Alert archive / Washington / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 2, NWS Portland, OR

May 2, 2009Clark County, Skamania County, Washington

NWS Portland, OR issued this severe thunderstorm warning at May 2, 2009, 4:31 PM PDT for Clark County, Skamania County, Washington. It was in force for 29 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
May 2, 2009, 4:31 PM PDT (23:31 UTC)
Expired
May 2, 2009, 5:00 PM PDT
In force
29 min
Issued by
NWS Portland, OR
Area
Storm-based polygon

Counties Clark County, WA, Skamania County, WA

The radar

The Portland,OR radar (KRTX), 63 km from the middle of the area, began a volume at 23:33 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 11.5 hours before the alert went out and 396 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, Medford/Jackson, OR at 12:00Z on 2009-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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, Medford/Jackson, OR at 12:00Z on 2009-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.1939587897Sfc1 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
6 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1069 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
242 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Portland, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 2:34 AM PDTSmall Craft Advisory for Rough BarPQR24 hr
May 2, 2:30 PM PDTSpecial Marine WarningPQR60 min
May 2, 2:57 PM PDTGale WatchPQR24 hr
May 2, 2:57 PM PDTSmall Craft Advisory for Rough BarPQR25 hr
May 2, 3:42 PM PDTSpecial Marine WarningPQR48 min
May 2, 3:54 PM PDTSevere Thunderstorm WarningPQRClackamas, Columbia, Multnomah, Washington36 min

Nearby

Severe Thunderstorm Warnings in Washington, 2009Every severe thunderstorm warning in 2009

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.