Alert archive / Oregon / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 41, NWS Pendleton, OR

July 10, 1998Wallowa County, Oregon

NWS Pendleton, OR issued this severe thunderstorm warning at Jul 10, 1998, 8:07 PM PDT for Wallowa County, Oregon. It was in force for 63 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: Jul 10, 1998, 8:07 PM PDT (03:07 UTC)
Expired: Jul 10, 1998, 9:10 PM PDT
In force: 63 min
Issued by: NWS Pendleton, OR
Area: Whole counties

County Wallowa County, OR

The radar

The Pendleton radar (KPDT), 131 km from the middle of the area, began a volume at 03:09 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 10, 5:15 PM PDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Boise Airport, ID (KBOI), launched 00:00Z, 3.1 hours before the alert went out and 237 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: 70 J/kg
Mixed-layer CIN: -121 J/kg
Mixed-layer LCL: 3136 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.4

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 10, 3:09 PM PDT, 4 hours 58 minutes earlier.

Area forecast discussion, Jul 10, 3:09 PM PDT, 4 hours 58 minutes before

NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
215 PM PDT FRI JUL 10 1998

CONVECTIVE DEBRIS FROM EARLIER THUNDERSTORMS IS MOVING OUT OFF
COUNTY WARNING AREA (CWA) ALLOWING SURFACE HEATING TO BEGIN WHICH
WILL STEEPEN LAPSE RATES NEAR THE SURFACE AND COLD AIR ADVECTION
WILL OCCUR IN MID-UPPER LEVELS WHICH WILL HELP TO FURTHER STEEPEN
LAPSE RATES IN THE MID-UPPER LEVELS. SHORT WAVE ON COAST WILL SWING
TO THE NE REMAINDER OF THIS AFTERNOON AND TONIGHT AND TRIGGER
THUNDERSTORMS...SOME OF WHICH ARE EXPECTED TO BECOME SEVERE BY LATE
AFTERNOON. A 60 KNOT UPPER LEVEL JET WILL SWING ACROSS CWA THIS
AFTERNOON. 18Z MESO ETA SHOWS STRONG VERTICAL SPEED SHEER AT KPDT
BY 00Z SAT. FORECAST LI VALUES OF -3 TO -5. MESO ETA FORECAST
DEWPOINT TEMP SOUNDING IS TOO DRY IN SURFACE-850MB LAYER AND
DERIVED CAPE IS THUS AN UNDERESTMATE. MODIFIED SOUNDING BASED ON
18Z MESO ETA AND CURRENT SURFACE OBS AT KPDT GIVE A CAPE OF 2126
FOR THIS AFTERNOON...VERY UNSTABLE. HIGH MOISTURE LEVELS MEAN
THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAIN IN CWA. SHOWERS AND
THUNDESTORMS WILL TAPPER OFF AFTER MIDNIGHT AND END SAT MORNING
IN BLUE MTNS. UPPER LEVEL TROUGH EXITS "CWA BY EARLY SAT MORNING.
THEN WESTERLY FLOW SETS IN OVER CWA SAT RESULTING IN COOLER TEMPS
THROUGH THE WEEKEND.  POLAN

PDT 3100   ALW 3100   PSC 3100   YKM 2100

.KPDT-88D...VCP21/CSR21.

.KPDT...NONE.

In the hours before

Local storm report, Jul 10, 5:41 PM PDT, 2 hours 26 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON, OR
541 PM PDT FRI JUL 10 1998

TIME(PDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0452 PM                              OR   WIND DAMAGE
07/10/98   JEFFERSON                      0.50 INCH HAIL. UP TO 10
                                          INCH DIAMETER TREE
                                          BRANCHES BLOWN DOWN ALONG
                                          JEFFERSON-WHEELER COUNTY
                                          LINE. (JEFFERSON-2).
0515 PM    FOSSIL                    OR   .75 INCH HAIL
07/10/98   WHEELER                        HEAVY RAIN RUNNING DOWN
                                          STREET. (PUBLIC REPORT).

Local storm report, Jul 10, 5:42 PM PDT, 2 hours 25 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON, OR
542 PM PDT FRI JUL 10 1998

TIME(PDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0452 PM                              OR   WIND DAMAGE
07/10/98   JEFFERSON                      0.50 INCH HAIL. UP TO 10
                                          INCH DIAMETER TREE
                                          BRANCHES BLOWN DOWN ALONG
                                          JEFFERSON-WHEELER COUNTY
                                          LINE. (JEFFERSON-2).

0515 PM    FOSSIL                    OR   .75 INCH HAIL
07/10/98   WHEELER                        HEAVY RAIN RUNNING DOWN
                                          STREET. (PUBLIC REPORT).

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 5:20 PM PDT	Severe Thunderstorm Warning	PDT	Umatilla, Union	50 min
Jul 10, 5:29 PM PDT	Severe Thunderstorm Warning	PDT	Gilliam	51 min
Jul 10, 5:56 PM PDT	Severe Thunderstorm Warning	PDT	Morrow	49 min
Jul 10, 7:21 PM PDT	Severe Thunderstorm Warning	PDT	Wallowa	49 min
Jul 10, 7:37 PM PDT	Severe Thunderstorm Warning	PDT	Benton	48 min
Jul 10, 8:12 PM PDT	Severe Thunderstorm Warning	PDT	Benton, Franklin	63 min

Nearby

Severe Thunderstorm Warnings in Oregon, 1998 Every severe thunderstorm warning in 1998

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.