Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
529 am CST Thursday Nov 26 2015
Updated for the 12z aviation discussion
Previous discussion... /issued 402 am CST Thursday Nov 26 2015/
.Heavy rain expected over portions of the midsouth over the
Thanksgiving Holiday weekend...
An upper ridge of high pressure remains located across the
southeastern United States this morning while a cold front
stretches from Minnesota to the Texas Panhandle. This cold front
will slowly shift south today and by sunrise tomorrow morning be
located just to the northwest of northeast Arkansas and the
Missouri bootheel. The front will bring chances for heavy rain for
northeast Arkansas...the Missouri bootheel and extreme northwest
Tennessee over the Holiday weekend.
However...Thanksgiving will be pleasant across the midsouth. Most
locations will see mostly to partly sunny skies with possibly the
exception of portions of east Arkansas as clouds from the
approaching front will continue to invade the area. Southerly
winds will help high temperatures reach into the upper 60s to
lower 70s across the County Warning Area. Generally rain free conditions will
occur across the area as well but did leave 20 probability of precipitation across
portions of northeast Arkansas and the Missouri bootheel in case a
stray shower ahead of the front probability of precipitation up.
Conditions will begin to deteriorate after midnight tonight
across northeast Arkansas and the Missouri bootheel as the front
approaches from the northwest. Expect widespread rain to begin
occurring across this area around sunrise or shortly thereafter.
The front will become stalled out over northeast Arkansas and the
Missouri bootheel Friday morning as the front runs into the upper
ridge. Several weak areas of low pressure will develop and move
along the front continuing widespread rain over the area. Expect
there will be a sharp gradient to where the rain is falling and
where conditions generally remain rain-free. In fact...areas south
and east of a Memphis to Jackson Tennessee line may actually see
dry conditions over much of the weekend. Meanwhile...tropical
moisture from the remnants of Sandra may also begin interacting
with the front over the weekend helping to produce heavier
rainfall amounts across the locations underneath the Flash Flood
Watch. A total of three to five inches with isolated higher
amounts is expected across northeast Arkansas...the Missouri
bootheel and extreme west Tennessee. It may take until Sunday for
the front to begin pushing southeast as an upper trough will move
into the area helping to push it south. The Flash Flood Watch may
need to be extended into Sunday but for now will leave as is until
there remains some timing issues amongst the models.
Models begin to diverge on solutions by the early part of next
week. The GFS clears the front much quicker than the European model (ecmwf).
However the GFS brings precipitation back into the midsouth
Tuesday night into Wednesday as the model places the midsouth in
an overrunning situation with a surface low developing along a stalled
front along the Gulf Coast. On the other hand...the European model (ecmwf) holds
onto the front longer but brings high pressure into the area by
Tuesday night into Wednesday. For now have tried to go with a
blend of the two.
12z taf cycle
VFR conditions should persist for most of the forecast period.
Some low clouds may move into the ktup area overnight producing
IFR ceilings. Some rain may move into portions of northeast
Arkansas overnight. Winds will be mainly from the south at around
10 knots with higher gusts possible this afternoon.
Arkansas...Flash Flood Watch from Friday morning through late Saturday
night for Clay-Craighead-cross-Greene-Lawrence-Mississippi-
MO...Flash Flood Watch from Friday morning through late Saturday
night for Dunklin-Pemiscot.
Tennessee...Flash Flood Watch from Friday morning through late Saturday
night for lake.