Area Forecast Discussion
Issued by NWS Little Rock, AR

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FXUS64 KLZK 141814
AFDLZK

Area Forecast Discussion
National Weather Service Little Rock AR
1214 PM CST Sat Jan 14 2017

.AVIATION...

For the 18Z TAFs...MVFR to IFR ceilings are expected to persist
across Arkansas for the next 24 hours.

Just before 18Z...a slow moving warm front was located near the
Arkansas/Louisiana border. This boundary is expected to become
stationary by sunset...and is likely to still reside south of all
area TAF sites. Assuming this position of the warm front is
accurate, expect that low MVFR to IFR stratus will remain in place
across much of the state. Visibilities have improved this
afternoon to MVFR or VFR levels...however visibility is likely to
fall into the IFR category once again as fog develops across the
state. Areas of dense fog are once again possible...however kept
visibilities at 1 mile for most TAF sites overnight for now. Low
clouds and IFR visibility appears likely to remain socked in over
the state as the frontal boundary is not expected to move north as
a warm front again until Sunday afternoon.

Cavanaugh


&&


Prev Discussion.../ Issued 322 AM CST Sat Jan 14 2017
DISCUSSION...

Main concerns in this forecast cycle are chances of rain each day,
any heavy rain later in the period which may lead to some flooding,
and a temperature forecast. Dense fog is present this morning over
much of AR, and a dense fog advisory is in effect through 9am CST.

On the surface map, the cold front has pushed to northern LA with
a northeast wind flow into AR. The surface high pressure was to
the north, and the colder air has saturated the atmosphere and
low ceilings and dense fog had formed over much of AR. Temperatures
were in the 30s north to central, while the 40s over the south. An
area of light rain was over northwest to northern AR, and was
moving northeast. Aloft, the upper ridging pattern over the
eastern plains has set up a southwest flow, and shortwave energy
was moving over northern parts of AR and to the north.

SHORT TERM...Today Through Sunday Night

The low clouds and fog will hold for much of the morning with
light winds and a very moist atmosphere over AR. Most of the rain
today will be focused over northwest and northern AR. and have
kept highest chance over that area. Rain amounts will generally be
less than one inch, as models show lower amounts of shortwave
energy over the region. Temperatures will be warmer today with
the 40s over northern AR, while the 50s central to 60s south.
Saturday night, fog and low clouds will again be seen, with lows
in the 40s most locations, with overall a slight to low chance of
rain. Sunday again will start cloudy with fog, with the low chance
of rain, while mainly focused over northwestern AR. The upper
ridge is forecast to build a bit more into the eastern Plains, and
highs warming to the 50s to 60s. To the west, the developing upper
and surface system will begin spreading better chances of rain
with some thunder Sunday night and into the coming week. Rain
amounts will also come up with better lift. Temperatures will
remain above normal until the cold front on Tuesday.

LONG TERM...Monday Through Friday

A potent upper level shortwave trough will be lifting NE across the
central CONUS at the start of the long term period...with a trailing
cold front moving east into AR Mon into Mon night. Ahead of this
front...a surge of Gulf moisture will be seen...as result of deep
SRLY SFC flow. Temps will warm well above normal for Mon as the
front moves into AR...and as a result...scattered to widespread
SHRA/TSRA are forecast. Some strong to SVR storms may be possible
along and ahead of this cold front Mon afternoon...with the best
potential for seeing strong storms across the SRN half of the state.

The cold front will slow Mon night into Tue as the front becomes
nearly parallel to the flow aloft. This front will then regain the
SEWD momentum by late Tue as another upper shortwave surges east
across the plains north of AR. This will push most of the potential
for SHRA/TSRA east of the state for Wed into Thu. While the threat
for widespread heavy rainfall has decreased some...do think rainfall
amounts of 1 to 3 inches remain possible...with locally higher
amounts. The axis of heaviest rainfall still remains uncertain...and
will depend on when/where the cold front slows Mon night into Tue.

Have introduced small chances for rainfall on Thu as some med range
model guidance is suggesting yet another upper wave lifting over the
state. However...considerable uncertainty exists this far out...
especially regarding timing...strength and timing. As a result...
have only mentioned some slight chance to low end chance POPs
Thu...with dry conditions expected to wrap up the forecast for
Fri.

&&

.LZK Watches/Warnings/Advisories...NONE.
&&

$$


Aviation...CAVANAUGH



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