Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KOAX 151724
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1124 AM CST Sun Jan 15 2017

.SHORT TERM...(today through Tuesday)
Issued at 404 AM CST Sun Jan 15 2017

...Significant Ice Storm Still Expected Today Through Monday...

Early morning water vapor imagery indicated the closed deep-layer
cyclone continued to rotate slowly east through northern Mexico.
Downstream the 00Z upper air analysis indicated a 100+ kt H25 jet
locked into place from the central Plains into the Great Lakes.
Broad diffluent flow ahead of the cyclone and the ageostrophic
circulation associated with the entrance region of this jet was
creating forcing for large-scale ascent over the Plains with a
large shield of precipitation over KS/OK, and even some lighter
activity moving along the KS/NEb border. The 00Z KOAX sounding
indicated we still had a good deal of dry air to overcome
associated with the ridge axis around H85, but we should slowly
see this erode through the day today. We will likely see periods
of light precipitation in the south through the morning associated
with this pattern that will slowly work north through the
afternoon. Although the majority of this activity will be light
freezing rain we have introduced some mix with rain over the
central CWA where we have increased highs in the mid 30s. We have
delayed the onset of the warning for today for areas along and
north of highway 30 where we have removed pops until after 00Z.

Models are in general agree with the period from tonight through
Monday although the GFS appeared to dry. We should continue to see
the light freezing rain move north through the area this evening
associated with the broad isentropic ascent. Late tonight as the
cyclone moves into the southern Plains the deformation band will
lift northward through KS and into the southern CWA, most likely
after 09Z. This band, although weakening in intensity with
northward extent, will continue to lift through the area on
Monday. We are likely to see our highest ice accumulations during
this time. We have lowered going highs on Monday, but this was
mainly due to the ongoing precip and clouds. We still expect areas
south of a line from HNR-OMA-LNK to climb slightly above freezing
during the morning on Monday. To the northwest of this line
temperatures should stay at or below freezing through the event.
Freezing rain is expected up to around LCG/OFK/BVN line with a mix
of some sleet and freezing rain to the northwest. Point forecast
soundings are consistent that some cooler air will work into this
area during the afternoon with the precipitation becoming snow
through the afternoon and evening. We have some 2-4 in
accumulations indicated in parts of Knox/Antelope/Cedar counties.
The cold air will work southeast through Monday evening with the
freezing rain ending as some light snow for the rest of the CWA.

We have adjusted some of the higher ice accumulations a bit
farther northwest with the most significant amounts from around
Fairbury and Seward up through Wahoo and Tekamah, although we have
warning criteria for all locations southeast of a line from SUX to
OLU. Other than some minor timing changes to the headlines we made
no changes with this package. We are not likely to meet warning
criteria in the northwest with either snow or ice, but will stay
with the warning for now with decent impacts expected.

.LONG TERM...(Tuesday night through Saturday)
Issued at 404 AM CST Sun Jan 15 2017

A marked warming trend is still expected into the middle and
latter half of the work week. Longer range models are fairly
consistent indicating additional precipitation chances as we head
toward next weekend, but little chance to look at this part of the
forecast.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1124 AM CST Sun Jan 15 2017

Mosaic radar data as of 17z indicated the northern edge of light
freezing rain along the I-80 corridor with a continued slow
northward shift of the precipitation shield this afternoon into
tonight. Expect the resultant deterioration of weather conditions
at the eastern NE TAF sites with the predominant precipitation
type being freezing rain through the duration of the forecast
period. IFR ceilings/visibilities will likely materialize at KLNK
and KOMA this evening and after midnight at KOFK.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Ice Storm Warning from 6 PM this evening to 3 AM CST Tuesday for
     NEZ015-032>034-042>045.

     Ice Storm Warning until 3 AM CST Tuesday for NEZ065>068-078-
     088>093.

     Ice Storm Warning until 3 AM CST Tuesday for NEZ050>053.

     Winter Storm Warning from 6 PM this evening to 3 AM CST Tuesday
     for NEZ011-012-016>018-030-031.

IA...Ice Storm Warning from 6 PM this evening to 3 AM CST Tuesday for
     IAZ043-055-056.

     Ice Storm Warning until 3 AM CST Tuesday for IAZ079-080-090-091.

     Ice Storm Warning until 3 AM CST Tuesday for IAZ069.

&&

$$

SHORT TERM...Boustead
LONG TERM...Boustead
AVIATION...Mead


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.