Area Forecast Discussion
Issued by NWS Little Rock, AR

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FXUS64 KLZK 201736 AAA

Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
1136 AM CST Fri Jan 20 2017

Updated for 18z Aviation Discussion.

Residual low clouds and associated MVFR conditions will continue
to clear out, leading to widespread VFR conditions in the
afternoon. Some broken low level clouds may persist just a bit
longer, mainly in Northeast Arkansas, outside of our forecast terminals.

VFR conditions will likely persist through the evening and early
overnight hours. However, late in the night, conditions will start
deteriorating once again. Ceiling are expected to drop fairly
quickly as we approach dawn, especially for the central and
southern terminals. As a result, widespread MVFR with areas of
IFR is expected by Saturday morning.

.PREV DISCUSSION...(ISSUED 523 AM CST Fri Jan 20 2017)

IFR/MVFR conditions will gradually improve over the next few
hours, with all areas VFR by mid day as wind picks up. Scattered
stratus will be possible tonight, but south winds of 5 to 10 knots
should keep conditions from deteriorating.


SHORT TERM...Today Through Sunday Night
Should be a dry day today, as the area will be between systems.
Southwest surface flow should scatter out any fog and low clouds
later this morning. Temperatures will max out in the 60s to lower
70s over much of the area.

Shortwave will move through in the mean flow late tonight and
early Saturday, with a weak surface low passing to the southeast
of Arkansas. This should allow for isolated showers/storms across
mainly the south and southeast portions of Arkansas.

Bigger show will be on Saturday night and Sunday. A deepening
surface low will push a boundary northward from Louisiana into
Arkansas. Uplift near and north of the boundary will allow
scattered to numerous showers and thunderstorms to develop as the
low pushes into Arkansas. This will be enhanced by a deepening
upper low, with the systems being nearly in phase with each other.

With this will come the threat of strong to severe thunderstorms.
The highest probability will be in the eastern quadrants of the
surface low, or more precisely in areas along and east of the I-30
and US-67 corridors. The most likely time period would be during
the overnight hours and into Sunday.

Given this particular pattern, my feeling is that storms should
evolve in the following way: Cells developing north of the front
initially, then storms developing ahead of the surface front in
the warm sector, then elevated post-frontal cells as the upper low
moves into eastern Arkansas on Sunday.

Given the abundance of cold air moving in aloft, large hail will
be the primary concern with any severe storms that develop. Given
the close proximity of the developing surface low, low level
helicity will be enhanced during the overnight hours Saturday
night and Sunday, which would yield the threat of a brief, weak
tornado or two, and this would be in areas mainly east of I-30 and
south of I-40. However, the larger tornado threat should be east
of Arkansas in Northern Mississippi.

Much of the remaining deep moisture will move out of the region
Sunday night, with rainfall coming to an end. Cooler air will
follow into the early week.

LONG TERM...Monday Through Thursday
With an upper level ridge over the central U.S. Monday, northwest
flow will be over Arkansas. As the ridge moves east Tuesday, an
upper low will move into the Plains. The upper low moves through the
Great Lakes Wednesday as a broad trough extends into the Four
Corners area. This broad trough sinks south Thursday and will
affect Arkansas.

Surface high pressure will be over the area to begin the long term
period with dry weather. Early Tuesday a warm front moves through
the state, then a cold front moves through Tuesday night. Only
including a slight chance of showers southeast as moisture will be
limited. A short wave will move through the southwest flow
Wednesday night and Thursday and bring a slight chance of showers.
Cooler air will be behind the front with highs in the 40s and 50s
Wednesday and Thursday instead of 50s and 60s which will be seen
Monday and Tuesday.

No significant fire weather issues are expected through the
period. Minimum humidity will remain above 50 percent through much
of the next seven days.


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


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