Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
101 PM EST Tuesday Feb 9 2016
an upper level disturbance will move across the Great Lakes
region over the next several days. This will keep temperatures
below normal through the weekend and lead to occasional snow
showers through Wednesday morning.
Near term /until 6 PM this evening/...
snow showers will continue into this afternoon due to a surface trough
across the north and daytime instability/cyclonic flow across the
south. Additional snow accumulations will be an inch or less.
Highs today will range from 25 to 30.
Short term /6 PM this evening through Thursday night/...
Tuesday night there should be a brief break in the snow as the
upper level low starts to edge off to the east. Very early
Wednesday morning another potent shortwave will dive south over
the Hudson Bay allowing low level winds to turn more northerly and
parallel to Lake Michigan. This will start lake effect snow across
northern Indiana with banding forecasted to set up across central
Ohio. During the day Wednesday 850 temperatures continue to drop
to near 16 degrees below zero. High temperatures Wednesday will likely be
in the lower 20s with lows Wednesday morning in the teens.
Wednesday afternoon low level winds will finally start to die down
a bit and turn westerly helping to taper off the lake effect snow.
Thursday morning looks even colder as the best ageostrophic
convergence approaches the area allowing low temperatures to fall into
the single digits. 850 mb temperatures Thursday also remains
around -18 degrees which will keep high temperatures right around
20 degrees. Have gone ahead and lowered high temperatures a bit to
account for this. Some peaks in the clouds will be possible
Thursday afternoon. Thursday night into Friday morning another
potent upper level low will start to dive south across the
Long term /Friday through Tuesday/...
models are consistent in starting the period out with a lingering
low level fetch off of Lake Michigan and across northern portions of
the forecast area. Therefore kept a mention of some snow showers for Thursday
morning. Surface high pressure ridge looks like it will build in enough
Thursday afternoon into Thursday night to bring an end to the
snow showers. Highs Thursday will only make the lower 20s and with
some breaks in the clouds Thursday night lows will drop to 5-15
Extended models continue to have their differences in the handling
of upper level level energy dropping out of central Canada into the
eastern U.S. 500 mb trough Friday. The European model (ecmwf) remains the strongest with the
system bringing a good swath of snow across the Ohio Valley Friday.
The GFS continues to limit precipitation south of an advancing
cold front...waiting until after frontal passage to create lake effect snow
showers. The Gem hemispheric leans more towards the European model (ecmwf)
solution but is not as strong with the system. Trended towards the
European model (ecmwf)/Gem solutions and added a chance of some snow to the region
Friday. Didnt go too high with the probability of precipitation yet.
Despite what happens Friday...all models drop more Arctic air across
the Great Lakes Friday night into Saturday. As a result...scattered
snow showers should affect the region. By Sunday...high pressure
will build south enough to cut the flow off of the lakes.
For Monday...another shot of 500 mb energy drops out of the plains into
the Ohio Valley. GFS and European model (ecmwf) are different on their timing and
location of the precipitation. Covered the system with chance probability of precipitation.
Temperatures will remain well below normal through the period.
Morning lows on Friday will be in the single digits...but warm into
the 20s. Over the weekend...highs will be in the teens to around 20
with morning lows in the single digits.
Aviation /18z Tuesday through Sunday/...
a large scale upper level trough will remain over the Great Lakes
and Ohio Valley through the taf period.
For this afternoon into early evening...a surface trough will
rotate east across the northern tat sites. This feature will bring
a period of MVFR ceilings and IFR visibilities to kday...kcmh...and
klck. Elsewhere...diurnal instability and cyclonic flow will
result in mainly light snow showers. MVFR ceilings/visibilities
with perhaps pockets of IFR visibilities are expected with this
For tonight...models suggest that an embedded disturbance will dig
southeast toward the region between 06z and 12z. Before
then...forecast area will have a relative lull in snow shower
activity. Thereafter...snow shower coverage should increase from
west to east. Have tried to time the higher probability of snow
showers at the taf sites. MVFR conditions will persist with an
occasional lower IFR visibility possible.
On Wednesday...embedded disturbance will move east. Snow showers
will taper to flurries west. MVFR conditions will persist.
Outlook...MVFR ceilings possible Wednesday night into Thursday.
MVFR ceilings and visibilities possible Friday afternoon into
Ohio...Winter Weather Advisory until 6 am EST Wednesday for ohz046-
Kentucky...Winter Weather Advisory until 6 am EST Wednesday for
In...Winter Weather Advisory until 6 am EST Wednesday for inz058-