Alert archive / Iowa / Mesoscale Discussions in 2017
Mesoscale Discussion 201
The Storm Prediction Center issued this mesoscale discussion at Feb 23, 2017, 9:48 PM CST for 5 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 23, 2017, 9:48 PM CST (03:48 UTC)
- Expired
- Feb 24, 2017, 12:15 AM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 91 counties
Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Buchanan County, IA, Cass County, IA, Cedar County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Fremont County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Henry County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Muscatine County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Henderson County, IL, Atchison County, KS, Brown County, KS, Doniphan County, KS, Jackson County, KS, Jefferson County, KS, Leavenworth County, KS, Marshall County, KS, Nemaha County, KS, Pottawatomie County, KS, Adair County, MO, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Linn County, MO, Livingston County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Sullivan County, MO, Worth County, MO, Cass County, NE, Johnson County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE
The radar
The Des Moines radar (KDMX), 116 km from the middle of the area, began a volume at 03:51 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 00:00Z, 3.8 hours before the alert went out and 205 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
- 540 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 333 m²/s²
- 0-3 km storm-relative helicity
- 826 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
020
ACUS11 KWNS 240349
SWOMCD
SPC MCD 240348
ILZ000-IAZ000-MOZ000-KSZ000-NEZ000-240615-
Mesoscale Discussion 0201
NWS Storm Prediction Center Norman OK
0948 PM CST Thu Feb 23 2017
Areas affected...Northeastern KS...far southeastern NE...northern
MO...and southern/central IA
Concerning...Severe potential...Watch unlikely
Valid 240348Z - 240615Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated marginally severe hail may occur with elevated
thunderstorms through the early overnight hours. Watch issuance is
unlikely.
DISCUSSION...A band of elevated convection located over far
southeastern NE as of 0330Z is associated with forcing for ascent
attendant to a shortwave trough over the central Plains and a
strengthening low-level jet over MO/IA. These thunderstorms will
very likely remain elevated to the north of a frontal boundary as a
surface low across southeastern KS translates northeastward across
MO toward western IL overnight. Although near-surface moisture will
be meager, sufficient low-level moisture centered around 850 mb per
the 00Z Topeka, KS sounding combined with steep mid-level lapse
rates in excess of 8 degrees C/km will generally support MUCAPE of
250-1000 J/kg, decreasing with northward extent into central IA.
Effective shear on the order of 40-60 kt will support updraft
organization, and isolated instances of marginally severe hail may
occur through the early overnight hours if thunderstorms can remain
relatively discrete. With time, clustering of thunderstorms cores
will likely occur as they move northeastward into an increasingly
marginal thermodynamic environment in central/northern IA.
..Gleason/Hart.. 02/24/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...DVN...DMX...EAX...OAX...TOP...
LAT...LON 39189605 39419667 40809630 41399589 42459369 42639224
42439137 41659092 40839089 39619344 39129518 39189605SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 24, 2:07 PM CST | Mesoscale Discussion | SPC | Clark, Crawford, Cumberland, Edgar, Vermilion | 2 hr |
| Feb 23, 6:05 PM CST | Mesoscale Discussion | SPC | Buena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee, Clay and 27 more | 6 hr |
| Feb 23, 11:54 PM CST | Mesoscale Discussion | SPC | Allamakee, Bremer, Buena Vista, Butler, Calhoun, Carroll and 33 more | 6 hr |
Nearby
Mesoscale Discussions in Iowa, 2017Mesoscale Discussions in Missouri, 2017Mesoscale 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.