Alert archive / Idaho / Winter Storm Warnings in 2011

Winter Storm Warning 9, NWS Spokane, WA

April 4, 20114 counties in Idaho

NWS Spokane, WA issued this winter storm warning at Apr 4, 2011, 5:52 AM PDT for 4 counties in Idaho. It took effect at Apr 4, 2011, 9:20 AM PDT. It was in force for 26 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
Apr 4, 2011, 5:52 AM PDT (12:52 UTC)
In effect from
Apr 4, 2011, 9:20 AM PDT
Expired
Apr 5, 2011, 11:01 AM PDT
In force
26 hr
Issued by
NWS Spokane, WA

Counties Benewah County, ID, Kootenai County, ID, Latah County, ID, Shoshone County, ID

The radar

The Spokane radar (KOTX), 97 km from the middle of the area, began a volume at 12:53 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, 0.9 hours before the alert went out and 49 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 2011-04-04Temperature 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 12:00Z on 2011-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 154 square meters per square second.1939587897117136Sfc1 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
1116 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
154 m²/s²
0-3 km storm-relative helicity
171 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.

128 
WWUS46 KOTX 041252
WSWOTX

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SPOKANE WA
552 AM PDT MON APR 4 2011

IDZ004-042100-
/O.UPG.KOTX.WS.A.0006.110405T0000Z-110406T0000Z/
/O.NEW.KOTX.WS.W.0009.110405T0000Z-110406T0000Z/
CENTRAL PANHANDLE MOUNTAINS-
552 AM PDT MON APR 4 2011

...WINTER STORM WARNING IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 PM PDT TUESDAY ABOVE 4500 FEET...

THE NATIONAL WEATHER SERVICE IN SPOKANE HAS ISSUED A WINTER STORM
WARNING ABOVE 4500 FEET FOR HEAVY SNOW WHICH IS IN EFFECT FROM 5
PM THIS AFTERNOON TO 5 PM PDT TUESDAY. THE WINTER STORM WATCH IS
NO LONGER IN EFFECT.

* SNOW ACCUMULATIONS: 5 TO 9 INCHES POSSIBLE.

* ELEVATION: ABOVE 4500 FEET.

* TIMING: SNOW LEVELS WILL FALL LATE THIS AFTERNOON AND REMAIN LOW
  ENOUGH TO PRODUCE ACCUMULATING SNOWS THROUGH TUESDAY.

* LOCATIONS INCLUDE: LOOKOUT PASS ALONG INTERSTATE 90.

* WINDS: WINDS WILL BECOME GUSTY MONDAY NIGHT AND TUESDAY... 
  WITH GUSTS AROUND 45 MPH POSSIBLE ON EXPOSED MOUNTAIN 
  RIDGES. THIS WILL PRODUCE BLOWING SNOW.

* IMPACTS: MOTORISTS SHOULD EXPECT HEAVY SNOW ACCUMULATIONS AT THE
  HIGHEST PASSES SUCH AS LOOKOUT PASS.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SIGNIFICANT AMOUNTS
OF SNOW ARE EXPECTED OR OCCURRING. SNOW ACCUMULATIONS WILL MAKE
TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

&&

$$
5 follow-up statements
847 
WWUS46 KOTX 041620 AAA
WSWOTX

URGENT - WINTER WEATHER MESSAGE...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
920 AM PDT MON APR 4 2011

IDZ004-050030-
/O.EXT.KOTX.WS.W.0009.110404T1620Z-110406T0000Z/
CENTRAL PANHANDLE MOUNTAINS-
920 AM PDT MON APR 4 2011

...WINTER STORM WARNING NOW IN EFFECT UNTIL 5 PM PDT TUESDAY
ABOVE 4500 FEET...

THE WINTER STORM WARNING ABOVE 4500 FEET IS NOW IN EFFECT UNTIL
5 PM PDT TUESDAY. 

* SNOW ACCUMULATIONS: 5 TO 10 INCHES. THOUGH 1 TO 2 INCHES WILL BE
  LIKELY AS LOW AS 3500 FEET.  

* ELEVATION: ABOVE 4500 FEET FOR THE HEAVIEST SNOWS. 

