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Area forecast discussion 
National Weather Service North Platte NE
907 PM CDT sun Sep 14 2014

issued at 340 PM CDT sun Sep 14 2014

500 mb analysis from this morning had a strong disturbance
over The Arrowhead of Minnesota with a secondary upstream trough
over far southwestern Saskatchewan. A nice 50 to 70 knots jet streak extended
from northern South Dakota...into southern Quebec and the Canadian Maritimes. WV
imagery this afternoon has the Saskatchewan disturbance over northestern
Montana. At the surface...a stationary front was located from northestern
Nebraska into the southern Nebraska Panhandle. North of this
feature...easterly winds were prevalent. In addition to easterly
winds...low cloudiness was present across the northern Nebraska
Panhandle and northwestern sandhills. South of this feature...winds were
southerly and southeasterly with partly cloudy skies. Temperatures
as of 3 PM CDT ranged from 61 at Ainsworth to 76 at Ogallala.


issued at 852 PM CDT sun Sep 14 2014

At 02z surface boundary visible on radar extending east to west
near Highway 2 through Thedford and south of Purdum. Tonight
clouds will steadily increase across the southwest as the main
frontal boundary sets up near the Nebraska and Kansas state line. The low
level jet is forecast to strengthen through midnight and kept the
isolated chance for thunderstorms over the southwest. Otherwise...clouds
increased across the southwest with stratus cloud deck to spread
north and linger through middle morning Monday.


Short term...(this evening through monday)
issued at 340 PM CDT sun Sep 14 2014

Main focus will be thunderstorm chances tonight. Stalled frontal
boundary across northeastern into central Nebraska will get a push
overnight to the south. Along/ahead of the front southerly winds
have brought dew points into the Lower/Middle 50s...which should be
sufficient for at least isolated thunderstorm development overnight.
Cap is holding strong so far...and expect development to occur as a
low level jet adds a little support to break the cap. Models not in
great agreement with timing and coverage have some
concern and will limit probability of precipitation to chance. Activity quickly moves
southeast overnight as high pressure builds in from the northern
plains. Skies clear briefly...however easterly then southeasterly
winds to the south/southwest of the high will favor upslope clouds
or fog. BUFKIT sounding tools suggest higher probability of stratus so no
mention of fog at this time. Cooler air to spread across the area
for tomorrow...with highs in the 60s. Some concern across western
Nebraska that stratus holds temperatures to around 60...however will follow
closer to guidance blend.

Long term...(monday night through sunday)
issued at 331 PM CDT sun Sep 14 2014

Monday night through Wednesday...the main forecasting
challenge deals with precipitation chances Tuesday night...along
with possible stratus development Monday night. High pressure will
track east into northern MO and southern Iowa Monday night. Southerly winds will
increase overnight...particularly across the western third of the
forecast area. Low level moisture over western Kansas...will begin to
push into far southwestern Nebraska by 12z Tuesday. Went ahead and increased
cloudiness in the southwest and west Tuesday morning as the GFS and
NAM solutions are indicating a nice tongue of 850 mb to h900 moisture
surging north Tuesday morning. Overnight lows will be coolest in the
east where drier air...light winds and mostly clear skies are
expected. In these areas...readings will be in the middle 40s.
Further west...lows will be in the lower 50s. On Tuesday...a weak
warm frontal boundary will push into the Panhandle allowing highs to
reach the lower 80s. East of the front...southerly winds...low level
moisture and the threat for cloudiness will keep highs in the upper
60s to lower 70s. The frontal boundary will push east into central
Nebraska Tuesday night. At the same time...weak middle level warm air
advection will track southeast across the forecast area leading to
an increased chance for isolated thunderstorms across northern
Kansas and southern Nebraska. Inherited forecast was
dry...however...the latest GFS and ec from last night have a meager
precipitation signal...which may impact the far southeastern zones. With this in
mind...introduced some slight chance probability of precipitation for Frontier
County...which fits in well with the forecast offices to the south and
southeast. With increased low level moisture and cloud cover...lows
Tuesday night will be mild with readings in the upper 40s to lower
50s expected.

Wednesday night through Sunday...the before mentioned frontal
boundary will remain anchored across central portions of the
forecast area. Highs Thursday will range from the middle 70s east of
the the middle 80s west of the front...over the eastern
Nebraska Panhandle. On Thursday night...the front will push east of
the forecast area as ridging builds east of the central rockies.
This will lead to highs in the 80s over the entire County Warning Area on Friday. On
Friday night...a strong northern stream disturbance will force a cold
front through the forecast area. As this feature plows into decent
bl moisture ahead of the front...showers and thunderstorms will
develop Friday night into Saturday morning. The front will push
south into Kansas Saturday night...shifting the threat for precipitation
south of the area. Highs behind the front Saturday and Sunday will
be in the 70s.


Aviation...(for the 00z tafs through 00z Monday evening)
issued at 612 PM CDT sun Sep 14 2014

Cold front currently moving south and visible on local radar south
of Valentine. Short term models continue to potential for stratus
development this evening beyond 03z. Then chance for isolated
thunderstorms through 06z. Primarily looking at visual flight
rules with the potential for marginal flight rules from 03z to 06z
in Valentine and 06z to near 15z at the North Platte terminal.
After 15z visual fight rules throughout on Monday.


Lbf watches/warnings/advisories...


short term...masek
long term...clb

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