Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
1128 am CST Friday Dec 19 2014
Previous discussion... /issued 921 am CST Friday Dec 19 2014/
Morning temperatures starting several degrees above forecast values. Adjusted
Friday high temperatures up a degree or two to account for current
trends. With extensive cloud cover continuing and light precipitation
approaching the southern County Warning Area...only minor adjustments are needed
at this time.
Previous discussion... /issued 535 am CST Friday Dec 19 2014/
Currently...high pressure stretches across the Ohio Valley with
cool NE flow across the midsouth. Low clouds are trapped across
the area and temperatures range from the middle 30s north to middle 40s south.
Today...low pressure will begin to track well south of the Gulf
Coast as a middle level trough approaches the midsouth. Rain will
spread north through the lower Mississippi Valley during the day
and into southern portions of the midsouth this afternoon. Cool NE
flow will continue and temperatures will be well below normal with highs
from around 40 north to middle 40s south.
Tonight...low pressure will continue to track well south of the
Gulf Coast. This system is looking a lot weaker and tracking much
further south than models depicted a couple of days ago. The rain
shield will quickly shift east this evening. Best chances for rain
will be south of I-40...especially across north Mississippi this
evening. Rain will mostly taper off by midnight with most places
dry between 06z-12z. A few snowflakes could mix in across NE parts
of west Tennessee after midnight but chances are precipitation will end before
that happens. Lows will range from the lower 30s north to upper
Saturday...models want to clear skies out quickly on Saturday but
given continued surface high pressure across the Ohio Valley and
NE surface flow across the midsouth concerned that low clouds
will hang on. Increased cloud cover during the morning with
partial clearing for the afternoon. Temperatures will be cool...in the
Saturday night through Sunday night...Saturday night should
partly cloudy and cool with temperatures in the 30s. Sunday will be dry
and slightly warmer with highs around 50. A system moving from
the Gulf into the southeast U.S. May throw a little bit of rain into the
very eastern sections of the midsouth Sunday night.
Monday...high pressure over the Ohio Valley heads east and
milder southerly flow develops over the midsouth ahead of an
approaching cold front. Highs will jump into the 50s.
Monday night through Tuesday...a cold front will move through
with rain likely across much of the area by Tuesday. Expect
falling temperatures as a much cooler airmass moves in Tuesday afternoon.
A few flakes could mix in across the north as the precipitation wraps up
Wednesday and Christmas...Wednesday looks cool and dry with highs
in the 40s and lingering stratocu. Sun should come out for Christmas
with milder SW flow and high pressure along the Gulf Coast. High temperatures
should be in the 50f to 55f range.
Aviation...18z taf cycle
Aviation should not be too problematic over the next 24 hours.
Generally VFR to MVFR ceilings associated with light showers moving
across the region are expected. Showers at any station should be
short lived with virtually no rain after midnight. Ceilings should
improve gradually between 06 and 12z with VFR conds area wide
shortly after sunrise. The greatest potential for rain on station
will be at tup between 00 and 04z. Tup is the only station where
I feel prevailing rain is expected. Decided to tempo rain for the
same time period at mem and just carry vcsh at jbr and mkl.
Prevailing visible should stay MVFR or greater. Winds will be east to
northeast between 3-8 kts.