* TIMING: SNOW LEVELS WILL BRIEFLY RISE THIS AFTERNOON...THEN FALL
  OVERNIGHT...AND REMAIN LOW ENOUGH TO PRODUCE ACCUMULATING SNOWS
  THROUGH TUESDAY. THE SNOW MAY BRIEFLY CHANGE TO RAIN AT LOOKOUT
  PASS THIS AFTERNOON...THEN TRANSITION TO SNOW THIS EVENING.  

* LOCATIONS INCLUDE: LOOKOUT PASS ALONG INTERSTATE 90.

* WINDS: WINDS WILL BECOME GUSTY TONIGHT AND TUESDAY... 
  WITH GUSTS AROUND 45 MPH POSSIBLE ON EXPOSED MOUNTAIN 
  RIDGES. THIS WILL PRODUCE BLOWING SNOW.

* IMPACTS: MOTORISTS SHOULD EXPECT HEAVY SNOW ACCUMULATIONS AT
  THE HIGHEST PASSES SUCH AS LOOKOUT PASS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SIGNIFICANT AMOUNTS
OF SNOW ARE EXPECTED OR OCCURRING. SNOW ACCUMULATIONS WILL MAKE
TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

&&

$$
254 
WWUS46 KOTX 042140
WSWOTX

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SPOKANE WA
240 PM PDT MON APR 4 2011

IDZ004-050600-
/O.CON.KOTX.WS.W.0009.000000T0000Z-110406T0000Z/
CENTRAL PANHANDLE MOUNTAINS-
240 PM PDT MON APR 4 2011

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM PDT TUESDAY
ABOVE 4500 FEET...

A WINTER STORM WARNING ABOVE 4500 FEET REMAINS IN EFFECT UNTIL
5 PM PDT TUESDAY. 

* SNOW ACCUMULATIONS: 5 TO 10 INCHES. THOUGH 1 TO 2 INCHES WILL 
  BE LIKELY AS LOW AS 3500 FEET. 

* ELEVATION: ABOVE 4500 FEET FOR THE HEAVIEST SNOWS.

* TIMING: SNOW LEVELS WILL BRIEFLY RISE...THEN FALL OVERNIGHT...AND
  REMAIN LOW ENOUGH TO PRODUCE ACCUMULATING SNOWS THROUGH TUESDAY.
  THE SNOW MAY BRIEFLY CHANGE TO RAIN AT LOOKOUT PASS THROUGH
  EARLY EVENING...BEFORE CHANGING BACK TO SNOW LATE THIS EVENING
  INTO TUESDAY.

* LOCATIONS INCLUDE: LOOKOUT PASS ALONG INTERSTATE 90.

* WINDS: WINDS WILL BECOME GUSTY TONIGHT AND TUESDAY... WITH 
  GUSTS AROUND 45 MPH POSSIBLE ON EXPOSED MOUNTAIN RIDGES. 
  THIS WILL PRODUCE BLOWING SNOW.

* IMPACTS: MOTORISTS SHOULD EXPECT HEAVY SNOW ACCUMULATIONS AT 
  THE HIGHEST PASSES SUCH AS LOOKOUT PASS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SIGNIFICANT AMOUNTS
OF SNOW ARE EXPECTED OR OCCURRING. SNOW ACCUMULATIONS WILL MAKE
TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

&&

$$
357 
WWUS46 KOTX 050418
WSWOTX

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SPOKANE WA
918 PM PDT MON APR 4 2011

IDZ004-051330-
/O.CON.KOTX.WS.W.0009.000000T0000Z-110406T0000Z/
CENTRAL PANHANDLE MOUNTAINS-
918 PM PDT MON APR 4 2011

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM PDT TUESDAY
ABOVE 4500 FEET...

A WINTER STORM WARNING ABOVE 4500 FEET REMAINS IN EFFECT UNTIL
5 PM PDT TUESDAY. 

* SNOW ACCUMULATIONS: 5 TO 10 INCHES. THOUGH 1 TO 2 INCHES WILL 
  BE LIKELY AS LOW AS 3500 FEET. 

