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Area forecast discussion 
National Weather Service Hastings NE
1207 am CST sun Dec 21 2014

issued at 630 PM CST Sat Dec 20 2014

Dense fog is once again beginning to settle in over our eastern
forecast area based on observations at gri...jyr...and auh...which
have all gone down to 1/4 sm in the last hour. Forecast models
including the rap...hrrr...and sref are all indicating the
potential of dense fog from the Hastings and Grand Island areas
and points off to the north and east from there. It is hard to say
how far west and south the dense fog will develop...but there is
less model support for dense fog as you get south and west of
Hastings. It is possible that the dense fog advisory may be
expanded to the south and west later in the night but confidence
is not there to go any further south and west with the advisory at
this point in time.


Short term...(this evening through sunday)
issued at 336 PM CST Sat Dec 20 2014

Satellite shows the area of persistent stratus in the eastern part
of the forecast area has moved little in the past couple hours but
the the high clouds moving over from the west the stratus is
becoming more difficult to see. In the stratus temperatures continue
to struggle in the 30s...but areas with sunshine have warmed more
this afternoon.

Main concern with this period once again is the fog chances for
tonight. A weak upper level wave moves through the forecast area
late tonight into Sunday. With this expect there to be some higher
clouds that move into the area...but dry conditions are expected.
The low level moisture continues across much of the area through the
night and into Sunday. The stratus seems to be the most persistent
in the northeast part of the forecast area. The rap relative
humidity at 925mb has been following the stratus the best this
afternoon and through most of the night the northeast remains with
clouds. In the southeast the higher relative humidity builds back
into the area late tonight. Expect there could be some fog near the
edges of the stratus. Will keep patchy fog across all but the far
west and areas of fog in the east where there is the best chance for
fog since visibility at kjyr still has low visibility. Once again
there is a potential for some lower visibilities late tonight into
Sunday morning and expect the east is the best chance.

By Sunday morning the winds will increase a little bit from the
south. This will help to mix things up a bit and the fog and stratus
may finally move out of the area.

Long term...(sunday night through saturday)
issued at 336 PM CST Sat Dec 20 2014

The biggest challenge will be determining precipitation chances.

We kick off the long term Sunday night with a longwave trough axis
over the Great a strong jet heads in on the backside of
the trough..from the Pacific northwest into the Great Basin. Most of
the energy is associated with the closed low in the northern I am not going all that high with chances here. A
smaller shortwave trough within the longwave trough will help kick
something up in the evening...the way it looks now...but small
features are difficult to be very exact with timing. Keeping this
all rain as temperatures do not appear to become cold enough before
the precipitation exits with this perturbation. Another perturbation
works around the trough by Monday night/Tuesday. Temperature
profiles appear to support some light snow Monday night into
Tuesday. Precipitation/snow amounts are expected to be light...with
snow accumulation no more than an inch anticipated with this next
piece of energy. Again...confidence is not the highest with
exact timing.

Flow is quite progressive and yet another trough makes its way into
The Rockies. A piece of energy is expected to break off ahead of the
main wave...but looks more focused just north of the County Warning Area. We could
get some snow out of this...but again...does not look like we will
get a lot out of snow. We should get a noticeable cool down Friday
behind the associated cold front. Highs will only be in the lower to
middle 30s and the wind could be quite gusty from the
northwest...making the day after Christmas potentially brisk and


Aviation...(for the 06z kgri/kear tafs through 06z Sunday night)
issued at 1207 am CST sun Dec 21 2014

LIFR conditions forecast at kgri tonight into Sunday morning. VFR
conditions currently forecast at kear through the next 24 hours.

A persistent band of stratus is noted over eastern Nebraska this
evening...with the western periphery of this stratus shield
extending from near kodx to near kgri and khsi. Fog...some of
which is dense...also exists within this stratus and could impact
kgri tonight into Sunday morning. Given all this...went ahead with
LIFR conditions at kgri until 17z...with MVFR conditions then
expected as stratus persists over the area during the day Sunday.
Another round of LIFR conditions are forecast at kgri starting 01z
Monday as guidance suggests another round of stratus will impact
the area. As for kear...stratus is currently situated to the east
and guidance suggests this will not change. Given this...went
ahead with VFR conditions at kear through the next 24 hours.
Obviously this will need to be closely monitored to ensure the
stratus does not make a push to the west tonight into Sunday
morning. The surface wind will remain from the south or southwest
during the taf period...starting at around 07kts to start the taf
period but increasing to near 15kts during the day Sunday.


Gid watches/warnings/advisories...
NE...dense fog advisory until 11 am CST Sunday for nez039>041-047>049-



long term...heinlein

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