Area Forecast Discussion
Issued by NWS Goodland, KS

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FXUS63 KGLD 202341

Area Forecast Discussion
National Weather Service Goodland KS
541 PM MDT Sat Apr 20 2019

.SHORT TERM...(This evening through Sunday)
Issued at 245 PM MDT Sat Apr 20 2019

Upper ridge axis will move east tonight and be followed by
southwest flow. There is a weak embedded shortwave in the flow,
but with lower levels bone dry think all that might materialize
tonight will be virga/isolated sprinkles. Tomorrow, cold front
will slowly settle into the forecast area, and by 21z be located
roughly along a Norton to Colby to Tribune line in northwest
Kansas. Instability axis will be located along/north of the front,
with the HREF mean showing 1000-1500 j/kg of CAPE along the
Colby/Norton segment, and 750-1000 j/kg along the Colby/Tribune
segment. Deep layer shear will be around 25kts. Area has been
upgraded to a marginal risk by SPC all the way to the Colorado
border and can see no reason to disagree. Shortwave trough will
move across the area at time of peak heating to provide synoptic
scale lift for scattered/numerous thunderstorms during the 21z to
03z time frame, then gradually diminishing through the remainder
of the night. QPF will generally be around a quarter of an inch,
though hires model output does show some isolated 1-3 inch
bullseyes during that period, so locally heavy rainfall will also
be possible.

Temperatures will be above normal tonight with lows in the upper
40s to lower 50s, then above normal again on Sunday with highs in
the 80s ahead of the front and 60s/70s behind the front. Relative
humidity does drop to near 15 percent in Greeley/Wichita counties
ahead of the front, but wind speeds are forecast to be light, so
not anticipating any fire weather concerns on Sunday.

.LONG TERM...(Monday through Saturday)
Issued at 1200 PM MDT Sat Apr 20 2019

Mon-Wed: The 12Z GFS/ECMWF are in relative good agreement that
the upper trough presently situated along the Pacific coast will
meander ESE/SE through the Intermountain West/Desert Southwest on
Mon-Tue and east across TX on Wed -- with SW flow aloft (Mon-Tue)
transitioning to northerly flow aloft (Wed) over the High Plains.
Sensible weather on Mon-Tue may be modulated by small amplitude
waves rounding the base of the trough / ejecting northeast from
the Desert Southwest to the Central Plains. As SW flow aloft
transitions to northerly flow aloft on Wed, sensible weather may
be modulated by small amplitude waves emanating from western
Canada and/or the northern Rockies.

Northerly low-level flow in the wake of a weak mid-latitude
cyclone on Mon may be perpetuated into Tue by pressure falls
attendant the upper trough progressing into TX, and increasing
mid-upper level cloud cover (via SW flow aloft) is likely Mon
night into Tue. With the above in mind, there is relatively high
confidence that cooler temperatures will prevail on Mon-Tue. Below
average confidence persists with regard to precipitation chances
in the Tri-State area. At this time, precipitation is generally
expected to remain along/south of Hwy 50, or along/south of a line
from Syracuse-Garden City-Dodge City.

Thu-Sat: Long range guidance diverges significantly with regard to
the evolution of the synoptic pattern over the CONUS late this
week into next weekend. As such, there is very, very little
confidence in sensible weather conditions in this period.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 527 PM MDT Sat Apr 20 2019

Vfr conditions are expected through the period. For Kgld, south
winds near 15 knots will continue until near 07z. At 07z those
winds will be southwest near 11 knots and will shift to the west
near 11 knots from 08z to 11z. At 21z the wind is expected to
shift to the north at 13 knots with gusts to near 21 knots as a
front begins to move through. No thunderstorms are in for this
period but expect thunderstorms to affect the site not too long
after 00z.

For Kmck, south winds near 13 knots will continue until 09z. At
that time the winds will shift to the east at 8 knots and continue
until 17z. At 17z the winds will become north at 10 knots. At 21z,
those north winds will increase to 15 knots with gusts to 23




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