Alert archive / Idaho / Snow Advisories in 2007

Snow Advisory 21, NWS Missoula, MT

April 17, 2007Idaho County, Idaho

NWS Missoula, MT issued this snow advisory at Apr 17, 2007, 2:24 AM PDT for Idaho County, Idaho. It took effect at Apr 17, 2007, 5:00 AM PDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Apr 17, 2007, 2:24 AM PDT (09:24 UTC)
In effect from
Apr 17, 2007, 5:00 AM PDT
Expired
Apr 17, 2007, 1:48 PM PDT
In force
9 hr
Issued by
NWS Missoula, MT

County Idaho County, ID

The radar

The Missoula radar (KMSX), 175 km from the middle of the area, began a volume at 09:28 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 00:00Z, 9.4 hours before the alert went out and 218 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 00:00Z on 2007-04-17Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Spokane, WA at 00:00Z on 2007-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1892 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
300 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.

000 
WWUS45 KMSO 170924
WSWMSO

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
324 AM MDT TUE APR 17 2007

...A DEVELOPING SPRING STORM SYSTEM WILL IMPACT MUCH OF THE
NORTHERN ROCKIES...

.A SLOW MOVING STORM SYSTEM WILL CONTINUE TO MOVE INTO THE NORTHERN
ROCKIES THIS MORNING BRINGING WIDESPREAD PRECIPITATION. THE SNOW
WILL BE MAINLY CONFINED TO THE HIGHER TERRAIN WITH THE SOUTHERN
CLEARWATER MOUNTAINS RECEIVING THE BULK OF THE SNOWFALL TODAY.
TONIGHT...THE SNOW LEVELS WILL LOWER AS A POTENTIALLY HEAVY BAND
OF SNOW IS EXPECTED TO DEVELOP ACROSS SOUTHWEST MONTANA AND
PORTIONS NORTH CENTRAL IDAHO.

IDZ006-171800-
/O.NEW.KMSO.SN.Y.0021.070417T1200Z-070418T0000Z/
/O.NEW.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
SOUTHERN CLEARWATER MOUNTAINS-
224 AM PDT TUE APR 17 2007

...SNOW ADVISORY IN EFFECT FROM 5 AM EARLY THIS MORNING TO 5 PM
PDT THIS AFTERNOON ABOVE 4500 FEET...
...WINTER STORM WATCH IN EFFECT FROM THIS AFTERNOON THROUGH
WEDNESDAY AFTERNOON...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A SNOW
ADVISORY ABOVE 4500 FEET...WHICH IS IN EFFECT FROM 5 AM EARLY
THIS MORNING TO 5 PM PDT THIS AFTERNOON. 2 TO 5 INCHES OF SNOW
ACCUMULATION...WITH LOCALLY UP TO 6 INCHES WILL FALL TODAY ACROSS
THE SOUTHERN CLEARWATER MOUNTAINS ABOVE 4500 FEET.

A WINTER STORM WATCH HAS ALSO BEEN ISSUED. THIS WINTER STORM
WATCH IS IN EFFECT FROM LATE THIS AFTERNOON THROUGH WEDNESDAY
AFTERNOON. A STRONG SPRING STORM SYSTEM IS EXPECTED TO IMPACT
CENTRAL IDAHO TONIGHT INTO WEDNESDAY. IF THE STORM FOLLOWS ITS
CURRENTLY FORECASTED TRACK...IT HAS THE POTENTIAL TO PRODUCE HEAVY
SNOWFALL ACROSS THE SOUTHERN CLEARWATER MOUNTAINS. 

A SNOW ADVISORY MEANS THAT PERIODS OF SNOW WILL CAUSE PRIMARILY
TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW COVERED ROADS AND
LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING.

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

$$

IDZ009-010-MTZ002-006-007-043-171800-
/O.NEW.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-WEST GLACIER REGION-
BITTERROOT/SAPPHIRE MOUNTAINS-BUTTE/BLACKFOOT REGION-
POTOMAC/SEELEY LAKE REGION-
324 AM MDT TUE APR 17 2007

...WINTER STORM WATCH IN EFFECT FROM THIS EVENING THROUGH
WEDNESDAY AFTERNOON...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A WINTER STORM
WATCH...WHICH IS IN EFFECT FROM THIS EVENING THROUGH WEDNESDAY
AFTERNOON. A STRONG SPRING STORM SYSTEM IS EXPECTED TO IMPACT
MUCH OF WESTERN MONTANA AND NORTH CENTRAL IDAHO TONIGHT INTO WEDNESDAY.
IF THE STORM FOLLOWS ITS CURRENTLY FORECASTED TRACK...IT HAS THE
POTENTIAL TO PRODUCE HEAVY SNOWFALL ACROSS MUCH OF THE NORTHERN
ROCKIES. 

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

$$
2 follow-up statements
000 
WWUS45 KMSO 171733 AAA
WSWMSO

URGENT - WINTER WEATHER MESSAGE...UPDATED
NATIONAL WEATHER SERVICE MISSOULA MT
1133 AM MDT TUE APR 17 2007

...A DEVELOPING SPRING STORM SYSTEM WILL IMPACT MUCH OF THE
NORTHERN ROCKIES...


