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000
FXUS63 KLBF 282332 AAA
AFDLBF

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
632 PM CDT SAT MAY 28 2016

.SHORT TERM...(This evening through Sunday)
Issued at 328 PM CDT Sat May 28 2016

Current radar imagery is showing some light rain
showers/thunderstorms moving into Sheridan county. Current
thinking is that these showers/thunderstorms will begin to fall
apart as they more southeastward and are not anticipated to become
severe. Will keep an eye on them, though, as they move into warmer
and slightly more humid air over the next couple hours. Otherwise,
rain showers across Boyd and Holt counties will continue to slowly
move eastward and come to an end as drier air filters into the
region. Scattered cumulus clouds will be the main story across the
sandhills and I-80 corridor with conditions remaining dry through
evening before clouds dissipate after sunset. Overnight low
temperatures drop into the low 50s across the entire CWA.

Sunday will begin dry and pleasant with high temperatures eventually
rising into the upper 70s and low 80s by afternoon. Rain and
thunderstorm chances arrive late Sunday (after 4pm). Confidence in
these storms developing is quite low as we will be fairly stable
through Sunday evening. Current model guidance shows the better
chance for thunderstorm development will be further south (Northern
Kansas). Therefore, only included a low chance pop (about 30
percent) for our southern counties for late Sunday afternoon and
evening at this time. However, any slight adjustment in moisture or
instability northward could significantly change the forecast. This
will definitely be something that will be watched tomorrow.

.LONG TERM...(Sunday night through Saturday)
Issued at 328 PM CDT Sat May 28 2016

Sunday night through Tuesday...opportunities for strong or severe
thunderstorms present themselves late Sunday and Monday. The NAM
suggests Nrn Neb Sunday while the GFS model suggests Swrn Neb. The
NAM also fires off storms across Swrn Neb Monday aftn while the GFS
develops storms across all of Wrn Neb. The locations of storm
activity will depend on focus and moisture convergence near the peak
heating period of the late aftn and early evening.

Moisture...shear and instability are fairly modest but lapse rates
are steep with K indices in the lower 40s C. Sfc dew points rise
into the upper 50s Monday providing good moisture support. The NAM
was carrying this portion of the fcst with higher precipitable
values...over an inch. The GFS indicated steeper lapse rates with
more low level heating. All of this suggests a mix of strong and
severe thunderstorms producing hail as a main concern.  Monday would
appear to be the better chance with more storm coverage.

SPC outlooked the fcst area for severe weather Monday with the
better chance for supercell development across Nwrn Neb where the
shear will be stronger.

As a result of the deep convection across Swrn-Scntl Neb
Monday...the NAM develops a closed H700mb low across Nern Neb
Tuesday morning. None of the other models show this happening so
Tuesday could turn out be dry as the GFS...GEM and ECM are nearly
dry. The GFS ensemble holds on to a likely pops across Scntl Neb.
Still the NAM has been verifying forecasting moisture correctly so
it will not be completely discounted for now. A blend of the model
data produces a 40 pop across Ncntl Neb Tuesday morning.

A Pacific cold front will move through the fcst area Tuesday and dry
out the atm. The ECM has led with the feature and the GEM...GFS and
its ensemble are close to the ECM carrying the upper low quickly
through the Nrn Plains.

Tuesday night through Saturday...a dry forecast is in place. The
Pacific cold front should drive moisture well south of the fcst area
with no signficant moisture return developing until Friday. The fcst
area will be northwest flow aloft as a strong upper level ridge
builds into the Cntl Rockies.

The models keep the moisture return off the the high plains but with
sfc low pressure forming across the Nrn High Plains...it would seem
conducive for isolated storm development which could be carried east
into the fcst area. It would appear that sfc high pressure across TX
will prevent more moist air from moving north up the high plains
and the fcst is dry for now.

High temperatures gradually warm from the upper 60s Wednesday to
lower 80s Saturday as a weak thermal ridge develops.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 628 PM CDT Sat May 28 2016

Widely scattered rainshowers and isolated thunderstorms will
continue ahead of a weak cold front moving out of the Nebraska
Panhandle into western Nebraska. VFR ceilings and visibilities
have been associated with the thunderstorms and VFR conditions are
expected to persist through Sunday afternoon. Light and variable
winds are expected tonight. Southeast winds Sunbday afternoon less
than 10kts.

&&

.HYDROLOGY...
Issued at 328 PM CDT Sat May 28 2016

Flooding along the North Platte River and main branch of the Platte
River will continue. While water levels will remain fairly steady
through the weekend, moderate flooding will continue along the North
Platte River at North Platte and Lewellen. Minor flooding will
continue at Lisco and Brady (along the main branch of the Platte
River). Although the South Platte river is not anticipated to flood
at this time, water level will remain elevated at both Roscoe and
North Platte.

