Alert archive / Washington / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 6, NWS Spokane, WA

April 23, 1998Okanogan County, Washington

NWS Spokane, WA issued this severe thunderstorm warning at Apr 23, 1998, 4:10 PM PDT for Okanogan County, Washington. It was in force for 50 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Apr 23, 1998, 4:10 PM PDT (23:10 UTC)
Expired: Apr 23, 1998, 5:00 PM PDT
In force: 50 min
Issued by: NWS Spokane, WA
Area: Whole counties

County Okanogan County, WA

The radar

The Spokane radar (KOTX), 184 km from the middle of the area, began a volume at 23:17 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.

What was reported inside it

Time	Report	Where	Remark
Apr 23, 4:10 PM PDT	Hail 1	Brewster, WA	1 inch hail

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 11.2 hours before the alert went out and 265 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1569 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 91 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.

968 
WUUS1 KGEG 232311 RRA
SVRGEG
WAC047-240000-

IMMEADIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SPOKANE WA
410 PM PDT THU APR 23 1998

THE NATIONAL WEATHER SERVICE IN SPOKANE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL OKANOGAN COUNTY IN NORTH CENTRAL WASHINGTON

* UNTIL 500 PM PDT

* SEVERE THUNDERSTORM WILL BE NEAR-
    OKANOGAN                    BY 425 PM PDT
    OMAK                        BY 435 PM PDT

* AT 410 PM PDT... SEVERE THUNDERSTORM INDICATED 17 MILES SOUTH OF
  OMAK OR 13 MILES SOUTH OF OKANOGAN... BY SPOTTERS... MOVING
  NORTHEAST 20 MPH.

LARGE HAIL IS LIKELY WITH THIS STORM. GO INSIDE A STURDY BUILDING
AND STAY AWAY FROM WINDOWS

MS/BA

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 Spokane, WA wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 23, 2:30 PM PDT, 1 hour 40 minutes earlier.

Area forecast discussion, Apr 23, 2:30 PM PDT, 1 hour 40 minutes before

EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WASHINGTON
230 PM PDT WED APR 23 1998

SPLIT UPPER LEVEL TROUGH AT 135W WITH S/W EJECTING INTO WA AT 09Z.
MID LEVEL MOISTURE PLENTIFUL WITH EJECTING S/W WITH LOCAL AREAS OF
MODERATE RAIN OVER THE PALOUSE.  AREAS OF RAIN MOVING NORTH ACROSS
THE ID PNHDL AND MOST SITES THERE WILL SEE SOME RAINFALL THIS
MORNING.  RADAR LOOP SHOWING A SMALL LINE OF SCATTERED SHOWERS IN THE
LOWER COLUMBIA BASIN.. ASSOCIATED WITH THE BACK EDGE OF UPPER LEVEL
S/W.  EXTRAPOLATION YIELDS THAT THIS LINE OF SCATTERED LIGHT SHOWERS
WILL REACH KGEG AROUND 12-13Z.  OVERALL EFFECT OF DEPARTING S/W WILL
BE MOISTENING THE LOWER LEVELS.. AND EXPECT SURFACE DEW POINTS TO
RISE INTO THE LOWER 50S ACROSS THE ENTIRE FORECAST AREA.  EXPECT
BRIEF CLEARING THIS MORNING BEHIND S/W FOR GOOD APRIL INSOLATION..
IDEAL SET UP FOR THUNDER THIS AFTERNOON WITH APPROACHING OFFSHORE
TROUGH PROVIDING LIFT.  EXPECT BEST RAINFALL THIS EVENING WITH
DEVELOPING COLD FRONTOGENESIS PROVIDING THE TRIGGER IN AN UNSTABLE
MOIST AIR MASS.  MODELS SHOW STRONG SURFACE RIDGE BUILDING RAPIDLY
BEHIND FRONTAL PASSAGE IMPLYING STRONG SURFACE COLD AIR ADVECTION
INTO FRIDAY YIELDING WINDY CONDITIONS.  DRAMATIC CHANGE IN TEMPS WITH
00Z ETA MODEL SHOWING H85 TEMPS FALLING FROM NEAR 14C TODAY TO 2C BY
SATURDAY AFTERNOON.

MANY SCREAMING MESSAGES IN THIS FORECAST PACKAGE.. 1. GOOD CHANCE OF
THUNDERSTORMS TODAY AND EVENING WITH HEAVY RAIN AND SMALL HAIL
POSSIBLE.. FOLLOWED BY 2. WINDY AND MUCH COOLER CONDITIONS ON FRIDAY.
FRISBIE

...PRODUCTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...
...PLEASE SEE SEACCFSEA AND ZONE FORECAST PRODUCTS...

GEG 073/045/056 673
CQV 075/043/059 674
S86 073/044/056 684
COE 072/043/054 683
WWP 071/042/053 7+5
LWS 069/048/060 783
MOS 070/045/057

.GEG...NONE.

