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Forecast Discussion
NWS Omaha/Valley, NE

FXUS63 KOAX 242305

Area Forecast Discussion
National Weather Service Omaha/Valley NE
605 PM CDT Sat Mar 24 2018

.SHORT TERM...(Tonight through Tuesday)
Issued at 308 PM CDT Sat Mar 24 2018

Latest water vapor imagery and mid-level RAP analysis indicates
weak short-wave ridging over the area behind a potent departing
shortwave trough currently moving east over central Iowa.
Upstream, a large trough has moved onto the Pacific northwest
coast and will send additional precipitation chances our way into
early next week.

Brisk northeast winds today will gradually turn to the southeast
overnight ahead of next lee cyclone deepening over northeast
Colorado. Low-level warm air advection increases into Sunday which
may allow light drizzle/freezing drizzle to develop across
northwestern portions of the CWA Sunday morning. Model trends
continue to lower QPF values but we will still keep drizzle to
light rain mention in for much of the day. Any light freezing
drizzle does not appear to last long and so is not anticipated to
be a much of an issue.

Better precipitation chances arrive later Sunday night and into
Monday in advance of an approaching western mid/upper-level trough.
A strong low-level jet Sunday night could lead to a few isolated and
elevated nocturnal thunderstorms. Also, ahead of this advancing
trough, strong low-level warm and moist advection will bring mid-
upper 40`s surface dewpoints into southeastern counties by Monday
afternoon. This is ahead of a surface front progged to extend
northeast from low pressure over the OK panhandle to north central
Iowa. Showers and thunderstorms are forecast along and around this
boundary into Monday evening.

.LONG TERM...(Tuesday night through Saturday)
Issued at 308 PM CDT Sat Mar 24 2018

A drier but cool airmass moves into the region behind departing
mid/upper level trough. A quick moving shortwave trough will drop
southeast through the Northern Plains bringing a quick shot of
precipitation to northern portions of the forecast area
Wednesday. Near-normal temperatures are expected throughout the
remainder of the week with highs generally in the 40s and 50s with
lows in the upper 20s to low 30s.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 601 PM CDT Sat Mar 24 2018

MVFR cigs around FL015 are forecast to persist through Sunday
afternoon with east to southeast winds of 10 to 15kt. Areas of
drizzle or light rain could affect all TAF sites after 18Z, but
most likely at KOFK where IFR cigs and MVFR vsbys are possible
after 21Z.





NWS OAX Office Area Forecast Discussion

Forecast Discussion
NWS Hastings, NE

FXUS63 KGID 250141

Area Forecast Discussion
National Weather Service Hastings NE
841 PM CDT Sat Mar 24 2018

...Short Term Update...

Issued at 834 PM CDT Sat Mar 24 2018

Adjusted the hourly temperature trend for the overnight and
morning hours as temperatures have fallen off more quickly than

Also adjusted PoPs slightly match neighboring offices and to
account for the HRRR/RAP starting to bring in (very light)
precipitation an hour or two earlier than forecast.

We are still expecting any drizzle to be very light, but if it
does develop, the slightly cooler temperatures could push the
freezing/nonfreezing line just slightly farther south.


.SHORT TERM...(This evening through Sunday)
Issued at 301 PM CDT Sat Mar 24 2018

Using the superblend of models for temperatures aloft yields
unrealistic precipitation type for Sunday morning. The blended
temperatures aloft are cooler than the individual models that are
more aggressive with the warm/moist air advection. In other
words, if we are actually going to see light precipitation we will
see the stronger warm/moist air advection into the region. If the
warm/moist air advection is less or delayed, then the cooler
temperatures could linger aloft, but then we will not be seeing
any light precipitation as it would be just dry or at least dry
until the warmer more moist air arrives.

When the superblend averages cool/dry with warm/moist based on
model and/or timing differences it makes it cold enough to get
snow or sleet but this is unlikely. Based on the 12Z NAM, 12Z ARW-
East, 12Z NMM- East, and 12Z GFS when the moisture arrives so
does the warmer air that brings the moisture especially at 850 mb.
Therefore, we are likely looking at just some spotty drizzle or a
slight chance of very light rain on Sunday. Will continue to
carry a slight chance of briefly seeing light freezing drizzle for
the northern half of the forecast area Sunday morning with sfc
lows right around freezing. However, any freezing drizzle if it
happens will likely be rather non-impactful given sfc air
temperatures will probably only dip down to right at or just a
hair below 32 and the ground will be warmer, thus the only
freezing may be on elevated surfaces. The most likely scenerio
is that we reach our lows of around freezing just prior to seeing
any precipitation and then drizzle begins and temperatures rise
to above freezing.

The raw NAM temperature output is about the coldest of any model
with Sunday afternoon temperatures hovering right around or just
above freezing across our northern zones. The NAM is likely too
cold while the raw 12Z GFS temperatures are likely too warm with
mid 40s into KGRI. Our forecast will call for Sunday highs in the
lower 40s north, but this could be a few degrees too high,
regardless it will not be a nice Sunday.

.LONG TERM...(Sunday night through Saturday)
Issued at 301 PM CDT Sat Mar 24 2018

Sunday night Through Monday Night...
Sunday night into Monday morning we will see elevated instability
increase across the southeastern half of our forecast area as an
upper trough pushes into the plains with an elongated sfc low in
the Oklahoma/southern Kansas area. Therefore, have expanded the
area of potential thunderstorms Sunday night into Monday morning
to include the southeastern half of our forecast area and then
the instability axis should slide east by Monday afternoon. Light
rain should end from west to east by Monday night. Any rainfall
Sunday night through Monday night should be rather light and
generally less than 0.25 inches for most areas.

Tuesday through Thursday...
Despite a broad upper level trough over the plains throughout this
period there will likely be little if any precipitation based on
most forecast models. Any precipitation would probably be just a
little brief light rain. We will see some warm up but probably
generally just below normal with normal highs now in the mid 50s.
Am not real confident in the near 60 forecast for Wednesday and
could see model blends lowering this in coming days.

Friday and Saturday...
The overall pattern will become more of a zonal/northwesterly flow
pattern over the central plains. Temperatures will probably not be
too far one way or another of normal and there is just a slight
chance of light precipitation.


.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 611 PM CDT Sat Mar 24 2018

Stratus is expected to persist through the overnight hours,
possibly dropping to IFR after midnight. As moisture increases, we
could see drizzle or a few spotty showers move through the area in
the morning. Low temperatures will be near freezing tonight, but
the confidence in any freezing precipitation is still low and
hasn`t been included in this forecast.

Stratus will persist through most of the day on Sunday as well,
but should lift back to the MVFR range by afternoon.




LONG TERM...Wesely

NWS GID Office Area Forecast Discussion