Alert archive / Iowa / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 68, NWS Omaha, NE

May 7, 2015Montgomery County, Pottawattamie County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at May 7, 2015, 4:41 PM CDT for Montgomery County, Pottawattamie County, Iowa. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 7, 2015, 4:41 PM CDT (21:41 UTC)
Expired: May 7, 2015, 5:15 PM CDT
In force: 34 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Montgomery County, IA, Pottawattamie County, IA

The radar

The Omaha radar (KOAX), 86 km from the middle of the area, began a volume at 21:41 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, 9.7 hours before the alert went out and 87 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 50 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 940 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 371 m²/s²
0-3 km storm-relative helicity: 287 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at May 7, 3:05 PM CDT, 1 hour 36 minutes earlier.

Area forecast discussion, May 7, 3:05 PM CDT, 1 hour 36 minutes before

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Hazardous weather outlook, May 7, 12:23 PM CDT, 4 hours 18 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1223 PM CDT THU MAY 7 2015

IAZ043-055-056-069-079-080-090-091-NEZ034-045-050>053-065>068-078-
088>093-080730-
MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT-
PAGE-BURT-WASHINGTON-BUTLER-SAUNDERS-DOUGLAS-SARPY-SEWARD-
LANCASTER-CASS-OTOE-SALINE-JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-
RICHARDSON-
1223 PM CDT THU MAY 7 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA AND SOUTHEAST
NEBRASKA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON ALONG A COLD
FRONT. SEVERE WEATHER IS GENERALLY NOT EXPECTED...THOUGH SMALL
HAIL AND GUSTY WINDS WOULD BE POSSIBLE WITH ANY STORM THAT DOES
DEVELOP SOUTHEAST OF A LINE FROM ONAWA TO OMAHA TO LINCOLN. THE
CHANCE OF NON-SEVERE THUNDERSTORMS CONTINUES OVERNIGHT IN FAR
SOUTHEAST NEBRASKA.

FLOODING OR ELEVATED RIVER LEVELS CONTINUE TO AFFECT THE BIG BLUE
RIVER...TURKEY CREEK...LINCOLN CREEK...THE SALT CREEK... AND
WAHOO CREEK.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THUNDERSTORMS WILL BE POSSIBLE FRIDAY AND SATURDAY. MORE STORMS
WITH HEAVY RAIN AND POSSIBLE SEVERE WEATHER COULD OCCUR SATURDAY
NIGHT INTO SUNDAY.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTERS WILL NOT BE NEEDED THIS AFTERNOON OR TONIGHT.

NEZ011-012-015>018-030>033-042>044-080730-
KNOX-CEDAR-THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-STANTON-
CUMING-PLATTE-COLFAX-DODGE-
1223 PM CDT THU MAY 7 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
NEBRASKA AND NORTHEAST NEBRASKA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT INTO SUNDAY. HEAVY
RAIN AND POSSIBLE SEVERE WEATHER COULD OCCUR.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTERS WILL NOT BE NEEDED THIS AFTERNOON OR TONIGHT.

In the hours before

Local storm report, May 7, 3:19 PM CDT, 1 hour 22 minutes before

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Special weather statement, May 7, 3:28 PM CDT, 1 hour 13 minutes before

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Special weather statement, May 7, 3:49 PM CDT, 52 minutes before

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Special weather statement, May 7, 4:25 PM CDT, 16 minutes before

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Special weather statement, May 7, 4:27 PM CDT, 14 minutes before

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Special weather statement, May 7, 4:37 PM CDT, 4 minutes before

