Special Weather Statement, NWS Omaha, NE

Area Forecast Discussion
National Weather Service Omaha/Valley NE
618 PM CDT Thu Jun 22 2017

.UPDATE...
Issued at 615 PM CDT Thu Jun 22 2017

So far, the cap has been holding. The synoptic scale cold front
is still northwest of Omaha and Lincoln, so still potential yet
this evening. Even after the front passes, there may be some
activity behind the boundary. 22Z SPC mesoanalysis suggests cap
is weakest to the north and northeast of Omaha, with lowest
100 mb MLCAPE around 2000 J/kg and CINH less than 25. RAP model
may be a bit overdone with precipitation coverage and amounts,
based on what happened last evening. 21Z ESRL HRRR suggest some
activity developing by 01Z and then even into tonight.

&&

.SHORT TERM...(Tonight through Sunday)
Issued at 302 PM CDT Thu Jun 22 2017

12z upper-air analysis revealed a belt of stronger cyclonic flow
from the northern Rockies into the Dakotas with an embedded short-
wave trough over the northern High Plains. This disturbance will
track southeast into the mid MO Valley tonight into early Friday,
enhancing forcing for ascent and vertical shear ahead of it. In
the low levels, mesoanalysis depicted a cold front stretching from
north-central IA through northeast into south-central NE as of
early afternoon. The boundary layer ahead of this front has been
warming and moistening today, which when coupled with the steep
lapse rates aloft is yielding a moderately unstable air mass this
afternoon.

Considerable elevated convection is ongoing across the area as of
19z, likely rooted within the EML/steep lapse-rate plume. And
latest convection-allowing model guidance remains relatively
consistent in suggesting that surface-based storms will become
increasingly probable in the 22-00z time frame, generally along
the I-80 corridor. A few of these storms could become strong to
severe this evening with locally damaging winds and hail being
the primary hazards.

Showers and thunderstorm chances should diminish from north to
south tonight into early Friday as a cooler, continental-polar
air mass advances south into the region. This air mass will remain
in place over the mid MO Valley through the weekend with daytime
highs in the 70s.

.LONG TERM...(Sunday night through Thursday)
Issued at 302 PM CDT Thu Jun 22 2017

Longwave troughing from Hudson Bay into the OH Valley at the onset
of the long-term forecast period will gradually shift east ahead
of an evolving trough over western Canada into the northwestern
states. The latter trough will subsequently progress east into the
north-central Plains, supporting an increase in precipitation
chances by about the middle of next week. Daytime highs will
gradually warm back through the 80s during the early to middle
part of the upcoming work week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 615 PM CDT Thu Jun 22 2017

Wind shift will move through the KOMA and KLNK areas early this
evening. Generally expect VFR conditions through the period.
Ceilings with any TSRA could drop below 2500 feet and vsby could
drop below 3 miles, but confidence on exactly when and where is
not high enough to include in TAFs. Will amend as needed. Expect
variable mid clouds after 06z. North winds may be a bit gusty
right behind the cold front for a while, then decrease.

&&

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

UPDATE...Miller
SHORT TERM...Mead
LONG TERM...Mead
AVIATION...Miller

Hazardous Weather Outlook
National Weather Service Omaha/Valley NE
915 PM CDT Thu Jun 22 2017

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-231615-
Monona-Harrison-Shelby-Pottawattamie-Mills-Montgomery-Fremont-
Page-Knox-Cedar-Thurston-Antelope-Pierce-Wayne-Boone-Madison-
Stanton-Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-
Saunders-Douglas-Sarpy-Seward-Lancaster-Cass-Otoe-Saline-
Jefferson-Gage-Johnson-Nemaha-Pawnee-Richardson-
915 PM CDT Thu Jun 22 2017

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

.DAY ONE...TONIGHT AND FRIDAY

Isolated to scattered thunderstorms will occur across parts of
mainly southeast Nebraska and southwest Iowa this evening and into
the early morning hours of Friday. This is generally along and
southeast of a line from Seward to Omaha and Harlan Iowa. A few of
these storms could be strong to severe and capable of locally
damaging winds, hail and heavy rain.

.DAYS TWO THROUGH SEVEN...FRIDAY NIGHT THROUGH THURSDAY

The chance of thunderstorms will return to the forecast Monday
night, and again Tuesday night into Thursday. Organized severe
weather is not currently anticipated.

.SPOTTER INFORMATION STATEMENT...

Storm spotter activation is not expected to be needed tonight or
Friday.

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1005 PM CDT THU JUN 22 2017

NEZ068-090-091-230345-
Otoe NE-Johnson NE-Nemaha NE-
1005 PM CDT THU JUN 22 2017

...Special Weather Statement...

