Alert archive / Nevada / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 25, NWS Reno, NV

July 21, 2002Washoe County, Nevada

NWS Reno, NV issued this severe thunderstorm warning at Jul 21, 2002, 8:37 PM PDT for Washoe County, Nevada. It was in force for 53 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 21, 2002, 8:37 PM PDT (03:37 UTC)
Expired: Jul 21, 2002, 9:30 PM PDT
In force: 53 min
Issued by: NWS Reno, NV
Area: Counties, with a storm outline in the text

County Washoe County, NV

The radar

The Reno radar (KRGX), 24 km from the middle of the area, began a volume at 03:39 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm 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

Reno, NV (KREV), launched 00:00Z, 3.6 hours before the alert went out and 134 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: 636 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 3399 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 5 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.

662 
WUUS55 KREV 220337
SVRREV
NVC031-220430-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE RENO NV
836 PM PDT SUN JUL 21 2002

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL WASHOE COUNTY IN WESTERN NEVADA

* UNTIL 930 PM PDT

* AT 830 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER SOUTH CENTRAL WASHOE COUNTY...OR ABOUT 13
  MILES NORTHEAST OF RENO...MOVING NORTH AT 5 MPH.

* THE SEVERE THUNDERSTORM WILL BE OVER THE SPANISH SPRINGS VALLEY AND PARTS
OF RURAL SOUTHERN WASHOE COUNTY

REPORT DAMAGING WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE.

LAT...LON 3960 11979 3964 11952 4001 11964 3994 11997

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 Reno, NV wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 3:12 AM PDT, 17 hours 25 minutes earlier.

Area forecast discussion, Jul 21, 3:12 AM PDT, 17 hours 25 minutes before

WESTERN NEVADA AND EASTERN CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
245 AM PDT SUN JUL 20 2002

COMBINATION OF UPPER LOW OFF THE SOUTH CENTRAL CALIFORNIA COAST AND
DESERT SOUTHWEST HIGH PRESSURE BOTH MOVING NORTH GIVING THE CWA
SOUTHERLY FLOW. SATELLITE LOOPS ARE IN AGREEMENT WITH RH PROGS
SHOWING INCREASING 500 AND 600 MB RH. THIS WILL COMBINE WITH STRONG
HEATING...UNSTABLE AIRMASS AND OROGRAPHICS TO INCREASE CONVECTION.
WILL ADD SOME MENTION OF THUNDERSTORMS TO THE ENTIRE CWA. PRECIP
WATER NOT INCREASING AND LOWER LAYERS REMAINING DRY SO SHOULD SEE
STRONG WIND GUSTS WITH STORMS AND WILL ADD TO FORECAST. OTHERWISE
TEMPS UP A FEW DEGREES THIS AFTERNOON. THE LOW CONTINUES UP THE COAST
ON MONDAY WITH FLOW INCREASING A LITTLE AND TRENDING TO THE
SOUTHWEST FOR MOST OF THE CWA. FOR NOW WILL GO ALONG WITH THE CURRENT
FORECAST AND LIMIT CONVECTION TO ZONES 5 AND 71. AIRMASS IS STILL
UNSTABLE A LITTLE FURTHER SOUTH OF THESE BUT WILL GO WITH THE
DRYING IN THE SOUTHWEST FLOW. DAY SHIFT CAN LOOK AT THIS ON THE NEXT
RUN. ON TUESDAY THE LOW REMAINS OFF THE NORTHERN CALIFORNIA COAST
WITH THE HIGH OVER UTAH RESULTING IN DRY AND STABLE SOUTHWEST CWA
WIDE WITH NO MENTION OF CONVECTION. LITTLE CHANGE IN TEMPS AS THEY
CONTINUE ABOVE NORMAL. DONALDSON

IN THE EXTENDED PERIOD...WEDNESDAY THROUGH SATURDAY...THE UPPER LOW
OFF NRN CA WEAKENS AND EJECTS WELL N OF NV WEDNESDAY THROUGH
THURSDAY.  A VERY WEAK TROUGH REMAINS NEAR THE NW COAST THROUGH
SATURDAY AS AN UPPER EAST/WEST RIDGE AXIS BUILDS SOUTH OF WRN NV.  A
WAVE MOVING AROUND THE WRN PERIPHERY OF THE SW HIGH BRUSHES JUST
SOUTH OF MINERAL AND MONO COUNTIES WEDNESDAY WITH SOME CLOUDS.
LIGHT LOW LEVEL SOUTHERLY FLOW WITH MARGINAL INSTABILITY REACHES AS
FAR NORTH AS EXTREME SOUTHERN MONO OR SE MINERAL UNDER STRONGER SW
WINDS ALOFT THURSDAY.  THE UKMET AND MRF THEN HOLD THE E/W RIDGE
WELL SOUTH OF THE AREA FRIDAY AND SATURDAY.  THE CAN AND EURO
SOLUTIONS TO BRING THE WEAK NW COAST TROUGH INLAND BY FRIDAY ARE
UNLIKELY WITH THE STRONG HEATING THIS TIME OF YEAR.  WEST TO
SOUTHWEST WINDS WILL BE STRONGER THAN RECENTLY WITH THE THERMAL
TROUGH SHIFTING EAST ACROSS THE GREAT BASIN.  THE STRONGEST WINDS
SHOULD BE WEDNESDAY WITH THE EXITING LOW AND AGAIN NORTH SATURDAY IF
A SHORT WAVE DROPS INTO THE NW COAST AS INDICATED IN THE MRF.
OSTERMAN.

.REV...NONE.

In the hours before

Local storm report, Jul 21, 4:27 PM PDT, 4 hours 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO, NV
427 PM PDT SUN JUL 21 2002

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

0805 PM    3 NW NIXON                NV   60 MPH TSTM WIND GUST
07/21/02   WASHOE                         AUTOMATED WIND SENSOR AT
                                          PYRAMID

Nearby

Severe Thunderstorm Warnings in Nevada, 2002 Every severe thunderstorm 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; radar from the NEXRAD Level II archive.