Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 151728

Area Forecast Discussion
National Weather Service North Platte NE
1128 AM CST Mon Jan 15 2018

Issued at 341 AM CST Mon Jan 15 2018

At 09z...Surface low pressure was centered in southern Wisconsin
with an arctic front trailing southwest through central Missouri
into far southern Kansas. The center of surface high pressure was
located in central Saskatchewan. the coldest temperatures was 35
below in northern Saskatchewan. The lowest wind chills were near 45
below in parts of central and northern Manitoba.


.SHORT TERM...(Today and tonight)
Issued at 341 AM CST Mon Jan 15 2018

A closed low in eastern Minnesota will drop into southern Wisconsin
by early this evening. Meanwhile arctic high pressure near 1055mb
will drop into western North Dakota. This will be a bitterly cold
airmass with 850mb temperatures ranging from -18C to -23C across
much of western Nebraska today. Highs were lower a few degrees from
previous forecast to near zero in the northeast and from 10 to 15
above across southwestern areas. Northwest winds from 15 to 30 mph
will produce wind chills from 15 below to 25 below across north
central and central Nebraska. Skies will clear out by mid morning
across the southwest with at least partly cloudy skies across the
east today.

For tonight, the strong arctic high pressure center will move into
central South Dakota, as the surface ridge extend all the way south
into central Texas. Overnight lows remain close to previous
forecast, except used a blend of CONSMOS to lower mins to around 15
below across the northeast panhandle into Cherry County. Otherwise
lows from 10 below to 12 below will be common across the area.
Factoring in wind chill, 20 to 29 below will be common throughout
the night. A few readings could exceed 30 below. Skies will remain
mostly clear in the west, with partly cloudy skies east.

Thew wind chill advisory will remain in effect today, through
tonight, and during the morning Tuesday. If wind chills do exceed 30
below, the advisory may need to be upgraded to a wind chill warning.
This would be possible across portions of north central Nebraska

.LONG TERM...(Tuesday through Sunday)
Issued at 341 AM CST Mon Jan 15 2018

Quite the pattern change occurs over the next several days for
western Nebraska. The closed low over the Great Lakes gets swept up
into the longwave trough, reverting the flow aloft to northwest.
Then, the amplified ridge over the Intermountain West progresses
onto the Plains, switching the flow to southwest late week. The
surface synoptic pattern is dominated by a Southeast U.S. high
pressure followed by a lee side low developing over CO/KS late week.

Tuesday... Wind Chill Advisory remains unchanged, due for expiration
at 18z. However, trends will need to be monitored for a possible
upgrade to Warning across the north as values approach (and locally
exceed) -30 early morning. Relatively breezy conditions continue
through mid-morning as a PV anomaly works through the state. For the
afternoon, nudged highs up toward MAV/MET guidance to account for
return flow at the sfc, notable WAA at H85, and full sunshine.
Continued WAA overnight and somewhat elevated winds (south 5 to 10
mph) will keep temps from plummeting again Tuesday night, precluding
any additional wind chill headlines.

Wednesday through Friday... Guidance came in much warmer during this
period as the heart of the upper ridge passes by and a strong
thermal ridge develops. With decent downsloping winds and H85 temps
near 15C Thu/Fri (near the 97%ile of climo), highs should easily
reach the 50s. The extended solutions still suggest a H5 closed
low sliding southeast out of the Prairie Provinces on Thursday,
but differences remain in the track. The GFS brings it across
SoDak and SW Minn with stronger fgen forcing (cooler temps for
W.Neb?), while ECM keeps it toward the MN Arrowhead and UP of Mich
and weaker. Regardless, both solutions suggest the lack of
moisture and have kept the forecast dry. Another concern, as noted
in the previous forecast discussion, is fog potential given
warm/moist advection. SREF is already showing increased probs
across the southwest Thu AM.

Saturday and Sunday... Still watching the potential major weather
maker for the Plains. Confidence has grown in impacts for western
Nebraska as the ECM is trending toward the GFS in developing a
closed low over Neb/KS and cutting the sfc low up through
central/eastern KS. The ECM also has a neutral trough, taking on a
slight negative tilt to the east of the area. Location and strength
have changed little between the 14/00z and 15/00z GFS runs. However,
have capped PoP at high chc considering there are still six days for
north-south shift or other dynamic changes to occur.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1128 AM CST Mon Jan 15 2018

Gusty post frontal northwest winds to continue through the
afternoon hours today, but then gradually weaken overnight.
Otherwise VFR is forecast for the entire area, except across
northern Nebraska where a scattered to broken deck of stratus has
lowered ceilings. Guidance doesn`t have a good fix on this stratus
deck, so updates may be needed. For now, we expect a gradual
lifting/clearing of the stratus such that KVTN will be VFR after
20z today.


Issued at 341 AM CST Mon Jan 15 2018

A Flood Advisory remains in effect for the Niobrara River near
Sparks. The river gage indicates minor fluctuations near 6.5 feet.
This is slightly above the flood stage of 6.0 feet. The forecast is
for a slow decrease in the river stage to below flood stage tonight.
However, with very cold temperatures the next two days, this may
delay the fall in the river stage. Mild temperatures into the low
40s Wednesday and around 50 Thursday and Friday, should help with
ice breakup.


Wind Chill Advisory until noon CST /11 AM MST/ Tuesday for



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