Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 222028
Area Forecast Discussion
National Weather Service Goodland KS
228 PM MDT SUN MAY 22 2016
.SHORT TERM...(This evening through Monday)
Issued at 222 PM MDT Sun May 22 2016
Latest upper air analysis has a closed low over far southeast
Canada and a short wave ridge over the plains. Water vapor shows
moisture wrapping around the low and around the ridge toward the
plains. A small area of subsidence is currently over East Central
Colorado, which is hindering any convection from occurring near
the dry line in Northwest Kansas.
For the rest of today windy conditions will persist across the
Tri- State area due to a strong low level jet mixing down.
Anticipate isolated storms to begin developing along the dry line
near Highway27 in the next couple of hours as a small area of
subsidence moves past the dry line. Storm coverage will gradually
increase through the afternoon as an upper level short wave trough
approaches from the southwest.
Regarding hazards...quarter size hail, damaging winds and tornadoes
will all be possible today and this evening. Deep layer shear is
not as strong as yesterday, which would support smaller hail.
Damaging winds are only expected during the afternoon. While deep
layer shear is weaker than yesterday, low level shear is already
around 20 kts, and should strengthen a bit more late this afternoon
as the low level jet intensifies. With a similar environment to
yesterday but weaker deep layer shear, am anticipating short lived
tornadoes, if they develop. The best window for tornadoes to
develop will be from 4 PM MT until 8 PM MT.
Early this evening the storm coverage will peak, south of I- 70
centered over Highway 25. The dry line will retreat during this
time, but the main upper level support will be to the east, and
the majority of the higher mid level mixing ratios will be east
of Highway 27. Therefore am not anticipating any storms to develop
west of Highway 27 despite the retreating dry line. Toward mid
evening the storm coverage will begin shifting east out of the
area. There will be a lull during the late evening and first few
hours after midnight before the next round of thunderstorms
Overnight another round of thunderstorms will develop east of
Highway 25 ahead of the cold front where elevated instability will
develop. Toward sunrise the elevated storms may become surface
based as the CINh drops to almost nothing. The ongoing rainfall may
also cause the environment to wet-bulb and erase the CINh present.
Regardless, storms may become surface based toward sunrise along the
east 1/3 of the area ahead of the cold front. Low level shear and
low cloud bases will be supportive of a tornado developing before
the storms exit the area.
Monday morning will be quiet storm-wise. During the afternoon the
cold front will move back north over the southeast half of the area.
Meanwhile the dry line will be east of Highway 83. An upper level
short wave trough will move over the dry line during the early
afternoon. Anticipate storms to begin firing an hour or so earlier
in the afternoon due to the stronger lift and lower CINh available.
Deep layer shear will be much stronger than today, but low level
shear will be much less. As a result large hail will be bigger, up
to soft ball size.
.LONG TERM...(Monday night through Sunday)
Issued at 131 PM MDT Sun May 22 2016
Southwest flow aloft will continue across the central High Plains
through Wednesday. Embedded weak shortwaves will result in
occasional chances for showers and thunderstorms. Best chances
will be along and north of Interstate 70. On Thursday the main
energy lifts out across the central and southern Rockies providing
stronger synoptic scale forcing for thunderstorms. Wraparound
precipitation will continue into Friday with the slow moving upper
system. More of a zonal flow is forecast for next weekend but
models continue to be quite wet with embedded shortwave troughs
aloft and copious low level moisture available. As for severe
potential...certainly ahead of the upper low Tuesday and
Wednesday shear and instability will be sufficient, but as the
upper low gets closer Wednesday through Friday deep layer shear
will decrease as does the severe threat. However, as the upper
flow increases again over the weekend with the zonal flow, may
see increasing threat once again depending on where the instability
axis ultimately sets up. Temperatures will be near to slightly
above normal through the period.
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1134 AM MDT Sun May 22 2016
VFR to MVFR conditions forecast for the TAFs. The breezy winds
will continue well into the night. Meanwhile isolated to scattered
storms are expected near the TAF sites during the late afternoon
and early evening. Late evening into the overnight hours low
level wind shear will develop ahead of a cold front that will move
through during the last few hours of the night. Behind the cold
front winds will turn to the northwest and become light.
Ahead of the frontal passage elevated thunderstorms will develop,
possibly near KMCK. If they do, it should only be for a couple
hours before storms are pushed east by the front.