Area Forecast Discussion
Issued by NWS Memphis, TN
FXUS64 KMEG 291747
Area Forecast Discussion
National Weather Service Memphis TN
1247 PM CDT Wed Mar 29 2017
Updated to add 18z Aviation Discussion.
.PREV DISCUSSION... /issued 1127 AM CDT Wed Mar 29 2017/
A warm front is lifting north across the Mid-South. At 16z the
front was located from Memphis into extreme NE Mississippi. A few
showers moved across the northern half of the area this morning
ahead of the front but these have lifted north of the region. The
warm front will push to the MO/KY border by the end of the day
with lower to mid 60s dewpoints overspreading the area. Expect a
good deal of sunshine this afternoon with temps warming into the
lower to mid 80s across much of the area...upper 70s extreme
Latest data indicates that the severe threat may continue
longer through the overnight as a potent mid level jet punches
into AR late tonight. Latest synoptic and mesoscale models show
quite a bit of development continuing into the 09z-12z time frame.
PREV DISCUSSION... /issued 341 AM CDT Wed Mar 29 2017/
Tranquil weather is occurring across the Mid-South this morning.
This will all change in roughly 18 hours as a couple of round of
severe storms will impact the area.
A stationary front is currently located roughly from Greenville
to Starkville, Mississippi. The front will lift northward across
the Mid-South as a warm front this morning. A few showers could
develop along the front otherwise dry conditions are expected
through the day. Expect clouds to break up quickly behind the
frontal passage. The combination of sunshine and winds turning
around to the south will allow temperatures to shoot up into the
lower to mid 80s from Interstate 40 southward.
All eyes will turn toward Western Arkansas by the evening hours as
severe thunderstorms will develop in association with the lead
shortwave ahead of a potent upper level low pressure system. The
storms will push into Eastern Arkansas between 10 PM and midnight
just as the low level jet is strengthening to around 60 KTS. The
combination of the strengthening low level jet and a warm,
unstable airmass (thanks to the near record high temperatures
expected today) will help maintain the storms at severe levels as
they push into Eastern Arkansas. There is enhanced risk for severe
storms for Eastern Arkansas late tonight with damaging winds,
large hail, and isolated tornadoes being the main threats from
these storms. Expect the storms to begin to diminish in intensity
as they push east of the Mississippi River from the further loss
of daytime heating.
By sunrise, expect lingering showers and isolated thunderstorms
to be occurring across areas of West Tennessee near the Tennessee
River and Northeast Mississippi. From sunrise to around 10 AM-noon
expect a lull in activity. Shortly before noon, thunderstorms will
begin generating along the approaching cold front roughly expected
to be located from West Plains, Missouri to Pine Bluff, Arkansas.
Models continue to indicate that the atmosphere will have enough
time to destabilize. Thus, storms should quickly become severe
over Eastern Arkansas and will likely intensify in intensity as
they push east of the Mississippi River. With the SFC low expected
to be near St. Louis, 0-3KM SRH values will be between 200-300
M2/S2 providing an environment favorable for tornadoes as well as
damaging winds and large hail. As a result, a moderate risk has
been issued for most of West Tennessee and North Mississippi. The
cold front will push east of the Tennessee River and into Alabama
by 10 PM Thursday Night ending the threat for severe weather.
Please stay tuned to the latest forecasts on the expected severe
weather, have a way to receive watches and warnings from late
tonight into Thursday evening, and know what to do if a tornado
warning is issued for your location.
Upper ridging will begin to occur over the Mid-South by Friday
evening behind the departing upper level low pressure system.
Thus, a pleasant and quiet weekend is expected across the Mid-South
with highs ranging in the upper 60s into the 70s.
Shower and thunderstorm chances will begin to occur by Sunday
evening across the Mid-South as another upper level low pressure
system approaches the area. The system will affect the region into
the beginning of next week.
The first round of showers and thunderstorms will begin to affect
TAF sites, first at JBR between 5-8Z, MEM between 8-11z, and
MKL/TUP Thursday morning. A second round of showers and
thunderstorms is expected mainly Thursday afternoon into Thursday
evening across areas mainly east of the MS river at MEM,MKL,TUP.
VFR conditions anticipated except during the time of
thunderstorms. Mainly S winds expected through much of the period
with some slight veering towards the SW late in the period and
becoming gusty at times later tonight into Thursday.