FXUS64 KLZK 191155 AAA
Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
655 AM CDT Fri Oct 19 2018
Updated to include the 12z aviation discussion.
VFR conditions will prevail through early Friday afternoon for
central and southern TAF sites. KHRO and KPBK should see VFR to
MVFR conditions by mid morning. Winds will light and variable
through the period. Stratiform precipitation will slowly
overspread from northwest to southeast today which will reduce
the remaining VFR TAF sites to MVFR by this evening. MVFR fog is
possible late Friday night at all terminals.
.PREV DISCUSSION...(ISSUED 358 AM CDT Fri Oct 19 2018)
SHORT TERM...Today Through Saturday Night
GOES 16 infrared satellite imagery indicates a large plume of
mid/high level moisture moving NE out of Mexico across the
Southern Plains into the Great Lakes region. This plume of
moisture is being transported in response to a large upper trough
over the Desert SW. Meanwhile, an upper level anticyclone can be
seen over the NE Gulf Coast.
Partly to mostly cloudy conditions will be seen across the state
early on Friday. At the surface, easterly flow has held dew
points in check with readings only in the 40s. Temperatures this
morning ranged from the lower 40s to the lower 50s.
By late morning, an upper trough will approach from the west, at
the same time, upper energy will be pivoting around the periphery
of the ridge in the east. These two features will aid in enhanced
forcing for ascent leading to the development of convection by
late morning across NW portions of AR/ portions of OK/ and
portions of KS. Due to a lack of return flow of low level rich
moisture, severe weather is not expected to be a factor as
precipitation moves into the area. PWATs will show a slight
rebound ahead of the precipitation as winds just above the surface
have a partial southern component. Most rainfall will be
stratiform in nature with periods of moderate rain mixed in with
primarily light rain. Showers should move into the state from the
NW this morning, overspreading the remainder of the state by late
This system will be a quick mover, as a surface frontal boundary
will will push through on Saturday. Surface high pressure will
build into the area behind the front. All rainfall will exit the
state by Saturday morning. Temperatures on Saturday afternoon will
be in the mid and upper 60s for highs despite a frontal passage.
However, temperatures will begin to fall overnight as much cooler
air advects into the region. Lows on Sunday morning will be in the
mid 30s across the northern three tiers of counties and 40s seen
elsewhere. Patchy frost will be possible across the northern
counties on Sunday morning.
LONG TERM...Sunday Through Thursday Night
At the beginning of the long term periods, a ridge of high pressure
will be over Arkansas. With little in the way of cloud cover and
light winds, there could be isolated areas with frost in portions of
northern Arkansas early Sunday and Monday morning. As the week
progresses, the longwave pattern will flatten out, with the surface
high drifting eastward. Surface flow will remain out of the east/
northeast, though, which will help to keep daytime maxes below
Late in the week, low pressure will develop along a stalled front in
the Gulf of Mexico, enhancing uplift into the region. At the same
time, southwest flow aloft will develop over Mexico, which will send
Pacific moisture across, along with a shortwave. The result will be
an increase in rain chances for much of Arkansas. At this time,
instability looks to be seriously lacking, so opted not to mention
thunder in the forecast.
No significant fire weather issues are expected the next seven days.
With the exception of Sunday, minimum humidity is largely expected
to remain above 50 percent. 20 foot winds are expected to remain
below critical thresholds, generally below 10 MPH. The highest rain
chances will be today and tonight.