* ELEVATION: ABOVE 4500 FEET FOR THE HEAVIEST SNOWS.

* TIMING: SNOW LEVELS WILL FALL OVERNIGHT...AND REMAIN LOW ENOUGH
  TO PRODUCE ACCUMULATING SNOWS THROUGH TUESDAY. THE SNOW MAY
  BRIEFLY CHANGE TO RAIN AT LOOKOUT PASS THROUGH EARLY
  EVENING...BEFORE CHANGING BACK TO SNOW LATE THIS EVENING INTO
  TUESDAY.

* LOCATIONS INCLUDE: LOOKOUT PASS ALONG INTERSTATE 90.

* WINDS: WINDS WILL BECOME GUSTY TONIGHT AND TUESDAY... WITH 
  GUSTS AROUND 45 MPH POSSIBLE ON EXPOSED MOUNTAIN RIDGES. 
  THIS WILL PRODUCE BLOWING SNOW.

* IMPACTS: MOTORISTS SHOULD EXPECT HEAVY SNOW ACCUMULATIONS AT 
  THE HIGHEST PASSES SUCH AS LOOKOUT PASS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SIGNIFICANT AMOUNTS
OF SNOW ARE EXPECTED OR OCCURRING. SNOW ACCUMULATIONS WILL MAKE
TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

&&

$$
572 
WWUS46 KOTX 051307
WSWOTX

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SPOKANE WA
607 AM PDT TUE APR 5 2011

IDZ004-052200-
/O.CON.KOTX.WS.W.0009.000000T0000Z-110406T0000Z/
CENTRAL PANHANDLE MOUNTAINS-
607 AM PDT TUE APR 5 2011

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM PDT THIS
AFTERNOON ABOVE 4500 FEET...

A WINTER STORM WARNING ABOVE 4500 FEET REMAINS IN EFFECT UNTIL
5 PM PDT THIS AFTERNOON. 

* SNOW ACCUMULATIONS: 5 TO 10 INCHES. 

* ELEVATION: ABOVE 4500 FEET.

* TIMING: SNOW LEVELS WILL CONTINUE TO FALL THIS MORNING AND
  REMAIN LOW ENOUGH FOR ACCUMULATING SNOWS THROUGH TODAY. 

* LOCATIONS INCLUDE: LOOKOUT PASS ALONG INTERSTATE 90.

* WINDS: WINDS WILL BECOME GUSTY TODAY... WITH GUSTS AROUND 45 MPH
  POSSIBLE ON EXPOSED MOUNTAIN RIDGES. THIS WILL PRODUCE BLOWING
  SNOW.

* IMPACTS: MOTORISTS SHOULD EXPECT HEAVY SNOW ACCUMULATIONS AT 
  THE HIGHEST PASSES SUCH AS LOOKOUT PASS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SIGNIFICANT AMOUNTS
OF SNOW ARE EXPECTED OR OCCURRING. SNOW ACCUMULATIONS WILL MAKE
TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

&&

$$
933 
WWUS46 KOTX 051801
WSWOTX

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SPOKANE WA
1101 AM PDT TUE APR 5 2011


IDZ004-051915-
/O.CAN.KOTX.WS.W.0009.000000T0000Z-110406T0000Z/
CENTRAL PANHANDLE MOUNTAINS-
1101 AM PDT TUE APR 5 2011

...WINTER STORM WARNING IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN SPOKANE HAS CANCELLED THE WINTER
STORM WARNING. 

THE THREAT OF WIDESPREAD SIGNIFICANT SNOW ACCUMULATIONS HAS ENDED.
WHILE SCATTERED SNOW SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE
DAY ABOVE 3500 TO 4000 FEET...MAINLY ISOLATED ACCUMULATIONS UP TO
2 INCHES ARE EXPECTED IN THE MORE PERSISTENT SHOWERS.

$$

The office that day

Everything else NWS Spokane, WA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 12:11 PM PDTAreal Flood AdvisoryOTXBenewah, Bonner, Boundary, Kootenai, Latah, Lewis and 2 more44 hr

Nearby

Winter Storm Warnings in Idaho, 2011Every winter storm warning in 2011

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.