Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
214 PM EDT Monday Mar 10 2014
southwesterly winds will allow temperatures to push well above
normal today and again on Tuesday. A low pressure system will move
through the Ohio Valley Tuesday night and Wednesday...bringing
widespread precipitation to the region. A much colder airmass will
move into the area behind the low pressure system on Wednesday.
Near term /until 6 PM this evening/...
some light showers have moved into extreme northern portions of
the forecast area due to a weak disturbance. Most of the light rain showers will
be confined to along and north of Interstate 70. Some sprinkles
will be possible south of this area however. Made only minor
adjustments to high temperatures for today and continued to go on
the warm side of guidance.
Short term /6 PM this evening through Wednesday night/...
a weak cold front will sag down from the north tonight and push
into our area through Tuesday as it washes out. Meanwhile some
weak middle level isentropic lift will develop through the day on
Tuesday...primarily across northern portions of our forecast area. The models
are hinting at perhaps a few sprinkles or showers with this.
However...with most of the moisture generally limited to the middle
levels...will maintain a dry forecast. Temperatures will remain
above normal with highs on Tuesday ranging from the middle 50s north
to the middle 60s across the south.
A progressive shortwave moving out of The Rockies on Tuesday will
help carve out a fairly high amplitude trough over the eastern
United States Wednesday into Wednesday night. The associated
strengthening surface low will track east from the middle Mississippi
Valley Tuesday night to the Middle Atlantic States by Wednesday
afternoon. A tightly packed thermal field will lead to good
frontogenetic forcing across our area later Tuesday night into
Wednesday morning. This will allow for widespread rain to
overspread the area Tuesday evening with precipitation changing over to
snow northwest to southeast across the area later Tuesday night
into Wednesday as colder air gets pulled in behind the low. How
fast this change over occurs will help dictate snowfall amounts.
Expect highest snowfall amounts across our northwest where the
precipitation will change to snow the earliest. At this point it looks like
4 or so inches of snow will be possible across our far northwest
counties. Expect snow amounts to decrease fairly quickly as we
progress further south and east from there...as heaviest precipitation should
be moving out as the precipitation changes to snow. This would result in 1
to 3 inches of accumulation possible along the I-70
corridor...with generally an inch or less farther South.
Strong cold air advection will overspread the area through the day on Wednesday
with 850 mb temperatures dropping off a good 15 degrees celsius
through the day. This will result in temperatures falling into the
20s during the day on Wednesday. The snow will taper off to
scattered snow showers through Wednesday afternoon before tapering
off by Wednesday evening. Expect lows Wednesday night ranging from
the single digits in the north to the middle teens across the south.
Long term /Thursday through Sunday/...
on Thursday high pressure will build across the upper Ohio
Valley. On Friday...a low will pass across the northern Great
Lakes...but it will drag a cold front into the region late Friday night
into Saturday. Right now it looks like the moisture with the front
will be limited...so left the forecast dry.
By Sunday...the models try to develop another storm system in the
middle of the country and move it east. Right now there is a wide
variation in model solutions...so went with a GFS/European model (ecmwf) blend.
Northerly cold air advection will limit highs on Thursday to only the upper 20s and
30s. Thanks to high pressure and warm air advection on Friday temperatures should
be back up to around 50 for highs. Temperatures should cool a
little over the weekend...with highs in the middle 40s to middle 50s
Saturday and the 40s to around 50.
Aviation /18z Monday through Saturday/...
middle and high clouds will be present across the taf sites this
afternoon into tonight. Winds will gust at times to around 20 to
25 knots through the early evening hours. Late in the overnight
hours model soundings indicate that IFR or lower ceilings will
be possible in addition to some MVFR visibilities. Added in a several
hour period of IFR ceilings at all the area taf sites except kcvg and
kluk. Went with MVFR ceilings at kcvg and kluk. Went with MVFR visibilities
at the taf sites. Cannot rule out some patchy drizzle late in the
overnight hours and into the early daytime hours on Tuesday
however confidence was not high enough to include in the tafs at
this time. Ceilings and visibilities will gradually improve by the end of the
Outlook...MVFR to IFR ceilings and visibilities likely Tuesday night
into Wednesday. MVFR ceilings may linger into Wednesday night.