Area Forecast Discussion
Issued by NWS Little Rock, AR
FXUS64 KLZK 150229
Area Forecast Discussion
National Weather Service Little Rock AR
929 PM CDT FRI OCT 14 2016
Latest surface analysis place a frontal boundary across northern
Louisiana with a few light showers over the far southeast corner
of the CWA. Shortwave trof on water vapor imagery straddling the
Mississippi river and slowly pulling off to the east.
Will hold onto precipitation chances for a few more hours over
the far southeast with low level moisture remaining plentiful.
Latest surface obs and satellite showing a nearly saturated air
mass and not seeing this changing overnight.
As such, will added patchy fog across the board and adjust
temperatures slightly as a result. However, temperatures are
expected to remain nearly steady through the night with the cloud
cover in place. Will need to watch for dense fog formation and
will advise the next shift accordingly. Updates out.
.PREV DISCUSSION...(ISSUED 614 PM CDT FRI OCT 14 2016
Short wave continues to move across the area resulting in
occasional showers over KPBF and particularly KLLQ. Activity
expected to diminish this evening as feature pulls out. Ample low
level moisture will keep IFR conditions in place for most of the
overnight hours although some brief clearing will be possible.
Conditions will improve to VFR rapidly Saturday as drier air and
high pressure moves in. Winds will remain from the south to
southeast but generally light.
PREV DISCUSSION...(ISSUED 301 PM CDT FRI OCT 14 2016
Short Term...Today through Sunday
Water vapor imagery continues to show a well defined upper level
shortwave swinging through the region. Models underestimated the
cold air damming effect of the Ozarks/Ouachitas this morning, so had
to adjust temperatures accordingly. Differential positive vorticity
advection, combined with efficient isentropic lift, and a moist
southwest flow, has resulted in showers and isolated thunderstorms
moving eastward along and north of a frontal boundary situated near
the Louisiana/Arkansas border.
Tonight...Despite the passing of the shortwave, surface features
reign in this pattern. Strong high pressure to the east and a
strengthening low across the high plains will keep low/mid level
flow southerly.As a result, temperatures are not expected to budge
much from this evening and lows will generally be in the 60s
statewide. Continued isentropic lift over a cooler surface layer
will again result in the formation/continuation of patchy fog and
low clouds over much of the state.
Saturday and Sunday...A return of zonally-oriented to northwest flow
aloft on the northeast side of an upper high, combined with
southerly flow in the low levels will result in warmer than average
temperatures this weekend. With no significant lifting mechanisms
and dry air located in the mid levels, no precipitation is expected
in this timeframe.
Long Term...Sunday Night through Friday
A return to summerlike wx conds wl transpire as we head into the
first half of the new work week. Upper lvl high pres rdg wl cont to
expand EWD over the Mid-South, with daytime highs climbing well into
the 80s. It still appears the warmest day wl be Tue as the center
of the upr rdg works acrs AR.
The upr high is fcst to work further EWD durg the latter half of the
week. However, the latest GFS wants to stall the upr high center off
the coast of the SERN U.S., which then allows an apchg upr lvl trof
to close off ovr the SWRN states late in the pd. The earlier runs of
the GFS were wanting to close the upr low off over the mid section
of the nation. Due to the contd inconsistencies, have opted to go
with the more progressive/consistent ECMWF solution.
Per the ECMWF...the aforementioned WRN U.S. upr trof is fcst to move
EWD acrs the SRN tier of the nation later in the week. This wl bring
another CDFNT thru AR arnd the late Wed into early Thu timeframe...
with cooler air to follow to close out the PD. Expect SCTD
convection to accompany the FROPA...but organized severe wx is not
anticipated at this time due to a lack of sig low lvl moisture