Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 2109

November 10, 201219 counties in Kansas; 28 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Nov 10, 2012, 1:53 PM CST for 19 counties in Kansas; 28 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Nov 10, 2012, 1:53 PM CST (19:53 UTC)
Expired: Nov 10, 2012, 4:00 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 47 counties

Barton County, KS, Cloud County, KS, Comanche County, KS, Edwards County, KS, Ellis County, KS, Ellsworth County, KS, Jewell County, KS, Kiowa County, KS, Lincoln County, KS, Mitchell County, KS, Osborne County, KS, Pawnee County, KS, Pratt County, KS, Republic County, KS, Rice County, KS, Rush County, KS, Russell County, KS, Smith County, KS, Stafford County, KS, Adams County, NE, Burt County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Fillmore County, NE, Franklin County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Jefferson County, NE, Kearney County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thayer County, NE, Washington County, NE, Webster County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 84 km from the middle of the area, began a volume at 19:59 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.

Severe Thunderstorm Watch 675Nov 10, 3:35 PM CST

The nearest sounding before it

Dodge City, (KDDC), launched 12:00Z, 7.9 hours before the alert went out and 239 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2146 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 211 m²/s²
0-3 km storm-relative helicity: 263 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.

555 
ACUS11 KWNS 101953
SWOMCD
SPC MCD 101953 
IAZ000-NEZ000-KSZ000-102200-

MESOSCALE DISCUSSION 2109
NWS STORM PREDICTION CENTER NORMAN OK
0153 PM CST SAT NOV 10 2012

AREAS AFFECTED...ERN NEB...CNTRL KS

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 101953Z - 102200Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...DISCRETE TSTMS ARE EXPECTED TO DEVELOP ALONG A
COLD/QUASI-STATIONARY FRONT AND DRYLINE BETWEEN 21-23Z. THIS
ACTIVITY SHOULD BECOME SUPERCELLULAR WITH PRIMARY INITIAL THREATS OF
SEVERE HAIL/WIND ALONG WITH A FEW TORNADOES...WITH UPSCALE GROWTH
PROBABLE DURING THE EVENING.

DISCUSSION...19Z SURFACE ANALYSIS PLACED A SERIES OF CYCLONES ALONG
A FRONTAL ZONE FROM E-CNTRL CO E/NEWD INTO NERN NEB. A DRYLINE
INTERSECTED THE FRONT NEAR GRI...EXTENDING S/SWWD INTO THE ERN TX
PANHANDLE. ASCENT ASSOCIATED WITH THE VIGOROUS SHORT WAVE TROUGH IN
THE LEE OF THE ROCKIES APPEARS TO BE STRENGTHENING IN THE HIGH
PLAINS...INFERRED BY DEEPENING CU DEVELOPMENT W OF THE DRYLINE. THIS
LOBE OF ASCENT INVOF CO/NEB/KS BORDER WILL OVERSPREAD THE
DRYLINE/FRONT INTERSECTION AROUND 22Z...WHERE SURFACE PRESSURE FALLS
ARE CURRENTLY MAXIMIZED. INITIAL TSTM DEVELOPMENT IS PROBABLE HERE
WITH ACTIVITY RIDING ALONG AND N OF THE FRONT. ADDITIONAL STORMS
WILL FIRE SOUTH ALONG THE DRYLINE BY 00Z.

AIR MASS AHEAD OF THE DRYLINE IS CHARACTERIZED BY 20-30 F SURFACE
TEMPERATURE/DEW POINT SPREADS...AS MODEST BOUNDARY LAYER MOISTURE
REMAINS THE PRIMARY LIMITING FACTOR TO A MORE ROBUST SEVERE THREAT.
EVEN WITH MODEST BUOYANCY...STEEP MID-LEVEL LAPSE RATES AND
STRENGTHENING DEEP-LAYER SHEAR WILL PROMOTE UPDRAFT ROTATION WITH
WIDELY SCATTERED SWATHS OF SEVERE HAIL/WIND PROBABLE. AS A PLUME OF
56-58 F SURFACE DEW POINTS IN S-CNTRL KS TO W-CNTRL OK IS DRAWN
NWD...A FEW TORNADOES MAY DEVELOP. OTHERWISE...ACTIVITY SHOULD
EVOLVE INTO BOWING STRUCTURES/SHORT-LINE SEGMENTS WITH A PRIMARY
RISK OF DAMAGING WIND.

..GRAMS/WEISS.. 11/10/2012

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

ATTN...WFO...OAX...TOP...ICT...GID...DDC...

LAT...LON   41269876 42079683 42129636 41589592 40509693 38539806
            37319893 37169928 37219966 37319988 37569984 39319925
            40759893 41269876

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 10, 3:36 PM CST	Severe Thunderstorm Watch	SPC	Barber, Barton, Clay, Cloud, Comanche, Dickinson and 31 more	7 hr
Nov 10, 12:11 PM CST	Mesoscale Discussion	SPC	Dawes, Sioux	4 hr
Nov 10, 5:10 PM CST	Mesoscale Discussion	SPC	Boyd, Cherry, Keya Paha	5 hr

Nearby

Mesoscale Discussions in Nebraska, 2012 Mesoscale Discussions in Kansas, 2012 Every mesoscale discussion in 2012

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.