Alert archive / Iowa / Mesoscale Discussions in 2008

Mesoscale Discussion 101

January 29, 20086 states

The Storm Prediction Center issued this mesoscale discussion at Jan 29, 2008, 7:39 AM CST for 6 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jan 29, 2008, 7:39 AM CST (13:39 UTC)
Expired
Jan 29, 2008, 12:45 PM CST
In force
5 hr
Issued by
the Storm Prediction Center
All 91 counties

Audubon County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass 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, Fremont County, IA, Greene County, IA, Hancock County, IA, Harrison County, IA, Howard County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Lyon County, IA, Mills County, IA, Mitchell County, IA, Monona County, IA, Montgomery County, IA, O'Brien County, IA, Osceola County, IA, Page County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Pottawattamie 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, Marshall County, KS, Nemaha County, KS, Washington County, KS, Blue Earth County, MN, Cottonwood County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Jackson County, MN, Martin County, MN, Mower County, MN, Nobles County, MN, Olmsted County, MN, Rice County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Atchison County, MO, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thayer County, NE, Thurston County, NE, Washington County, NE, York County, NE, Union County, SD

The radar

The Des Moines radar (KDMX), 118 km from the middle of the area, began a volume at 13:39 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

Omaha, NE (KOAX), launched 12:00Z, 1.7 hours before the alert went out and 130 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, Omaha, NE at 12:00Z on 2008-01-29Temperature 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, Omaha, NE at 12:00Z on 2008-01-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 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
789 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
668 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.

000 
ACUS11 KWNS 291340
SWOMCD
SPC MCD 291339 
IAZ000-MNZ000-MOZ000-NEZ000-KSZ000-SDZ000-291845-

MESOSCALE DISCUSSION 0101
NWS STORM PREDICTION CENTER NORMAN OK
0739 AM CST TUE JAN 29 2008

AREAS AFFECTED...ERN NEB...EXTREME NERN KS AND NW MO...WRN AND NRN
IA...SRN MN

CONCERNING...BLIZZARD 

VALID 291339Z - 291845Z

BANDS OF LOCALLY HEAVY SNOW WILL COMBINE WITH VERY STRONG WINDS TO
PRODUCE BLIZZARD CONDITIONS AT TIMES.

A NARROW NE/SW BAND OF MDT TO HVY SNOW HAS DEVELOPED WITHIN ZONE OF
DEEP FRONTOGENETICAL FORCING FROM NWRN IA ACROSS E CNTRL NEB AND
INTO NRN KS. RADAR TRENDS ALSO INDICATE NEW BANDS DEVELOPING ACROSS
NRN IA INTO SRN MN MOST LIKELY RELATED TO FRONTOGENESIS IN THE
700-800 MB LAYER. 

AS UPPER TROUGH CONTINUES TO DEEPEN...ZONE OF THERMAL
PACKING/FORCING WILL BE MAINTAINED AS IT SHIFTS EWD OUT OF NEB INTO
WRN IA...WITH ADDITIONAL AREAS FILLING IN ACROSS NRN IA/SRN MN.
BRIEF SNOWFALL RATES NEAR 1/HR ARE LIKELY...WHICH WILL COMBINE WITH
VERY STRONG WIND GUSTS OF 30-40 MPH TO PRODUCE NEAR ZERO VISIBILITY
AT TIMES.

..JEWELL.. 01/29/2008

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...ARX...MPX...DMX...EAX...FSD...OAX...TOP...GID...

40099799 42369702 43299638 43989551 44429307 44389213
43309159 42819257 42659364 41529474 40099535 39479622
39479718

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 29, 12:19 PM CSTMesoscale DiscussionSPCAppanoose, Benton, Cedar, Clinton, Davis, Delaware and 20 more4 hr
Jan 29, 10:34 AM CSTMesoscale DiscussionSPCHouston, Wabasha, Winona4 hr
Jan 29, 10:21 AM CSTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Dunklin, Mississippi, New Madrid and 3 more54 min
Jan 29, 10:54 AM CSTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Dunklin, Iron and 12 more66 min
Jan 29, 11:32 AM CSTTornado WatchSPCBollinger, Butler, Cape Girardeau, Carter, Crawford, Dent and 24 more7 hr
Jan 29, 3:56 PM CSTMesoscale DiscussionSPCBollinger, Cape Girardeau, Mississippi, New Madrid, Perry, Scott and 1 more64 min

Nearby

Mesoscale Discussions in Iowa, 2008Mesoscale Discussions in Nebraska, 2008Mesoscale Discussions in Minnesota, 2008Every mesoscale discussion in 2008

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.