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fxus64 kmeg 180539 aaa 
afdmeg

Area forecast discussion...updated
National Weather Service Memphis Tennessee
1139 PM CST Sat Feb 17 2018

Update...
updated for 06z aviation forecast discussion below.

&&

Previous discussion... /issued 1041 PM CST Sat Feb 17 2018/

Update...

Clearing skies, light to calm winds, and saturated grounds have
combined to create dense fog conditions across the northern third
of the forecast area. A few stations have already reported 1/4
mile or less visibility at times. Latest GOES-east satellite also
supports fog formation across areas that have seen clearing skies
over the past hour or so. As skies continue to clear to the south,
expansion of the advisory may be needed. Elsewhere, patchy fog is
anticipated through the morning hours.

Updated sky grids, nudged temperatures a bit, and issued the dense
fog advisory. The rest of the forecast is on track.

Ac3

Previous discussion... /issued 548 PM CST Sat Feb 17 2018/

Update...
updated for 00z aviation forecast discussion below.

Previous discussion... /issued 307 PM CST Sat Feb 17 2018/

Discussion...surface analysis this afternoon places a cold front
over portions of central/southern Mississippi and northern
Alabama. Regional WSR-88D radar trends indicate the back edge of a
band of rain was located east of a line from Decaturville to
Bolivar Tennessee to Clarksdale, Mississippi. As of 2 PM CST,
temperatures across the mid-south are in the 40s at most locations
with the exception of Monroe County, Mississippi where
temperatures are still in the lower to middle 50s.

Rain will gradually taper off across the mid-south for the
remainder of this afternoon into this evening. A combination of
residual low level moisture and temperatures falling back into
the upper 30s to lower 40s may result in the development of patchy
fog overnight. Highs on Sunday will remain cool in the 50s.

Short term models indicate the downstream cold front will begin to
return back north as a warm front on Sunday with rain chances
increasing especially Sunday afternoon into Sunday night. It
appears there may be some potential for relatively rain free
conditions across portions of the mid-south with the exception of
northeast Arkansas Monday into Monday night. Highs on Monday are
expected to rise back into the lower to middle 70s.

Long term models indicate chances for showers and a few
thunderstorms will return to the mid-south for Tuesday into
Wednesday as a cold front approaches the lower Mississippi Valley.
Mild temperatures are expected to persist into Tuesday but
gradually cool for the middle of next week north of I-40.
Temperatures will moderate slightly for the remainder of next week
along with continued rain chances each day.

Cjc

&&

Aviation...
06z tafs

Ground fog had developed around jbr late Saturday evening, behind
departing MVFR stratus and in an area of calm winds. Similar
conditions prevailed further east near and north of mkl.

It's probable that mem will not escape at least some fog
overnight. Lamp guidance winds showed 3 to 5 knots winds prevailing
at mem Saturday evening, when winds were actually 0 to 3 knots
through the evening. The trend of less than 3 knots winds will
likely continue through the predawn hours, potentially leaving
the urban heat island and scattered high clouds the only limiters
on dense fog formation.

Few changes for the Sunday afternoon and evening periods. MVFR
deck should arrive late afternoon. Ceilings should lower Sunday
evening, with the approach of tropical maritime warm front
lifting north through MS.

Pwb

&&

Meg watches/warnings/advisories...
Arkansas...dense fog advisory until 8 am CST Sunday for Clay-Craighead-
Greene-Lawrence-Mississippi-Poinsett-Randolph.

MO...dense fog advisory until 8 am CST Sunday for Dunklin-Pemiscot.

MS...none.
Tennessee...dense fog advisory until 8 am CST Sunday for Carroll-Crockett-
Dyer-Gibson-Henry-Lake-Lauderdale-Obion-Weakley.

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