Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 230324
Area Forecast Discussion
National Weather Service Goodland KS
924 PM MDT SUN MAY 22 2016
Issued at 910 PM MDT Sun May 22 2016
Just completed an update. Had to rearrange the orientation of
pops. Initial convection has stayed in the far south. However
still left low chance pops in the eastern portion. Concern now
turns the incoming cold front. Hires/convective allowing
guidance...especially the hrrr/rap...are develop a strong and
extensive line of thunderstorms along the cold front. That has
been shown a while before anything developed and now the line is
expanding in coverage and intensity to my north.
So raised pops/qpf in the north. Kept a mention of severe since
spc mesoanalysis and forecast elements would indicate the
possibility of severe with this line of storms. Also raised the
winds a little behind the front due to trends upstream...a rather
tight pressure gradient...and three hour pressure rises near 8 mb.
However I may not have been able to raise them enough. Everything
else looks fine at this time.
.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 00Z TAFS through 00Z Monday evening)
Issued at 546 PM MDT Sun May 22 2016
Vfr conditions are expected for both sites through the period.
However uncertain how the thunderstorm forecast is going to turn
For kgld...it will be close but it looks like this evenings
thunderstorms will stay just east of the site. however will keep a
vcts mention for a few hours. Southerly winds near 25 knots with
gusts 30 to 35 knots through the evening hours. A cold front moves
through after midnight and depending on which model you choose
there could be a decent chance to affect the site. Due to
uncertainty...chose to keep a vcts mention. After the front moves
through the winds will become light and shifting. Another chance
for thunderstorms looks to occur very late tomorrow with no
mention at this time.
For kmck...through this evening there looks to be a little better
chance to have thunderstorms to affect the site. However, that
also depends on which high resolution model you choose. Have a
mention of -tsra from 01z to 03z. Some wind shear will be in place
from 03z to 07z. It appears that the better chance for
thunderstorms could occur after 07z when a cold front moves
through. However, this also depneds on which model you choose to
look at. At this time just have vcts but that may change at the
next issuance. Decreasing northerly winds will occur after this.
Another chance for thunderstorms looks to occur very late
tomorrow with no mention at this time and will leave out at this