Area Forecast Discussion
Issued by NWS Little Rock, AR

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770
FXUS64 KLZK 140540
AFDLZK

Area Forecast Discussion
National Weather Service Little Rock AR
1140 PM CST Fri Dec 13 2019

.AVIATION...
Updated for the 06Z TAF cycle.

Somewhat similar pattern in place across the forecast area tonight
as compared to Thursday night with the development of LIFR/IFR
CIGS/VSBYS over the southeastern and southwestern counties. Low
end flight category weather will be an issue through around 15Z
Saturday morning, but otherwise VFR conditions to prevail across
the forecast area through the TAF period with weak winds generally
below 10 knots.

&&

.PREV DISCUSSION...(ISSUED 621 PM CST Fri Dec 13 2019)
AVIATION...14/00Z TAF CYCLE

An area of MVFR/low end VFR CIGS were noted acrs central and
southern AR this evening. Initial hi-res model data still having
some difficulty with this cloud deck, but indications are that it
wl sloly work to the E this evening. Model data also showing a
similar scenario like this mrng, with low clouds/fog forming ovr
mainly the Delta region of AR late tngt into Sat mrng. Have indcd
lower conds(IFR/LIFR) at KPBF and KLLQ. Weak front wl move thru
much of the FA on Sat, with a slow improvement expected late. /44/

PREV DISCUSSION...(ISSUED 253 PM CST Fri Dec 13 2019)
SHORT TERM...Today Through Sunday

20Z mesoanalysis reveals a large and relatively diffuse area of
low pressure at the surface over much of the central CONUS,
underneath broad upper troughing that continues progressing east
this afternoon. Model progs show a subtle low-level wave
on the southern end of larger-scale upper troughing traversing
southern AR tonight, which will enhance cloud cover, although
rainfall is not expected. Low stratus and at least patchy fog will
be favored tonight, especially across the southern and eastern
portions of the state. Dense fog will be possible again.

Another large upper trough will come ashore and traverse the
southwestern CONUS in the Sat/Sun timeframe. The positioning and
movement of this feature will contribute to surface cyclogenesis
deep in TX. Ahead of the developing cyclone, a warm front will
lift north towards the area late in the period. Increasing
thermal/moisture advection and isentropic forcing will support
increasing rain probabilities Sunday afternoon. Some mixed precip
will be possible in extreme northern AR, although no impacts are
expected.

Temperatures will slowly moderate this period ahead of the
aforementioned system. Expecting values near to slightly above
average.

LONG TERM...Sunday Night Through Thursday Night

Much of the focus for the long term portion of the forecast will
reside within the first 24 hours of the period. At the surface, low
pressure will be in place southwest of the area with a cold front
trailing to its southwest and a warm front extending eastward across
central Arkansas.

Aloft, the flow will become more amplified as an H500 trough moves
toward the Central Plains. From Sunday night to Monday, a broad
region of 75-85kt winds within the SW-NE oriented H500 layer will be
in place over the state. Through the morning hours on Monday as the
cold front approaches from the west and the warm front lifts north a
bit further, H850 winds of 45-55kt will increase across the
southeastern third of the state.

During this timeframe, rain and thunderstorms are expected to
develop with a potential risk for a few severe storms into Monday
morning across the southeast quarter of the state roughly. If the
location of the low works out and the warm air has lifted far enough
north, a few of these storms could be capable of producing
tornadoes/damaging wind gusts.

Beyond Monday, the upper trough will move east and drier/calmer
conditions will be seen across the forecast area. Temperatures will
be near normal through the period.

&&

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

$$

Short Term...19 / Long Term...46
Aviation...19



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