Area Forecast Discussion
Issued by NWS Little Rock, AR

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FXUS64 KLZK 261537

Area Forecast Discussion
National Weather Service Little Rock AR
1037 AM CDT FRI AUG 26 2016

Observational data indicate areas of convection affecting
northern sections of the forecast area. Most concentrated activity
has been occurring along a well defined instability
gradient...extending from near LIT to STL. Expect some increase in
convective coverage during the afternoon instability
increases across the forecast area.



Updated for the 12z aviation discussion below.


Radar trends across Arkansas indicate -SHRA developing over the
western half of the state. Expect coverage to continue to expand
through the morning hours...with southeastern parts of the state
the last to see convection develop. Have mentioned -TSRA at
KLIT...KPBF...and KLLQ today as instability looks to be the best
in that part of the state. Elsewhere I stuck with just showers.
Flight categories are expected to be largely VFR...with the
exception of some fog/low clouds at a few sites this morning and
of course any thunderstorms could lower conditions to MVFR levels
as well.


SHORT TERM...Today Through Saturday night

The main concern in the short term really is the chance of rain
across the forecast area. Upper level high pressure was centered
over the southern Appalachians this morning, with an upper trough
over the rockies and zonal to west- southwest flow from the Great
Lakes region back towards the four corners area. Meanwhile a
stalled frontal boundary was located beneath that zonal/southwest
flow...just to the northwest of Arkansas. Southerly flow around
the periphery of the upper high continues to pump gulf moisture
northward into Arkansas over the next couple of days...though with
waning influence as the upper high shifts east towards the
Atlantic seaboard. This gulf moisture coincident with a nearby
frontal boundary and weak disturbances passing through the
southern plains and into southern Missouri will subsequently to
produce showers and occasional thunderstorms over the forecast
area today and again on Saturday. The best chance for convection
over the next 48 hours will be today actually...with fairly
widespread coverage expected by this afternoon.

Late tonight and into Saturday the northern Rockies trough will
move off towards the Great Lakes region...allowing upper heights
to increase slightly across Arkansas and a minima in the
precipitable water field to slide west into the state. This is
characterized by forecast PWAT values falling from around 2.00
inches yesterday evening back to around 1.50 inches by Saturday
morning. While it appears likely that some shower activity will be
seen Saturday...conditions do not appear as favorable for
widespread rainfall.

LONG TERM...Sunday Through Thursday

The extended forecast will start with the center of the upper high
pressure ridge having moved a bit more into the eastern Plains,
which will push most of the convection chances over central to
western AR. Monday through Thursday, the upper high pressure ridge
will dominate the pattern over AR, and the overall chance of
convection will lower to slight to low chance, and mainly be during
the heat of the day to early evening. Temperatures will be around
normal values to a bit above. Lows will mainly be from the upper
60s to mid 70s, while highs from the upper 80s to lower 90s.

Late in the extended, a tropical low pressure system may be near the
Florida peninsula or Gulf of Mexico, and the movement of this
feature will be monitored for its possible influence on AR.


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


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