Alert archive / Iowa / Mesoscale Discussions in 2016

Mesoscale Discussion 71

February 2, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Feb 2, 2016, 7:50 AM CST for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 2, 2016, 7:50 AM CST (13:50 UTC)
Expired
Feb 2, 2016, 11:45 AM CST
In force
4 hr
Issued by
the Storm Prediction Center
All 72 counties

Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clay County, IA, Crawford County, IA, Dickinson County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Howard County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Mitchell County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Jackson County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN, Burt County, NE, Butler County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Madison County, NE, Pierce County, NE, Platte County, NE, Saunders County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Union County, SD

The radar

The Des Moines radar (KDMX), 111 km from the middle of the area, began a volume at 13:53 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

Minneapolis, MN (KMPX), launched 12:00Z, 1.8 hours before the alert went out and 243 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, Minneapolis, MN at 12:00Z on 2016-02-02Temperature 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 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2016-02-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.1939587897117Sfc1 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
770 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

784 
ACUS11 KWNS 021351
SWOMCD
SPC MCD 021350 
IAZ000-MNZ000-NEZ000-SDZ000-021745-

MESOSCALE DISCUSSION 0071
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CST TUE FEB 02 2016

AREAS AFFECTED...NERN NEB THROUGH CNTRL AND NRN IA AND SRN MN

CONCERNING...BLIZZARD 

VALID 021350Z - 021745Z

SUMMARY...BAND OF MODERATE TO HEAVY SNOW INITIALLY FROM ERN NEB
THROUGH CNTRL IA AS OF 14Z WILL CONTINUE DEVELOPING NWD THROUGH THE
MORNING WITH RATES LOCALLY UP TO 1-2 INCHES PER HOUR.

DISCUSSION...EARLY THIS MORNING A BAND OF HEAVY SNOW DEVELOPING
WITHIN ZONE OF STRONG FRONTOGENETIC FORCING EXTENDS FROM ERN NEB
THROUGH CNTRL IA. THIS ZONE OF FORCING WILL CONTINUE TO MOVE NWD
WITHIN EXIT REGION OF A PROGRESSIVE 150 KT UPPER JET. THE DURATION
OF HEAVIER SNOW BAND IN MOST AREAS WILL BE LIMITED SOMEWHAT BY THE
PROGRESSIVE NATURE OF THE SHORTWAVE TROUGH...WITH MID-LEVEL DRY SLOT
ADVECTING NWD THROUGH SERN NEB AND SWRN IA. CORRIDOR OF GREATEST
DURATION WILL LIKELY BE FROM NERN NEB INTO NWRN IA AND SWRN MN. RAP
PFCS INDICATE 6.5-7 C/KM LAPSE RATES AND LAYER OF WEAK INSTABILITY
BETWEEN 700-500 MB...AND SOME CONVECTIVE ENHANCEMENT WILL REMAIN
LIKELY AS ACTIVITY DEVELOPS NWD INTO NRN IA AND SRN MN LATER THIS
MORNING. IN ADDITION TO HEAVY SNOW...THE STRONG GRADIENT BETWEEN A
DEEPENING CYCLONE OVER NERN KS AND HIGH PRESSURE OVER THE NRN PLAINS
WILL CREATE BLIZZARD CONDITIONS WITH WINDS GUSTING TO 35-40+ KT.

..DIAL.. 02/02/2016

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

ATTN...WFO...DVN...ARX...MPX...DMX...FSD...OAX...GID...

LAT...LON   42459216 41989388 40889725 42099802 44139499 44239245
            43329167 42459216

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 2, 3:39 AM CSTMesoscale DiscussionSPCCarroll, Cherokee, Crawford, Harrison, Ida, Monona and 3 more6 hr
Feb 2, 11:35 AM CSTMesoscale DiscussionSPCAllamakee, Bremer, Buena Vista, Cerro Gordo, Cherokee, Chickasaw and 20 more5 hr
Feb 1, 7:37 PM CSTMesoscale DiscussionSPCDundy, Furnas, Harlan, Hitchcock, Red Willow5 hr

Nearby

Mesoscale Discussions in Iowa, 2016Mesoscale Discussions in Nebraska, 2016Mesoscale Discussions in Minnesota, 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.