Scientific Forecaster Discussion
fxus64 kmeg 281138
Area forecast discussion
National Weather Service Memphis Tennessee
638 am CDT sun may 28 2017
updated to add 12z aviation discussion.
Previous discussion... /issued 550 am CDT sun may 28 2017/
Updated to issue a short fused Wind Advisory for northeast
Arkansas and the Missouri bootheel.
A wake low has developed and is producing strong southerly winds
sustained between 20 and 35 mph, with gusts as high as 50 mph over
northeast Arkansas and the Missouri bootheel. These winds should
persist for a few more hours before abruptly diminishing. A Wind
Advisory has been issued to cover these winds. Additional
scattered power outages and downed trees will be possible along
with difficult travel. Please use caution if traveling across
these areas through mid morning.
Previous discussion... /issued 301 am CDT sun may 28 2017/
Widespread convection over the mid south early this morning will
gradually diminish in coverage towards sunrise. The atmosphere
will attempt to recover behind the diminished convection but there
remains uncertainty as to how well recovery occurs. The primary
upper level trough remains over the Central Plains and will move
east today as a shortwave rotates through the base of the trough
and swings across our region later today. The latest cam models
suggest that the best airmass recovery will occur along and south
of Interstate 40 where MLCAPE values surge back between 2000-3000
j/kg by later this afternoon. In addition, model guidance
continues to suggest that mid level lapse rates will steepen again
in association with the shortwave trough. Scattered to numerous
showers and thunderstorms should redevelop again by this afternoon
and continue through the evening and overnight hours south of
Interstate 40, with the greatest coverage along and south of the
Interstate corridor. This will all occur ahead of a surface cold
front that will drop south across the region through tonight. Deep
layer shear between 30-40 kts combined with the anticipated
moderate instability should support the potential for severe
thunderstorms again this afternoon and evening. This severe
potential will again hinge on airmass recovery and undoubtedly
brings higher uncertainty in this type of pattern. The primary
severe risks will again be damaging winds and large hail.
Temperatures should again recover into the lower to middle 80s
The front should stall out across north Mississippi Sunday night
and linger across the area through Tuesday. Abundant moisture and
instability in the vicinity of the front will support continued
chances for showers and thunderstorms through early portions of
the week across southern areas. Further north, mainly dry
conditions can be expected. Temperatures will remain seasonable
for this time of year with highs mainly in the lower to middle 80s
and lows in the 60s.
Northwesterly flow aloft will remain in place for much of next
week with a series of weak shortwave disturbances sending
stalling weak cold fronts across the area through the end of the
week. This will keep chances for showers and thunderstorms in
place through the end of the week.
By next weekend, continued wet and stormy conditions are expected
as a weak upper level low pressure lifts northeast towards the
region from the Southern Plains. Deep tropical moisture will
advect into the region ahead of this feature potentially leading
to higher coverage by next weekend. Temperatures should remain
seasonable through the extended forecast period.
Showers with embedded thunderstorms should continue to diminish
over the next 2-3 hours. Gusty south winds associated with a wake
low should begin to subside this morning. Potential still exists
for MVFR ceilings to affect taf sites this morning and improve to
VFR conditions this afternoon. Thunderstorms in the vicinity may develop at mem/mkl/tup
late this afternoon but confidence is not particularly high in
this taf set due to effects of the overnight convective activity.
Winds will gradually veer northwest/north tonight with the passage of a cold
Arkansas...Wind Advisory until 9 am CDT this morning for Clay-Craighead-
MO...Wind Advisory until 9 am CDT this morning for Dunklin-Pemiscot.