURSDAY ABOVE 4500 FEET FOR
     NORTHERN CLEARWATER MOUNTAINS-SOUTHERN CLEARWATER MOUNTAINS.

&&

SHORT TERM...BAUCK
LONG TERM....STEGEMILLER
AVIATION...BAUCK

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 6, 9:03 PM MSTDense Fog AdvisoryMSOFlathead, Lake, Sanders8 hr
Feb 7, 2:30 PM MSTSnow AdvisoryMSOFlathead, Granite, Lake, Lincoln, Mineral, Missoula and 3 more24 hr

Nearby

Heavy Snow Warnings in Montana, 2007Every heavy snow warning in 2007

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.