Flash Flood Warning 4, NWS Pendleton, OR

Issued

Aug 20, 2002, 4:20 PM PDT (23:20 UTC)

Expired

Aug 20, 2002, 6:00 PM PDT

In force

100 min

Issued by

NWS Pendleton, OR

Area

Counties, with a storm outline in the text

County Wallowa County, OR

The Pendleton radar (KPDT), 133 km from the middle of the area, began a volume at 23:20 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.

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

000 
WGUS51 KPDT 202320
FFWPDT
ORC063-210100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PENDLETON OR
414 PM PDT TUE AUG 20 2002

THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  JOSEPH AND WALLOWA LAKE AREA OF CENTRAL WALLOWA COUNTY IN 
  NORTHEAST OREGON

* UNTIL 600 PM PDT

* AT 414 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  THAT OVER AN INCH OF RAIN HAS FALLEN SOUTH OF JOSEPH IN THE 
  STEEP TERRAIN OF THE WALLOWA MOUNTAINS. HEAVY RAIN WILL CONTINUE
  THROUGH 5 PM WITH FLASH FLOODING LIKELY IN THIS AREA.
   
EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO
TRIGGER ROCK AND MUDSLIDES IN STEEP TERRAIN.

LAT...LON 4542 11729 4529 11711 4571 11690 4579 11718

NWS Pendleton, OR wrote its last area forecast discussion before this flash flood warning went out at Aug 20, 2:35 PM PDT, 1 hour 45 minutes earlier.

NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
235 PM PDT TUE AUG 20 2002

FIRE WEATHER...THE MAIN FIRE WEATHER CONCERN IS THE LIGHTNING.
HOWEVER...THE AIR MASS HAS MOISTENED ENOUGH FOR SIGNIFICANT SHOWERS
WITH MOST STORMS. ONE FIRE SOUTHWEST OF JOHN DAY REPORTED SMALL HAIL
WITH A STORM.  THE MAIN MESSAGE WILL BE HIGHER HUMIDITIES AND SOME
PRECIPITATION WITH SHOWERS.

A VERY COOL UPPER LEVEL LOW PRESSURE IS DEVELOPING OVER NORTHEAST
OREGON NEAR PENDLETON THIS AFTERNOON.  THIS LOW IS LIKELY TO PERSIST
OVER NORTHEAST OREGON INTO WEDNESDAY BEFORE DRIFTING INTO SOUTHERN
OREGON BY FRIDAY. THE MAIN AFFECT WILL BE TO KEEP THE ATMOSPHERE
QUITE COOL...MOIST AND UNSTABLE WEDNESDAY WITH SOME DRYING THURSDAY.
 HIGHER PEAKS OF EASTERN OREGON MAY ALSO SEE A DUSTING OF SNOW
OVERNIGHT AS SNOW LEVELS FALL TO NEAR 7500 FEET.  LOTS OF
UNCERTAINTY IN THE TRACK OF THIS UPPER LOW PAST 72 HOURS...BUT
BELIEVE IS WILL SHIFT AGAIN NORTHWARD FRIDAY AFTERNOON AND SATURDAY.
ALSO...TYPICALLY UPPER LOWS IN SUCH A LIGHT UPPER LEVEL WIND PATTERN
TEND TO PERSIST LONGER THAN THE MODELS SHOW.  AS SUCH WILL KEEP SOME
SHOWERS IN THE FORECAST OVER THE WEEKEND ACROSS NORTHEAST OREGON AND
SOUTHEAST WASHINGTON.  A DRIER WESTERLY FLOW MAY DEVELOP EARLY NEXT
WEEK.  HENRY/BAUCK

PDT 3221  ALW 3221  PSC 2110 YKM 2000

KPDT...VCP21/PRECIP MODE...OPERATIONAL.

.KPDT...NONE.

Flash Flood Warnings in Oregon, 2002Every flash flood warning in 2002

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.