Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
113 am EST sun Dec 28 2014
precipitation along a cold front will affect the area tonight and
Sunday. High pressure arriving behind the front will provide dry
weather and seasonable temperatures through middle week.
Near term /until 6 am this morning/...
a cold front has entered our northwest County warning forecast area this evening. The front will
continue to move slowly east/southeast through the remainder of
the forecast area overnight. Precipitation is expected to be
categorical in coverage along and just behind frontal passage due
to low to middle level frontogenesis. Colder air will filter in
behind the front. As precipitation tapers off across our northwest late
tonight...some wet snowflakes may mix in. Little to no snow
accumulation is expected. Lows will range from the lower 30s northwest to
the lower 40s far southeast.
Short term /6 am this morning through 6 PM Monday/...
for Sunday morning...there will be variability across the area in
terms of precipitation coverage...with locations to the southeast near the
front having categorical probability of precipitation while places northwest of Dayton may
already be dry. Precipitation will diminish and exit southeast Sunday
afternoon with the front. A large area of high pressure will then
take over...bringing dry weather Sunday night through Monday
Temperatures will trend downward to seasonal normals with the
frontal passage. Highs averaging around 40 on Sunday will peak in
the morning before cold advection results in steady or slowly
falling readings during the afternoon. For Monday...further cold
advection should bring highs in the middle and upper 30s most
locations...with a few 40s possible in the south.
Long term /Monday night through Saturday/...
the 12z model runs show upper level low pressure becoming more
entrenched across the southwest states Tuesday and Wednesday next
week...while a longwave trough extends across much of the eastern
part of the country. A couple shortwaves will rotate through the
Great Lakes Tuesday and Wednesday...though a relatively dry airmass
will preclude much in the way of precipitation across the area.
Anything that does occur would be in the form of light snow
showers...or a mix of light rain and snow showers.
A period of dry weather is expected Wednesday and Thursday before
the upper level low in the southwest starts to eject toward the
Southern Plains on Friday. Overrunning precipitation should spread
well ahead of the upper level system...with rain and snow possibly
developing on Friday across the area. The 12z models...as well as
previous runs have shown various solutions with the speed and track
of this system. The latest GFS is much faster than the European model (ecmwf).
However...the 12z GFS ensemble and parallel GFS 500 mb pattern are more
in line with the European model (ecmwf)...so some preference is shown to the slower
European model (ecmwf) progression of the system in this forecast package. Given this
scenario...the chance for rain and snow should tend toward mostly
rain by Saturday...before diminishing Saturday night.
Aviation /06z Sunday through Thursday/...
showers will occur over the taf sites through about
9-10z...possibly as late as 11-12z at kcmh/klck. IFR ceilings will
bounce up at times and once winds shift north behind the front
visibilities will become VFR even if the ceilings take the better part of the
rest of the morning to work out. A nose of drier air will push
into western County Warning Area and affect kday this afternoon with generally clear
skies. This dry punch may not make it as far south as Kiln or
kcvg/luk until after daylight hours have passed.
Outlook...MVFR visibilities are possible Monday morning.