&&

.LBF Watches/Warnings/Advisories...
None.
&&

$$

SHORT TERM...Kulik
LONG TERM...CDC
AVIATION...Power
HYDROLOGY...Kulik





000
FXUS63 KLBF 281212
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
712 AM CDT SAT MAY 28 2016

.SYNOPSIS...
Issued at 322 AM CDT Sat May 28 2016

The H5 pattern tonight is fairly active across the lower
48 states. Low pressure was located over western Kansas, while
ridging was present across the eastern quarter of the US. This
ridging extended from the Carolinas north to the eastern Great
Lakes. Further west, and north of the low over western Kansas, a
ridge was present over Saskatchewan and Manitoba. Upstream of this
ridge, a trough of low pressure was present from the Alaskan
panhandle south into northern Washington and the Idaho panhandle. As
of the overnight hours, the low had transitioned east and was
roughly centered over Hastings Nebraska as of 1 AM CDT. On the
western periphery of the low, showers extended from Holt county,
southwest into Custer county. This area of showers was very slowly
transitioning east overnight. Across western and north central
Nebraska, skies were cloudy in the east where the showers were
located, to mostly cloudy in the west, where a shroud of high clouds
was present from the sandhills, west to the eastern Nebraska
panhandle. Temperatures as of 3 AM were generally in the lower to
middle 50s...with some upper 40s in the eastern panhandle.

&&

.SHORT TERM...(Today and tonight)
Issued at 322 AM CDT Sat May 28 2016

Today and tonight: Precipitation chances will be the
main forecast challenge over the next 24 hours. For today:  The
upper level low will accelerate northeast today and will make it
into southwest Minnesota by 00z Sunday. As this feature tracks from
south central into northeastern Nebraska this morning into the early
afternoon hours, the threat for precipitation will continue on the
western flank of the low. This is where the best lift associated
with the deformation zone is located. In these areas, have held onto
the highest pops. The threat for precipitation will linger into the
afternoon hours in the northeastern CWA as lapse rates will steepen
in proximity to the closed low. Elsewhere, mainly dry conds are
expected today, thanks to westerly winds, drier boundary layer air
and subsidence behind the exiting low and trough of low pressure.
Breaks in cloudiness are expected by the afternoon hours, which will
allow temperatures to climb into the middle 70s. For tonight, there
will be a limited threat for thunderstorms in the west, then north
overnight. A shortwave trough of low pressure will lift east of the
front range of Wyoming this evening with an increased threat for
thunderstorms in the west this evening. Thunderstorms may hold
together into the overnight hours across the northern CWA INVOF of a
stalled out surface boundary. ATTM confidence in the location of
this boundary is suspect, so will keep pops around 20 percent.

.LONG TERM...(Sunday through Friday)
Issued at 322 AM CDT Sat May 28 2016

The bifurcated polar low currently in place will eventually merge
back into one main low by next weekend and GFS/ECM are similar with
this hemispheric trend. In the meantime, upper ridge anchored over
the Norwegian Sea keeps most of the progressive systems in the
western hemisphere though these systems are small in amplitude
through mid week since a Rex block across AK and into nrn Pac ocean
keeps systems from becoming too organized. However, as upper high
over AK retrogrades to ern Russia, this allows more organized east
Asian upper jet to develop and extend across the nrn Pac which
serves to develop deep upper low by next weekend over the gulf of
AK. The downstream response is to develop a higher amplitude ridge
across the Rockies toward the end of the week. After a cooler mid
week, warmer temps should therefore return by next weekend.

As for specific details, an initially weak upper low develops and
strengthens over the northern Plains Sunday and Monday. A surface
high will be in place across the midwest behind the departing upper
low now moving through and with mainly zonal flow aloft, a trough of
low pressure will develop along the High Plains area. This would be
a pattern conducive to support serly low level flow keeping higher
dew points in place east of the panhandle, while drier air begins to
surge east in the higher terrain further west. This should set the
stage for the return of thunderstorms forced along the dryline
initially in the panhandle, then closer to the upper forcing, along
the sewd advancing cold front through Monday night. This agrees with
the current Day 3 placement of a slight risk for severe storms by
SPC. If LLJ develops as per GFS Monday night, initial convection
should grow upscale into an MCS or two from the Dakotas into KS.

After the passage of the strong cold front Monday night into
Tuesday, cooler air will make its way into the area with primarily
subsidence in place across western and north central NE through mid
week. As mentioned earlier, upper ridge build across the Rockies and
will put the area under nwrly flow aloft. The aforementioned cold
front will slow its swd progress in the southern Plains while the
nrn end of the front will continue to race ewd tied to the good
height falls aloft. A reinforcing cold front will move through the
area Tuesday night into Wed and will scour low level moisture from
the area as surface dew point temps fall into the 40s by late Wed.
Again the result should be a mainly dry forecast for the remainder
of the week with cooler temps midweek, but under mainly sunny skies.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 712 AM CDT Sat May 28 2016

Expect mid to high cloudiness across western and north central
Nebraska today. For both the KLBF and KVTN terminals, scattered to
broken CIGS of 10000 to 25000 FT AGL are expected over the next 24
hours.

