Alert archive / Wyoming / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 51, NWS Riverton, WY

July 5, 2013Johnson County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jul 5, 2013, 5:45 PM MDT for Johnson County, Wyoming. It was in force for 60 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 5, 2013, 5:45 PM MDT (23:45 UTC)
Expired
Jul 5, 2013, 6:45 PM MDT
In force
60 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

County Johnson County, WY

The radar

The Riverton/Lander radar (KRIW), 187 km from the middle of the area, began a volume at 23:47 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

Riverton, WY (KRIW), launched 12:00Z, 11.8 hours before the alert went out and 182 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, Riverton, WY at 12:00Z on 2013-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2013-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 square meters per square second.19395878Sfc1 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
11 J/kg
Mixed-layer CIN
-276 J/kg
Mixed-layer LCL
1342 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
111 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 Riverton, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 5, 1:59 PM MDT, 3 hours 46 minutes earlier.

Area forecast discussion, Jul 5, 1:59 PM MDT, 3 hours 46 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
159 PM MDT FRI JUL 5 2013

.SHORT TERM...TONIGHT AND SATURDAY
ANOTHER ACTIVE THUNDERSTORM PERIOD AS UNUSUALLY MOIST ATMOSPHERE
REMAINS OVER THE AREA COMBINED WITH SEVERAL WEAK DISTURBANCES AND
NOW A SERIES OF JET STREAKS. HARD TO PINPOINT ANY DISTURBANCES TO
DIRECTLY AFFECT OUR AREA THROUGH THIS AFTERNOON EXCEPT POSSIBLY
THE FAR NORTH...AND NW...BUT THINGS GET MORE INTERESTING TONIGHT
AND SATURDAY MORNING. TODAY WILL STILL BE VERY ACTIVE WITH SURFACE
DEW POINTS IN THE 50S ACROSS THE LOWER ELEVATIONS AND 40S IN THE
HIGH COUNTRY. ALTHOUGH THESE WILL MIX OUT ACROSS THE CENTRAL AND
SWRN AREAS DURING THE AFTERNOON A GOOD 10 DEGREES. WEAK SURFACE
BOUNDARY MAY PROVIDE SOME LOW LEVEL CONVERGENCE ACROSS THE NERN
THIRD. TONIGHT A DISTURBANCE OVER NERN NV MOVES INTO THE SW ABOUT
THE SAME TIME THAT A JET STREAK IS EXPECTED TO PROVIDE SOME RIGHT
ENTRANCE REGION JET STREAK DYNAMICS. THIS FORCING THEN LIFTS INTO
CENTRAL WYOMING AROUND 12Z SATURDAY WHICH WOULD PROVIDE FOR
MORNING THUNDERSTORMS ACROSS THIS AREA. SOME OF THESE NOCTURNAL
INTO SATURDAY MORNING STORMS COULD BE QUITE STRONG TO POTENTIALLY
EVEN SEVERE. SATURDAY LOOKS TO BE ANOTHER ACTIVE AFTERNOON AND
EVENING ALSO WITH GOOD INSTABILITY AND HIGH PW'S. ADJUSTED
SOUNDINGS INDICATE CAPES OF AT LEAST 500-1000 J/KG WITH MUCH
HIGHER CAPES WHERE DEW POINTS CAN STAY IN THE 50S ACROSS THE LOWER
ELEVATIONS.

.LONG TERM..SATURDAY NIGHT THROUGH FRIDAY
CONVECTION WILL STILL BE ONGOING SATURDAY NIGHT AS AN UPPER LEVEL
DISTURBANCE SHIFTS EAST...TAKING THE FOCUS OF THE SHOWERS AND
THUNDERSTORMS WITH IT. UNSETTLED SOUTHWEST FLOW REMAINS THROUGH
THE WEEKEND AND INTO NEXT WEEK. THE MODELS ATTEMPT TO DRY THE MID
LEVELS WEDNESDAY AND THURSDAY WITH A LESS CHANCE OF SHOWERS AND
STORMS AS THE RIDGE TRIES TO MIGRATE NORTH AND PLACE THE REGION
ENTIRELY UNDER ITS HOT DRY INFLUENCE. NEXT FRIDAY LOOK MORE MOIST
FOR AN INCREASED CHANCE OF SHOWERS/STORMS AS THE RIDGE AXIS SHIFTS
EAST. TEMPERATURES WILL REMAIN SUMMER-LIKE WITH 80S TO MID 90S FOR
THE BASINS...80S FOR THE FAR WEST VALLEYS AND 65-75 MOUNTAINS.

