Alert archive / Kansas / Mesoscale Discussions in 2005

Mesoscale Discussion 621

April 20, 200521 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2005, 11:50 PM CDT for 21 counties in Kansas. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Apr 20, 2005, 11:50 PM CDT (04:50 UTC)
Expired
Apr 21, 2005, 1:15 AM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 21 counties

Brown County, KS, Clay County, KS, Cloud County, KS, Ellis County, KS, Geary County, KS, Jackson County, KS, Jewell County, KS, Lincoln County, KS, Marshall County, KS, Mitchell County, KS, Nemaha County, KS, Osborne County, KS, Ottawa County, KS, Phillips County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Rooks County, KS, Shawnee County, KS, Smith County, KS, Washington County, KS

The watches that followed

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

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 4.8 hours before the alert went out and 194 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, Topeka, KS at 00:00Z on 2005-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2735 joules per kilogram.LCLLFCEL10008507005003002001001 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, Topeka, KS at 00:00Z on 2005-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.1939Sfc1 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
2735 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1421 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
0.8
Supercell composite
8.1

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 210451
SWOMCD
SPC MCD 210450 
KSZ000-210615-

MESOSCALE DISCUSSION 0621
NWS STORM PREDICTION CENTER NORMAN OK
1150 PM CDT WED APR 20 2005

AREAS AFFECTED...NCNTRL/NERN KS

CONCERNING...SEVERE THUNDERSTORM WATCH 171...

VALID 210450Z - 210615Z

TSTMS HAVE FINALLY SHOWN A MARKED INCREASE IN BOTH INTENSITY AND
NUMBER ACROSS NCNTRL/NERN KS WITHIN WS #171.  LARGE HAIL WILL BE THE
PRIMARY SEVERE THREAT WITH THESE STORMS.

SCNTRL KS/OK MCS/S HAVE BEGUN TO DIMINISH...WITH THE LLJ BEGINNING
TO INCREASE NOW ACROSS ALL OF OK AND SCNTRL KS.  NOSE OF THE LLJ WAS
BLOWING PERPENDICULAR TO A E-W BAROCLINIC ZONE SITUATED ALONG THE
KS/NEB BORDER. AS A RESULT...TSTMS HAVE BEGUN TO INCREASE IN THE
ENHANCED WARM/MOIST ADVECTION ALONG/NORTH OF THE FRONT.  00Z TOP
SOUNDING EXHIBITED STEEP LAPSE RATES IN THE H85-H7 LAYER...THOUGH
THE EFFECTIVE SHEAR WAS WEAK.  STORMS MAY TEND TO GROW VIGOROUSLY
AND PRODUCE LARGE HAIL...BUT ANY SUSTAINED ORGANIZATION MAY BE
LIMITED BY WEAK KINEMATIC PROFILES.

ACTIVITY WILL ALSO PRODUCE HEAVY RAINFALL AS STORMS DEVELOP ACROSS
SCNTRL NEB/NCNTRL KS AND TRAIN ESEWD INTO NERN KS.

..RACY.. 04/21/2005

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

ATTN...WFO...EAX...TOP...ICT...GID...DDC...

39829937 39879549 38979546 38919935

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 20, 7:25 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Gove, Logan, Norton, Rawlins and 4 more95 min
Apr 20, 9:29 PM CDTMesoscale DiscussionSPCClay, Cloud, Dickinson, Geary, Jackson, Jewell and 13 more61 min
Apr 20, 9:45 PM CDTSevere Thunderstorm WatchSPCAtchison, Brown, Clay, Cloud, Dickinson, Douglas and 21 more7 hr
Apr 20, 9:51 PM CDTMesoscale DiscussionSPCBarber, Clark, Comanche, Edwards, Ford, Kingman and 4 more84 min
Apr 20, 11:00 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Rawlins6 hr
Apr 21, 12:48 AM CDTMesoscale DiscussionSPCCheyenne, Decatur, Graham, Norton, Phillips, Rawlins and 4 more57 min
Apr 21, 1:00 AM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Graham, Norton, Phillips, Rawlins and 4 more4 hr
Apr 21, 3:34 AM CDTMesoscale DiscussionSPCBrown, Doniphan116 min
Apr 21, 11:13 AM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Jackson, Jefferson, Marshall and 4 more2 hr
Apr 21, 11:35 AM CDTTornado WatchSPCClay, Cloud, Jackson, Jewell, Marshall, Nemaha and 4 more5 hr
Apr 21, 1:45 PM CDTSevere Thunderstorm WatchSPCBourbon, Cherokee, Crawford, Linn5 hr
Apr 21, 1:48 PM CDTMesoscale DiscussionSPCAtchison, Jackson, Marshall, Nemaha, Pottawatomie, Riley and 1 more87 min
Apr 21, 3:05 PM CDTMesoscale DiscussionSPCAnderson, Atchison, Brown, Doniphan, Douglas, Franklin and 11 more85 min
Apr 21, 3:35 PM CDTTornado WatchSPCAnderson, Atchison, Brown, Doniphan, Douglas, Franklin and 11 more7 hr
Apr 21, 4:51 PM CDTMesoscale DiscussionSPCAtchison54 min
Apr 21, 5:52 PM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Douglas, Jackson, Jefferson and 5 more53 min
Apr 21, 6:10 PM CDTTornado WatchSPCBourbon, Cherokee, Crawford, Linn7 hr
Apr 21, 6:51 PM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Douglas, Franklin, Jackson and 7 more84 min

Nearby

Mesoscale Discussions in Kansas, 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.