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Area forecast discussion 
National Weather Service Memphis Tennessee
1215 PM CST Tuesday Mar 3 2015

Update... /issued 945 am CST Tuesday Mar 3 2015/

It looks like fog will persist a while longer across the
midsouth. Extended the dense fog advisory through noon. Clouds and
fog will likely curb temperatures a bit as well...all warming will
have to be the result of wwa and winds have not responded to the
tightening pressure gradient. We will probably still see stronger
southerly flow this afternoon...but maybe too little too late to
reach the middle 60s near Memphis and low 70s in north
Mississippi. Thunderstorms also look less likely especially in
west Tennessee...east Arkansas and the Missouri bootheel.

&&

Discussion... /issued 728 am CST Tuesday Mar 3 2015/

Stable conditions have lifted into the northern midsouth counties
over the past hour...with observations showing decreasing
visibilities. Have expanded the dense fog advisory to encompass
the entire midsouth through 10 am. Also removed mention of showers
and replaced with patchy drizzle through noon.

Jab

&&

Previous discussion... /issued 305 am CST Tuesday Mar 3 2015/

Currently the midsouth was cloudy and cool with either calm or
light southeast winds. Patchy fog was being observed along with
patchy drizzle...though radar was clear.

A lot of weather to talk about for the next 48 hours as the
midsouth does another rollercoaster ride with temperatures and
precipitation types. The two main culprits showing up on water
vapor...the first off the coast of Southern California driving
subtropical moisture up over northern Mexico and into the Southern
Plains. The second a very cold airmass reflected by a potent
shortwave entering the Dakotas. Both with crosshairs pointing at
US. For today morning temperatures in the 30s and 40s will climb a
good twenty five to thirty degrees by evening as strong warm air advection drives
a warm front from southern Mississippi to the Midwest. Extensive
cloud cover with patchy drizzle and a few scattered showers can be
expected throughout the day. However the heavier rainfall will
arrive tonight as the Arctic front moves across Missouri. With
recent precipitation over the bootheel and northwest Tennessee the
ground may not be able to handle two inches of rainfall...let
alone up to the possible 4 inches...so have issued a Flash Flood
Watch for this area from this evening through noon Wednesday. In
addition...embedded thunderstorms will also occur ahead of the
front tonight as temperatures remain quite mild.

Have gone with a GFS and Euro blend with regards to quantitative precipitation forecast amounts
and timing of subfreezing air/winter precipitation changeover. The
NAM seems to be an outlier...very similar to the president's day
storm a couple of weeks back. Latest 00z runs indicate the precipitation
switch beginning as early as 7 am over Randolph and Clay
counties...then slowly reaching the I-40 corridor by early
afternoon...and finally northeast Mississippi by early evening.
Significant amounts of ice...sleet and snow are expected...with
the bulls eye north of a Clarksdale Mississippi to Savannah
Tennessee line. A Winter Storm Warning has been issued for this
area. Have increased freezing rain amounts along and just south
of I-40 where model guidance holds on to the elevated warm layer
a bit longer. But believe this region will changeover to mostly
sleet by evening. Heavier amounts of snow will likely remain over
the far northern counties...especially in northwest Tennessee.
Finally the southern counties have been left in a Winter Storm
Watch as an additional model run today will help hone in both
precipitation amounts and types.

In addition to the heavy rain and wintry weather...strong
northerly winds will flirt with advisory criteria by tomorrow
night along and west of the Mississippi River. This may aid in
causing sporadic power outages...and it will certainly drive
windchills down into the single digits and low teens through the
night. Precipitation will taper off near sunrise Thursday morning
across the far southeast counties. Though the Euro hangs on to it
a bit longer.

Thursday and Friday...will be cold and dry. Have gone below model
guidance on both highs and lows...due to the ice and snow
remaining. Mostly clear skies Thursday night coupled with east
winds 4-8 miles per hour will trigger windchills at or below zero for a
large portion of the midsouth...a windchill advisory would be
needed.

Extended period...dry conditions as an upper ridge builds
overhead....though the Euro does indicate a Gulf coastal low
bringing moisture to the region Monday night and Tuesday. For now
have left the midsouth dry into early next week as this feature
may track farther south. A slow warm up is also anticipated.

Jab

&&

Aviation...

18z taf set

Vlifr and LIFR conditions will be predominate over the next 24
hours. Although...there could be some brief improvement around 00z
at ktup and around 5-6z at kmem. Widespread rain will begin to
spread into kjbr this evening. There could be some isolated thunderstorms and rain showers
embedded in the rain. Rain will change over to freezing rain
and/or sleet between 16-18z at kjbr. S winds will increase as they
become southwesterly this afternoon into this evening. Expect
speeds increasing to around 12 kts. Winds will turn around to
north or northwest overnight into the early morning hours.

Krm

&&



&&

Meg watches/warnings/advisories...
Arkansas...dense fog advisory until noon CST today for Clay-Craighead-
Crittenden-cross-Greene-Lawrence-Lee Arkansas-Mississippi-
Phillips-Poinsett-Randolph-St. Francis.

Winter Storm Warning from 6 am Wednesday to 6 am CST Thursday
for Clay-Craighead-cross-Greene-Lawrence-Mississippi-
Poinsett-Randolph.

Winter Storm Warning from noon Wednesday to 6 am CST Thursday
for Crittenden-Lee AR-Phillips-St. Francis.

MO...dense fog advisory until noon CST today for Dunklin-Pemiscot.

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

Flash Flood Watch from 6 PM CST this evening through Wednesday
morning for Dunklin-Pemiscot.

MS...dense fog advisory until noon CST today for Alcorn-Benton MS-
Calhoun-Chickasaw-Coahoma-DeSoto-Itawamba-Lafayette-Lee MS-
Marshall-Monroe-Panola-Pontotoc-Prentiss-Quitman-
Tallahatchie-Tate-Tippah-Tishomingo-Tunica-Union-Yalobusha.

Winter Storm Warning from noon Wednesday to 6 am CST Thursday
for Alcorn-Benton MS-Coahoma-DeSoto-Marshall-Panola-Quitman-
Tate-Tippah-Tunica.

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

Tennessee...dense fog advisory until noon CST today for Benton Tennessee-Carroll-
Chester-Crockett-Decatur-Dyer-Fayette-Gibson-Hardeman-
Hardin-Haywood-Henderson-Henry-Lake-Lauderdale-Madison-
McNairy-Obion-Shelby-Tipton-Weakley.

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

Winter Storm Warning from noon Wednesday to 6 am CST Thursday
for Benton Tennessee-Carroll-Chester-Decatur-Fayette-Hardeman-
Hardin-Haywood-Henderson-Madison-McNairy-Shelby-Tipton.

Flash Flood Watch from 6 PM CST this evening through Wednesday
morning for Benton Tennessee-Carroll-Dyer-Gibson-Henry-Lake-Obion-
Weakley.

&&

$$

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