Alert archive / Washington / Flash Flood Warnings in 2012

Flash Flood Warning 1, NWS Seattle, WA

July 17, 2012Lewis County, Washington

NWS Seattle, WA issued this flash flood warning at Jul 17, 2012, 4:32 PM PDT for Lewis County, Washington. It was in force for 58 min. 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, 4:32 PM PDT (23:32 UTC)
Expired: Jul 17, 2012, 5:30 PM PDT
In force: 58 min
Issued by: NWS Seattle, WA
Area: Storm-based polygon
Flood severity: None

County Lewis County, WA

The radar

The Portland,OR radar (KRTX), 140 km from the middle of the area, began a volume at 23:32 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

Salem/Mcnary, OR (KSLE), launched 12:00Z, 11.5 hours before the alert went out and 208 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: 942 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 135 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.

019 
WGUS56 KSEW 172332
FFWSEW
WAC041-180030-
/O.NEW.KSEW.FF.W.0001.120717T2332Z-120718T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

URGENT - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SEATTLE WA
432 PM PDT TUE JUL 17 2012

THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN LEWIS COUNTY IN WEST CENTRAL WASHINGTON...

* UNTIL 530 PM PDT.

* AT 427 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY AND PERSISTENT RAIN WITH THE POTENTIAL FOR FLASH  
  FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE THE AREA SOUTHEAST OF PACKWOOD
  BETWEEN THE HAMILTON BUTTES AND TIETON PEAK. THIS INCLUDES THE 
  WALUPT LAKE AREA AND CAMPGROUND...THE CHAMBERS LAKE CAMPGROUND AND 
  NFD ROAD 23. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RUNOFF FROM THE HEAVY RAINS COULD TRIGGER LANDSLIDES AND DEBRIS
FLOWS.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE 
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY 
AUTOMOBILE.

&&

LAT...LON 4640 12188 4668 12173 4655 12141 4653 12145
      4651 12145 4650 12142 4647 12143 4646 12141
      4642 12139 4639 12140

$$

CERNIGLIA
WEATHER.GOV/SEATTLE

1 follow-up statement

846 
WGUS76 KSEW 180027
FFSSEW

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SEATTLE WA
527 PM PDT TUE JUL 17 2012

WAC041-180034-
/O.EXP.KSEW.FF.W.0001.000000T0000Z-120718T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LEWIS-
527 PM PDT TUE JUL 17 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 530 PM PDT FOR SOUTHEASTERN
LEWIS COUNTY...

THE HEAVIEST RAINS ARE NOW OCCURING EAST OF THE CREST AND NOT OVER 
THE WARNING AREA IN EXTREME SOUTHEAST LEWIS COUNTY. RUNOFF FROM THE 
HEAVY RAINS COULD STILL TRIGGER LANDSLIDES AND DEBRIS FLOWS. 

LAT...LON 4640 12188 4668 12173 4655 12141 4653 12145
      4651 12145 4650 12142 4647 12143 4646 12141
      4642 12139 4639 12140

$$

CERNIGLIA
WEATHER.GOV/SEATTLE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 3:02 AM PDT	Small Craft Advisory	SEW		24 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.