Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 210420 AAB

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
1120 PM CDT Sat May 20 2017

.SHORT TERM...(This evening through Sunday)
Issued at 312 PM CDT Sat May 20 2017

Complicated forecast in the near-term. Local radar shows a swath
of precipitation rotating slowly over western NEB. The latest
surface plot and web cams show a wintry mix to all snow over
portions of the central Sandhills. Changeover to all snow or mix
could be attributable to dynamic cooling in the column with the
heavier precip rates and a low freezing level. Temps are about
34-36 with dew points around 32-35 where snow or the mix is being
observed. While hi-res guidance has struggled with the
precipitation type, it appears to be handling the general
evolution of the precipitation swath/areal coverage. Based on
trends and hi- res guidance anticipate the threat for snow/mix to
continue through the afternoon over mainly the central Sandhills.
Precip should begin to move northeastward through the evening and
start diminishing over north central mid-late evening. Outside the
Sandhills, p-type will be predominantly liquid.

Drier air flow is expected to prevail tonight based on isentropic
analysis as the system begins to move into the Middle Missouri
valley. Sky cover should decrease from southwest NEB to north
central NEB. This will then bring the potential for frost over
much of the area with low sky cover and winds lessening, notably
over river valleys and low lying areas that are more susceptible.
Thereafter, frost threat will quickly diminish after sunrise. Main
concern with the frost advisory in place will be affect winds
will have on the areal coverage of frost. Nonetheless, a cool day
is expected tomorrow, albeit dry compared to today, with highs 5
to 10 degrees cooler than seasonal normal values.

.LONG TERM...(Sunday night through Saturday)
Issued at 312 PM CDT Sat May 20 2017

Beyond Sunday, temperatures are expected to remain on the cool
side through Wednesday with highs expected to approach seasonal
normals Thursday and Friday. Broad large scale trough dominates
much of the central and eastern CONUS through Wednesday.
Meanwhile, a ridge over the West Coast Sunday will be displaced
eastward Tuesday and Wednesday, and will then extend near the
ARKLATEX region to the Upper Mississippi Valley Thursday. Early
sensible weather impacts revolve around Monday into Monday night
wherein a cold front will advance southward. Increased
precipitation chances with thunderstorms exist Monday afternoon
and evening. Later in the period, Wednesday morning, the forecast
will need to be monitored as frost may become a concern for parts
of northwest NEB.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1120 PM CDT Sat May 20 2017

Local IFR/LIFR may be forming in the river valleys east and south
of a line from KLBF-KTIF-KBUR. The NAM suggests this in the
visibility product and it appears to be underway at KLBF.

VFR is generally expected all areas 14z Sunday through 06z Sunday

Local MVFR could develop in isolated showers and thunderstorms
18z-02z Sunday. At 04z...the disturbance on satellite between
KGGW-KHVR-KGTF dives south Sunday. The HRRR model suggests this
disturbance could produce the showers as early as 18z Sunday. Most
other models miss this event.


Frost Advisory from 3 AM CDT /2 AM MDT/ to 8 AM CDT /7 AM MDT/
Sunday for NEZ004>006-008>010-022>029-035>038-056>059-070-071-



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