Alert archive / Iowa / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 57, NWS Omaha, NE

May 29, 2018Harrison County, Pottawattamie County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at May 29, 2018, 3:54 PM CDT for Harrison County, Pottawattamie County, Iowa. It was in force for 36 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 29, 2018, 3:54 PM CDT (20:54 UTC)
Expired: May 29, 2018, 4:30 PM CDT
In force: 36 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Harrison County, IA, Pottawattamie County, IA

The radar

The Omaha radar (KOAX), 61 km from the middle of the area, began a volume at 20:57 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 29, 2:40 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.9 hours before the alert went out and 61 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1666 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 140 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 29, 3:02 PM CDT, 52 minutes earlier.

Area forecast discussion, May 29, 3:02 PM CDT, 52 minutes before

Area Forecast Discussion
National Weather Service Omaha/Valley NE
302 PM CDT Tue May 29 2018

.SHORT TERM...(Tonight through Friday)
Issued at 300 PM CDT Tue May 29 2018

Convection ongoing at the start of the period this afternoon as
first in a series of short waves lifts across the area in advance
of strong upper trough over the western high plains.

Additional storms are likely into the late night hours as this
system works its way across the region with storms ending by
morning in eastern parts of the area as the main trough shifts to
the east. Once this system is east of the area hot temperatures
return for a short time as upper ridging moves back over the
central plains for Thursday and Friday.

.LONG TERM...(Friday night through Tuesday)
Issued at 300 PM CDT Tue May 29 2018

Stormy conditions return to the region Friday night into Saturday
as another strong upper trough sweeps across the northern and
central plains. A strong cold front will accompany the upper
system and bring more seasonal temperatures to the area through
Monday before ridging again builds back for the middle of next
week with another round of mid summer temperatures for the area.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday morning)
Issued at 102 PM CDT Tue May 29 2018

Showers and thunderstorms expected periodically this afternoon and
tonight. Kept conditions VFR outside of thunderstorms and
mentioned gusty winds...otherwise southeast through southwest
winds 5 to 15kts.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&

SHORT TERM...Fobert
LONG TERM...Fobert
AVIATION...Zapotocny

Hazardous weather outlook, May 29, 3:50 PM CDT, 4 minutes before

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In the hours before

Special weather statement, May 29, 2:17 PM CDT, 1 hour 37 minutes before

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
217 PM CDT TUE MAY 29 2018

IAZ069-079-080-291945-
Pottawattamie IA-Mills IA-Montgomery IA-
217 PM CDT TUE MAY 29 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MONTGOMERY...
NORTHEASTERN MILLS AND SOUTHEASTERN POTTAWATTAMIE COUNTIES UNTIL 245
PM CDT...

At 216 PM CDT, Doppler radar was tracking a strong thunderstorm 4
miles north of Emerson, or 29 miles southwest of Atlantic, moving
north at 25 mph.

Dime size hail and wind gusts up to 50 mph will be possible with this
storm.

Locations impacted include...
Carson, Macedonia, Henderson and Farm Creek Public Wildlife Area.

LAT...LON 4102 9535 4104 9543 4127 9545 4124 9522
TIME...MOT...LOC 1916Z 189DEG 24KT 4108 9538

BLB

Local storm report, May 29, 2:29 PM CDT, 1 hour 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
229 PM CDT TUE MAY 29 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0220 PM     TSTM WND GST     5 MILES NW LESHARA      41.39N 96.49W
05/29/2018  E60 MPH          SAUNDERS           NE   PUBLIC

            ESTIMATED 50-60MPH WIND GUSTS WITH NICKLE
            SIZED HAIL.

&&

Local storm report, May 29, 2:30 PM CDT, 1 hour 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
230 PM CDT TUE MAY 29 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0210 PM     HAIL             2 NE YUTAN              41.26N 96.37W
05/29/2018  E0.75 INCH       SAUNDERS           NE   PUBLIC

            40 MPH WINDS GUST.

&&

CZ

Local storm report, May 29, 3:32 PM CDT, 22 minutes before

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Local storm report, May 29, 3:36 PM CDT, 18 minutes before

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Local storm report, May 29, 3:49 PM CDT, 5 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 29, 2:33 AM CDT	Special Weather Statement	OAX	Nemaha	12 min
May 29, 2:46 AM CDT	Special Weather Statement	OAX	Cass, Douglas, Johnson, Nemaha, Otoe, Richardson and 2 more	29 min
May 29, 2:55 AM CDT	Severe Thunderstorm Warning	OAX	Pawnee, Richardson	35 min
May 29, 3:16 AM CDT	Special Weather Statement	OAX	Nemaha, Otoe, Richardson	44 min
May 29, 1:47 PM CDT	Special Weather Statement	OAX	Sarpy	28 min
May 29, 2:01 PM CDT	Severe Thunderstorm Warning	OAX	Douglas, Saunders	29 min
May 29, 2:20 PM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Saunders, Washington	25 min
May 29, 2:45 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Washington	17 min
May 29, 3:18 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Otoe	27 min
May 29, 4:18 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Otoe	42 min
May 28, 7:21 PM CDT	Special Weather Statement	OAX	Fremont, Mills	24 min
May 29, 2:17 PM CDT	Special Weather Statement	OAX	Montgomery	28 min
May 29, 2:34 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Pottawattamie	26 min
May 29, 2:50 PM CDT	Severe Thunderstorm Warning	OAX	Shelby	14 min
May 29, 3:24 PM CDT	Severe Thunderstorm Warning	OAX	Harrison, Pottawattamie, Shelby	21 min
May 29, 3:27 PM CDT	Severe Thunderstorm Warning	OAX	Harrison, Shelby	18 min
May 29, 3:45 PM CDT	Severe Thunderstorm Warning	OAX	Harrison, Shelby	30 min
May 29, 4:20 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Page, Pottawattamie	40 min
May 29, 4:28 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	32 min
May 29, 4:58 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Pottawattamie	47 min
May 29, 5:37 PM CDT	Areal Flood Advisory	OAX	Montgomery, Page, Pottawattamie	3 hr
May 29, 5:44 PM CDT	Special Weather Statement	OAX	Pottawattamie	46 min
May 28, 7:43 PM CDT	Special Weather Statement	OAX	Holt	32 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2018 Every severe thunderstorm warning in 2018

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.