In the hours before

Local storm report, Apr 23, 2:32 PM PDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
132 PM PST THU APR 23 1998

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

1158 AM    NESPELEM                  WA   .5 INCH HAIL
04/23/98   OKANOGAN

1200 PM    8 N REPUBLIC              WA   .5 INCH HAIL
04/23/98   FERRY                          SPOTTER ESTIMATED WINDS
                                          30-40 MPH

Local storm report, Apr 23, 2:32 PM PDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
132 PM PST THU APR 23 1998

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

1158 AM    NESPELEM                  WA   .5 INCH HAIL
04/23/98   OKANOGAN

1200 PM    8 N REPUBLIC              WA   .5 INCH HAIL
04/23/98   FERRY                          SPOTTER ESTIMATED WINDS
                                          30-40 MPH

Special weather statement, Apr 23, 2:50 PM PDT, 1 hour 20 minutes before

WAZ031>038-IDZ001>004-240000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
250 PM PDT THU APR 23 1998

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 PM PDT FOR THE
FOLLOWING EASTERN WASHINGTON COUNTIES:

...OKANOGAN...FERRY...STEVENS...PEND OREILLE...CHELAN...GRANT...
DOUGLAS...LINCOLN...SPOKANE...ADAMS...WHITMAN...GARFIELD...AND
ASOTIN.

A SEVERE THUNDERSTORM WATCH HAS ALSO BEEN ISSUED FOR NORTHERN IDAHO AND
IS IN EFFECT UNTIL 900 PM PDT FOR THE FOLLOWING IDAHO COUNTIES:

...BONNER...BOUNDARY...KOOTENAI...SHOSHONE...BENEWAH...LATAH...
NEZ PERCE...AND LEWIS.

SEVERE THUNDERSTORMS HAVE DEVELOPED IN NORTHEAST OREGON AND IN CENTRAL
WASHINGTON WITH HAIL UP TO ONE INCH AND WIND GUSTS OVER 50 MPH.

RESIDENTS IN THE WATCH AREA SHOULD KEEP ABREAST OF RAPIDLY CHANGING
CONDITIONS...AND BE PREPARED TO TAKE SHELTER IF THREATENING
WEATHER DEVELOPS.

Special weather statement, Apr 23, 2:50 PM PDT, 1 hour 20 minutes before

WAZ031>038-IDZ001>004-240000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
250 PM PDT THU APR 23 1998

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 PM PDT FOR THE
FOLLOWING EASTERN WASHINGTON COUNTIES:

...OKANOGAN...FERRY...STEVENS...PEND OREILLE...CHELAN...GRANT...
DOUGLAS...LINCOLN...SPOKANE...ADAMS...WHITMAN...GARFIELD...AND
ASOTIN.

A SEVERE THUNDERSTORM WATCH HAS ALSO BEEN ISSUED FOR NORTHERN IDAHO AND
IS IN EFFECT UNTIL 900 PM PDT FOR THE FOLLOWING IDAHO COUNTIES:

...BONNER...BOUNDARY...KOOTENAI...SHOSHONE...BENEWAH...LATAH...
NEZ PERCE...AND LEWIS.

SEVERE THUNDERSTORMS HAVE DEVELOPED IN NORTHEAST OREGON AND IN CENTRAL
WASHINGTON WITH HAIL UP TO ONE INCH AND WIND GUSTS OVER 50 MPH.

RESIDENTS IN THE WATCH AREA SHOULD KEEP ABREAST OF RAPIDLY CHANGING
CONDITIONS...AND BE PREPARED TO TAKE SHELTER IF THREATENING
WEATHER DEVELOPS.

Local storm report, Apr 23, 3:06 PM PDT, 1 hour 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
206 PM PST THU APR 23 1998

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

1058 AM    NESPELEM                  WA   .5 INCH HAIL
04/23/98   OKANOGAN

1100 AM    8 N REPUBLIC              WA   .5 INCH HAIL
04/23/98   FERRY                          ESTIMATED WINDS 30-40 MPH

0135 PM    BARSTOW                   WA   1 INCH HAIL
04/23/98   FERRY

0150 PM    OTHELLO                   WA   1 INCH HAIL
04/23/98   ADAMS

Local storm report, Apr 23, 3:06 PM PDT, 1 hour 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
206 PM PST THU APR 23 1998

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

1058 AM    NESPELEM                  WA   .5 INCH HAIL
04/23/98   OKANOGAN

1100 AM    8 N REPUBLIC              WA   .5 INCH HAIL
04/23/98   FERRY                          ESTIMATED WINDS 30-40 MPH

0135 PM    BARSTOW                   WA   1 INCH HAIL
04/23/98   FERRY

0150 PM    OTHELLO                   WA   1 INCH HAIL
04/23/98   ADAMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 23, 12:41 PM PDT	Severe Thunderstorm Warning	OTX	Ferry, Okanogan	49 min
Apr 23, 1:44 PM PDT	Severe Thunderstorm Warning	OTX	Ferry	66 min
Apr 23, 2:42 PM PDT	Severe Thunderstorm Warning	OTX	Stevens	33 min
Apr 23, 2:55 PM PDT	Severe Thunderstorm Warning	OTX	Adams	50 min

Nearby

Severe Thunderstorm Warnings in Washington, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.