Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
617 am CDT Friday Mar 14 2014
updated for 12z aviation discussion
Previous discussion... /issued 331 am CDT Friday Mar 14 2014/
Currently...high pressure is situated over the Carolinas and
Georgia. The strengthening pressure gradient is already resulting
in southerly winds of 10-15 kts across the Delta this
morning...lighter east of the MS river. Skies are clear.
Today...a breezy and mild day on tap for the midsouth. A strong
pressure gradient between the surface high and an approaching
cold front will result in gusty S/SW winds...especially across
the Delta. Winds will approach advisory criteria over NE Arkansas and
the MO bootheel. Plenty of sunshine this morning following by
increasing middle and high clouds as an upper trough and weakening
cold front skirt the region to the north. Temperatures will climb well
into the 60s. An isolated shower is within the realm of
possibility but not likely.
Tonight...weak cold front falls apart over the midsouth. Left the
small pop after midnight since some weak overrunning develops
late. Most places will remain dry. Cloud cover will continue to
increase and low temperatures will range from the middle 40s to around 50.
Saturday...models are slower bringing the upper level trough out
of Texas. As a result the surface low is still over the Red River
valley at 00z sun with most of the rain remaining west of the
area. Dropped probability of precipitation back into the slight chance/chance categories and
warmed high temperatures up a bit. The day is not looking like a wash out
at this point and may be halfway decent.
Saturday night into Sunday...main show takes place during these
periods. Models are coming into better agreement moving the surface
low to the lit-mem area by 12z sun and then into north Alabama or
north Georgia by 00z Monday. Strong lift and deep moisture will push
into the midsouth Saturday night. Upped probability of precipitation to 90 percent. Not
much instability...surface or elevated...but given the dynamic
nature of the system kept a mention of thunder in the forecast
Saturday night. By Sunday the heaviest rain will push to northern
and eastern sections as a dry slot pushes into the southwest part
of the County Warning Area. As the low heads east cooler air will start to wrap
into much of the area on gusty north winds.
Sunday night...this period is starting to look interesting as
colder air filters into the region. The GFS moves the system out and
ends precipitation rather quickly. Meanwhile the European model (ecmwf) and especially the
NAM are slower with a well defined deformation band across the
midsouth Sunday night. The NAM actually has 1 to 2 inches of snow
across a good portion of the County Warning Area. Not ready to bite on that but
did expand the area of rain/snow mix across northern sections late
Sunday night. Much colder air will be filtering in with lows in
Monday and Monday night...clearing and cool as weak high pressure
builds in. Highs only in the 50 to 55 degree range and lows in the
Tuesday...southerly flow redevelops and temperatures climb back toward
Tuesday night into Wednesday...a weak moisture starved cold front
will move through with a small chance of showers. Temperatures will be at
or slightly below normal.
Thursday...high pressure and dry weather expected with seasonable
06z taf cycle
Gusty southwest winds will be the biggest aviation concern. Winds
will increase this morning with frequent gusts in the 20-26 knots
range depending on site. Winds will diminish this evening as
surface high pressure passes overhead. VFR conditions...though tup
may flirt with a MVFR ceiling layer after 09z.
Preliminary point temps/pops...
mem 68 50 68 53 / 10 20 50 90
mkl 67 45 68 50 / 0 20 40 90
jbr 67 46 64 49 / 10 20 40 90
tup 68 48 68 55 / 0 20 40 90