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The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 6, 7:19 PM CDT	Special Weather Statement	OAX	Saline	41 min
May 6, 7:35 PM CDT	Tornado Warning	OAX	Jefferson	25 min
May 6, 7:43 PM CDT	Flash Flood Watch	OAX	Butler, Jefferson, Lancaster, Saline, Saunders, Seward	8 hr
May 6, 7:55 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Lancaster, Saline, Saunders, Seward	50 min
May 6, 7:58 PM CDT	Tornado Warning Tornado observed	OAX	Jefferson	32 min
May 6, 8:22 PM CDT	Tornado Warning	OAX	Saline	11 min
May 6, 8:33 PM CDT	Tornado Warning	OAX	Lancaster	27 min
May 6, 8:34 PM CDT	Flash Flood Warning	OAX	Jefferson, Saline	4 hr
May 6, 8:41 PM CDT	Special Weather Statement	OAX	Saline	49 min
May 6, 8:46 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson, Saline	44 min
May 6, 9:08 PM CDT	Special Weather Statement	OAX	Saunders	52 min
May 6, 9:17 PM CDT	Special Weather Statement	OAX	Lancaster	28 min
May 6, 9:34 PM CDT	Areal Flood Advisory	OAX	Gage, Lancaster, Saline, Seward	3 hr
May 6, 9:35 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson	40 min
May 6, 9:56 PM CDT	Flash Flood Warning	OAX	Gage, Lancaster, Saline, Seward	3 hr
May 6, 10:21 PM CDT	Severe Thunderstorm Warning	OAX	Gage	39 min
May 6, 10:22 PM CDT	Special Weather Statement	OAX	Lancaster	23 min
May 6, 10:38 PM CDT	Tornado Warning	OAX	Gage, Lancaster	24 min
May 6, 10:53 PM CDT	Tornado Warning	OAX	Gage, Jefferson	37 min
May 6, 11:00 PM CDT	Tornado Warning	OAX	Gage, Lancaster, Otoe	30 min
May 6, 11:21 PM CDT	River Flood Warning	OAX	Saline	63 hr
May 6, 11:21 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	39 min
May 6, 11:39 PM CDT	Areal Flood Advisory	OAX	Cass, Douglas, Sarpy, Saunders	3 hr
May 6, 11:40 PM CDT	Special Weather Statement	OAX	Gage, Lancaster, Saline	35 min
May 6, 11:51 PM CDT	River Flood Warning	OAX	Lancaster	30 hr
May 7, 12:02 AM CDT	Special Weather Statement	OAX	Cass, Douglas, Otoe, Sarpy	43 min
May 7, 12:20 AM CDT	River Flood Warning	OAX	Saunders	45 hr
May 7, 12:20 AM CDT	River Flood Warning	OAX	Lancaster	32 hr
May 7, 12:20 AM CDT	River Flood Warning	OAX	Cass	47 hr
May 7, 12:28 AM CDT	Flash Flood Warning	OAX	Gage, Jefferson, Lancaster, Saline, Seward	7 hr
May 7, 12:42 AM CDT	Special Weather Statement	OAX	Seward	33 min
May 7, 12:56 AM CDT	Special Weather Statement	OAX	Cass, Otoe	34 min
May 7, 12:58 AM CDT	River Flood Warning	OAX	Gage	4 days
May 7, 12:58 AM CDT	River Flood Warning	OAX	Gage	4 days
May 7, 1:00 AM CDT	River Flood Warning	OAX	Jefferson	71 hr
May 7, 1:51 AM CDT	Areal Flood Advisory	OAX	Saunders	6 hr
May 7, 2:32 AM CDT	Areal Flood Advisory	OAX	Butler, Lancaster, Saline, Saunders, Seward	6 hr
May 7, 2:38 AM CDT	Areal Flood Advisory	OAX	Cass, Douglas, Sarpy, Saunders	6 hr
May 7, 4:02 AM CDT	River Flood Warning	OAX	Saline	4 days
May 7, 4:25 AM CDT	River Flood Warning	OAX	Saunders	61 hr
May 7, 5:14 AM CDT	Areal Flood Warning	OAX	Saunders	6 hr
May 7, 7:19 AM CDT	River Flood Warning	OAX	Saunders	7 days
May 7, 7:27 AM CDT	Areal Flood Warning	OAX	Gage, Jefferson, Lancaster, Saline	12 hr
May 7, 8:25 AM CDT	Areal Flood Advisory	OAX	Butler, Lancaster, Saline, Saunders, Seward	9 hr
May 7, 8:30 AM CDT	Areal Flood Advisory	OAX	Cass, Douglas, Sarpy, Saunders	5 hr
May 7, 9:46 AM CDT	River Flood Warning	OAX	Otoe	50 hr
May 7, 9:46 AM CDT	River Flood Warning	OAX	Nemaha	61 hr
May 7, 9:46 AM CDT	River Flood Warning	OAX	Richardson	66 hr
May 7, 10:33 AM CDT	River Flood Warning	OAX	Cass	54 hr
May 7, 2:13 PM CDT	Special Weather Statement	OAX	Johnson	17 min
May 7, 2:32 PM CDT	Special Weather Statement	OAX	Johnson	28 min
May 7, 2:42 PM CDT	Special Weather Statement	OAX	Gage	48 min
May 7, 2:50 PM CDT	Severe Thunderstorm Warning	OAX	Gage	25 min
May 7, 3:28 PM CDT	Special Weather Statement	OAX	Nemaha	32 min
May 7, 3:49 PM CDT	Special Weather Statement	OAX	Gage	41 min
May 7, 4:27 PM CDT	Special Weather Statement	OAX	Nemaha	33 min
May 7, 4:37 PM CDT	Special Weather Statement	OAX	Pawnee	53 min
May 7, 5:14 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Pawnee, Richardson	16 min
May 7, 5:35 PM CDT	Special Weather Statement	OAX	Gage, Pawnee	40 min
May 7, 6:39 PM CDT	Severe Thunderstorm Warning	OAX	Johnson	17 min
May 7, 6:55 PM CDT	Severe Thunderstorm Warning	OAX	Pawnee, Richardson	35 min
May 7, 6:59 PM CDT	Special Weather Statement	OAX	Otoe	46 min
May 7, 2:46 PM CDT	Special Weather Statement	OAX	Mills	44 min
May 7, 4:25 PM CDT	Special Weather Statement	OAX	Montgomery	50 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2015 Every severe thunderstorm warning in 2015

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.