Alert archive / Washington / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 48, NWS Spokane, WA

July 20, 2012Ferry County, Okanogan County, Washington

NWS Spokane, WA issued this severe thunderstorm warning at Jul 20, 2012, 4:30 PM PDT for Ferry County, Okanogan County, Washington. It was in force for 30 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 20, 2012, 4:30 PM PDT (23:30 UTC)
Expired: Jul 20, 2012, 5:00 PM PDT
In force: 30 min
Issued by: NWS Spokane, WA
Area: Storm-based polygon

Counties Ferry County, WA, Okanogan County, WA

The radar

The Spokane radar (KOTX), 158 km from the middle of the area, began a volume at 23:30 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.

What was reported inside it

Time	Report	Where	Remark
Jul 20, 4:32 PM PDT	TSTM WND DMG	2 Wsw Malo, WA	STRONG WINDS BROUGHT 50YR OLD PINE TREES DOWN. VERY HARD RAIN AT TIME OF REPORT. 2 TO 4 FOOT WAVES ON LAKE CURLEW.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 20, 11:38 AM PDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 11.5 hours before the alert went out and 214 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2619 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 66 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.

021 
WUUS56 KOTX 202330
SVROTX
WAC019-047-210000-
/O.NEW.KOTX.SV.W.0048.120720T2330Z-120721T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SPOKANE WA
430 PM PDT FRI JUL 20 2012

THE NATIONAL WEATHER SERVICE IN SPOKANE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN OKANOGAN COUNTY IN NORTH CENTRAL WASHINGTON...
  NORTHERN FERRY COUNTY IN NORTHEAST WASHINGTON...

* UNTIL 500 PM PDT

* AT 430 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED 8 MILES NORTHWEST OF CURLEW LAKE STATE PARK...OR
  10 MILES NORTH OF REPUBLIC...AND MOVING NORTHEAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MALO...CURLEW...LAUIER AND DANVILLE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM WILL ALSO PRODUCE EXTREMELY HEAVY RAINFALL. IF DRIVING
THROUGH THE STORM REDUCE YOUR SPEED TO LOWER THE RISK OF
HYDROPLANING. ALSO BE PREPARED FOR PONDING OF WATER IN LOW LYING
AREAS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM PDT FRIDAY
EVENING FOR CENTRAL IDAHO AND NORTHEASTERN WASHINGTON.

&&

LAT...LON 4900 11819 4898 11822 4897 11821 4862 11849
      4873 11907 4901 11893 4901 11887 4900 11886
      4901 11879 4900 11878 4901 11877
TIME...MOT...LOC 2331Z 208DEG 30KT 4879 11879

$$

RFOX.RFOX

2 follow-up statements

985 
WWUS56 KOTX 202340
SVSOTX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
440 PM PDT FRI JUL 20 2012

WAC019-047-210000-
/O.CON.KOTX.SV.W.0048.000000T0000Z-120721T0000Z/
FERRY WA-OKANOGAN WA-
440 PM PDT FRI JUL 20 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM PDT
FOR NORTHEASTERN OKANOGAN AND NORTHERN FERRY COUNTIES...

AT 434 PM PDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
THUNDERSTORM CAPABLE OF DAMAGING WINDS IN EXCESS OF 60 MPH.  
THIS STORM WAS LOCATED 8 MILES WEST OF MALO...OR 11 MILES NORTH 
OF REPUBLIC...MOVING NORTHEAST AT 35 MPH. QUARTER SIZE HAIL IS
ALSO POSSIBLE. 

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
CURLEW...LAUIER AND DANVILLE.

A SPOTTER REPORTED 2 TO 4 FOOT WAVES ON LAKE CURLEW AND TREES 
BLOWN DOWN BY STRONG WINDS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM...SEEK SAFE SHELTER AND STAY 
AWAY FROM WINDOWS!

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM PDT FRIDAY
EVENING FOR CENTRAL IDAHO AND NORTHEASTERN WASHINGTON.

