Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 150530
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1130 PM CST Sat Jan 14 2017
Issued at 359 PM CST SAT JAN 14 2017
Forecast largely remains on track for the likelihood of a
significant ice storm to impact the forecast area. This discussion
focuses on changes in current forecast anticipations. First, an
expanding area of precipitation continues to move through portions of
southern/western Kansas into northwest Oklahoma and Texas Panhandle.
Operational and high-res models continue to struggle with this
initial round/leading edge of precipitation, and have been too
aggressive when moving this area of liquid and dissipating it into
the dry air currently downstream from precip. In reality, this
large area of freezing rain has been expanding and progressing
towards eastern Kansas. Likewise, have increased precipitation
chances and ice amounts across the southwest quarter of the CWA
after 00Z when some form of this activity should move into the
area. This would include the next potential round of glaze for
the KC Metro area.
Most models have trended a little more aggressive in the way of
precipitation between midnight and noon Sunday. Have adjusted ice
amounts up from this morning, with most locations projected to
receive a quarter to one-half inch of ice. That said, probability
is increasing that a narrow zone, perhaps a line from KC to
Moberly, favorable for locally higher amounts of ice accumulation
will develop where the longest duration of ice will exist. Across
northern Missouri, some of the precipitation may be mixed with
sleet where a cooler elevated warm layer exists, and that may
lower some ice amounts. Again, prepare for a widespread ice event,
with ice accumulations averaging 0.25-0.50" with locally higher
amounts especially from KC to Moberly.
Uncertainty continues to how far north and how quickly the freezing
line will move from south to north during Sunday afternoon. The
latest thinking places the surface freezing line at noon Sunday
still south of the Interstate 70 corridor. This line slowly shifts
north to along or just north of Interstate 70 by 6pm Sunday. The
slower change provides a slightly longer window for freezing rain to
occur along and north of Interstate 70 during Sunday afternoon and
evening. It should be noted that impacts from the ice may continue
for at least several hours after the freezing line passes, so extra
caution should be exercised if travel is necessary, even when
temperatures initially warm above 32 degrees.
Periods of precipitation will continue Sunday night into Monday.
Warmer air will continue to advect into the area ahead of the storm
system, with all areas reaching above freezing by sunrise Monday
morning, effectively ending all freezing rain. Surface low pressure
will move across the CWA Monday evening, with the area dry-slotted
thereafter and precipitation ending. The work week ahead looks dry
with above normal temperatures.
.Aviation...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1126 PM CST SAT JAN 14 2017
Dry air has moved into the terminals tonight however IFR cigs are
lifting into the area from the south and should lift into the
terminals btn 08Z-10Z. Expect -fzra and reduced vsbys to 2-4SM
move into the terminals at this same time. Freezing rain/reduced
vsbys/IFR cigs will cont to affect the terminals thru tomorrow
afternoon when freezing rain will transition to liquid rain.
However, IFR cigs and 2-4SM vsbys are expected to persist thru
the remainder of the TAF pd.
KS...Ice Storm Warning until 3 PM CST Sunday for KSZ057-060.
Ice Storm Warning until 6 AM CST Monday for KSZ025-102.
Ice Storm Warning until midnight CST Sunday night for KSZ103>105.
MO...Ice Storm Warning until 3 PM CST Sunday for MOZ033-038>040-
Ice Storm Warning until 6 AM CST Monday for MOZ001>008-011>017-
Ice Storm Warning until midnight CST Sunday night for MOZ025-