Alert archive / Utah / Mesoscale Discussions in 2005

Mesoscale Discussion 2249

September 21, 20054 counties in Colorado; 18 counties in Utah; Sweetwater County, Uinta County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Sep 21, 2005, 3:04 PM MDT for 4 counties in Colorado; 18 counties in Utah; Sweetwater County, Uinta County, Wyoming. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Sep 21, 2005, 3:04 PM MDT (21:04 UTC)
Expired
Sep 21, 2005, 5:00 PM MDT
In force
116 min
Issued by
the Storm Prediction Center
All 24 counties

Garfield County, CO, Mesa County, CO, Moffat County, CO, Rio Blanco County, CO, Box Elder County, UT, Cache County, UT, Carbon County, UT, Daggett County, UT, Davis County, UT, Duchesne County, UT, Emery County, UT, Grand County, UT, Morgan County, UT, Rich County, UT, Salt Lake County, UT, Summit County, UT, Tooele County, UT, Uintah County, UT, Utah County, UT, Wasatch County, UT, Wayne County, UT, Weber County, UT, Sweetwater County, WY, Uinta County, WY

The radar

The Salt Lake City radar (KMTX), 211 km from the middle of the area, began a volume at 21:06 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 9.1 hours before the alert went out and 143 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, Salt Lake City I, UT at 12:00Z on 2005-09-21Temperature 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, Salt Lake City I, UT at 12:00Z on 2005-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1237 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
183 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.

000 
ACUS11 KWNS 212104
SWOMCD
SPC MCD 212104 
WYZ000-COZ000-UTZ000-IDZ000-212300-

MESOSCALE DISCUSSION 2249
NWS STORM PREDICTION CENTER NORMAN OK
0404 PM CDT WED SEP 21 2005

AREAS AFFECTED...NRN/ERN UT...WRN CO AND SWRN WY

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 212104Z - 212300Z

THREAT FOR ISOLATED SVR WIND/HAIL WILL EXIST FOR THE REMAINDER OF
THE AFTERNOON ACROSS THE AREA IN ASSOCIATION WITH STRONG UPPER
TROUGH MOVING ACROSS NRN UT. OVERALL MARGINAL NATURE OF SVR THREAT
IS EXPECTED TO LIMIT THE NEED FOR A WW. 

LATEST VIS IMAGERY INDICATES CIRRUS WAS CLEARING AHEAD OF CONVECTIVE
LINE OVER ERN UT. CONSEQUENTLY...CONTINUED SFC HEATING WILL SUPPORT
MLCAPE VALUES RISING TO AROUND 1000 J/KG AND INTENSIFICATION OF
CONVECTIVE LINE OVER THE NEXT FEW HRS. THE COMBINATION OF STRONG
SHEAR / AROUND 50 KTS ACROSS ERN UT/WRN CO/ AND MODERATE INSTABILITY
WILL SUPPORT AT LEAST SOME ISOLATED WIND/HAIL THREAT WITH THE
STRONGEST STORMS WITHIN THE CONVECTIVE LINE. FURTHER NW...STEEP MID
LEVEL LAPSE RATES UNDERNEATH THE UPPER LOW WILL SUPPORT RISK FOR
ISOLATED MARGINALLY SVR HAIL OVER NRN UT AND FAR SWRN WY BEFORE
ONSET OF DIURNAL COOLING AROUND 01Z.

..CROSBIE.. 09/21/2005

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CYS...RIW...GJT...SLC...PIH...

42181065 41591326 41121366 39971346 39491105 38491151
37941140 37721062 38100885 39310790 40160741 41100741
42350850

Nearby

Mesoscale Discussions in Utah, 2005Mesoscale Discussions in Colorado, 2005Mesoscale Discussions in Wyoming, 2005Every mesoscale discussion in 2005

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.