Alert archive / Nevada / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 31, NWS Reno, NV

July 28, 2009Lyon County, Nevada

NWS Reno, NV issued this severe thunderstorm warning at Jul 28, 2009, 5:24 PM PDT for Lyon County, Nevada. It was in force for 51 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 28, 2009, 5:24 PM PDT (00:24 UTC)
Expired: Jul 28, 2009, 6:15 PM PDT
In force: 51 min
Issued by: NWS Reno, NV
Area: Storm-based polygon

County Lyon County, NV

The radar

The Reno radar (KRGX), 85 km from the middle of the area, began a volume at 00:24 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 nearest sounding before it

Reno, NV (KREV), launched 00:00Z, 0.4 hours before the alert went out and 105 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: 164 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 3716 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: -4 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 28, 2:50 PM PDT, 2 hours 34 minutes earlier.

Area forecast discussion, Jul 28, 2:50 PM PDT, 2 hours 34 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
ISSUED BY NATIONAL WEATHER SERVICE SACRAMENTO CA
250 PM PDT TUE JUL 28 2009

.DISCUSSION...
MAIN FORECAST PROBLEM CONTINUES TO BE THE PROGRESSION OF UPPER LOW
THAT IS FORECAST TO MOVE TOWARD THE NORTHERN CALIFORNIA COAST.
DETERMINISTIC RUNS HAVE MERGED A BIT IN THEIR CONSENSUS THROUGH
FRIDAY (CENTERS UPPER LOW NEAR 130W). HOWEVER BEYOND FRIDAY...THE
GFS MAINTAINS A SLOW EASTWARD TRACK CLOSE TO THE NORTHERN CALIFORNIA
COAST THIS WEEKEND WHILE THE ECMWF MAINTAINS A 130W POSITION. THE
UKMET AND CANADIAN ALSO MAINTAIN A MORE WESTWARD SOLUTION AND GIVEN
STRENGTH OF EASTERN NORTH AMERICAN TROUGH AND INTERMOUNTAIN WEST
RIDGE...THESE SOLUTIONS ALONG WITH THE ECMWF PROVIDE A MORE
REASONABLE CONSENSUS AND MAKE THE GFS AN OUTLIER. IN ADDITION THERE
WAS STILL QUITE A BIT OF SPREAD IN THE GFS ENSEMBLE SUITE WITH THE
12Z DETERMINISTIC RUN ACTUALLY SLOWING THINGS DOWN A BIT DESPITE ITS
PROGRESSIVE BIAS. SO THIS FORECAST LEANS MORE ON THE ECMWF WHICH IS
SLOWER TO PUSH CONVECTION AWAY FROM THE CREST LATE WEEK.

INSTABILITY PARAMETERS AND 500MB RH FIELDS IN THE GFS ARE REASONABLE
THROUGH FRIDAY. ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS SHOULD
CONTINUE TO SPREAD NORTH AND COVER MOST AREAS WITH MUCH LESS PUSH
EAST ON FRIDAY THAN PREVIOUSLY FORECAST. LACK OF UPPER LEVEL FORCING
SHOULD KEEP THUNDER ISOLATED AND CLOSE TO THE SIERRA THROUGH
WEDNESDAY WITH A SLIGHT INCREASE THURSDAY AS UPPER RIDGE AXIS AND
THERMAL TROUGH BEGIN TO FAVOR THE GREAT BASIN AND ALLOW INCREASING
SFC CONVERGENCE. CONVECTION WAS MAINTAINED FRIDAY IN RESPONSE TO A
SLOWER MODEL EVOLUTION BUT COVERAGE MAY NEED TO BE INCREASED FROM
MONO UP INTO PARTS OF WESTERN NV ALONG STRENGTHENING CONVERGENCE. A
LOT WILL DEPEND ON FINAL LOCATION OF UPPER LOW. WINDS SHOULD REMAIN
FAIRLY LIGHT UNTIL FRI-SAT WHEN INCREASING WEST SFC WINDS AFFECT
RIDGES AND LEE MTN VALLEYS.

NO CHANGES WERE MADE OVER THE WEEKEND AND BEYOND DUE TO THE
UNCERTAINTY OF FEATURES IN THE SHORT TERM. CURRENT FORECASTS FOR
SATURDAY SHOW EVENTUAL DRYING WITH CONVECTION PUSHING OFF THE TO THE
EAST AND LIMITED TO SOUTHERN AREAS BY EARLY NEXT WEEK. TEMPERATURES
WILL SEE A SLIGHT DIP DOWNWARD OVER THE WEEKEND BUT REBOUND UNDER
INCREASING RIDGE/HEIGHTS NEXT WEEK. OVERALL READINGS WILL REMAIN
ABOVE NORMAL AND NEAR THE TOP END OF THE GEFS MOS ENSEMBLE. HOHMANN
&&

.AVIATION...
ISOLD THUNDER WILL AFFECT MAINLY THE KTVL-KTRK-KRNO AREAS THROUGH
ABOUT 03Z. CONVECTIVE GUSTS TO 45KT ARE POSSIBLE NEAR ANY
THUNDERSTORMS. HOHMANN
&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&

HTTP://WEATHER.GOV/RENO

The office that day

Everything else NWS Reno, NV issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 28, 6:21 PM PDT	Special Weather Statement	REV	Storey	39 min
Jul 28, 6:32 PM PDT	Special Weather Statement	REV		43 min
Jul 28, 6:41 PM PDT	Special Weather Statement	REV	Storey	79 min
Jul 28, 7:00 PM PDT	Severe Thunderstorm Warning	REV	Douglas	60 min
Jul 28, 7:02 PM PDT	Special Weather Statement	REV	Storey	43 min
Jul 28, 7:06 PM PDT	Special Weather Statement	REV	Storey	39 min
Jul 28, 7:32 PM PDT	Severe Thunderstorm Warning	REV	Washoe	28 min
Jul 28, 9:01 PM PDT	Special Weather Statement	REV		59 min
Jul 29, 1:32 PM PDT	Special Weather Statement	REV		118 min
Jul 29, 2:48 PM PDT	Special Weather Statement	REV	Douglas	87 min
Jul 29, 2:57 PM PDT	Severe Thunderstorm Warning	REV	Douglas, Lyon	33 min
Jul 29, 3:15 PM PDT	Special Weather Statement	REV	Storey	60 min
Jul 29, 4:24 PM PDT	Special Weather Statement	REV		51 min
Jul 28, 8:11 PM PDT	Special Weather Statement	REV	Sierra	49 min

Nearby

Severe Thunderstorm Warnings in Nevada, 2009 Every severe thunderstorm warning in 2009

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.