Alert archive / Iowa / Mesoscale Discussions in 2016
Mesoscale Discussion 1313
The Storm Prediction Center issued this mesoscale discussion at Jul 17, 2016, 11:40 PM CDT for 15 counties in Iowa; 7 counties in Missouri; 8 counties in Nebraska. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Jul 17, 2016, 11:40 PM CDT (04:40 UTC)
- Expired
- Jul 18, 2016, 1:15 AM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 30 counties
Adair County, IA, Adams County, IA, Audubon County, IA, Cass County, IA, Decatur County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Union County, IA, Andrew County, MO, Atchison County, MO, Gentry County, MO, Harrison County, MO, Holt County, MO, Nodaway County, MO, Worth County, MO, Cass County, NE, Douglas County, NE, Johnson County, NE, Nemaha County, NE, Otoe County, NE, Richardson County, NE, Sarpy County, NE, Washington County, NE
The radar
The Omaha radar (KOAX), 114 km from the middle of the area, began a volume at 04:40 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, 4.7 hours before the alert went out and 114 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
- 1666 J/kg
- Mixed-layer CIN
- -72 J/kg
- Mixed-layer LCL
- 1396 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 90 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 3.3
The text
As transmitted.
225
ACUS11 KWNS 180441
SWOMCD
SPC MCD 180440
MOZ000-IAZ000-NEZ000-180615-
MESOSCALE DISCUSSION 1313
NWS STORM PREDICTION CENTER NORMAN OK
1140 PM CDT SUN JUL 17 2016
AREAS AFFECTED...SOUTHWEST IA...SOUTHEAST NEB...NORTHWEST MO
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 180440Z - 180615Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED SEVERE HAIL AND POSSIBLY STRONG WIND GUSTS MAY
DEVELOP WITH ELEVATED CONVECTION ACROSS PARTS OF THE LOWER MO
VALLEY.
DISCUSSION...STORMS HAVE GRADUALLY INCREASED IN COVERAGE/INTENSITY
ACROSS PARTS OF SOUTHEAST NEB AND SOUTHWEST IA. THIS DEVELOPMENT
APPEARS TO BE IN RESPONSE TO LOW-LEVEL WAA DOWNSTREAM OF A
STRENGTHENING CENTRAL GREAT PLAINS LLJ. WHILE THIS LATTER FEATURE
SHOULD DIMINISH BETWEEN 09-12Z...A CLUSTER OF CONVECTION WILL
PROBABLY PERSIST ACROSS PARTS OF THE LOWER MO VALLEY FOR THE NEXT
SEVERAL HOURS. OAX VWP DATA SAMPLED A PRONOUNCED WEAKNESS IN THE
HODOGRAPH FROM 2-4 KM AGL. HOWEVER...MODERATE SPEED SHEAR ABOVE THIS
LAYER IN CONJUNCTION WITH STEEP MID-LEVEL LAPSE RATES EVIDENT IN
AREA 00Z RAOBS SHOULD SUPPORT A RISK FOR ISOLATED SEVERE HAIL IN THE
MOST ROBUST UPDRAFTS. PREDOMINANT CLUSTER MODE ALONG WITH WEAK
MID-LEVEL HEIGHT RISES SHOULD TEND TO MARGINALIZE THE OVERALL RISK.
..GRAMS/WEISS.. 07/18/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DMX...EAX...OAX...
LAT...LON 41649631 41849579 41659474 41229391 40709364 40179376
39929428 39929490 40069559 40329622 40989662 41649631SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 9:46 PM CDT | Mesoscale Discussion | SPC | Des Moines, Henry, Jefferson, Lee, Louisa, Washington | 89 min |
| Jul 17, 8:06 PM CDT | Mesoscale Discussion | SPC | Clark, Knox, Lewis, Scotland | 84 min |
| Jul 18, 4:37 PM CDT | Mesoscale Discussion | SPC | Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more | 83 min |
Nearby
Mesoscale Discussions in Iowa, 2016Mesoscale Discussions in Nebraska, 2016Mesoscale Discussions in Missouri, 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.