Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 191855
Area Forecast Discussion
National Weather Service Goodland KS
1155 AM MST Thu Jan 19 2017
Issued at 1154 AM MST Thu Jan 19 2017
The dense fog has lifted, so updated the forecast to cancel the
.SHORT TERM...(Today and tonight)
Issued at 233 AM MST Thu Jan 19 2017
Latest upper air analysis continues to depict a closed low over the
Central Plains within a long wave trough over the majority of the
CONUS. Upstream another short wave trough was moving on shore. At
the surface a trough was bisecting the Tri-State Area. East of the
trough areas of dense fog had developed due to the higher dew points
present. Visibilities ranged from near zero to four miles.
This morning the dense fog coverage will remain largely unchanged
until the late morning when it begins to dissipate. The west edge
of the fog will move some from west to east following the movement
of the surface trough. This will cause locations along the west
edge, specifically the Highway 25 corridor, to have rapid changes in
visibility. Freezing fog is expected for some locations which will
leave a light glaze of ice on bridges and overpasses. Some
locations could see lingering minimal fog around noon CT. The
current dense fog advisory goes until noon CT to account for the fog
lingering longer than normal. The latest visibility forecast is
beginning to indicate a corridor of dense fog along the surface
trough which may linger into the early afternoon before completely
burning off. If this occurs the advisory will need to be extended.
Highs for today will be cooler for the east half of the Tri-State
Area due to the persistent cloud cover. Locations east of Highway
83 will not see the sun today. Due to the fairly high dew points of
low 40s, was not sure how cool highs would be in the cloud cover
over the east. Near term guidance all pointed to highs in the mid
40s for the east part of the area, but this may be too warm with the
Tonight the fog will return after midnight east of the nearly
stationary surface trough as dew point depressions close to zero.
Expect a similar trend for the fog compared to last night, with a
corridor of dense fog forming along the trough axis initially then
expanding in coverage after midnight east of the surface trough.
Lows will be similar to last night.
.LONG TERM...(Friday through Wednesday)
Issued at 216 AM MST Thu Jan 19 2017
Friday morning the fog will gradually end as temperatures warm.
Meanwhile another upper level short wave trough will move across the
forecast area. Some light snow may develop over the far southwest
part of the area where mid and low level moisture increases along
with lift. Very little if any accumulation is expected.
Friday afternoon the upper level short wave trough slowly moves east
across the area bringing chances for precipitation with it. The best
chance for precipitation will be over East Central Colorado where
lift will be the strongest. Highs will be a few degrees cooler due
to the cloud cover over the forecast area.
Friday night the upper level short wave trough will depart the
forecast area. As the trough moves east it will push the surface
trough east with it. Lows will be similar to the last couple nights.
Saturday and Saturday night the forecast will be dry as an upper
level short wave ridge moves through during the day followed by a
closed upper level short wave trough. Due to the trough tracking
over the Southern Plains, any precipitation with it will be well
south of the Tri-State Area. Highs and lows will be very similar to
the last couple of days.
A relatively active and progressive pattern emerges through the
extended period. H5 shortwave ridge will prevail on Sunday,
traversing the region from west to east through the day and into
early Monday. This weak ridge will push to the east later in the day
as a closed H5 low moves out of the northern Intermountain West,
across the central Rockies, and into the central High Plains as we
head into Tuesday. At this time, there is good spatial and temporal
agreement between the GFS and ECMWF with both solutions indicating a
nearly perfectly stacked low pushing across the northern portions of
the CWA by midday Tuesday. Slgt chc PoPs are in the forecast
overnight Monday and into Tuesday morning with chc PoPs more
representative as the day progresses. Antecedent conditions will be
relatively warm and precipitation will likely begin as rain or a
rain/snow mix before changing over to all snow sometime Monday
night. Snow chances will prevail Tuesday morning with the rain/snow
line possibly retreating westward slightly through the day. This
will largely depend upon the amount of CAA experienced and there is
some disagreement between the high temperature solutions as wet
bulbing is likely not being considered by some of the medium range
guidance. This being considered, Tuesday`s high temperatures are
likely too warm and may need to be lowered. The low will move east
to northeast and out of the area early Wednesday with precipitation
chances decreasing from west to east. CAA continues through the day
on Wednesday and high temperatures will struggle to climb into the
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1029 AM MST Thu Jan 19 2017
VLIFR/LIFR conditions continue at the start of the TAF period as
fog burns off this afternoon. Moisture stays in place as
temperatures cool this evening and overnight, leading to a return
of fog and potentially a return to VLIFR, after a brief reprieve.
Meanwhile, cloud cover moves in from the west overnight as a lee
trough slowly shifts east. Winds are anticipated to remain light
through the period.