&&

.HYDROLOGY...
Issued at 322 AM CDT Sat May 28 2016

Along the North Platte and main stem Platte river, minor
to moderate flooding continues. At Lewellen and North Platte
moderate flooding will continue for the foreseeable future, while
minor flooding is expected at Lisco and Brady as well. Along the
South Platte river, elevated river stages will continue at North
Platte and Roscoe. North Platte river stages overnight were 8.9 feet
and 6.8 feet at Lewellen and North Platte respectively. Lisco and
Brady were 4.3 and 7.5 feet as of 2 AM CDT. River levels are
expected to remain steady for the next several days.

&&

.LBF Watches/Warnings/Advisories...
None.
&&

$$

SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Stoppkotte
AVIATION...Buttler
HYDROLOGY...Buttler





000
FXUS63 KLBF 271822
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
122 PM CDT FRI MAY 27 2016

.SYNOPSIS...
Issued at 345 AM CDT Fri May 27 2016

Surface low pressure along SW Nebraska/NW Kansas border this
morning. The 500 MB low is a little to the west of the sfc low,
over east central Colorado. Good moisture rotating around the low
pressure system with a couple of bands of showers/embedded thunder
rotating to the north/west across the CWA. 3 am temps generally in
the 50s.

&&

.SHORT TERM...(Today and tonight)
Issued at 345 AM CDT Fri May 27 2016

The low pressure system will dominate the weather the next 24 hours.
Models in good agreement as the low slowly pushes to the east today
across western KS then picks up a little speed as it lifts to the
northeast into eastern Nebraska tonight. Moisture will continue to
wrap into/around the system with a several bands expected to pivot
across the CWA today and tonight. A dry slot early this morning
across SW Nebraska but is expected to fill in during the morning
hours with a good chance for rain across the area. So far not much
in the way of thunder and expect this to continue for the morning
hours. Once we get a little daytime heating we add a little more
instability and increase the chances for some thunder. The SPC does
include the eastern portion of the CWA in a marginal risk for severe
weather, and it can not be ruled out. Wind and hail would be the
threat as the better low level shear is to the southeast of the CWA.
As the low lifts to the northeast overnight, dry air will get drawn
into the back side of the system and bring an end to the showers in
the west. As for temps, cooler today as the clouds/showers will keep
temps from rising to far. Expect some breaks as the bands move
across the area and temps could yo yo from the mid 50s to the mid
60s and locally across N central around 70. Tonight cool in the west
as some clearing allow for temps to fall into the 40s...otherwise
lower to mid 50s in the east.

.LONG TERM...(Saturday through Thursday)
Issued at 345 AM CDT Fri May 27 2016

Upper level low will be in the process of opening up and moving
northeast across the region Saturday. Models agree on a fairly wet
morning, with at least scattered showers and thunderstorms expected
along and east of Highway 83. Decent lift and moisture in this area,
and the ECMWF even indicating a trowal signature across eastern
portions of north central Nebraska. By afternoon as system begins to
move off to the northeast, some sunshine expected west of Highway
83, but to the east expect some stratocumulus to linger at the very
least, so little in the way of sun until perhaps early evening.

Drier and warmer weather is expected Sunday. Models still showing
850mb temps rising into the upper teens to lower 20s, so pretty
confident most areas should see highs near 80 degrees or in the
lower 80s.

The next upper low will drop into the northern rockies and into the
northern plains Memorial Day through mid week. Gulf moisture will
surge back north Memorial Day, and as a cold front surges southeast
across the area Monday night expect showers and storms to become
likely once again.

As the upper low tracks towards the Great Lakes Wednesday, drier
northwest flow aloft will develop. At the surface expect mild
temperatures, with a mix of Canadian and Pacific airmasses keeping
highs in the upper 60s to mid 70s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 121 PM CDT Fri May 27 2016

Scattered rain showers and isolated thunderstorms will
continue throughout the afternoon. Rain showers will result in a
reduction in visibilities and a lowering of ceilings. Expecting
showers to move out of the region tonight with the potential of
some light fog developing behind the rain showers especially near
the KLBF terminal. Tomorrow looks dry across both terminals with
overcast skies around 7000 feet.

&&

.HYDROLOGY...
Issued at 345 AM CDT Fri May 27 2016

The first wave from the increased releases from Lake McConaughy has
starting to push the North Platte River at North Platte up above
moderate flood stage (6.5 feet) and will continue to rise as the
next wave arrives over the next 24 to 36 hours. This will push the
river close to major flood stage (7.0 feet). The added water will
also return the Platte River at Brady back above minor flood stage.
Otherwise little change to the area rivers at the moment. However
with the additional rainfall yesterday and today, will likely see
some slight rises on a few of the rivers and this will be monitored
closely. Watch for updates as reports come in and the RFC produces
new model guidance.

&&

.LBF Watches/Warnings/Advisories...
None.
&&

$$

SYNOPSIS...Masek
SHORT TERM...Masek
LONG TERM...Taylor
AVIATION...Kulik
HYDROLOGY...Masek





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