Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Memphis Tennessee
1135 PM CST Wednesday Dec 17 2014


Aviation discussion updated for 06z tafs


Update discussion... /issued 748 PM CST Wednesday Dec 17 2014/

Light precipitation continues to move across western portions of
the middle south this evening and will overspread much of the
remainder of the area overnight. Temperatures are currently near
freezing across portions of northwest Tennessee and should hover
there through the night. After review of nearby sounding
data...there are indications that a mix of light wintry
precipitation to include all modes (snow...sleet...rain...and
freezing rain) should develop across northwest Tennessee. In areas
where temperatures are at or slightly below freezing there may be
some icy spots developing on elevated Road surfaces such as
bridges and overpasses. Precipitation rates should remain quite
light and not expecting any significant travel issues at this
time. An Special Weather Statement has been issued for these areas
to highlight the potential for minor travel inconveniences.

Elsewhere...some sleet will likely mix at times with rain to the
north of Interstate 40. No accumulations are expected in these
areas nor any travel issues as temperatures remain above freezing.
Further south...all rain is anticipated.

Updated zones...grids...and Special Weather Statement have been sent. Plan to monitor
closely through the evening in case conditions deteriorate more
than currently expected.


Previous discussion...

Current surface analysis shows a surface low over south Texas. An inverted
surface trough extends north out of the surface low. Another surface low is
located over the Oklahoma Panhandle. The lows will track eastward
overnight. Latest radar shows an area of precipitation that covers
much of western Arkansas...eastern Oklahoma...and southwest
Arkansas. The precipitation is mainly falling in the form of rain
but occasional sleet is mixed in. With the abundant thick cirrus
shield moving in across the not see temperatures
dropping that much tonight so expect most of the precipitation to
fall in the form of rain. Although can/T rule out sleet mixing in
at times especially on the onset of the precipitation. No
accumulation is expected from any sleet that fall. Lows will be in
the 30s.

On Thursday...precipitation may linger through middle-morning but
expect mainly dry conditions for much of the day. Cloudy
conditions will continue and expect highs to be similar to what is
occurring today.

Next system will move into the area on Friday as another surface low
will develop along the Gulf Coast. Widespread rain will spread
into the midsouth by late Friday afternoon into Friday evening.
Rain could change over to all snow across portions of northeast
Arkansas...the Missouri bootheel...and northwest Tennessee during
the overnight hours. Right now if this does occur...accumulations
would be an inch or less. Stay tuned. Precipitation will taper off
on Saturday.

Expect tranquil weather over the rest of the weekend. The next
system will be a cold front that will move through the midsouth
Monday night into Tuesday. Chances for rain will occur ahead of
the front. Both the European model (ecmwf) and GFS indicate colder air will filter
into the area behind the front on Wednesday.



06z taf cycle

Vicinity showers and light rainfall is currently ongoing across
all terminals...however...cigs have remained above 7000 feet for
the most part. Expect that these will lower through the night in
continued shower activity. There could be some sleet mix in
sporadically at jbr however the large majority of this activity
should stay north. For Thursday...showers will contiue through the
morning with some fog...especially early. Not a great fog signal
at this time but have at least mentioned it in the tafs. There is
a good signal that ceilings will fall to below MVFR for the majority
of the day tomorrow. Tup should be the first to begin seeing
improvements Thursday night.



Meg watches/warnings/advisories...


National Weather Service Glossary of Abbreviations