Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
509 am EST Thursday Jan 29 2015
a cold front will move through the region today. An upper level
disturbance and winds off of Lake Michigan will keep precipitation
chances in the forecast through the morning hours on Friday. High
pressure will briefly work into the area for Friday night and
Saturday before a stronger system brings the chance for
accumulating snow to the region beginning Saturday night.
Near term /until 6 PM this evening/...
an area of rain will move through the forecast area this morning. Southerly
flow will allow for temperatures to continue to increase this
morning. Most locations across the SW half of the forecast area are now above
freezing while locations across the NE half of the forecast area are still
below freezing. Even in areas where air temperatures are above
freezing some of the Road temperatures are below freezing. This
will allow for some slick spots across the area. Continued Special Weather Statement for
locations not included in the Freezing Rain Advisory. Added some
more counties onto the Freezing Rain Advisory where Road and air
temperatures were cooler.
As warmer air continues to move into the area today all locations
will go above freezing. There will be a lull in the precipitation
after this initial band of precipitation moves through however
expect additional precipitation chances later today as the cold
front approaches and moves through the region. As the colder air
begins to work into the forecast area rain showers will begin to transition
over to snow showers.
Winds will increase across the area through the day. Wind gusts
will increase as well with some gusts around 30 miles per hour possible at times.
Short term /6 PM this evening through Saturday night/...
most locations will have already transitioned over to snow showers
by the start of the short term period. An upper level disturbance
and 800 mb winds off of Lake Michigan will keep precipitation chances
in the forecast through Friday morning before tapering off Friday
afternoon. A band of snow off of the lake will likely bring some
light snow accumulation to portions of the forecast area tonight into Friday
morning. Snow accumulations are generally expected to be light and
under an inch. Winds will continue to gust at times through the
overnight hours tonight and into the day on Friday.
High pressure will begin to work into the area for Friday night
and remain across the area for Saturday. This will allow for dry
conditions across the forecast area. A larger system will begin to move into
the forecast area Saturday night bringing snow to the area.
Long term /Sunday through Wednesday/...
00z GFS and European model (ecmwf) in relatively good agreement in keeping
approaching short wave with modest amplitude while the Canadian is
deeper/sharper and thus slower. Have trended forecast towards
GFS/European model (ecmwf) which also has support from the 00z gefs mean. This would
suggest that a comparatively weak surface low will pass well south
of the forecast area. However a large precipitation shield will be
across the region at the start of the period with most if not all of
this snow. This is forecast to continue through the day and move off
to the east Sunday night. Still plenty of room for error as models
have been struggling with this system. But felt confident enough in
measurable precipitation occurring to bump probability of precipitation up slightly from
earlier forecast. There is a very good chance of seeing accumulating
snow from this although it is way too early to think about specifics
in terms of amounts.
Modified Arctic high pressure will build in Monday and move off to
the east Tuesday. Temperatures will be well below normal. Depending
on snow on the ground and sky cover there is the potential to be
even colder particularly Monday night. 00z models showing some
discrepancies with timing of the next system. GFS seemed too fast
and so ignored it. Thus brought a cold front into the region on
Wednesday with a chance of snow showers.
Aviation /10z Thursday through Monday/...
VFR conditions will prevail through the early part of the taf
period. Showers falling out of a middle deck will spread into the
region around 12z and quickly move through with a chance of
precipitation for only a couple of hours at any one locations.
Will be a close call...but latest high resolution guidance
suggests that temperatures will be just rising above freezing as
precipitation moves through. While tafs only mention rain...there
still is a chance of freezing rain at all but the Cincinnati
Once this band of precipitation moves through expect winds to
become gusty. MVFR ceilings will move in ahead of a cold front.
Expect frontal passage between 18z and 22z. Winds will veer to the
west and remain gusty with ceilings lower a bit further. Cannot
rule out a few showers with the front but probability does not
look too high so only included vcsh. Winds will diminish a bit
after 00z with a slight improvement in ceilings.
Outlook...MVFR ceilings will likely continue through Friday. IFR
ceilings and visibilities likely Sunday into Sunday night with
MVFR conditions possibly continuing into Monday.
Ohio...Freezing Rain Advisory until 11 am EST this morning for ohz026-