Alert archive / Utah / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 63, NWS Salt Lake City, UT

August 5, 2010Box Elder County, Tooele County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 5, 2010, 4:52 PM MDT for Box Elder County, Tooele County, Utah. It was in force for 23 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
Aug 5, 2010, 4:52 PM MDT (22:52 UTC)
Expired
Aug 5, 2010, 5:15 PM MDT
In force
23 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon

Counties Box Elder County, UT, Tooele County, UT

The radar

The Salt Lake City radar (KMTX), 63 km from the middle of the area, began a volume at 22:54 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

Boise Airport, ID (KBOI), launched 12:00Z, 10.9 hours before the alert went out and 384 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, Boise Airport, ID at 12:00Z on 2010-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Boise Airport, ID at 12:00Z on 2010-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
4455 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
74 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 Salt Lake City, UT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 5, 4:11 PM MDT, 41 minutes earlier.

Area forecast discussion, Aug 5, 4:11 PM MDT, 41 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
411 PM MDT THU AUG 5 2010

.SYNOPSIS...A MOIST AIR MASS WILL REMAIN IN PLACE ACROSS THE AREA
TODAY...PARTICULARLY ACROSS EASTERN AND SOUTHERN UTAH. A SLIGHT
DRYING TREND IS EXPECTED OVER WESTERN UTAH FRIDAY THROUGH
SATURDAY...BUT MOISTURE WILL REMAIN OVER CENTRAL AND EASTERN
PORTIONS OF THE STATE. A PACIFIC TROUGH WILL IMPACT THE STATE SUNDAY
INTO MONDAY.

&&

.DISCUSSION...SEVERAL WEAK IMPULSES ACROSS THE CENTRAL/EASTERN
GREAT BASIN ARE VISIBLE IN THIS AFTERNOONS WATER VAPOR
IMAGERY...IMPULSES EJECTING NORTHEAST FROM THE BROAD PACIFIC
TROUGH DIGGING ALONG THE CALIFORNIA COASTLINE. ANTICIPATE
CONVECTIVE DEVELOPMENT WILL BE DRIVEN BY SAID VORT MAXES FOR THE
REMAINDER OF THE AFTERNOON INTO THIS EVENING AS THEY TRACK
NORTHEAST THROUGH WESTERN/NORTHERN UTAH.

FOCUSING IN...VORT MAX OVER FAR SOUTHWESTERN UTAH WILL CONTINUE TO
LIFT NORTH INTO CENTRAL UTAH THROUGH THIS EVENING. A SECONDARY
FEATURE JUST NORTH OF KELY WILL LIFT NORTHEAST THROUGH NORTHERN
UTAH LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. SATELLITE
TRENDS/RUC13/NAM12 SUPPORT THIS THINKING. DEVELOPMENT WAS SLOW TO
FORM THROUGH MIDDAY...BUT BOUNDARY LAYER HEATING HAS RAPIDLY
OVERCOME SIGNIFICANT CIN AND DEVELOPMENT HAS ENSUED. ALREADY
SEEING ISOLATED STRONG CELLS DEVELOPING FROM THE AZ BORDER NORTH
TO THE GREAT SALT LAKE...MOSTLY OVER THE WESTERN HALF OF THE
STATE...WITH COVERAGE INCREASING RAPIDLY OVER WEST/CENTRAL UTAH.
THUNDERSTORMS EXPECTED TO CONTINUE TO TRACK NORTHEAST AHEAD OF AND
WITH PASSING VORT MAXES...WITH STORMS IMPACTING THE WASATCH MAINLY
DURING THE EVENING HOURS THROUGH THE MIDDLE OF THE NIGHT.

