Scientific Forecaster Discussion
fxus63 keax 111134
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
534 am CST Mon Dec 11 2017
issued at 400 am CST Monday Dec 11 2017
Not much has changed in regards to the upper level pattern. We
remain under northwest flow aloft between persistent ridging over
the western US and persistent troughing over the eastern US.
Multiple shortwave troughs will round the trough throughout the
week before the pattern begins breaking down Friday, allowing more
zonal flow to return this weekend.
The first shortwave trough will move through the area today. Its
associated surface low has shifted winds to the south, allowing
warmer air to advect into the area. This will result in highs in the
upper 40s along our northern border and 50s for the rest of the
area. In addition, this system will tighten the pressure gradient
enough to see wind gusts in the 30-40 mph range, with the higher end
in northwest MO and northeast Kansas. Finally, we will remain rather dry
ahead of this system. All of these conditions, in addition to the
already very dry fuels, is going to lead very high fire danger
for most of our area this afternoon. Therefore, a red flag warning
has been issued for most of our counties south of Highway 36 and a
fire weather Special Weather Statement has been issued for areas
north. Additional information can be found in the fire weather
Winds will shift to the northwest later this morning as the
attendant cold front move through. This will be another dry
frontal passage with surface high pressure and cold air moving in
behind it. This will knock temperatures back down in the 30s and
40s for Tuesday. On Wednesday, another shortwave trough and cold
front will approach the area. The wind shift to the south will
allow temperatures to warm back into the upper 40s and 50s. But
once again, a dry cold front will move through Wednesday night,
resulting in high temperatures in the upper 30s and 40s for
Thursday and Friday. The upper level pattern begins to break
down on Friday returning zonal flow aloft. At the surface, high
pressure will slide east, south of the area, returning
temperatures to the 50s for Saturday. Sunday, another trough and
attendant cold front will move through and will again,
unfortunately, be dry.
Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 533 am CST Monday Dec 11 2017
VFR conditions are expected for this period, but winds will be a
concern. A cold front will push through the area later this
morning veering winds to the northwest. Winds will really start to
pick up behind the front. Sustained northwesterly winds of 20-25
kts are expected with gusts between 30 and 40 kts. Northwest MO
and northeast Kansas will experience the stronger winds. The strong
winds will continue tonight, eventually decreasing after midnight.
Clouds around 4kft will move into the area behind the cold front
as well, with northeast MO possibly seeing 2kft ceilings. It is
possible ceilings lower to around 3kft for the rest of the area,
but the general consensus is conditions will remain VFR.
issued at 400 am CST Monday Dec 11 2017
Very high fire danger is expected today across much of the area.
First, fuels are very dry. Second, winds will shift to the
northwest late this morning and should be between 20-30 mph with
gusts reaching and exceeding 30-35 mph through tonight. The
strongest winds will be in northwest MO and northeast Kansas. Finally,
relative humidities should bottom out early this afternoon with
values 25% or less in southern MO and KS, near 30% in central
MO/KS, and in the 40s along the MO/Iowa border. These values should
gradually increase for the remainder of the afternoon and evening.
It is Worth noting though that this system's attendant cold front
is currently scheduled to move through the area late this morning,
with lower-end mid-level clouds moving in from the north in the
early afternoon. If the front and clouds move in quicker or
slower, the forecast may need to be altered as this would affect
high temperatures and relative humidities. Even if the timing does
change, fire weather will still be a concern with the strong
winds and very dry fuels. Therefore, outdoor burning is highly
discouraged today across the entire area.
Kansas...red flag warning from 10 am this morning to 6 PM CST this
evening for ksz025-057-060-102>105.
MO...red flag warning from 10 am this morning to 6 PM CST this
evening for moz020>022-028>031-037>040-043>046-053-054.