Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 120522

Area Forecast Discussion
National Weather Service North Platte NE
1222 AM CDT Sat Aug 12 2017

.SHORT TERM...(This evening through Saturday)
Issued at 257 PM CDT Fri Aug 11 2017

Northwest flow aloft will be present across western Nebraska
tonight as an upper trough in southern Saskatchewan and Manitoba
drops into Montana and North Dakota. Weak upper ridging will exist
across the Great Basin. A weak disturbance in the flow will exit
eastern Wyoming and western South Dakota and move into western
Nebraska overnight. Mesoscale models indicate scattered storms
will push off the Black Hills and move into Sheridan and western
Cherry county mid evening and overnight. Other showers and a few
storms possible mainly west of highway 83 overnight, as warm air
advection increases within the stronger 850 mb winds present.

.LONG TERM...(Saturday night through Friday)
Issued at 257 PM CDT Fri Aug 11 2017

On Saturday, a fairly strong upper trough located across Montana
eastward through North Dakota, will drop southeast and bring good
chances for thunderstorms Saturday afternoon into Saturday night.
While scattered showers and a few thunderstorms expected in the
morning, by midday models indicate a few supercells may begin to
develop in Sheridan and Cherry county, and congeal into an MCS
with a south southeastward movement expected. While models
differ on the timing and location, synoptic scale conditions area
favorable for an MCS or two to develop. Thickness diffluence and
higher PWAT vales of 1.25-1.5 inches suggest some areas Saturday
afternoon and evening could receive heavy rainfall in excess of an
inch. Local rainfall amounts near two inch are possible. For this
reason, there is a slight risk for excessive rainfall which could
lead to flash flooding. This would be mainly across southwest
into central Nebraska. While thunderstorm chances should diminish
in the west after midnight, the eat half of the forecast area
should experience better thunderstorms chances, on the southern
end of thunderstorms expected across eastern South Dakota.

Thunderstorm chances continue Sunday, behind the northern stream
trough, within fairly zonal flow extending west across the central
Rockies. During the day Sunday, instability and moderate wind
shear may trigger isolated thunderstorms across the forecast
area, especially near any existing outflow boundaries. A moderate
disturbance across Colorado and south central Wyoming will trigger
storms to move east Sunday night, especially across the southern
half of western Nebraska.

Daily thunderstorms chances across some portions of the forecast
area Monday through Friday. Coverage looks to be much more
limited however, with the exception of Tuesday. On Tuesday, a
trough in the western Conus will emerge onto the Central
Plains. This should trigger scattered storms Tuesday afternoon and
Tuesday night with pops from 40 to 50 percent. Highs in the lower
80s Monday and Tuesday Tuesday warm into the mid to upper 80s
Wednesday through Friday.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1222 AM CDT Sat Aug 12 2017

Skies are clearing out from west to east from the Nebraska Panhandle
into western Nebraska. Thunderstorms will move across southwest
Nebraska from KIML through KMCK through the early morning hours.
Clouds will move in through the morning on Saturday. KLBF and KVTN
will see ifr conditions through Saturday.




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