Scientific Forecaster Discussion
fxus63 koax 172318
Area forecast discussion
National Weather Service Omaha/valley NE
618 PM CDT sun may 17 2020
..updated for 00z aviation forecast discussion...
issued at 256 PM CDT sun may 17 2020
cool again tomorrow and then warming gradually. Increasing storm
chances from Thursday into next weekend.
an intense, deep-layer cyclone over Iowa this afternoon will drift
southeast in response to upstream height rises over the High
Plains. A moist, cold-conveyor air stream associated with the low
will maintain considerable cloudiness across our area tonight,
though the blustery, northwest winds will diminish.
Monday through wednesday:
a high-amplitude, mid-level ridge will reside over the Great
Plains into mid week, supporting dry conditions with highs in the
60s to lower 70s on Monday, and 70s on Tuesday and Wednesday.
Thursday and friday:
a shortwave trough will pivot through the northern plains on
Thursday with indications of a trailing, more subtle impulse
tracking into the mid MO valley on Friday. The lead disturbance
will aid in the poleward advection of a warm and increasingly
moist air mass through the plains with a chance of showers and
thunderstorms, especially across our western counties. It appears
that the subsequent system on Friday will have access to a
moderately unstable air mass (due in part to the Thursday system)
over the mid MO valley, and current model guidance suggests there
could be some severe weather threat.
Highs will be in the mid 70s to lower 80s.
Saturday and sunday:
latest medium-range model data are suggestive that a more
prominent mid-level trough will move through the intermountain
west toward the Great Plains next weekend. Surface Lee troughing
over the High Plains should maintain a warm, moist, and unstable
air mass over the mid MO valley with a continued chance of
Highs should be mainly in the 80s.
Aviation...(for the 00z tafs through 00z Monday evening)
issued at 615 PM CDT sun may 17 2020
Somewhat tricky aviation forecast for tonight into Monday morning.
As of 6 PM, conditions were VFR at klnk and kofk, but MVFR at
koma. It appears that MVFR conditions will move back into the kofk
and klnk areas later tonight, persist into mid morning Monday,
then become VFR. For koma, it appears that conditions will remain
mostly MVFR overnight into early Monday afternoon, with a period
of VFR ceilings possible for a while this evening. Gusty wind have
already started to decrease a bit and should be mostly under 14
knots by about 8 or 9 PM.