Alert archive / Nebraska / Mesoscale Discussions in 2016

Mesoscale Discussion 1815

November 17, 2016Phillips County, Sedgwick County, Yuma County, Colorado; Cheyenne County, Kansas; 9 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Nov 17, 2016, 5:02 PM MST for Phillips County, Sedgwick County, Yuma County, Colorado; Cheyenne County, Kansas; 9 counties in Nebraska. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Nov 17, 2016, 5:02 PM MST (00:02 UTC)
Expired
Nov 17, 2016, 9:00 PM MST
In force
4 hr
Issued by
the Storm Prediction Center

Counties Phillips County, CO, Sedgwick County, CO, Yuma County, CO, Cheyenne County, KS, Arthur County, NE, Chase County, NE, Deuel County, NE, Dundy County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, Lincoln County, NE, Perkins County, NE

The radar

The Goodland radar (KGLD), 124 km from the middle of the area, began a volume at 00:06 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

Denver, CO (KDEN), launched 00:00Z, 0.0 hours before the alert went out and 117 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 00:00Z on 2016-11-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2016-11-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
589 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

908 
ACUS11 KWNS 180002
SWOMCD
SPC MCD 180002 
NEZ000-KSZ000-COZ000-180400-

MESOSCALE DISCUSSION 1815
NWS STORM PREDICTION CENTER NORMAN OK
0602 PM CST THU NOV 17 2016

AREAS AFFECTED...FAR NORTHEASTERN CO...EXTREME NORTHWESTERN
KS...SOUTHWEST NEB

CONCERNING...HEAVY SNOW 

VALID 180002Z - 180400Z

SUMMARY...SNOWFALL RATES AROUND 1 INCH PER HOUR ARE POSSIBLE ACROSS
THE REGION FOR THE NEXT SEVERAL HOURS.

DISCUSSION...SURFACE OBSERVATION AT HEQ /IN FAR NORTHEAST CO/
RECENTLY STARTED REPORTING HEAVY SNOW AND SYF /IN FAR NORTHWEST KS/
RECENTLY REPORTED MODERATE SNOW...WITH BOTH STATIONS EXPERIENCING A 3
DEGREE DROP IN THE SURFACE TEMPERATURE OVER THE PAST HOUR. THESE
OBSERVATIONS CONFIRM THE WET-BULBING SUGGESTED BY RECENT RAP
SOUNDINGS. FRONTOGENETIC FORCING IS EXPECTED TO PERSIST ACROSS THIS
REGION FOR THE NEXT FEW HOURS AS THE SHORTWAVE TROUGH PIVOTS
NORTHEASTWARD INTO THE PLAINS AND THE RESULTING LIFT AND COLUMN
COOLING ARE EXPECTED TO SUPPORT A CONTINUED TRANSITION FROM RAIN TO
MODERATE/HEAVY SNOW. GIVEN THE STRENGTH AND LOCATION OF THE
STRONGEST FORCING FOR ASCENT...SNOWFALL RATES AROUND 1 INCH PER HOUR
ARE POSSIBLE FOR THE NEXT FEW HOURS.

..MOSIER/NONE.. 11/18/2016

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

ATTN...WFO...LBF...GLD...BOU...CYS...

LAT...LON   40300346 41770193 41370012 40370078 39250201 39730274
            40300346

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 18, 1:42 AM MSTMesoscale DiscussionSPCBoyd, Holt, Knox, Rock4 hr

Nearby

Mesoscale Discussions in Nebraska, 2016Mesoscale Discussions in Colorado, 2016Mesoscale Discussions in Kansas, 2016Every mesoscale discussion in 2016

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.