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Area forecast discussion
National Weather Service Omaha/valley NE
546 PM CST Thu Nov 21 2019

..updated aviation forecast discussion...

issued at 250 PM CST Thu Nov 21 2019

continued cool on Friday with a chance of light precipitation
near the Kansas border. Turning warmer this weekend into early
next week with the next chance of precipitation on Monday night
into Tuesday.

Tonight into Friday night:
early afternoon water vapor imagery depicted a mid-level low over
the lower Colorado valley with a downstream impulse ejecting through the
southern rockies into the southern High Plains. Energetics from
the former disturbance will be transfered to the latter which will
evolve into a closed mid-level low over Kansas on Friday. In the low
levels, a broad surface high will build from the northern plains
through the mid MO valley. The high will weaken on Friday owing to
the influence of the deepening cyclone over Kansas.

A north-south erosion of low clouds should occur this evening with
coldest overnight lows occurring over northeast NE where
comparatively greater radiational cooling is expected. A cold,
Continental air mass will remain entrenched across the area on
Friday with highs generally around 40. Best precipitation chances
will exist near the Kansas border in closer proximity to the
aforementioned mid-level system. Precipitation should be light,
potentially beginning as a rain-snow mix before transitioning to
rain by afternoon. The mid-level system and associated
precipitation chances will shift east/southeast of the area Friday

Saturday into monday:
mid-level ridging from the northern rockies into the northern High
Plains this weekend will gradually break down by early next week
as a strong upper-level jet develops from the northeast Pacific
into the central rockies. In the low levels, a predominant
westerly, downslope pattern will prevail across the region with
high temperatures of 45 to 50 on Saturday. Readings will warm into
the 50s on Sunday and Monday.

Monday night into thursday:
latest deterministic and ensemble model data continue differ in
the evolution of the mid-level pattern across the central U.S. In
the Monday night to Tuesday night time frame. The 12z
deterministic European model (ecmwf) and GFS, and gefs ensemble mean solutions
depict the amplification of a mid-level trough over the Southern
Plains with the system subsequently tracking into the Ohio Valley.
The Canadian model is considerably less amplified. While we will
continue to indicate the potential for rain or snow from Monday
night into Tuesday night, any precipitation appears to be light.
Greater precipitation coverage/intensity would likely remain to
our south/southeast.

On Wednesday into Thanksgiving, the models are in better agreement
in the evolution of a trough along the Pacific coast and
downstream ridging across the Great Plains. That pattern would
yield warmer temperatures with only a low chance of precipitation.


Aviation...(for the 00z tafs through 00z Friday evening)
issued at 541 PM CST Thu Nov 21 2019

MVFR ceilings expected to erode from the northwest first at kofk
then koma/klnk. It may take until around 06-10z for the lower
ceilings to improve. Northwest winds 10-15kts with some gusts 15
to 20kts to diminish to under 12kts by 02/03z, becoming light
north and eventually light south Friday.


Oax watches/warnings/advisories...

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