Flash Flood Watch 2, NWS North Platte, NE

803 
WGUS63 KLBF 112041
FFALBF

Flood Watch
National Weather Service North Platte NE
341 PM CDT Sun Aug 11 2019

...FLASH FLOODING IS POSSIBLE ACROSS PORTIONS OF SOUTHWESTERN AND
CENTRAL NEBRASKA LATE THIS AFTERNOON AND TONIGHT...

.Thunderstorms are expected to track across western and
southwestern Nebraska late this afternoon into the nighttime
hours. With abundant low level moisture in place and weak winds
aloft, thunderstorms will be slow moving and be capable of
producing heavy rain. At this time, the greatest threat for heavy
rain is along and south of a line from Ogallala to Broken Bow.

NEZ038-057>059-069>071-121045-
/O.CON.KLBF.FF.A.0002.190811T2100Z-190812T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Custer-Keith-Perkins-Lincoln-Chase-Hayes-Frontier-
Including the cities of Broken Bow, Ogallala, Paxton, Grant, 
North Platte, Champion, Enders, Imperial, Wauneta, Hayes Center, 
Curtis, Eustis, and Maywood
341 PM CDT Sun Aug 11 2019 /241 PM MDT Sun Aug 11 2019/

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY MORNING...

The Flash Flood Watch continues for

* Portions of central Nebraska and southwest Nebraska, including 
  the following areas, in central Nebraska, Custer. In southwest 
  Nebraska, Chase, Frontier, Hayes, Keith, Lincoln, and Perkins. 

* Through Monday morning

* Slow moving thunderstorms are expected to develop this evening 
  with periods of heavy rainfall possible into the overnight 
  hours. 

* Heavy rainfall may lead to flash flooding and cause roadways 
  to wash out or become impassable. Some creeks and rivers may 
  flood. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a VERY DANGEROUS SITUATION.

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

Thorne

974 
WGUS63 KLBF 120805
FFALBF

Flood Watch
National Weather Service North Platte NE
305 AM CDT Mon Aug 12 2019

...The threat for flash flooding has ended across southwestern and
portions of central Nebraska...

NEZ038-057>059-069>071-120915-
/O.CAN.KLBF.FF.A.0002.000000T0000Z-190812T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Custer-Keith-Perkins-Lincoln-Chase-Hayes-Frontier-
Including the cities of Broken Bow, Ogallala, Paxton, Grant, 
North Platte, Champion, Enders, Imperial, Wauneta, Hayes Center, 
Curtis, Eustis, and Maywood
305 AM CDT Mon Aug 12 2019 /205 AM MDT Mon Aug 12 2019/

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of central Nebraska and
southwest Nebraska has been cancelled. The threat for additional
flash flooding has ended. 

$$

CLB

Area Forecast Discussion
National Weather Service North Platte NE
1157 PM CDT Sat Aug 10 2019

.SHORT TERM...(This evening through Sunday night)
Issued at 359 PM CDT Sat Aug 10 2019

Bottom line, we issued a Flash Flood Watch beginning this evening
at 00z for Lincoln, Frontier and Hayes Counties. The Flash Flood
Watch is in effect until 12z Sunday. Confidence is not as high as
we would wish but the overall trend of the latest CAMS is that
convection will fire off the High Plains and slowly move eastward
into a more favorable environment with the development of a Plains
low level jet. The CAMs favor southwest Nebraska and along the
Kansas border, but some upgrowth northward is expected. The
steering flow is not overly impressive and given large warm cloud
depths and PWATs that are progged to be 2SD or move above the
mean, flooding rains are possible across our southern zones. Not
to be overlooked but there is some severe potential late this
afternoon and evening as well. Latest mesoanalysis highlights high
/>3000 j/kg/ of MUCAPE with more than ample effective bulk shear
for storm updraft maintenance. Large hail and strong wind are the
main threats this evening. Overnight the pattern is messy and the
models are struggling to latch onto a solution. An argument can be
made for additional upgrowth during the pre-dawn hours across our
northern zones with additional isolated activity elsewhere.
Again, confidence is rather low, especially since the CAMs and
near term guidance has struggled as of recently with nocturnal
convection.