IDZ006-172130-
/O.CON.KMSO.SN.Y.0021.000000T0000Z-070418T0000Z/
/O.CON.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
SOUTHERN CLEARWATER MOUNTAINS-
1033 AM PDT TUE APR 17 2007

...SNOW ADVISORY REMAINS IN EFFECT UNTIL 5 PM PDT THIS AFTERNOON
ABOVE 4500 FEET...
...WINTER STORM WATCH REMAINS IN EFFECT FROM 5 PM PDT THIS
AFTERNOON THROUGH WEDNESDAY AFTERNOON...

A SNOW ADVISORY ABOVE 4500 FEET REMAINS IN EFFECT UNTIL 5 PM PDT
THIS AFTERNOON. A WINTER STORM WATCH REMAINS IN EFFECT FROM 5 PM
PDT THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON. 

A WINTER STORM WATCH HAS ALSO BEEN ISSUED. THIS WINTER STORM
WATCH IS IN EFFECT FROM LATE THIS AFTERNOON THROUGH WEDNESDAY
AFTERNOON. A STRONG SPRING STORM SYSTEM IS EXPECTED TO IMPACT
CENTRAL IDAHO TONIGHT INTO WEDNESDAY. IF THE STORM FOLLOWS ITS
CURRENTLY FORECASTED TRACK...IT HAS THE POTENTIAL TO PRODUCE
HEAVY SNOWFALL ACROSS THE SOUTHERN CLEARWATER MOUNTAINS.

A SNOW ADVISORY MEANS THAT PERIODS OF SNOW WILL CAUSE PRIMARILY
TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW COVERED ROADS AND
LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING.

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

$$

IDZ009-010-MTZ002-006-007-043-172130-
/O.CON.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-WEST GLACIER REGION-
BITTERROOT/SAPPHIRE MOUNTAINS-BUTTE/BLACKFOOT REGION-
POTOMAC/SEELEY LAKE REGION-
1133 AM MDT TUE APR 17 2007

...WINTER STORM WATCH REMAINS IN EFFECT FROM 6 PM MDT THIS
EVENING THROUGH WEDNESDAY AFTERNOON...

A WINTER STORM WATCH REMAINS IN EFFECT FROM 6 PM MDT THIS EVENING
THROUGH WEDNESDAY AFTERNOON. 

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

$$
000 
WWUS45 KMSO 172048
WSWMSO

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
248 PM MDT TUE APR 17 2007

.A DEVELOPING SPRING STORM SYSTEM WILL IMPACT MUCH OF THE NORTHERN
ROCKIES TONIGHT AND WEDNESDAY. A SURFACE TROUGH AND ASSOCIATED
COLD FRONT WILL DEEPEN DURING THE DAY AS IT PASSES THROUGH THE
REGION. GOOD UPPER LEVEL SUPPORT...COLDER AIR ALOFT AND THE
LOCATION OF THIS SYSTEM IN SOUTHERN IDAHO ARE COMBINING TO CREATE
A SIGNIFICANT SNOW EVENT FOR IDAHO IN THE SOUTHERN CLEARWATERS AND
LEMHI COUNTY AND IN WESTERN MONTANA FROM THE SOUTHWEST PORTION OF
THE STATE NORTH THROUGH GLACIER NATIONAL PARK.

IDZ006-180400-
/O.CAN.KMSO.SN.Y.0021.000000T0000Z-070418T0000Z/
/O.UPG.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
/O.NEW.KMSO.HS.W.0009.070418T0000Z-070419T0000Z/
SOUTHERN CLEARWATER MOUNTAINS-
148 PM PDT TUE APR 17 2007

...HEAVY SNOW WARNING IN EFFECT FROM 5 PM THIS AFTERNOON TO 5 PM
PDT WEDNESDAY...
...SNOW ADVISORY IS CANCELLED...
...WINTER STORM WATCH NO LONGER IN EFFECT...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A HEAVY SNOW
WARNING...WHICH IS IN EFFECT FROM 5 PM THIS AFTERNOON TO 5 PM PDT
WEDNESDAY. THE SNOW ADVISORY HAS BEEN CANCELLED. THE WINTER STORM
WATCH IS NO LONGER IN EFFECT. 

SNOW ACCUMULATIONS OF 8 TO 12 INCHES WITH LOCAL AMOUNTS UP TO 18
INCHES WILL OCCUR IN THE SOUTHERN CLEARWATER MOUNTAINS. THE HIGHER
VALLEYS WILL RECEIVE 3 TO 6 INCHES BY WEDNESDAY AFTERNOON.

