Alert archive / Washington / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 12, NWS Spokane, WA

August 6, 2010Asotin County, Washington; Nez Perce County, Idaho

NWS Spokane, WA issued this severe thunderstorm warning at Aug 6, 2010, 2:21 PM PDT for Asotin County, Washington; Nez Perce County, Idaho. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 6, 2010, 2:21 PM PDT (21:21 UTC)
Expired
Aug 6, 2010, 3:00 PM PDT
In force
39 min
Issued by
NWS Spokane, WA
Area
Storm-based polygon

Counties Nez Perce County, ID, Asotin County, WA

The radar

The Pendleton radar (KPDT), 158 km from the middle of the area, began a volume at 21:22 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, 9.4 hours before the alert went out and 166 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 2010-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 300 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, Spokane, WA at 12:00Z on 2010-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.19395878Sfc1 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
300 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
2136 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Spokane, WA wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 6, 10:39 AM PDT, 3 hours 42 minutes earlier.

Area forecast discussion, Aug 6, 10:39 AM PDT, 3 hours 42 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1039 AM PDT FRI AUG 6 2010

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL BECOME ESTABLISHED OVER THE INLAND NORTHWEST
THROUGH EARLY NEXT WEEK. THIS WILL RESULT IN A COOLING TREND WITH
TEMPERATURES FALLING TO SLIGHTLY BELOW NORMAL. THERE WILL BE
LIMITED MOISTURE WITH THIS TROUGH...RESULTING IN A CHANCE OF
MAINLY MOUNTAIN SHOWERS.

&&

.DISCUSSION...
THE FORECAST HAS BEEN UPDATED FOR THE REMAINDER OF THIS MORNING
BASED ON CURRENT SATELLITE AND RADAR TRENDS. THE TROUGH AXIS AT
500MB HAS PUSHED INTO CENTRAL WASHINGTON WITH INCREASED WESTERLY
FLOW BRINGING IN STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE
INTO MUCH OF CENTRAL AND PORTIONS OF EASTERN WASHINGTON. HOWEVER
AN AXIS OF INSTABILITY WITH 700-500MB THETA E LAPSE RATES OF -1 TO
-2 C/KM REMAINS OVER SOUTHEAST WASHINGTON...EXTENDING NORTHEAST
TOWARDS THE CENTRAL PANHANDLE MTNS AND THE N IDAHO PANHANDLE. THUS
REDEVELOPMENT OF ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN
POSSIBLE THROUGH THE MORNING WITH ONE SUCH CELL BEING PICKED UP ON
RADAR NEAR POMEROY. MEANWHILE THE DISTURBANCE WHICH BROUGHT
ABUNDANT LIGHTNING TO N IDAHO OVERNIGHT IS EXITING THE AREA WITH A
FEW LINGERING SHOWERS AND THUNDERSTORMS EXPECTED FROM THIS WAVE
OVER BOUNDARY COUNTY NEAR BONNERS FERRY THROUGH MID MORNING.  JW

&&

.AVIATION...
ISOLD TSRA WILL DEVELOP MAINLY OVER THE MTNS THIS AFTERNOON AT THE
ATMOSPHERE DESTABILIZES.  A POCKET OF MID LEVEL INSTABILITY NEAR
KLWS SHOULD PUSH SLIGHTLY TO THE EAST THIS AFTERNOON...SO WHILE
THERE IS A CHANCE OF TSRA OPTED TO LEAVE MENTION OUT OF TAF FCST
GIVEN BEST CHANCES WILL BE SOUTH AND EAST OF KLWS.  THE ATMOSPHERE
WILL STABILIZE AFTER SUNSET ENDING THE ISOLD THUNDERSTORMS OVER THE
MTNS WITH JUST SCT HIGH CIRRUS EXPECTED.  FOR KEAT...WINDS WILL
BECOME BREEZY AND GUSTY NEAR 00Z AS A LEESIDE TROUGH SHIFTS INTO THE
COLUMBIA BASIN ALLOWING NW WINDS TO INCREASE.  JW

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        87  59  82  58  80  56 /  10  10  10  10  10  10
COEUR D'ALENE  86  56  80  55  79  53 /  10  10  10  10  20  20
PULLMAN        87  51  82  50  80  48 /  20  10  10  10  10  10
LEWISTON       94  62  90  61  88  59 /  30  10  10  10  10  10
COLVILLE       90  55  82  53  83  51 /  10  10  20  20  30  30
SANDPOINT      83  54  79  53  76  50 /  20  10  20  20  20  20
KELLOGG        86  56  79  54  77  52 /  30  20  10  20  20  20
MOSES LAKE     94  59  88  58  85  55 /   0   0   0   0  10  10
WENATCHEE      90  64  85  62  84  59 /   0   0  10  10  10  10
OMAK           91  58  85  56  85  55 /  10   0  20  20  20  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 6:46 PM PDTSpecial Weather StatementOTXAsotin59 min
Aug 5, 6:54 PM PDTSpecial Weather StatementOTXChelan51 min
Aug 6, 2:53 PM PDTSevere Thunderstorm WarningOTXAsotin, Whitman35 min
Aug 6, 2:23 PM PDTSpecial Weather StatementOTXBoundary67 min
Aug 6, 2:45 PM PDTSevere Thunderstorm WarningOTXLewis, Nez Perce18 min

Nearby

Severe Thunderstorm Warnings in Washington, 2010Severe Thunderstorm Warnings in Idaho, 2010Every severe thunderstorm warning 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.