Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 231129
Area Forecast Discussion
National Weather Service Goodland KS
529 AM MDT Sun Apr 23 2017
.SHORT TERM...(Today and tonight)
Issued at 319 AM MDT Sun Apr 23 2017
Latest upper air analysis depicts a ridge building southeast onto
the Central Plains. Rounding the ridge were higher water vapor
concentrations leading to cirrus.
Today winds will quickly increase this morning as the surface
pressure gradient tightens. Late this morning, and into the
afternoon, winds will continue to increase as the low level jet
mixes to the ground. Due to the cirrus, which should be over the
Tri-State Area in the afternoon, kept winds a bit lower than
preferred due to the clouds hindering some of the mixing. Winds
will reach their peak mid afternoon then decline in the late
afternoon. Wind gusts of 35-40 MPH are expected this afternoon. The
south winds will cause temperatures to be warmer than yesterday.
Tonight winds will be breezy due to the tight surface pressure
gradient persisting. However winds will not be as strong as during
the day due to the low level jet not mixing through the inversion.
Overnight a surface trough will move through. Behind the surface
trough winds will be light as the surface pressure gradient relaxes.
An upper level short wave trough will move through overnight behind
the exiting ridge, but the dry environment will only allow clouds to
form. The winds will cause lows to be warmer than yesterday.
.LONG TERM...(Monday through Saturday)
Issued at 229 AM MDT Sun Apr 23 2017
Monday warmer air will move through behind the surface trough from
Sunday night. Highs will be warmest in the east where winds will be
more from the south than southwest. In the afternoon wind gusts
around 25 MPH are expected over Cheyenne and western Kit Carson
counties. The added effect of low relative humidity may lead to
hazardous fire weather conditions for a few hours in the afternoon.
Monday night an upper level short wave trough will move across the
Tri-State Area. Models disagree with how far south the environment
will saturate. Have highest confidence of rainfall occurring north
of Highway 36, with lower confidence to the south. The best chance
for rainfall will be during the overnight hours when lift with the
upper level short wave trough will be strongest. Accompanying the
upper level short wave trough will be a cold front. The cold front
will be through the forecast area before Tuesday morning.
Tuesday will be cooler due to the passage of the cold front. There
could be some lingering rain, mainly north of Highway 36, due to the
upper level short wave trough from Monday night lingering before
moving east of the forecast area. During the late afternoon a
backdoor cold front will begin moving into the forecast area. This
front will be stronger than the one from Monday night. Behind the
front north winds will increase. Meanwhile another, stronger upper
level short wave trough will begin to move over the forecast area
from the west. Soundings show the environment saturating deeper
than Monday night, which will mean better chances for rainfall.
Tuesday night the cold front moves through the rest of the forecast
area. Meanwhile rain chances spread southeast with the upper level
short wave trough. Due to the path of the upper level short wave
trough, the best chance for rainfall will be over the southwestern
and southern halves of the forecast area. Cloud cover should
prevent any frost from forming late Tuesday night into Wednesday
Wednesday through Saturday
The upper trough that moves east of the Rockies late Tuesday moves
east of the forecast area during the day on Wednesday. A couple
smaller impulses move quickly through the region Thursday and
Thursday night ahead of the upper low center that deepens
dramatically over the four corners region by early Saturday. The
cooler high pressure area moving into the central high plains region
on the back side of the exiting upper and surface low will remain in
place across the region from Wednesday through early Thursday before
being pushed east by late Thursday. High pressure will provide a
brief break in the possibility of precipitation on Wednesday before
the next system affects the forecast area.
The ECMWF and GFS are now in closer agreement deepening the upper
low over the western U.S. Friday and Friday night than they were
yesterday. The GFS and ECMWF now also follow similar trajectories
lifting the low out across the central rockies and into the northern
plains by late Sunday, but the GFS leads the ECMWF in timing and
position lifting it out across the high plains. Without a strong
kicker moving into the western U.S. to displace the low, tend to
favor the slower progression of the ECMWF this time around.
With the low moving through the 4-corners area and lifting out
through the central high plains region, there is a favorable setup
to see precipitation continue across the forecast area from
Wednesday night through Saturday night before the system lifts out
of the area on Sunday. There could be a mix of rain and snow during
the overnight hours as temperatures dip into the middle to lower 30s
and even a few thunderstorms Thursday and Friday evening.
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 526 AM MDT Sun Apr 23 2017
VFR conditions forecast for the TAFs. Main impact will be the
strong winds today. South winds will increase this morning,
reaching a peak around 21z, then gradually decline. A surface
trough will move through from the west after 6z. Behind the trough
winds will slow further. LLWS will develop tonight as a very
strong LLJ develops overhead.
KS...Frost Advisory until 8 AM MDT /9 AM CDT/ this morning for
CO...Frost Advisory until 8 AM MDT this morning for COZ090>092.
NE...Frost Advisory until 8 AM MDT /9 AM CDT/ this morning for