Alert archive / Colorado / Mesoscale Discussions in 2003

Mesoscale Discussion 1985

July 26, 200318 counties in Colorado; 7 counties in Idaho; 13 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2003, 12:33 PM MDT for 18 counties in Colorado; 7 counties in Idaho; 13 counties in Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 26, 2003, 12:33 PM MDT (18:33 UTC)
Expired: Jul 26, 2003, 3:00 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 38 counties

Boulder County, CO, Chaffee County, CO, Clear Creek County, CO, Eagle County, CO, Fremont County, CO, Gilpin County, CO, Grand County, CO, Gunnison County, CO, Jackson County, CO, Jefferson County, CO, Lake County, CO, Larimer County, CO, Park County, CO, Pitkin County, CO, Routt County, CO, Saguache County, CO, Summit County, CO, Teller County, CO, Bannock County, ID, Bear Lake County, ID, Bonneville County, ID, Caribou County, ID, Franklin County, ID, Oneida County, ID, Teton County, ID, Albany County, WY, Carbon County, WY, Converse County, WY, Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Lincoln County, WY, Natrona County, WY, Platte County, WY, Sublette County, WY, Sweetwater County, WY, Uinta County, WY, Washakie County, WY

The radar

The Riverton/Lander radar (KRIW), 206 km from the middle of the area, began a volume at 18:30 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, 6.6 hours before the alert went out and 205 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: 1528 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 885 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 147 m²/s²
0-3 km storm-relative helicity: 210 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

884 
ACUS11 KWNS 261833
SWOMCD
SPC MCD 261833 
WYZ000-COZ000-IDZ000-UTZ000-262100-

MESOSCALE DISCUSSION 1985
NWS STORM PREDICTION CENTER NORMAN OK
0133 PM CDT SAT JUL 26 2003

AREAS AFFECTED...SERN ID...SRN WY...CNTRL CO

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 261833Z - 262100Z

A SEVERE TSTM WATCH MAY BE NEEDED OVER PORTIONS OF THE ROCKY
MOUNTAINS THIS AFTERNOON. CURRENTLY...THE GREATEST CHANCE FOR ACTIVE
STRONG TO SEVERE STORMS APPEARS ACROSS PARTS OF SERN ID AND
SRN/CNTRL WY.

CONVECTION WAS INCREASING ACROSS THE CO/WY ROCKIES...AS WELL AS OVER
THE MOUNTAINS OF SERN ID EARLY THIS AFTERNOON. MONSOON MOISTURE
EMBEDDED WITHIN LARGE MID/UPPER ANTICYCLONIC CIRCULATION... COUPLED
WITH STRONG ELEVATED HEAT SOURCE OVER THE MOUNTAINS SHOULD CONTINUE
TO PROMOTE TSTM DEVELOPMENT THROUGH THE AFTERNOON. LATEST SURFACE
ANALYSIS SHOWED A WEAK FRONT/WIND SHIFT HAS MOVED SWWD INTO ERN
WY/NERN CO...WHILE SATELLITE AND SHORT RANGE MODEL DATA INDICATE A
MID LEVEL IMPULSE MOVING EWD FROM NERN NV/SRN ID.

MOIST POST-FRONTAL UPSLOPE FLOW AND APPROACH OF ID IMPULSE WILL ACT
ON INCREASINGLY UNSTABLE AIRMASS AND RESULT IN TSTMS BECOMING MORE
NUMEROUS OVER WY OVER THE NEXT COUPLE OF HOURS. WLY MID LEVEL FLOW
OF 25-30KT BETWEEN CO UPPER HIGH CENTER AND CANADIAN BORDER ATOP
WEAK ELY LOW LEVEL FLOW WILL PROVIDE MARGINALLY SUPPORTIVE
DIRECTIONAL AND SPEED SHEAR FOR STORM ORGANIZATION/PERSISTENCE WITH
HAIL AND HIGH WINDS POSSIBLE FROM THIS ACTIVITY.

GENERALLY LIGHT AND VARIABLE FLOW NEAR THE HIGH CENTER OVER CO
SUGGESTS THAT STORMS IN THIS AREA SHOULD REMAIN WEAKLY ORGANIZED
WITH AN ISOLD STRONG WIND/BRIEF HAIL THREAT PROBABLY REMAINING OVER
THE MOUNTAINS.

..CARBIN.. 07/26/2003

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

ATTN...WFO...UNR...PUB...BOU...CYS...RIW...GJT...SLC...PIH...

41360498 39400515 38240518 37580676 38280788 41000761
41340875 41191064 42111093 41951323 43971117 44050860
44170601 43320473

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 26, 4:36 PM MDT	Mesoscale Discussion	SPC	Sedgwick	114 min
Jul 26, 4:01 PM MDT	Mesoscale Discussion	SPC	Ada, Boise, Canyon, Elmore, Gem, Owyhee and 2 more	119 min

Nearby

Mesoscale Discussions in Colorado, 2003 Mesoscale Discussions in Wyoming, 2003 Mesoscale Discussions in Idaho, 2003 Every mesoscale discussion in 2003

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.