&&

LAT...LON 4900 11820 4898 11822 4896 11822 4887 11828
      4884 11832 4867 11845 4878 11904 4901 11892
      4900 11886 4901 11879 4900 11878 4901 11877
TIME...MOT...LOC 2338Z 208DEG 30KT 4884 11875

$$

RFOX.RFOX

851 
WWUS56 KOTX 202352
SVSOTX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
452 PM PDT FRI JUL 20 2012

WAC019-047-210001-
/O.EXP.KOTX.SV.W.0048.000000T0000Z-120721T0000Z/
FERRY WA-OKANOGAN WA-
452 PM PDT FRI JUL 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN OKANOGAN AND
NORTHERN FERRY COUNTIES WILL EXPIRE AT 500 PM PDT...

DOPPLER RADAR INDICATED THE STORM WAS NO LONGER SEVERE AND THE
WARNING WAS ALLOWED TO EXPIRE. EXPECT HEAVY RAIN...WIND GUSTS 
TO 30 MPH AND OCCASIONAL LIGHTNING WITH THIS STORM. 

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM PDT FRIDAY
EVENING FOR CENTRAL IDAHO AND NORTHEASTERN WASHINGTON.

LAT...LON 4900 11820 4898 11822 4896 11822 4887 11828
      4884 11832 4867 11845 4878 11904 4901 11892
      4900 11886 4901 11879 4900 11878 4901 11877
TIME...MOT...LOC 2351Z 208DEG 30KT 4893 11867

$$

RFOX.RFOX

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 12:26 AM PDT	Special Weather Statement	OTX	Okanogan	49 min
Jul 20, 1:09 AM PDT	Special Weather Statement	OTX	Okanogan	51 min
Jul 20, 1:10 AM PDT	Areal Flood Advisory	OTX	Okanogan	4 hr
Jul 20, 11:34 AM PDT	Special Weather Statement	OTX		56 min
Jul 20, 12:17 PM PDT	Flash Flood Warning	OTX	Asotin	28 min
Jul 20, 12:19 PM PDT	Special Weather Statement	OTX	Asotin	41 min
Jul 20, 12:39 PM PDT	Severe Thunderstorm Warning	OTX	Asotin	51 min
Jul 20, 12:59 PM PDT	Severe Thunderstorm Warning	OTX	Grant	46 min
Jul 20, 1:04 PM PDT	Areal Flood Advisory	OTX	Asotin	4 hr
Jul 20, 1:15 PM PDT	Flash Flood Warning	OTX	Grant	60 min
Jul 20, 1:15 PM PDT	Severe Thunderstorm Warning	OTX	Grant	60 min
Jul 20, 1:46 PM PDT	Severe Thunderstorm Warning	OTX	Douglas, Grant	44 min
Jul 20, 2:08 PM PDT	Areal Flood Advisory	OTX	Grant	3 hr
Jul 20, 2:22 PM PDT	Flash Flood Warning	OTX	Okanogan	83 min
Jul 20, 2:29 PM PDT	Severe Thunderstorm Warning	OTX	Garfield, Whitman	46 min
Jul 20, 2:33 PM PDT	Special Weather Statement	OTX	Okanogan	57 min
Jul 20, 2:34 PM PDT	Flash Flood Warning	OTX	Okanogan	86 min
Jul 20, 2:47 PM PDT	Severe Thunderstorm Warning	OTX	Okanogan	58 min
Jul 20, 3:17 PM PDT	Severe Thunderstorm Warning	OTX	Ferry, Grant, Lincoln, Okanogan, Spokane, Stevens	43 min
Jul 20, 3:18 PM PDT	Areal Flood Advisory	OTX	Whitman	117 min
Jul 20, 3:20 PM PDT	Severe Thunderstorm Warning	OTX	Lincoln, Spokane, Whitman	40 min
Jul 20, 3:27 PM PDT	Severe Thunderstorm Warning	OTX	Douglas, Okanogan	34 min
Jul 20, 3:35 PM PDT	Areal Flood Warning	OTX	Pend Oreille	4 hr
Jul 20, 3:37 PM PDT	Severe Thunderstorm Warning	OTX	Pend Oreille	53 min
Jul 20, 3:47 PM PDT	Flash Flood Warning	OTX	Ferry, Okanogan	88 min
Jul 20, 4:22 PM PDT	Special Weather Statement	OTX	Ferry	38 min

Nearby

Severe Thunderstorm Warnings in Washington, 2012 Every severe thunderstorm warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.