At 1005 PM CDT, Doppler radar was tracking a strong thunderstorm 4
miles east of Douglas, or 25 miles southeast of Lincoln, moving
southeast at 25 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Syracuse, Cook, Talmage, Lorton and Brock.

LAT...LON 4059 9637 4068 9632 4062 9600 4052 9593
      4042 9600 4043 9614
TIME...MOT...LOC 0305Z 299DEG 20KT 4059 9631

MAYES

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1039 PM CDT THU JUN 22 2017

IAZ069-079-NEZ053-067-230430-
Pottawattamie IA-Mills IA-Cass NE-Sarpy NE-
1039 PM CDT THU JUN 22 2017

...Significant Weather Advisory for MILLS...SOUTH CENTRAL
POTTAWATTAMIE...SOUTHEASTERN SARPY AND NORTHEASTERN CASS COUNTIES
UNTIL 1130 PM CDT...

At 1039 PM CDT, Doppler radar was tracking a strong thunderstorm over
Pacific Junction, or 20 miles southeast of Omaha, moving northeast at
25 mph.

Dime size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Plattsmouth, Glenwood, Malvern, Treynor, Pacific Junction, Macedonia,
Silver City, Henderson, Hastings and Old Town Park.

This includes the following highways...
 Highway 34 in Iowa between mile markers 1 and 23.
 Highway 59 in Iowa near mile marker 37.
 Highway 75 in Nebraska near mile marker 73.
 Interstate 29 between mile markers 29 and 37.

LAT...LON 4093 9585 4103 9592 4124 9563 4121 9544
      4111 9539 4099 9545
TIME...MOT...LOC 0339Z 245DEG 21KT 4102 9579

MAYES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
1107 PM CDT THU JUN 22 2017

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

1052 PM     HAIL             1 S GLENWOOD            41.03N 95.74W
06/22/2017  E1.75 INCH       MILLS              IA   LAW ENFORCEMENT

            DEPUTY REPORTED GOLF BALLS OR LARGER

&&

DERGAN

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1144 PM CDT THU JUN 22 2017

NEZ091-093-230530-
Nemaha NE-Richardson NE-
1144 PM CDT THU JUN 22 2017

...Significant Weather Advisory for SOUTH CENTRAL NEMAHA AND
NORTHWESTERN RICHARDSON COUNTIES UNTIL 1230 AM CDT...

At 1144 PM CDT, Doppler radar was tracking a strong thunderstorm 5
miles south of Auburn, or 21 miles northwest of Falls City, moving
southeast at 15 mph.

Dime size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Verdon, Stella, Shubert and 7 Miles South Of Auburn.

This includes Highway 75 in Nebraska between mile markers 14 and 23.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4029 9591 4036 9581 4029 9562 4020 9562
      4015 9571 4015 9582
TIME...MOT...LOC 0444Z 315DEG 12KT 4030 9584

MAYES

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1207 AM CDT FRI JUN 23 2017

NEZ093-230530-
Richardson NE-
1207 AM CDT FRI JUN 23 2017

...Significant Weather Advisory for EASTERN RICHARDSON COUNTY UNTIL
1230 AM CDT...

At 1207 AM CDT, Doppler radar was tracking a strong thunderstorm 6
miles northeast of Falls City, moving southeast at 30 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Falls City, Verdon, Stella, Shubert, Rulo, Preston, Barada, Sac and
Fox Nation Reservation and Iowa (KS-NE) Reservation.

LAT...LON 4024 9581 4025 9550 4023 9547 4018 9548
      4016 9544 4013 9543 4012 9540 4004 9542
      4003 9540 4003 9536 4000 9531 4000 9558
TIME...MOT...LOC 0507Z 303DEG 26KT 4015 9554

MILLER

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1221 AM CDT FRI JUN 23 2017

IAZ069-230545-
Pottawattamie IA-
1221 AM CDT FRI JUN 23 2017

...Significant Weather Advisory for EASTERN POTTAWATTAMIE COUNTY
UNTIL 1245 AM CDT...

At 1220 AM CDT, Doppler radar was tracking a strong thunderstorm over
Carson, or 24 miles southwest of Atlantic, moving east at 25 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Oakland, Carson, Macedonia, Hancock, Old Town Park and Farm Creek
Public Wildlife Area.

This includes Highway 59 in Iowa between mile markers 41 and 58.

LAT...LON 4116 9550 4131 9557 4148 9516 4117 9516
TIME...MOT...LOC 0520Z 252DEG 23KT 4125 9544

MILLER