Alert archive / Iowa / Mesoscale Discussions in 2003
Mesoscale Discussion 974
The Storm Prediction Center issued this mesoscale discussion at May 14, 2003, 12:40 PM CDT for 28 counties in Iowa; Atchison County, Missouri; 20 counties in Nebraska. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- May 14, 2003, 12:40 PM CDT (17:40 UTC)
- Expired
- May 14, 2003, 2:15 PM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
All 49 counties
Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Harrison County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Atchison County, MO, Butler County, NE, Cass County, NE, Colfax County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Hamilton County, NE, Johnson County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Washington County, NE, York County, NE
The radar
The Omaha radar (KOAX), 42 km from the middle of the area, began a volume at 17:42 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 5.7 hours before the alert went out and 42 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
- 2025 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 6 m²/s²
- 0-3 km storm-relative helicity
- 67 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
012 ACUS11 KWNS 141741 SWOMCD SPC MCD 141740 IAZ000-MOZ000-NEZ000-141915- MESOSCALE DISCUSSION 0974 NWS STORM PREDICTION CENTER NORMAN OK 1240 PM CDT WED MAY 14 2003 AREAS AFFECTED...ERN NEB / WRN IA... CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 141740Z - 141915Z THUNDERSTORM DEVELOPMENT SHOULD CONTINUE / INCREASE ACROSS E CENTRAL NEB / W CENTRAL AND SWRN IA OVER THE NEXT 1 TO 2 HOURS. WW MAY BE REQUIRED FOR THE THREAT OF LARGE HAIL. TCU / CB DEVELOPMENT IS OBSERVED ON LATEST VISIBLE IMAGERY IN A W-E BAND ACROSS E CENTRAL NEB INTO W CENTRAL IA INVOF WEAK SURFACE CONFLUENCE ZONE INDICATED BY LATEST ANALYSIS. DAYTIME HEATING BENEATH COLD /AROUND -20C/ MID-LEVEL TEMPERATURES / STEEP LAPSE RATES ASSOCIATED WITH UPPER LOW IS CONTRIBUTING TO MARGINAL AIRMASS INSTABILITY /AROUND 500 J/KG MEAN-LAYER CAPE/. ALTHOUGH INSTABILITY / LOW-LEVEL MOISTURE IS LIMITED ACROSS THIS REGION...AREA IS ON NRN FRINGE OF 60 KT MID-LEVEL JET STREAK. RESULTING DEEP-LAYER SHEAR WITHIN UNIDIRECTIONAL DEEP-LAYER WIND PROFILE WILL BE SUFFICIENT TO SUPPORT ORGANIZED / ROTATING MID-LEVEL UPDRAFTS. THIS COMBINED WITH COLD TEMPERATURES ALOFT WILL PROVIDE FAVORABLE CONDITIONS FOR HAIL UP TO 1.75 IN DIAMETER...IN ADDITION TO THE POTENTIAL FOR AN ISOLATED DAMAGING GUST. ..GOSS.. 05/14/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DMX...EAX...OAX...GID... 41359831 41709699 41949507 42219389 41819285 40849284 40289603 40629851
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 13, 8:38 PM CDT | Mesoscale Discussion | SPC | Fremont, Page | 2 hr |
| May 14, 12:36 PM CDT | Mesoscale Discussion | SPC | Des Moines, Henry, Johnson, Lee, Louisa, Muscatine and 1 more | 84 min |
| May 14, 2:00 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Appanoose, Audubon, Cass, Clarke and 34 more | 5 hr |
| May 14, 3:23 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Cass, Clarke and 33 more | 97 min |
| May 14, 6:45 PM CDT | Severe Thunderstorm Watch | SPC | Lincoln | 5 hr |
Nearby
Mesoscale Discussions in Iowa, 2003Mesoscale Discussions in Nebraska, 2003Mesoscale Discussions in Missouri, 2003Every mesoscale discussion in 2003
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.