Alert archive / Washington / Flash Flood Warnings in 2012

Flash Flood Warning 2, NWS Pendleton, OR

July 17, 2012Columbia County, Washington

NWS Pendleton, OR issued this flash flood warning at Jul 17, 2012, 4:39 PM PDT for Columbia County, Washington. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 17, 2012, 4:39 PM PDT (23:39 UTC)
Expired: Jul 17, 2012, 6:45 PM PDT
In force: 2 hr
Issued by: NWS Pendleton, OR
Area: Storm-based polygon
Flood severity: None

County Columbia County, WA

The radar

The Pendleton radar (KPDT), 114 km from the middle of the area, began a volume at 23:39 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, 11.7 hours before the alert went out and 181 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: 126 J/kg
Mixed-layer CIN: -169 J/kg
Mixed-layer LCL: 1286 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

759 
WGUS56 KPDT 172339
FFWPDT
WAC013-180145-
/O.NEW.KPDT.FF.W.0002.120717T2339Z-120718T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PENDLETON OR
439 PM PDT TUE JUL 17 2012

THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL COLUMBIA COUNTY IN SOUTHEAST WASHINGTON...

* UNTIL 645 PM PDT

* AT 436 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA. THIS STORM 
IS NEARLY STATIONARY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

&&

LAT...LON 4616 11776 4639 11784 4647 11790 4648 11774
      4646 11772 4644 11770 4641 11770 4638 11766
      4635 11766 4633 11760 4615 11760

$$

DC

1 follow-up statement

303 
WGUS76 KPDT 180143
FFSPDT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PENDLETON OR
643 PM PDT TUE JUL 17 2012

WAC013-180151-
/O.EXP.KPDT.FF.W.0002.000000T0000Z-120718T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COLUMBIA WA-
643 PM PDT TUE JUL 17 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 645 PM PDT FOR EAST CENTRAL
COLUMBIA COUNTY...

THE STORM THAT PRODUCED THE HEAVY RAIN HAS DECREASED IN INTENSITY. 
FLASH FLOODING IS NO LONGER EXPECTED.

LAT...LON 4616 11776 4639 11784 4647 11790 4648 11774
      4646 11772 4644 11770 4641 11770 4638 11766
      4635 11766 4633 11760 4615 11760

$$

DC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 9:08 PM PDT	Areal Flood Advisory	PDT	Benton, Columbia, Franklin, Walla Walla	4 hr
Jul 16, 9:23 PM PDT	Special Weather Statement	PDT	Walla Walla	37 min
Jul 16, 9:40 PM PDT	Special Weather Statement	PDT	Franklin	35 min
Jul 17, 4:25 PM PDT	Flash Flood Warning	PDT	Yakima	2 hr

Nearby

Flash Flood Warnings in Washington, 2012 Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.