Alert archive / Oregon / Flash Flood Warnings in 2002

Flash Flood Warning 1, NWS Pendleton, OR

July 18, 2002Wallowa County, Oregon

NWS Pendleton, OR issued this flash flood warning at Jul 18, 2002, 6:58 PM PDT for Wallowa County, Oregon. It was in force for 62 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 18, 2002, 6:58 PM PDT (01:58 UTC)
Expired
Jul 18, 2002, 8:00 PM PDT
In force
62 min
Issued by
NWS Pendleton, OR
Area
Counties, with a storm outline in the text

County Wallowa County, OR

Did it verify

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.

The nearest sounding before it

Boise Airport, ID (KBOI), launched 00:00Z, 2.0 hours before the alert went out and 221 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, Boise Airport, ID at 00:00Z on 2002-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 81 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, Boise Airport, ID at 00:00Z on 2002-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.193958Sfc1 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
81 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
2486 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
1 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPDT 190202
FFWPDT
ORC063-190500-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PENDLETON OR...CORRECTED
658 PM PDT THU JUL 18 2002

CORRECTED THE EXPIRATION TIME

THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL WALLOWA COUNTY IN NORTHEAST OREGON

* UNTIL 1000 PM PDT

* AT 656 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM OVER WALLOWA LAKE...OR ABOUT 8 MILES SOUTH OF         
  JOSEPH...MOVING NORTH AT 10 MPH THAT MAY CAUSE ADDITIONAL FLASH    
  FLOODING.

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 4529 11739 4525 11714 4558 11700 4563 11734

What forecasters said that day

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

NWS Pendleton, OR wrote its last area forecast discussion before this flash flood warning went out at Jul 18, 2:30 PM PDT, 4 hours 28 minutes earlier.

Area forecast discussion, Jul 18, 2:30 PM PDT, 4 hours 28 minutes before
NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PDT THU JUL 18 2002

FIRE WEATHER...AN UPPER LEVEL TROUGH LOCATED ALONG THE NORTHERN
CALIFORNIA AND NEVADA BORDER HAS PRODUCED NUMEROUS THUNDERSTORMS
WITH HEAVY RAIN REPORTED NEAR THE LAKE TAHOE AREA. SOME MID AND HIGH
LEVEL CLOUDS HAVE SPREAD INTO SOUTHEAST OREGON...AND RADARS AT
BOISE  AND MEDFORD ARE ESTIMATING LIGHT RAINFALL OVER SOUTHERN
OREGON.  THE UPPER LEVEL TROUGH WILL WEAKEN AS IT MOVES
NORTHEAST TONIGHT.  MOST OF THE PRECIPITATION FROM SHOWERS AND
THUNDERSTORMS WILL BE IN SOUTHEAST OREGON.  HOWEVER...LINGERING
MOISTURE AND INSTABILITY OVER THE OCHOCO MOUNTAINS AND THE NORTHEAST
OREGON MOUNTAINS WILL RESULT IN ISOLATED SHOWERS AND THUNDERSTORMS
THERE. THE AIR MASS HAS MOISTENED SO STORMS ARE NOT EXPECTED TO BE
DRY TONIGHT.

COOLER AND MORE STABLE CONDITIONS ARE EXPECTED ON FRIDAY ASSOCIATED
WITH A WEAK MARINE PUSH. A LARGE UPPER LEVEL TROUGH MOVING ACROSS
BRITISH COLUMBIA AND NORTHERN WASHINGTON WILL HELP TO STEEPEN THE
MARINE LAYER.  BREEZY TO WINDY CONDITIONS CAN BE EXPECTED OVER THE
KITTITAS VALLEY AND THE EASTERN COLUMBIA GORGE.  ALTHOUGH MODELS ARE
NOT SHOWING A VERY TIGHT GRADIENT OVER THE BASIN...EXPECT OCCASIONAL
BREEZY WINDS FRIDAY AND FRIDAY EVENING. WILL KEEP A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS OVER THE EASTERN MOUNTAINS FRIDAY
AFTERNOON AND EVENING. NO PRECIPITATION IS EXPECTED ON SATURDAY.
SMITH

EXTENDED...AN UPPER LOW PRESSURE SYSTEM OFF THE CALIFORNIA COAST
WILL BRING MOISTURE TO THE OREGON BORDER ON SUNDAY. HOWEVER...
WESTERLY FLOW ALOFT OVER NORTHERN OREGON AND WASHINGTON WILL PREVENT
THE MOISTURE FROM ENTERING THE FORECAST AREA ON SUNDAY. THE
AFOREMENTIONED LOW WILL MOVE NORTH AND INLAND TO NORTHERN CALIFORNIA
AND SOUTHERN OREGON ON MONDAY. ALSO ON MONDAY A SHORT WAVE WILL MOVE
SOUTHEAST ACROSS BRITISH COLUMBIA THUS COMING INTO PHASE WITH
AFOREMENTIONED UPPER LOW. THIS WILL OPEN UP THE SOUTHERLY FLOW ALOFT
OVER OREGON AND ALLOW MOISTURE TO MOVE INTO CENTRAL OREGON FOR A
SLIGHT CHANCE OF THUNDERSTORMS IN CENTRAL OREGON AND THE OCHOCO-JOHN
DAY HIGHLANDS ON MONDAY AND TUESDAY. ON WEDNESDAY AND THURSDAY...
HIGH PRESSURE OVER THE FOUR CORNERS STRENGTHENS AND BUILDS WESTWARD
ACROSS CALIFORNIA WHILE THE WESTERLIES WILL DOMINATE THE PACIFIC
NORTHWEST FOR DRY CONDITIONS ACROSS THE REGION .  POLAN

PDT 0000  ALW 0000  PSC 0000  YKM 0000

KPDT...VCP21..OPERATIONAL.

.KPDT...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 7:02 PM PDTFlash Flood WarningPDTWallowa3 hr
Jul 19, 4:11 PM PDTFlash Flood WarningPDTWallowa109 min

Nearby

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

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.