Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
411 PM EDT sun Mar 29 2015
a cold front will pass east over the Ohio Valley this evening.
High pressure will build over the Mississippi Valley on Monday and
slowly move to the East Coast. At this same time...a surface low
will pass from the upper Midwest to the middle Atlantic on Tuesday
skimming the Northern Ohio valley and draping another cold front
through the region Tuesday afternoon and evening.
Near term /until 6 am Monday morning/...
an area of showers over Indiana is weakening as they push eastward
into Ohio. The initial surge is occurring where southerly surface flow
is still occurring. It appears that the leading edge is well away
from the source of lift and mainly continuing an eastward
progression into an area of somewhat favorable moisture. It is not
until later this evening that the showers will get squeezed out
when the front sags south and eastward. Even as the winds pick up
from the west overnight...temperatures will not experience a
tremendous Post-frontal drop as upstream dewpoints remain in the
30s...hampering large temperature swings.
Kept the same chances of probability of precipitation overnight - 70 percent. I would
have gone with a more scattered approach to the shower activity
but did not want to drop probability of precipitation with an area of rain actively pushing
into County Warning Area.
Short term /6 am Monday morning through Tuesday night/...
high pressure builds behind the front and skies should experience
at least some clearing and allow for insolation to warm things up
during the daylight hours Monday and Tuesday. Middle level moisture
will increase northeast of the region Monday night and a surface
low will track southeast through Michigan. This will skim
northeast Ohio and increase the threat for a shower on
Tuesday northeast of Columbus. A trailing cold front is noted on
the models and a few are starting to indicate that precipitation may
develop along it Tuesday afternoon and evening. Showers that may
fire along this line will be weak and short-lived. High pressure
will quickly build north of the region overnight Tuesday.
Looking for milder overnight temperatures as moisture gets pulled into
the region and daytime highs will make a return to more normal
Long term /Wednesday through Sunday/...
forecast period begins with a high pressure ridge centered over the
upper Ohio Valley. This should provide dry and slightly above
seasonal temperatures. Highs will range from the middle 50s in the
northeast to the middle 60s in the tri-state.
As the high slips into the Appalachians Wednesday night...a cold
front swings out of the plains and into the MS valley. Models are
showing a difference in timing with this system. The European model (ecmwf) is much
slower than the pack of other deterministic models lead by the
GFS/CMC. The GFS/CMC are showing better continuity with the previous
thinking so will bring likely probability of precipitation into the forecast area Thursday. Instability
increases ahead of the front will keep the mention of thunderstorms.
The GFS/CMC push the front through Thursday night...stalling it in
Kentucky. Upper level energy in the fast westerly flow causes a
ripple on the front and pulls precipitation back north across the region
Friday. Best chance of precipitation will be across the southern counties.
Instability looks like it stays shunted to the south...so only went
with showers for now.
High pressure builds in for Saturday and Sunday.
Bumped highs up a couple of degrees for Thursday. Highs in the lower
70s for most of the region. Lows will drop into the middle 40s to lower
50s Thursday night behind the front and only will recover into the
50s and lower 60s on Friday. Cooler air will settle in with the high
over the weekend with slightly below normal temperatures. Highs will
be the upper 40s to lower 50s Saturday. On Sunday a trough axis will
bring some clouds limiting temperatures in the NE to middle 40s while
southern locations will push into the lower to middle 50s.
Aviation /19z Sunday through Friday/...
winds out of the south will be gusty through the afternoon hours.
Wind gusts around 20 knots will increase to around 25 knots as the
afternoon progresses. Although wind gusts will subside this
evening expect winds to stay up through the night and into the
day on Monday. Additional wind gusts will be possible later this
evening into tonight at kday and Kiln. Southerly winds will shift
to become westerly winds tonight.
Rain showers will begin to move into the area late in the
afternoon and into the evening hours before tapering off tonight.
Hi res models show three waves of light shower activity moving through
the taf sites during this time. Do not expect rain showers to be
heavy enough to reduce visibilities.
Ceilings will gradually lower tonight with MVFR ceilings expected to
develop and move into the area overnight. MVFR ceilings will last
longer at Kiln...kcmh...and klck.
Outlook...MVFR ceilings and visibilities possible on Thursday.