Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
640 am 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/...
a weak and fast moving short wave will drop down across the
eastern Great Lakes later this morning into this afternoon. The
global models are trying to smear some precipitation into our
northern areas with this while most of the higher res models are
indicating just some spotty showers at best...and generally
remaining North/East of our area. Forecast soundings are indicating
primarily middle level moisture across northern areas through early
afternoon so think the main result will just be some continued
cloudiness...but suppose it will be tough to rule out a few
sprinkles. Otherwise...high pressure will be shunted off to our
south through this afternoon. Westerly low level flow will lead to
developing warm air advection through the day. Expect highs to push into the
upper 50s to lower 60s through the afternoon hours.
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 father 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 /12z Monday through Friday/...
a disturbance passing by the area to our north will help to bring
an increase in middle level clouds and southwesterly flow today. A
few light showers associated with this disturbance may pass near
kcmh/klck late this morning/early afternoon before they dissipate.
Winds this afternoon will gust as high as 25 knots. Winds will
subside to around 10 knots after sunset with skies expected to
become mostly clear. Winds will become light after midnight
tonight. These light winds combined with mostly clear skies may
produce patchy fog during the early morning Tuesday.
Outlook...MVFR to IFR ceilings and visibilities likely Tuesday night
into Wednesday. MVFR ceilings may linger into Wednesday night