Alert archive / Kansas / Mesoscale Discussions in 2007

Mesoscale Discussion 921

May 29, 200713 counties in Colorado; 20 counties in Kansas; 10 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 29, 2007, 5:40 PM MDT for 13 counties in Colorado; 20 counties in Kansas; 10 counties in Nebraska. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 29, 2007, 5:40 PM MDT (23:40 UTC)
Expired
May 29, 2007, 7:15 PM MDT
In force
95 min
Issued by
the Storm Prediction Center
All 43 counties

Baca County, CO, Bent County, CO, Cheyenne County, CO, Crowley County, CO, Huerfano County, CO, Kiowa County, CO, Kit Carson County, CO, Las Animas County, CO, Lincoln County, CO, Otero County, CO, Prowers County, CO, Pueblo County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Finney County, KS, Gove County, KS, Grant County, KS, Greeley County, KS, Hamilton County, KS, Kearny County, KS, Lane County, KS, Logan County, KS, Morton County, KS, Norton County, KS, Rawlins County, KS, Scott County, KS, Sheridan County, KS, Sherman County, KS, Stanton County, KS, Thomas County, KS, Wallace County, KS, Wichita County, KS, Chase County, NE, Dawson County, NE, Dundy County, NE, Frontier County, NE, Furnas County, NE, Gosper County, NE, Hayes County, NE, Hitchcock County, NE, Lincoln County, NE, Red Willow County, NE

The radar

The Goodland radar (KGLD), 63 km from the middle of the area, began a volume at 23:39 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.7 hours before the alert went out and 165 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, Denver, CO at 12:00Z on 2007-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2007-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -86 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
18 J/kg
Mixed-layer CIN
-196 J/kg
Mixed-layer LCL
1497 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-86 m²/s²
0-3 km storm-relative helicity
-23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 292340
SWOMCD
SPC MCD 292340 
KSZ000-NEZ000-OKZ000-COZ000-300115-

MESOSCALE DISCUSSION 0921
NWS STORM PREDICTION CENTER NORMAN OK
0640 PM CDT TUE MAY 29 2007

AREAS AFFECTED...PORTIONS ERN CO...WRN KS...SWRN NEB.

CONCERNING...TORNADO WATCH 304...305...

VALID 292340Z - 300115Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 304...305...CONTINUES.

SVR TSTM POTENTIAL IS EXPECTED TO SHIFT/DEVELOP SEWD INTO MORE OF
W-CENTRAL/SWRN KS DURING NEXT SEVERAL HOURS...AND ADDITIONAL WW
LIKELY WILL BE REQUIRED SE OF 304 AND E OF 305.  

MEANWHILE...INITIAL COMPLEX OF SVR TSTMS CONTINUES TO MOVE GENERALLY
ESEWD ACROSS ERN CO.  VERY WELL DEFINED OUTFLOW BOUNDARY IS EVIDENT
AS OF 2320Z FROM NRN PUEBLO COUNTY CO ENEWD ACROSS WRN CHEYENNE
COUNTY CO...THEN NEWD OVER CHEYENNE COUNTY KS -- WELL AHEAD OF MOST
ACTIVITY ACROSS ERN CO. THIS OUTFLOW IS FOLLOWED BY STG PRESSURE
RISES AND VERY COLD AIR -- E.G. 46 F AT LIC DURING PAST HOUR -- AND
SHOULD CONTINUE TO SURGE SEWD OVER REMAINDER SERN CO AND INTO WRN KS
DURING NEXT FEW HOURS.  TORNADO THREAT WILL BE GREATLY REDUCED
BEHIND THIS BOUNDARY BECAUSE OF DEEPENING/STRONG LAYER OF STATIC
STABILITY FROM SFC THROUGH SUBCLOUD LAYER...HOWEVER TSTMS OVER
OUTFLOW AIR STILL WILL BE CAPABLE OF LARGE HAIL AND HEAVY RAINFALL. 


OVER AREA S OF BOUNDARY...ADDITIONAL DEVELOPMENT IS EXPECTED AND
SHOULD REMAIN SFC-BASED WITH POTENTIAL FOR DAMAGING WIND AND PERHAPS
TORNADOES...UNTIL BEING UNDERCUT BY PROGRESSIVE COLD POOL.  MODIFIED
RAOBS AND RUC/NAM-KF SOUNDINGS SUGGEST AROUND 2000 J/KG MLCAPES
SUPPORTED BY SFC TEMPS MID-UPPER 70S F AND SFC DEW POINTS MID 50S F.
 DEW POINT DEPRESSIONS AND LCL EACH WILL LOWER SOMEWHAT DURING NEXT
2-3 HOURS IN AIR MASS AHEAD OF OUTFLOW SURGE...IN ASSOCIATION WITH
ANVIL SHADOWING AND DIABATIC SFC COOLING.  EFFECTIVE BULK SHEAR
PEAKS NEAR I-25 AT 40-50 KT AND WEAKENS TO 25-30 KT EWD INTO
KS...INDICATING MOST FAVORABLE POTENTIAL FOR FURTHER
DISCRETE/SFC-BASED SUPERCELLS IN CO WILL BE BETWEEN OUTFLOW
BOUNDARY...RTN MESA...I-25...AND N-S LINE THRU LHX.  MEANWHILE
EMBEDDED SUPERCELLS MAY STILL POSE RISK OF TORNADOES...LARGE HAIL
AND DAMAGING GUSTS BETWEEN DUNDY-DAWSON COUNTIES NEB..BEFORE THAT
ACTIVITY IS OVERTAKEN BY CO COLD SURGE.

REF SPC MESOSCALE DISCUSSION 920 FOR MORE DETAILS ON HEAVY RAIN
THREAT OVER THIS REGION.

..EDWARDS.. 05/29/2007

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

ATTN...WFO...GID...LBF...DDC...GLD...AMA...PUB...BOU...

36970197 37010512 38280486 39140416 39780270 40670189
41469999 40639954 40239949 38710020 37690091 37060174

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 12:12 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Bent, Broomfield, Cheyenne, Crowley and 16 more93 min
May 29, 12:29 PM MDTTornado WatchSPCAdams, Arapahoe, Denver, Douglas, Elbert, El Paso and 9 more8 hr
May 29, 2:52 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Bent, Broomfield, Cheyenne, Crowley and 16 more53 min
May 29, 4:34 PM MDTMesoscale DiscussionSPCCheyenne, El Paso, Kit Carson, Lincoln, Yuma3 hr
May 29, 5:08 PM MDTTornado WatchSPCBaca, Bent, Cheyenne, Crowley, Huerfano, Kiowa and 4 more4 hr
May 28, 8:03 PM MDTMesoscale DiscussionSPCHayes87 min

Nearby

Mesoscale Discussions in Kansas, 2007Mesoscale Discussions in Colorado, 2007Mesoscale Discussions in Nebraska, 2007Every mesoscale discussion in 2007

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.