FLASH FLOODING...EJECTING SHORT WAVE THAT RESIDED OVER
SOUTHEASTERN UTAH THIS MORNING HAS LIFTED RAPIDLY INTO EAST
CENTRAL UTAH THIS AFTERNOON. NVA COUPLED WITH FAIRLY ABUNDANT
DAYTIME CLOUD COVER SEEMS TO HAVE SUPPRESSED CONVECTIVE
DEVELOPMENT OVER THE SOUTHEAST THUS FAR. PWATS GREATER THAN AN
INCH AND SBCAPE GREATER THAN 1000 J/KG REMAIN IN PLACE. ANTICIPATE
DEVELOPMENT WILL BUILD OVER THE TERRAIN FROM WEST TO EAST ACROSS
THE WATCH AREA OVER THE NEXT 2 TO 3 HOURS THEN HOLD THROUGH LATE
THIS EVENING BEFORE DIURNAL TRENDS WANE ACTIVITY. FLASH FLOOD WATCH
REMAINS IN PLACE THROUGH 10 PM TONIGHT.

SHARP CONTRAST IN PWAT OVER WESTERN NEVADA...IN WAKE OF PASSING
VORT MAX. SHORT TERM GUIDANCE CONTINUES TO ADVECT THIS DRIER AIR
INTO FAR WESTERN UTAH FRIDAY LIMITING CONVECTIVE POTENTIAL FOR
AREAS WEST OF THE INTERSTATE 15 CORRIDOR THROUGH SATURDAY. POP
TRENDS REFLECT THIS IN FORECAST.

AFOREMENTIONED TROUGH ALONG THE CALIFORNIA COAST WILL EJECT INLAND
LATE THIS WEEKEND INTO EARLY NEXT WEEK. GLOBAL MODELS KEYED IN ON
TIMING OF TROUGH PASSAGE SUNDAY NIGHT INTO MONDAY. MOISTURE WILL
SURGE NORTH AND WEST AGAIN AHEAD OF THIS FEATURE ON SUNDAY
BRINGING A THREAT FOR CONVECTION STATEWIDE ONCE AGAIN...THEN A
DRYING SOUTHWESTERLY FLOW WILL ENSUE IN WAKE OF TROUGH PASSAGE
EARLY NEXT WEEK WITH TUESDAY LIKELY BEING THE FIRST DRY DAY STATEWIDE.

&&

.AVIATION...THERE IS A 50 PERCENT CHANCE OF THE SLC TERMINAL BEING
IMPACTED BY THUNDERSTORMS THIS AFTERNOON AND EVENING...WITH GUSTY
ERRATIC WINDS BEING THE MOST LIKELY IMPACT. THE MOST LIKELY
TIMEFRAME FOR THUNDERSTORMS TODAY IS 22Z TO 03Z.

&&

.FIRE WEATHER...WETTING RAINS WILL CONTINUE TO ACCOMPANY
THUNDERSTORMS TODAY...ESPECIALLY THOSE EAST OF THE INTERSTATE 15
CORRIDOR...WITH DRIER BUT STILL ACTIVE CONDITIONS IN THE WESTERN
HALF OF THE STATE. SOUTH WINDS AND SUBSTANTIAL DRYING WILL BRING THE
FIRST THREAT OF CRITICAL CONDITIONS TO THE NORTHWEST DESERT FRIDAY
AND SATURDAY...THOUGH FUELS ARE NOT REPORTED AS CRITICAL AT THIS
TIME. AS UPPER TROUGH MOVES VERY SLOWLY INLAND...THESE DRYING AND
BREEZY CONDITIONS WILL LIKELY SPREAD ACROSS ALL WESTERN VALLEYS BY
EARLY NEXT WEEK.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR
     UTZ009>014-020-021-517-518.

