Flash Flooding and Flooding in Nebraska, May 27 to 28, 2019

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1155 PM CDT Mon May 27 2019

.SHORT TERM...(Tonight through Thursday)
Issued at 351 PM CDT Mon May 27 2019

Surface low at 19z was located along the MN/IA border, with the
cold front now between Lincoln and Beatrice. Short wave ridging
aloft was in place across the region, thus we're in a temporary
lull of activity. CAMS suggest that there remains at least an
isolated chance for a couple of storms along cold front yet early
this evening in southeast NE, but the main show will begin to
develop later, with stronger storms possible along the cold front,
but more importantly, an MCS moving off the high plains after
midnight and beyond. This could have a wind and hail risk as
storms roll in from the west after 06z. There is some concern that
additional heavy rains could compound ongoing flooding problems
in Platte county that received 3 to 6.5 inches of rain last night,
but other locations can likely take the incoming rainfall.

The tail end of the MCS could be crossing the river by 12z, but
there could be lingering showers across the area Tuesday morning.
The overnight convection could also suppress the front to the
south along the KS/NE border, but the front is expected to lift
northward as a warm front as the upper low moves off the front
range. This front could lift as far north as I80 through peak
heating per recent Nam (GFS remains just a little farther south),
which helps support the enhanced risk for severe storms along and
southeast of a line from the Lincoln/Omaha areas. Severe
parameters looks good for our area in the warm sector, with the
threat for large hail, damaging winds, and a few tornadoes, with
severe threat lingering through the evening.

Surface low moves to central IA through daybreak Wednesday. We
could have some wraparound showers in northeast NE that day but
severe threat is low. Still a few showers possible on Thursday.

.LONG TERM...(Thursday night through Monday)
Issued at 351 PM CDT Mon May 27 2019

There are sporadic precip chances in the extended period with near
normal temps, but nothing looks significant or extreme at this
time.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1141 PM CDT Mon May 27 2019

Thunderstorms are starting to make their way through the area.
Storms will impact LNK and OMA in the 6-9Z timeframe. Multiple
models indicate there will be a lull, before a 2nd round of storms
passes through the area from 10-14Z. Conditions will mostly be at
MVFR through the day with intermittent periods of IFR. After the
passage of the 2nd line of storms, winds will be from the ENE at
15 mph gusting up to 25. MVFR criteria are likely to prevail for
most of the forecast period.

&&

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

SHORT TERM...DeWald
LONG TERM...DeWald
AVIATION...Fajman

Hazardous Weather Outlook
National Weather Service Omaha/Valley NE
521 PM CDT Mon May 27 2019

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-281230-
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-
521 PM CDT Mon May 27 2019

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 Tuesday

There is a slight risk for severe storms tonight. Isolated storms
could develop along a stalled cold front in southeast Nebraska
this evening. And strong storms could move in from central
Nebraska after midnight. Large hail and damaging winds are the
primary threat. Due to heavy rainfall last night, localized areas
could experience flooding.

There is an enhanced risk for severe storms Tuesday afternoon and
evening for southeast Nebraska and southwest Iowa. The stalled
boundary near the Kansas and Nebraska border is expected to lift
northward toward Interstate 80 as a warm front. Large hail and
damaging winds would be the main threat Tuesday, along with
isolated tornadoes. Points north and northwest of Interstate 80
would have a lower severe threat Tuesday.

Otherwise, minor flooding will be possible near Seward on the
Lincoln Creek, and from Wahoo to Ithaca on the Wahoo Creek.
Flooding will also continue on the Missouri River downstream from
Blair.

.DAYS TWO THROUGH SEVEN...Tuesday night through Monday

Minor to moderate river flooding will continue along the Missouri
River from Blair south to Rulo. Other small rivers and streams
will continue to run high.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will probably not be needed tonight, but may be
needed along and south of Interstate 80 on Tuesday afternoon and
evening.