A HEAVY SNOW WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST
THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF
YOU MUST...KEEP AN EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR
VEHICLE IN CASE OF AN EMERGENCY.

$$

MTZ007-043-180400-
/O.UPG.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
/O.NEW.KMSO.HS.W.0009.070418T0900Z-070419T0000Z/
BUTTE/BLACKFOOT REGION-POTOMAC/SEELEY LAKE REGION-
248 PM MDT TUE APR 17 2007

...HEAVY SNOW WARNING IN EFFECT FROM 3 AM TO 6 PM MDT WEDNESDAY...
...WINTER STORM WATCH NO LONGER IN EFFECT...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A HEAVY SNOW
WARNING...WHICH IS IN EFFECT FROM 3 AM TO 6 PM MDT WEDNESDAY. THE
WINTER STORM WATCH IS NO LONGER IN EFFECT. 

SNOW ACCUMULATIONS OF 8 TO 12 INCHES WITH LOCAL AMOUNTS UP TO 16
INCHES WILL OCCUR IN THE BUTTE BLACKFOOT AND POTOMAC SEELEY LAKE
REGIONS. INCREASED AFTERNOON WINDS MAY CREATE AREAS OF BLOWING AND
DRIFTING SNOW...ESPECIALLY OVER THE PASSES. THE HIGHER VALLEYS
WILL RECEIVE 3 TO 6 INCHES BY WEDNESDAY AFTERNOON.

A HEAVY SNOW WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST
THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF
YOU MUST...KEEP AN EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR
VEHICLE IN CASE OF AN EMERGENCY.

$$

MTZ006-180400-
/O.UPG.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
/O.NEW.KMSO.HS.W.0009.070418T0000Z-070419T0000Z/
BITTERROOT/SAPPHIRE MOUNTAINS-
248 PM MDT TUE APR 17 2007

...HEAVY SNOW WARNING IN EFFECT FROM 6 PM THIS EVENING TO 6 PM
MDT WEDNESDAY...
...WINTER STORM WATCH NO LONGER IN EFFECT...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A HEAVY SNOW
WARNING...WHICH IS IN EFFECT FROM 6 PM THIS EVENING TO 6 PM MDT
WEDNESDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT. 

SNOW ACCUMULATIONS OF 8 TO 12 INCHES WITH LOCAL AMOUNTS UP TO 18
INCHES WILL OCCUR IN THE BITTERROOT AND SAPPHIRE MOUNTAINS. THE
HIGHER VALLEYS WILL RECEIVE 3 TO 6 INCHES BY WEDNESDAY AFTERNOON.

A HEAVY SNOW WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST
THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF
YOU MUST...KEEP AN EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR
VEHICLE IN CASE OF AN EMERGENCY.

$$

IDZ009-010-180400-
/O.UPG.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
/O.NEW.KMSO.HS.W.0009.070418T0300Z-070418T1200Z/
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-
248 PM MDT TUE APR 17 2007

...HEAVY SNOW WARNING IN EFFECT FROM 9 PM THIS EVENING TO 6 AM
MDT WEDNESDAY ABOVE 6000 FEET...
...WINTER STORM WATCH NO LONGER IN EFFECT...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A HEAVY SNOW
WARNING ABOVE 6000 FEET...WHICH IS IN EFFECT FROM 9 PM THIS
EVENING TO 6 AM MDT WEDNESDAY. THE WINTER STORM WATCH IS NO
LONGER IN EFFECT. 

SNOW ACCUMULATIONS OF 4 TO 9 INCHES WILL OCCUR IN THE MOUNTAINS OF LEMHI
COUNTY ABOVE 6000 FEET.

A HEAVY SNOW WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST
THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF
YOU MUST...KEEP AN EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR
VEHICLE IN CASE OF AN EMERGENCY.

$$

MTZ002-180400-
/O.UPG.KMSO.WS.A.0009.070418T0000Z-070419T0000Z/
/O.NEW.KMSO.HS.W.0009.070418T0900Z-070419T0600Z/
WEST GLACIER REGION-
248 PM MDT TUE APR 17 2007

...HEAVY SNOW WARNING IN EFFECT FROM 3 AM WEDNESDAY TO MIDNIGHT
MDT WEDNESDAY NIGHT...
...WINTER STORM WATCH NO LONGER IN EFFECT...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A HEAVY SNOW
WARNING...WHICH IS IN EFFECT FROM 3 AM WEDNESDAY TO MIDNIGHT MDT
WEDNESDAY NIGHT. THE WINTER STORM WATCH IS NO LONGER IN EFFECT. 

SNOW ACCUMULATIONS OF 8 TO 14 INCHES WITH LOCAL AMOUNTS UP TO 18
INCHES WILL OCCUR IN THE WEST GLACIER REGION. THE HIGHER VALLEYS
WILL RECEIVE UP TO 6 INCHES BY WEDNESDAY EVENING.

A HEAVY SNOW WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST
THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF
YOU MUST...KEEP AN EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR
VEHICLE IN CASE OF AN EMERGENCY.

$$
DEROSA/MEAD/WHITMORE

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 17, 2:24 AM PDTWinter Storm WatchMSOIdaho, Lemhi11 hr
Apr 17, 1:48 PM PDTHeavy Snow WarningMSOIdaho, Lemhi31 hr

Nearby

Snow Advisories in Idaho, 2007Every snow advisory 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.