Area Forecast Discussion
Issued by NWS Little Rock, AR

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FXUS64 KLZK 221122 AAA

Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
622 AM CDT Tue Aug 22 2017


Updated to include the 12Z aviation discussion below...



What patchy fog that is in place this morning will dissipate
shortly...with general VFR conditions expected through the early
afternoon hrs. The complex of SHRA/TSRA across MO will continue to
move south...with some impacts for the NRN terminals possible this
morning. The front associated with this convection will drop south
into the state this evening and overnight...with additional
SHRA/TSRA expected this afternoon and overnight. Winds will
switch to the north behind this front...with the drier and more
stable air expected by later on Wed.


.PREV DISCUSSION...(ISSUED 320 AM CDT Tue Aug 22 2017)

.SHORT TERM...Today Through Wednesday Night

Another quiet night is ongoing across the CWA again this
morning...with just some patchy fog observed. Attention turns to the
north across MO and KS where a large complex of SHRA/TSRA is
currently moving east over time. This activity has developed in
response to forcing from a cold front and upper level shortwave
trough. These features will drop SE towards AR this
afternoon...pushing south into AR this evening and overnight.

Will see increasing chances for SHRA/TSRA across the north by this
afternoon as the front and any outflow boundaries move towards NRN
AR. Further south...expect little if any precip...with maybe an
isolated SHRA or TSRA possible. This will also allow temps to warm
back above normal for this afternoon in the central/SRN sections of
the state. By the evening hrs...the front should be dropping south
over the Ozarks of NRN AR...with POPs increasing further south.
Expect this front to be along the AR/LA border by around sunrise

The potential for SVR Wx looks limited at this time...but do think a
few strong to SVR storms may develop with plenty of SFC based
instability initially in place during the afternoon/evening hrs
across the NRN and portions of central AR. Expect what SVR threat
that does develop to decrease by the time the front reaches SRN
sections of the state before sunrise Wed. The primary threats with
the strongest storms will be damaging winds...large hail and locally
heavy rainfall.

Drier and more stable air will move south into the state during the
daytime hrs on Wed. The chances for precip will decrease as a
result...with cooler conditions expected to end the short term
period and persist into the first part of the long term.

.LONG TERM...Thursday Through Monday

Surface high pressure will move through the region at the beginning
of the period, as the cold front stalls out to the south/southwest
of the state. Northeast surface flow will keep temperatures 5-10
degrees below average for late August.

Late in the weekend, the focus will then shift to the remnants of
"Harvey". Latest model data shows a land fall around Friday on the
lower Texas coast, then stalling out for 24-36 hours. The system
will push the remnants of the front back to the north a bit, with
rain chances returning to the forecast by Sunday.

The potential track of Harvey will determine how the forecast pans
out beyond this point. Model solutions show the front getting
absorbed by the low, and the upper cyclone getting absorbed into an
trough digging down into the central/southern conus as ridging over
the western Gulf of Mexico breaks down. This will give the cyclone
some traction, and it will gain forward speed.

Upper ridging will remain over the southeast conus, and this will
likely push the aforementioned low close to or even over the region.
What could this mean for us? Higher rain chances versus what is
currently in the forecast, and potential heavy rainfall. Right now,
it`s still far enough out that the forecast can and likely will
change to a degree between now and late this weekend. But, it`s
something to keep in the back of your mind for sure.


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


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