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Area forecast discussion 
National Weather Service Hastings NE
403 PM CDT Friday Aug 28 2015

Short term...(this evening through Saturday daytime)
issued at 400 PM CDT Friday Aug 28 2015

The pattern aloft featured an upper ridge of high pressure from the
Desert Southwest north into The Rockies. Across the plains...a
shortwave trough was translating east out of Nebraska into
Iowa/southern Minnesota with an associated cold frontal boundary extending
near the Missouri River into eastern Kansas. Cooler temperatures have settled
onto the plains behind the front with readings averaging in the 70s
and 80s.

Heading into tonight...surface high pressure will nose south onto
the plains behind the front with the ridge axis oriented across
central and eastern Nebraska Saturday morning. Along and east of
the ridge axis tonight...cannot rule out the potential for fog
development and will carry patchy fog mention for locations east of
Highway 281.

On Saturday...cloud cover may linger into the morning in our eastern
zones followed by increasing insolation during the day. Heights rise
aloft as the upper ridge axis expands east of The Rockies and onto
the plains ahead of a trough reaching the West Coast. The airmass
moderates across our region and temperatures will be on the upswing
with the warmest temperatures forecast for our western zones in proximity
to the thermal ridge axis. Generally expect highs to average in the
80s...with some readings near 90f in the west.

Long term...(saturday evening through friday)
issued at 400 PM CDT Friday Aug 28 2015

Taking a broad overview of this 6-day period...it remains a
"primarily" dry forecast...with high confidence in at least
slightly-above average/normal temperatures throughout.
However...as was fully suspected as a decent possibility here 24
hours ago...the entire forecast is no longer "dry"
throughout...and now contains various 20 percent slight chances
(pops) for showers/storms within parts of the County Warning Area Monday night-
Tuesday night...and again Thursday night-Friday.
However...in the nearer-term...confidence still remains rather high
that the Saturday night-Monday daytime will in fact remain dry
area-wide.

A few comments regarding precipitation/storm chances; as can be inferred
by the fact the rain chances that do exist are only 20 percent
chances...confidence in occurrence is still rather low. If nothing
else...this means that for those who follow our forecast
closely...there is a decent chance that some of these low rain
chances will likely "jump around" a bit both in timing and/or area
over the coming days...so don't get too "hung up" on them. In
other words...a few days/nights that are currently dry may end up
being assigned slight chances in later forecasts...and some
days/nights currently with the slight chances may trend dry. As
for severe weather chances next week...although it certainly is
not out of the question on an isolated basis...nothing looks like
an "obvious concern" yet...and thus it is far too soon to start
talking any legit possibilities.

Briefly taking a closer look at temperatures...although certainly
nothing has been changed drastically from previous forecast...if
anything have nudged up highs 1-2 degrees on most days...and
more-so 2-3 degrees for Thursday. The net result is that although
not blazing hot by any means...it will definitely feel like Summer
with highs mainly in the middle-80s to low-90s range...and overnight
lows somewhere in the 60s...except for some upper 50s in some
western/northern counties right away Saturday night.

Saturday night fog potential: just as the short term forecaster
has introduced some fog potential within mainly the eastern 1/2 of
the County Warning Area for late tonight...have also decided to follow suit and
likewise introduce generic "patchy fog" wording for late Saturday
night/early Sunday morning for generally this same area. Based on
sref/NAM visibility products...there could be some chance that fog
becomes impactful/dense...especially within our eastern-most two
columns of counties where the overall-lightest breezes should
reside. However...with this still being out in the 3rd-4th
forecast period...will not get carried away yet and just start
things out with baseline wording.

Briefly glossing over some day-to-day details in mainly 12-36
hours blocks:

Saturday night: high confidence its dry with a large-
scale...positively-tilted ridge axis centered over the region. As
the surface...ridge axis will slowly slide by promoting light
southerly breezes...in fact very light in eastern zones. As just
mentioned in previous paragraph...will have to watch fog
potential...especially within the eastern 1/4 of the County Warning Area.

Sunday/Sunday night: could be lingering fog for a few hours Post-
sunrise...especially east. Continued high confidence in dry
conditions with the ridge axis remaining dominant. South-
southeast breezes pick up mainly during the afternoon with
sustained speeds potentially 15+ miles per hour in western zones.

Monday/Monday night: should be another warm/dry day with decent
southerly breezes. For Monday night...have introduced a slight
chance of showers/storms to mainly the northwest 1/2 of the County Warning Area as
the upper ridge gets shunted more to the southeast and weak
shortwave energy starts affecting mainly western portions of the
Central Plains.

Tuesday/Tuesday night: the ridge breaks down even more...with flow
aloft becoming more quasi-zonal. While there is little apparent
large-scale support for convection...both the European model (ecmwf)/GFS hint at
some slight potential...so have slight probability of precipitation going in parts of the
County Warning Area.

Wednesday/Wednesday night: have kept these 24 hours dry area-wide...as
there are hints that the southern Continental U.S. Ridge could build back
north.

Thursday-Friday daytime: left Thursday daytime dry...but have
allowed some slight chances to stand for Thursday night-Friday as
weak energy works back into the area in southwesterly flow
aloft...but still well-downstream from a larger-scale trough
hanging back over the northwest Continental U.S..

&&

Aviation...(for the 18z kgri/kear tafs through 18z Saturday afternoon)
issued at 1214 PM CDT Friday Aug 28 2015

The main issue for the terminals will be at the onset of the taf
period with fairly widespread MVFR ceilings...trending to VFR this
afternoon. The low clouds are associated with a low pressure system
crossing the plains. Cloud cover will diminish this evening behind
the departing system and with loss of daytime heating. Have some
concern for patchy fog development toward Saturday morning along
the surface ridge axis but confidence is not high enough to include
just yet. Winds will favor a northerly component.

&&

Gid watches/warnings/advisories...
NE...none.
Kansas...none.
&&

$$

Short term...Fay
long term...pfannkuch
aviation...Fay

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