Alert archive / Kansas / Mesoscale Discussions in 2017
Mesoscale Discussion 487
The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2017, 5:46 PM CDT for 11 counties in Kansas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2017, 5:46 PM CDT (22:46 UTC)
- Expired
- Apr 12, 2017, 8:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Clay County, KS, Cloud County, KS, Ellis County, KS, Hamilton County, KS, Jewell County, KS, Lane County, KS, Mitchell County, KS, Osborne County, KS, Rooks County, KS, Scott County, KS, Trego County, KS
The radar
The Dodge City radar (KDDC), 122 km from the middle of the area, began a volume at 22:49 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
Dodge City, (KDDC), launched 12:00Z, 10.8 hours before the alert went out and 119 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2330 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 215 m²/s²
- 0-3 km storm-relative helicity
- 260 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
909
ACUS11 KWNS 122246
SWOMCD
SPC MCD 122246
KSZ000-130115-
Mesoscale Discussion 0487
NWS Storm Prediction Center Norman OK
0546 PM CDT Wed Apr 12 2017
Areas affected...North-central to southwest KS
Concerning...Severe potential...Watch unlikely
Valid 122246Z - 130115Z
Probability of Watch Issuance...20 percent
SUMMARY...A few strong to severe storms will persist into the early
evening across mainly north-central to southwest KS, though overall
coverage is not expected to warrant watch issuance.
DISCUSSION...Sustained thunderstorms developed during peak heating
mainly in north-central through southwest KS in vicinity of a
stalling cold front. The presence of steep lapse rates within a
moist environment (precipitable water around 1 inch) has resulted in
MLCAPE of 1000-1500 J/kg. Trends in mosaic radar imagery indicated
more robust storms with greater attainable sustenance appear to be
in central to north-central KS (Trego/Ellis Counties to Osborne
County), given closer proximity to a better deep-layer forcing for
ascent and relatively stronger shear. These factors favor hail
being the primary threat, though locally strong winds cannot be
ruled out with the presence of steeper low-level lapse rates.
Water-vapor imagery showed a progressive shortwave trough advancing
east through the upper MS Valley, with the trailing portion of this
trough extending into northern KS.
As this midlevel through moves farther away from the discussion
area, the cold front is expected to stall with storms continuing
with slow movement. The likelihood for robust/sustained updrafts
should gradually diminish after early evening, with the departure of
the trough and subsequent weakening of deep-layer ascent and shear.
And, the loss of daytime heating will aid in reducing available
instability.
..Peters/Hart.. 04/12/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TOP...ICT...GID...DDC...GLD...
LAT...LON 38130096 37900156 37990191 38240195 38690067 39379936
39799873 39909789 39489702 39319685 39119815 38719953
38130096Nearby
Mesoscale Discussions in Kansas, 2017Every mesoscale discussion in 2017
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.