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Area forecast discussion 
National Weather Service Memphis Tennessee
543 PM CST Tuesday Mar 3 2015

Update...

Updated aviation discussion for 00z tafs below...

&&

Previous discussion... /issued 343 PM CST Tuesday Mar 3 2015/

Discussion...
fairly significant timing changes this afternoon with respect to
the upcoming winter storm. In a nutshell things look to have
slowed down a bit meaning rain will last longer...before the
cangeover to freezing rain...sleet and snow. Additionally sleet
and snow accumulations have increased...especially in the
Missouri bootheel and northern portions of western Tennessee.

As the result of fog early in the day and extensive cloud
cover...high temperatures did not quite make their mark today.
Middle afternoon temperatures range from the middle 40s in
northeast Arkansas to the low 60s in eastern portions of north
Mississippi. Southerly winds have been slower than expected to
respond to a a developing low in the plains...but we are finally
beginning to see speeds in the 10kt range. Deep moisture from
southern Mississippi has moved into much of the midsouth...south
of Interstate 40 with dew points in the middle to upper 50s across
much of north Mississippi. Upper level dynamic support will
approach the region overnight enhancing lift. As a result
precipitation should increase in both coverage and intensity. A
few thunderstorms are possible...but do not look as likely as they
did 24 hours or so ago.

Temperatures this afternoon will be the warmest we see for quite
sometime...possibly for a week or longer. Temperatures will
likely remain fairly steady for much of the night...maybe cooling
a bit toward morning...but the real cooldown will take place
tomorrow. Freezing temperatures should arrive in northeast
Arkansas middle morning...northern portions of west Tennessee around
noon...and across the remainder of the midsouth except eastern
portions of north Mississippi. Far eastern portions of north
Mississippi may not reach freezing until just before midnight.
However...keep in mind that sleet and snow can fall with
temperatures well above freezing...as warm as 37 degrees in some
situations...so don't rely on the freezing line to determine when
show/sleet may begin. Freezing rain still looks to be a lesser
threat...maybe as high as one quarter of an inch in east central
Arkansas into southwest Tennessee...but the more significant
threat will come from accumulating sleet. Sleet can accumulate at
temperatures well above freezing...even warmer than snow. Up to 6
inches of sleet may accumulate in northern portions of west
Tennessee and the Missouri bootheel. With much of west Tennessee
and east Arkansas seening 2-4 inches of accumulation. Temperatures
will continue to cool overnight with morning lows ranging from the
middle teens to middle 20s. Latest guidance keeps wintry
precipitation around well into the day Thursday...especially in
north Mississippi. Watches/warnings may need to be extended even
further in time. Temperatures Thursday are not expected to climb
above freezing...and if significant sleet/snow in on the ground as
expected...making it into the upper 20s might be optimistic. Any
snow/sleet accumulation will linger.

Frigid conditions will continue Friday and Saturday. Highs Friday
may climb above freezing...but once again...if significant
sleet/snow accumulations linger climbing out of the middle 30s might
be a struggle. Morning lows Friday will range from the low single
digits to middle teens. Hopefully we will all see above freezing
temperatures Saturday...but morning lows will be in the teens
across most of the area.

Sunday into Monday temperatures will trend warmer...but remain
below normal. Near normal temperatures may return by Tuesday...no
significant precipitation is expected Saturday through midweek.

30

Aviation...

00z taf set

A large majority of the next 24 hours should feature IFR/LIFR
conditions. The caveat to this will be the first 6 hours as a
warm front has been lifting north. Tup has scattered out to 2700
feet but has been erratic over the last hour. Mem has also shown
some tendency to lift...but LIFR conditions are still noted south.
Believe that this brief reprieve should last for the next 3 to 6
hours before ceilings crash once more. Thunder has been inserted
at jbr and tup overnight as elevated instability is noted in
forecast soundings. Best chance for this should be after midnight
at jbr and between 02z and 06z at tup.

During the day tomorrow...a front will sink south bringing a wind
shift along with a change in precipitation type at all terminals except
tup. Believe the change will occur around 16z at jbr with a later
change at mem and mkl...toward 23z. Freezing rain...sleet...and
snow are all possible during the late afternoon hours with
IFR/LIFR ceilings. Winds will also change to the north-northeast
sustained near 12 knots gusting to 18 kts.

Tvt

&&

Meg watches/warnings/advisories...
Arkansas...Winter Storm Warning from 6 am Wednesday to noon CST Thursday
for Clay-Craighead-cross-Greene-Lawrence-Mississippi-
Poinsett-Randolph.

Winter Storm Warning from noon Wednesday to noon CST Thursday
for Crittenden-Lee AR-Phillips-St. Francis.

MO...Winter Storm Warning from 6 am Wednesday to noon CST Thursday
for Dunklin-Pemiscot.

Flash Flood Watch through Wednesday morning for Dunklin-Pemiscot.

MS...Winter Storm Warning from noon Wednesday to noon CST Thursday
for Alcorn-Benton MS-Coahoma-DeSoto-Marshall-Panola-Quitman-
Tate-Tippah-Tunica.

Winter Storm Watch from Wednesday evening through Thursday
morning for Calhoun-Chickasaw-Itawamba-Lafayette-Lee MS-
Monroe-Pontotoc-Prentiss-Tallahatchie-Tishomingo-Union-
Yalobusha.

Tennessee...Winter Storm Warning from 6 am Wednesday to noon CST Thursday
for Crockett-Dyer-Gibson-Henry-Lake-Lauderdale-Obion-
Weakley.

Winter Storm Warning from noon Wednesday to noon CST Thursday
for Benton Tennessee-Carroll-Chester-Decatur-Fayette-Hardeman-
Hardin-Haywood-Henderson-Madison-McNairy-Shelby-Tipton.

Flash Flood Watch through Wednesday morning for Benton Tennessee-
Carroll-Dyer-Gibson-Henry-Lake-Obion-Weakley.

&&

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