Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

FXUS63 KLBF 122142

Area Forecast Discussion
National Weather Service North Platte NE
342 PM CST Thu Jan 12 2017

.SHORT TERM...(This evening through Friday)
Issued at 342 PM CST Thu Jan 12 2017

Another upper level disturbance will quickly move northeast across
western and north central Nebraska tonight. Models have been
handling these types of systems poorly, with a tendency to over due
the amount of dry air, and thus not producing enough snow
accumulation. With that in mind, have increased the chances for snow
tonight across western and north central Nebraska. Short term model
sounding profiles support this, especially across northern/northwest
Nebraska, where up to an inch or so of snow is possible. Snow to
liquid ratios remain fairly high, so this will be a fluffy/powdery
type snow. Winds will be light tonight, and as surface high pressure
moves east of the area, light southeast winds will develop by
morning. South to southeast winds will increase further on Friday,
but generally not exceed 15 MPH. It will remain cold as arctic air
is recycled back north across the area on the back side of the
surface high, with highs remaining in the 20s.

.LONG TERM...(Friday night through Thursday)
Issued at 342 PM CST Thu Jan 12 2017

A closed upper low will cross Baja Mexico, to the south of
Arizona on Saturday as an upper ridge extends from the
southeastern U.S. into the southern and central Plains. The
system will take on a negative tilt Saturday night and Sunday as
it moves into eastern New Mexico. This will draw Gulf moisture
northward into Nebraska by Sunday. A chance for snow to begin on
Sunday. especially by afternoon in the south. Skies will become
mostly cloudy with a light southeast wind. Highs to mainly reach
the mid 30s.

The closed low associated with the system will move into western
Kansas Sunday night, and into eastern Nebraska or north central
Kansas Monday. Likely to categorical snow chances Sunday night
into Monday across the southeast. Medium range models have made an
adjustment a bit further northwest. It appears a well defined
deformation zone will develop from eastern Colorado into northwest
Kansas and southwest Nebraska and extend northeast through
northeast Nebraska. Model differences do exist. The GFS continues
to show a northern stream influence ahead of the advancing upper
low. This may act to cause a sharp gradient to the snowfall and a
further southeast position than the European and Canadian models
indicate. Continue to prefer the consistent European model with
upper ridging holding ahead of the upper low and little if any
northern stream influence until the system weakens and moves east
Monday evening.

A look at model soundings favor snow as the main precip type. Some
sleet may mix in Sunday night in eastern areas. Otherwise snow is
expected. Given an anomalously high precipitable water value near
six tenths of an inch at North Platte Sunday evening, heavy snow
is possible. Snow ratios should be low however near 10 to 1.
Accumulating snow in excess of 6 inches looks increasingly likely
southeast of a line from Ogallala through Ainsworth, with a sharp
cutoff in amounts northwest of this line. Northerly winds should
increase Sunday night into Monday to 10 to 20 mph, which could
cause some blowing snow issues. Due to increased confidence with
the approaching system, have issued a winter storm watch for
Sunday night and Monday for the southeastern half of the forecast
area, mainly near and east of an Ogallala through Ainsworth line.

Snow chances should come to an end Monday night as system fills
and lifts into the western Great Lakes. The upper flows is
forecast to become fairly zonal by Wednesday with temperatures
potentially warming into the lower 40s.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 118 PM CST Thu Jan 12 2017

A weak upper level disturbance will bring a band of light snow
across northern Nebraska tonight. Local MVFR conditions are
expected as the system quickly moves across the region. The MVFR
should remain north of a KSNY to KTIF to KONL line. Winds tonight
will become east to southeast around 5 to 10KT.


Issued at 342 PM CST Thu Jan 12 2017

Frazzle ice continues to impact area streams and rivers.  The North
Platte River above Lake Mcconaughy has seen fluctuations due to
minor ice jamming the past several days, most notably at Lewellen
and Lisco.  Warmer temperatures helped alleviate some of the ice
issues early this week, but colder temperatures have returned.  Will
continue a RVS for both sites until the ice issues are fully
resolved and upgrade if needed.


Winter Storm Watch from Sunday evening through Monday afternoon
for NEZ007>010-025>029-036>038-057>059-069>071.



LONG TERM...Roberg
HYDROLOGY...Roberg is the U.S. government's official web portal to all federal, state and local government web resources and services.