Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
1230 am EST Wednesday Jan 28 2015
high pressure and a dry and cold airmass will push across the area
tonight and Wednesday. A cold front will bring mixed precipitation
on Thursday. Cold and dry conditions will return with high
pressure on Friday.
Near term /until 6 am this morning/...
skies have cleared as an area of SC that affected central Ohio
pushes into southeast Ohio and West Virginia. High pressure will center
itself over the region by morning. This will create good
conditions for radiational cooling...with clear skies and near
calm winds. Add on a still fresh snow pack...so dropped lows north
of I-70 for tonight to around zero. Some spots in the country will
be below zero. Around the Ohio River lows will drop to the teens.
Short term /6 am this morning through Thursday night/...
as it moves east...high pressure will keep dry weather over the
region on Wednesday. Clouds will increase with isentropic lift
well ahead of developing low pressure over the plains.
The low will travel to the Great Lakes on Thursday...trailing a
cold front across the iln area. Models indicate rather limited
and shallow moisture and lift with this system...producing light
precipitation. Model temperature profiles indicate a mixed bag of
precipitation. Current thinking is that precipitation will begin as a brief
period of freezing rain...mixing with sleet and then changing to
rain as warm advection brings above freezing temperatures ahead of the
front. Will mention chance for freezing precipitation area wide in
updated severe weather potential statement. May eventually need Winter Weather Advisory for light
icing when timing...location and temperatures become clearer
closer to the event. All precipitation should change to snow toward the
tail end of the event in cold advection behind the front...with
only minor accumulations expected Thursday night.
With NAM and GFS MOS in close agreement...highs are forecast to reach
the 20s and 30s on Wednesday. Model differ for Thursday...with the
GFS predicting warmer conditions. Split the difference for this
package resulting in highs up to 40 for most locations.
Long term /Friday through Tuesday/...
cold air advection and slightly cyclonic low level flow may allow for a few
lingering snow showers across our east early Friday morning.
Otherwise...surface high pressure will build into the
region...leading to decreasing clouds through the day on Friday.
Highs on Friday will be seasonably cool...ranging from the lower 20s
north to lower 30s south. The surface high will slide across our
area Friday night...leading to mostly clear skies and lows down into
the single digits to middle teens.
Low level flow will begin to back around to the west and then
southwest Saturday into Saturday night as the high pushes off to the
east and short wave energy approaches from the west. The models
appear to be having some difficulty in resolving how much to phase
the northern stream short wave with the energy moving across the
Gulf Coast states. As a result...there are some differences between
the 12z GFS/CMC/ECMWF in the placement and timing of the associated
surface features and their resulting thermal fields. That being
said...they are all still in general agreement spreading a decent
chance of precipitation across our area late Saturday night into Sunday. At
this point it looks like we would be cold enough for mostly
snow...but will introduce a rain snow/mix across the south as both
the GFS and European model (ecmwf) are suggesting that a little warmer air may sneak
up into our area.
Precipitation will begin to taper off Sunday night as the wave moves off to
the east. However...developing cold air advection and a fetch off of Lake Michigan
will allow for some lingering snow showers later Sunday night into
Monday morning. In good cold air advection...expect only a minimal rise in temperatures on
Monday...ranging from the middle teens north to middle 20s south. Surface
high pressure will build east across the region Monday night into
Tuesday. With clearing skies Monday night...low temperatures will
likely end up being dependent on how much snow is possibly on the
ground from the system on Sunday.
Aviation /06z Wednesday through Sunday/...
some mist has developed at a few sites which should last through
the early part of the taf period. Once this dissipates VFR
conditions will prevail through the taf period. Cirrus will
overspread the area and thicken with time. Light and variable
winds will become south southeast at less than 10 knots.
Outlook...MVFR ceilings and visibilities along with a period of
freezing rain possible Thursday. MVFR ceilings and visibilities
possible again Sunday.