WY...NONE.
&&

MERRILL/SCHOENING

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)

FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
Hazardous weather outlook, Aug 5, 2:48 AM MDT, 14 hours 4 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
248 AM MDT THU AUG 5 2010

UTZ001>016-019>021-517-518-WYZ021-061200-
CACHE VALLEY/UTAH PORTION-NORTHERN WASATCH FRONT-
SALT LAKE AND TOOELE VALLEYS-SOUTHERN WASATCH FRONT-
GREAT SALT LAKE DESERT AND MOUNTAINS-WASATCH MOUNTAIN VALLEYS-
WASATCH MOUNTAINS I-80 NORTH-WASATCH MOUNTAINS SOUTH OF I-80-
WESTERN UINTA MOUNTAINS-WASATCH PLATEAU/BOOK CLIFFS-
WESTERN UINTA BASIN-CASTLE COUNTRY-SAN RAFAEL SWELL-
SANPETE/SEVIER VALLEYS-WEST CENTRAL UTAH-SOUTHWEST UTAH-
UTAHS DIXIE AND ZION NATIONAL PARK-SOUTH CENTRAL UTAH-
GLEN CANYON RECREATION AREA/LAKE POWELL-CENTRAL MOUNTAINS-
SOUTHERN MOUNTAINS-SOUTHWEST WYOMING-
248 AM MDT THU AUG 5 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS OF
UTAH AND SOUTHWEST WYOMING.

.DAY ONE...TODAY AND TONIGHT

A VERY MOIST AIRMASS REMAINS ACROSS EASTERN...CENTRAL AND PORTIONS
OF SOUTHERN UTAH...POSING AN ELEVATED RISK FOR FLASH FLOODING. SLOT
CANYONS...SMALL STREAMS..AND NORMALLY DRY WASHES MAY BE
PARTICULARLY HAZARDOUS LOCATIONS TODAY. OTHER THREATS FROM THESE
STORMS INCLUDE LIGHTNING...WIND GUSTS IN EXCESS OF 50 MPH AND
SMALL HAIL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A DRIER AIRMASS IS EXPECTED FRIDAY THROUGH NEXT WEEKEND. THERE IS
AN INCREASING THREAT OF CRITICAL FIRE WEATHER CONDITIONS
ESPECIALLY ACROSS WESTERN UTAH BEGINNING SATURDAY AND BECOMING
MORE LIKELY EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

ROGOWSKI

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)

In the hours before

Special weather statement, Aug 5, 4:29 PM MDT, 23 minutes before
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Special weather statement, Aug 5, 4:39 PM MDT, 13 minutes before
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Special weather statement, Aug 5, 4:45 PM MDT, 7 minutes before
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The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 4, 6:02 PM MDTSpecial Weather StatementSLCWasatch43 min
Aug 4, 6:23 PM MDTSpecial Weather StatementSLCSalt Lake37 min
Aug 4, 6:41 PM MDTSevere Thunderstorm WarningSLCUtah, Wasatch34 min
Aug 4, 6:44 PM MDTFlash Flood WarningSLCEmery3 hr
Aug 4, 7:12 PM MDTSpecial Weather StatementSLCWasatch48 min
Aug 5, 2:48 AM MDTFlash Flood WatchSLC19 hr
Aug 5, 3:55 PM MDTSevere Thunderstorm WarningSLCTooele35 min
Aug 5, 3:58 PM MDTFlash Flood WarningSLCKane, Washington2 hr
Aug 5, 4:12 PM MDTFlash Flood WarningSLCWashington6 hr
Aug 5, 4:26 PM MDTSevere Thunderstorm WarningSLCTooele34 min
Aug 5, 4:29 PM MDTSpecial Weather StatementSLCDavis46 min
Aug 5, 4:39 PM MDTSpecial Weather StatementSLCEmery51 min
Aug 5, 4:45 PM MDTSpecial Weather StatementSLC45 min
Aug 5, 4:56 PM MDTSevere Thunderstorm WarningSLCTooele49 min
Aug 5, 5:04 PM MDTSevere Thunderstorm WarningSLCKane26 min
Aug 5, 5:11 PM MDTSevere Thunderstorm WarningSLCBox Elder, Tooele64 min
Aug 5, 5:12 PM MDTSpecial Weather StatementSLCDuchesne48 min
Aug 5, 5:29 PM MDTSpecial Weather StatementSLCKane46 min

Nearby

Severe Thunderstorm Warnings in Utah, 2010Every severe thunderstorm warning in 2010

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.