Sunday afternoon through early Monday have big potential for
additional rounds of heavy rainfall and severe weather. A mid-
level impulse will work on a boundary and PWATs nearing 2.0" to
promote the heavy rain threat. The available guidance is pointing
to a widespread event where most locations see an inch to 3 inches
of rainfall. This will complicate the flooding concerns further.
We debated the need for an additional Flash Flood Watch which
would cover most areas /save for our far northwest and possibly
western Sandhills zones/, but wanted to go one headline at a time
and see how the convective debris/feedback from the expected
overnight storms tonight will change the storm bearing fields. In
terms of the severe potential, moderate instability and increasing
shear will aid in the development of High Plains severe
thunderstorms Sunday afternoon. The models are fixed on a solution
where upscale growth to line segments or clusters move across most
areas of western and north central Nebraska. Severe wind gusts
would be likely, though at least initially, large hail would be
possible as well. SPC has an enhanced risk for severe storms
Sunday across across our entire southern third of the forecast
area.

.LONG TERM...(Monday through Saturday)
Issued at 359 PM CDT Sat Aug 10 2019

12z Monday and beyond.  The long term forecast period begins with a
broad upper level ridge across the southern states and a pair of
troughs, the first off British Columbia and the next near the
Canadian maritimes.  This favors a quasi-zonal pattern across most
of the continental U.S. through the first half of the upcoming work
week.  In time the BC trough deepens and allows for some
amplification of a intermountain west ridge.  By late week the
trough settles over the PAC NW forcing the ridge axis east across
the Plains.  Temperatures will stay seasonal early in the week, but
trend warmer for the latter half of the work week as the ridge
advances east. Several models are pointing to a disturbance working
with some monsoonal moisture to bring precipitation back to SW Neb
Tuesday evening and early Wednesday with additional monsoonal tap
late in the week as the CWA will sit largely on the backside of the
advancing ridge.  Given a relatively low amplitude pattern through
much of the long term forecast, confidence is somewhat low owing to
difficulties in timing and magnitude of the
shortwave/disturbances.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1157 PM CDT Sat Aug 10 2019

MVFR ceilings are expected into southwest Nebraska after 09z
until 17Z and should affect KOGA and KIML. MVFR ceilings may also
affect the KLBF terminal, but are not included attm. MVFR ceilings
also expected in north central NE including KVTN from 10Z until
16Z. Late Sunday afternoon and evening, numerous thunderstorms
will develop and move eastward across western NE, to affect the
KLBF and KVTN terminals after 00Z/12th. A few severe storms
possible with large hail and damaging winds. Very heavy rainfall
also expected with many of the storms.

&&

.HYDROLOGY...
Issued at 359 PM CDT Sat Aug 10 2019

Several rounds of convective thunderstorms will impact portions of
Northern and West Central through early Monday morning. PWATs are
progged to be abnormally high through the event with values
approaching their peak of 2.0" Sunday evening. Tonight, coverage
will be isolated to scattered and mainly target areas south of
Interstate 80. There are concerns that upwind propagation vectors
will align with the mean flow leading to a prolonged period of
rainfall. Storms will be highly efficient rain producers with the
high PWATs and deep warm cloud depths. The flooding threat expands
across most areas from southwest to north central Nebraska on
Sunday and early Monday. PWATs remain abnormally high with deep
warm cloud depths. Several models show a skinny CAPE signature
once nightfall occurs. It should be noted that the NAM model is
suggesting a period of record PWATs at KLBF Sunday evening with
2.44".

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 7 AM CDT Sunday for NEZ059-070-071.

&&

SHORT TERM...Jacobs
LONG TERM...Jacobs
AVIATION...Roberg
HYDROLOGY...Jacobs

Hazardous Weather Outlook...UPDATED
National Weather Service North Platte NE
1142 PM CDT Sat Aug 10 2019

NEZ004>010-022>029-035>038-056>059-069>071-094-120445-
Sheridan-Eastern Cherry-Keya Paha-Boyd-Brown-Rock-Holt-Garden-
Grant-Hooker-Thomas-Blaine-Loup-Garfield-Wheeler-Arthur-McPherson-
Logan-Custer-Deuel-Keith-Perkins-Lincoln-Chase-Hayes-Frontier-
Western Cherry-
1142 PM CDT Sat Aug 10 2019 /1042 PM MDT Sat Aug 10 2019/

This Hazardous Weather Outlook is for portions of western and
north central Nebraska.

.DAY ONE...TONIGHT.

