Alert archive / Iowa / Mesoscale Discussions in 2003
Mesoscale Discussion 1749
The Storm Prediction Center issued this mesoscale discussion at Jul 9, 2003, 7:43 PM CDT for 24 counties in Iowa; 15 counties in Minnesota. It was in force for 32 min.
The area
The outline as issued.
The facts
- Issued
- Jul 9, 2003, 7:43 PM CDT (00:43 UTC)
- Expired
- Jul 9, 2003, 8:15 PM CDT
- In force
- 32 min
- Issued by
- the Storm Prediction Center
All 39 counties
Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Delaware County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Kossuth County, IA, Linn County, IA, Mitchell County, IA, Tama County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Le Sueur County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Rice County, MN, Scott County, MN, Steele County, MN, Waseca County, MN
The radar
The La Crosse radar (KARX), 139 km from the middle of the area, began a volume at 00:43 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
Minneapolis, MN (KMPX), launched 00:00Z, 0.7 hours before the alert went out and 194 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
- 166 J/kg
- Mixed-layer CIN
- -87 J/kg
- Mixed-layer LCL
- 669 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 159 m²/s²
- 0-3 km storm-relative helicity
- 188 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.1
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 100044 SWOMCD SPC MCD 100043 IAZ000-MNZ000-100115- MESOSCALE DISCUSSION 1749 NWS STORM PREDICTION CENTER NORMAN OK 0743 PM CDT WED JUL 09 2003 AREAS AFFECTED...SERB MN / NERN IA CONCERNING...TORNADO WATCH 698...699... VALID 100043Z - 100115Z TORNADO WATCHES 698 AND 699 ARE SET TO EXPIRE AT 10/01Z...BUT IT APPEARS THAT A TORNADO THREAT MAY PERSIST FOR A FEW HOURS BEYOND THIS TIME. THUS...NEW TORNADO WATCH WILL BE REQUIRED ACROSS PARTS OF SERN MN AND NERN IA. SURFACE ANALYSES AND 00Z RAOBS SUGGEST A NARROW CORRIDOR WHERE KINEMATIC AND THERMODYNAMIC ENVIRONMENT SUPPORTS A CONTINUED TORNADO THREAT -- NE OF SURFACE LOW / WARM FRONT OVER CENTRAL IA BUT SOUTHEAST OF MORE STABLE AIR OVER S CENTRAL WI. ALTHOUGH GREATER INSTABILITY REMAINS SOUTH OF WARM FRONT IN WARM SECTOR...LOW-LEVEL / ABOVE SURFACE FLOW IS MUCH MORE VEERED RESULTING IN A GENERALLY UNIDIRECTIONAL / WEAKLY-SHEARED WIND PROFILE AND THUS MUCH LESS LOW-LEVEL VORTICITY. NEW TORNADO WATCH WILL LIKELY INCLUDE PARTS OF SERN MN AND NERN IA...WITH AREAS FARTHER SOUTH INTO THE WARM SECTOR PERHAPS BEING INCLUDED IN A NEW SEVERE THUNDERSTORM WATCH. ..GOSS.. 07/10/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DVN...ARX...MPX...DMX... 44999331 43759166 42529118 42099132 41939181 42119286 42819423 43839465
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 9, 7:50 PM CDT | Tornado Watch | SPC | Black Hawk, Bremer, Butler, Cerro Gordo, Chickasaw, Floyd and 10 more | 5 hr |
| Jul 9, 8:04 PM CDT | Mesoscale Discussion | SPC | Davis, Des Moines, Henry, Jefferson, Lee, Louisa and 3 more | 56 min |
| Jul 9, 8:20 PM CDT | Severe Thunderstorm Watch | SPC | Des Moines, Henry, Iowa, Jefferson, Johnson, Keokuk and 5 more | 6 hr |
| Jul 9, 10:00 PM CDT | Mesoscale Discussion | SPC | Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo, Chickasaw and 11 more | 60 min |
Nearby
Mesoscale Discussions in Iowa, 2003Mesoscale Discussions in Minnesota, 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.