Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 222003

Area Forecast Discussion
National Weather Service Omaha/Valley NE
303 PM CDT Thu Jun 22 2017

.SHORT TERM...(Tonight through Sunday)
Issued at 302 PM CDT Thu Jun 22 2017

12z upper-air analysis revealed a belt of stronger cyclonic flow
from the northern Rockies into the Dakotas with an embedded short-
wave trough over the northern High Plains. This disturbance will
track southeast into the mid MO Valley tonight into early Friday,
enhancing forcing for ascent and vertical shear ahead of it. In
the low levels, mesoanalysis depicted a cold front stretching from
north-central IA through northeast into south-central NE as of
early afternoon. The boundary layer ahead of this front has been
warming and moistening today, which when coupled with the steep
lapse rates aloft is yielding a moderately unstable air mass this

Considerable elevated convection is ongoing across the area as of
19z, likely rooted within the EML/steep lapse-rate plume. And
latest convection-allowing model guidance remains relatively
consistent in suggesting that surface-based storms will become
increasingly probable in the 22-00z time frame, generally along
the I-80 corridor. A few of these storms could become strong to
severe this evening with locally damaging winds and hail being
the primary hazards.

Showers and thunderstorm chances should diminish from north to
south tonight into early Friday as a cooler, continental-polar
air mass advances south into the region. This air mass will remain
in place over the mid MO Valley through the weekend with daytime
highs in the 70s.

.LONG TERM...(Sunday night through Thursday)
Issued at 302 PM CDT Thu Jun 22 2017

Longwave troughing from Hudson Bay into the OH Valley at the onset
of the long-term forecast period will gradually shift east ahead
of an evolving trough over western Canada into the northwestern
states. The latter trough will subsequently progress east into the
north-central Plains, supporting an increase in precipitation
chances by about the middle of next week. Daytime highs will
gradually warm back through the 80s during the early to middle
part of the upcoming work week.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 640 AM CDT Thu Jun 22 2017

Generally VFR conditions are forecast through Friday morning.
A cold front will turn winds from south to north around 22Z at
KOFK, and near 00Z at KOMA and KLNK. Speeds should average 10 to
15kt ahead of and behind the front. There is a chance for
thunderstorms along and behind the front as well, however coverage
looks to be isolated around TAF sites. There is a slightly better
chance storms will affect KLNK and KOMA between 00Z and 05Z, but
low confidence in occurrence and coverage precludes more than a
mention of VCTS in TAF at this time.




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