Forecast Discussion


000
FXUS64 KMEG 182146
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
346 PM CST Sun Nov 18 2018

.DISCUSSION...

Latest surface analysis places an area of low pressure over Little
Rock, Arkansas with a cold front extending northeast across
Jonesboro, Arkansas and northwest up into Paris, Tennessee. North
of the front, temperatures are in the 40s with low stratus and
patchy fog. South of the front, temperatures are in the mid to
upper 60s under partly sunny skies. Just a couple weak radar
echoes on KNQA across southeast Arkansas at this hour.

The aforementioned front is expected to stall near Memphis and
Jackson, Tennessee over the next hour or so as the low pressure
system lifts northeast. This will keep main shower activity along
and just west of the river through late this evening. As the low
lifts overnight, expect light rain to overspread the rest of the
Mid-South. Models are now showing a shortwave, currently over the
Oklahoma Panhandle, pivoting through the Mid-South tomorrow
afternoon. This will enhance lift behind the front and squeeze out
the remaining moisture, mainly over north Mississippi. Latest QPF
values are still around one tenth of an inch, with up to a
quarter of an inch over north Mississippi. The wave and cold front
will exit the region by late tomorrow night.

Surface high pressure will build into the Mid-South on Tuesday
behind a dry reinforcing front. Sunshine will return to the
entire Mid-South during the day, but decent cold air advection
will keep temperatures down in the mid to upper 40s during the
day. Temperatures will drop quickly after sunset with lows near or
below freezing by Wednesday morning.

Slightly warmer conditions can be expected during the day on
Wednesday, with highs in the low to mid 50s areawide. High
pressure will shift east by Thursday with winds kicking around to
the south. Thanksgiving Day looks nice with highs around 60
degrees and light southerly winds.

A rather potent shortwave will drop down across the Southern
Plains by Friday morning and help push a cold front into the Mid-
South Friday night. Models are in reasonable agreement with the
timing. Showers will overspread the area by Friday afternoon and
push out of the area Saturday morning. Beyond Saturday, the models
are still having problems resolving a wave dropping down out of
the Pacific Northwest. Went with low end POPS through early next
week until models sort out the details. Stay tuned.

AC3

&&

.AVIATION...
18Z TAFs

A cold front was analyzed in the vicinity of JBR-HKA line at
1730Z, moving very slowly southeast, if not stationary. Post-
frontal IFR stratus had edged southward down the west side of
Crowley`s Ridge earlier this morning, but southward movement had
halted when this shallow stable saturated layer encountered deeper
low level mixing immediately ahead of the nearly stall-ed front.

Despite post frontal winds backing to the northwest this evening,
movement should remain slow through the overnight, crossing the
MS River around 09Z. Wind fields either side of the front will
remain weak, complicating flight category forecasts. At this time,
it appears best chance for IFR will occur following post-frontal,
pre-sunrise showers.

PWB

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

$$