.AVIATION.../00Z ISSUANCE/

ACTIVE SHOWER AND THUNDERSTORM PERIOD ACROSS THE ENTIRE AREA THROUGH
THE WEEKEND. EVEN THE NIGHTTIME AND MORNING PERIODS WILL SEE AT
LEAST ISOLATED THUNDERSTORMS WITH SCATTERED TO NUMEROUS STORMS IN
THE AFTERNOON AND EVENING. ALL TERMINALS COULD BE IMPACTED AT ONE
TIME OR ANOTHER. THE PEAK PERIODS WILL BE DURING THE AFTERNOON AND
EVENING BUT ANY PERIOD COULD BE IMPACTED BY A THUNDERSTORM.

.FIRE WEATHER...

AN ACTIVE PERIOD OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH
THE WEEKEND ACROSS THE AREA. THE PEAK PERIOD FOR STORMS WILL BE IN
THE AFTERNOON AND EVENING BUT SOME THUNDERSTORMS WILL BE POSSIBLE
DURING THE OVERNIGHT AND MORNING HOURS THROUGH THE WEEKEND.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

SHORT TERM...SKRBAC
LONG TERM...ALLEN
AVIATION...SKRBAC
FIRE WEATHER...SKRBAC
Hazardous weather outlook, Jul 5, 4:43 PM MDT, 1 hour 2 minutes before
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In the hours before

Special weather statement, Jul 5, 3:58 PM MDT, 1 hour 47 minutes before
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Special weather statement, Jul 5, 4:50 PM MDT, 55 minutes before
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Local storm report, Jul 5, 5:13 PM MDT, 32 minutes before
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Special weather statement, Jul 5, 5:17 PM MDT, 28 minutes before
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Special weather statement, Jul 5, 5:28 PM MDT, 17 minutes before
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Special weather statement, Jul 5, 5:42 PM MDT, 3 minutes before
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The office that day

Everything else NWS Riverton, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 6:00 PM MDTSpecial Weather StatementRIWBig Horn45 min
Jul 4, 6:39 PM MDTSpecial Weather StatementRIWJohnson51 min
Jul 4, 7:08 PM MDTSpecial Weather StatementRIWSheridan52 min
Jul 4, 7:28 PM MDTSpecial Weather StatementRIWNatrona47 min
Jul 4, 7:55 PM MDTSpecial Weather StatementRIWJohnson65 min
Jul 5, 1:55 PM MDTSpecial Weather StatementRIW50 min
Jul 5, 2:37 PM MDTSpecial Weather StatementRIWFremont38 min
Jul 5, 2:53 PM MDTSpecial Weather StatementRIW52 min
Jul 5, 2:56 PM MDTSpecial Weather StatementRIWHot Springs49 min
Jul 5, 3:03 PM MDTSpecial Weather StatementRIWBig Horn27 min
Jul 5, 3:07 PM MDTSevere Thunderstorm WarningRIWHot Springs, Park53 min
Jul 5, 3:24 PM MDTSpecial Weather StatementRIWBig Horn51 min
Jul 5, 3:43 PM MDTSpecial Weather StatementRIW47 min
Jul 5, 3:51 PM MDTSevere Thunderstorm WarningRIWHot Springs, Washakie54 min
Jul 5, 3:58 PM MDTSpecial Weather StatementRIWWashakie47 min
Jul 5, 4:41 PM MDTSevere Thunderstorm WarningRIWHot Springs, Washakie64 min
Jul 5, 4:50 PM MDTSpecial Weather StatementRIW55 min
Jul 5, 5:17 PM MDTSpecial Weather StatementRIWWashakie43 min
Jul 5, 5:28 PM MDTSpecial Weather StatementRIWNatrona32 min
Jul 5, 5:42 PM MDTSpecial Weather StatementRIW48 min
Jul 5, 5:54 PM MDTSpecial Weather StatementRIWNatrona51 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2013Every severe thunderstorm warning in 2013

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.