There is a chance for thunderstorms overnight, mainly across
southwest into central Nebraska. A few of the storms may be slow
moving and contain heavy rainfall which will increase the
flooding potential.

A Flash Flood Watch remains in effect through 7:00 AM CDT Sunday
for portions of southwest Nebraska. Refer to the Flash Flood
product for the latest information.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

Scattered thunderstorms are likely late Sunday afternoon through
the evening and overnight. Storms may be strong to severe with
large hail, damaging winds, and an isolated tornado all possible.
Thunderstorms will also be capable of producing torrential
rainfall leading to a localized flooding concern.

Additional chances for thunderstorms exist Tuesday, Wednesday,
and Friday. At this time, the threat for severe weather is
uncertain. Check with later forecasts for more information
regarding this potential.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed late Sunday afternoon and evening.

&&

Get your weather, hydrological, and climate information at
http://www.weather.gov/northplatte

Roberg

Special Weather Statement
National Weather Service North Platte NE
911 PM CDT Sat Aug 10 2019

NEZ059-110300-
Lincoln NE-
911 PM CDT Sat Aug 10 2019

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LINCOLN COUNTY UNTIL
1000 PM CDT...

At 910 PM CDT, Doppler radar was tracking a strong thunderstorm 10
miles east of Wellfleet, moving east at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Vroman and Hansen Memorial Reserve State Wildlife Management Area.

This includes Interstate 80 in Nebraska near mile marker 207.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

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.

&&

LAT...LON 4086 10053 4096 10023 4085 10022 4071 10023
      4071 10058
TIME...MOT...LOC 0210Z 257DEG 22KT 4077 10043

Roberg

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
928 PM CDT SAT AUG 10 2019

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

0920 PM     FLASH FLOOD      2 WSW HAYES CENTER      40.50N 101.06W
08/10/2019                   HAYES              NE   EMERGENCY MNGR

            A COUNTY ROAD CROSSING BLACKWOOD CREEK WAS COMPLETELY
            WASHED OUT.

&&

ROBERG

Special Weather Statement
National Weather Service North Platte NE
937 PM MDT Sat Aug 10 2019

NEZ004-110415-
Sheridan NE-
937 PM MDT Sat Aug 10 2019

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN SHERIDAN COUNTY
UNTIL 1015 PM MDT...

At 937 PM MDT, Doppler radar was tracking a strong thunderstorm 18
miles north of Ellsworth, or 27 miles south of Rushville, moving east
at 15 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Billys Lake, Wolf Hill and Argo Hill.

This includes Highway 250 between mile markers 18 and 24.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

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.

&&

LAT...LON 4230 10247 4246 10239 4246 10207 4216 10205
TIME...MOT...LOC 0337Z 291DEG 13KT 4233 10229

Roberg

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1130 PM CDT SAT AUG 10 2019

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

0540 PM     TSTM WND GST     6 SE GRANT              40.78N 101.64W
08/10/2019  E60.00 MPH       PERKINS            NE   PUBLIC

            PUBLIC ESTIMATED 60 MPH WINDS WITH THUNDERSTORM.

0605 PM     TSTM WND GST     6 N WAUNETA             40.50N 101.37W
08/10/2019  E60.00 MPH       CHASE              NE   PUBLIC

            PUBLIC REPORT OF 60 MPH WINDS AND NICKEL SIZE HAIL.

0726 PM     HAIL             4 SSE HAYES CENTER      40.46N 100.99W
08/10/2019  M0.50 INCH       HAYES              NE   TRAINED SPOTTER

0800 PM     HEAVY RAIN       6 N WAUNETA             40.50N 101.37W
08/10/2019  M4.00 INCH       CHASE              NE   PUBLIC

            PUBLIC REPORTED 4 INCHES OF RAINFALL IN LESS THAN AN
            HOUR.

0813 PM     FLASH FLOOD      6 NNE WAUNETA           40.50N 101.33W
08/10/2019                   HAYES              NE   PUBLIC

            A COUNTY ROAD HAD SIGNIFICANT FLASH FLOODING WITH 3 TO 5
            FEET OF WATER OVER THE ROAD.

0920 PM     FLASH FLOOD      2 WSW HAYES CENTER      40.50N 101.06W
08/10/2019                   HAYES              NE   EMERGENCY MNGR

            A COUNTY ROAD CROSSING BLACKWOOD CREEK WAS COMPLETELY
            WASHED OUT.

&&

ROBERG