Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Wilmington Ohio
104 PM 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/...
dry slot and warmer temperatures moving into SW Ohio with
temperatures above freezing across the forecast area. Therefore...have dropped
the Freezing Rain Advisory. Based on upstream temperatures have
nudged up temperatures slightly.

Previous discussion...
middle level short wave and associated 800 mb axis of low level convergence has
led to a band of light to moderate rain. With cold and dry air in
place...initial precipitation type along the leading edge was freezing
rain. This initial band of precipitation is moving east and the temperatures
are warming up.

Additional precipitation developing in warm sector ahead of approaching cold
front moving into western Indiana. Have dropped counties across
the west central Ohio where temperatures have warmed into the middle
30s and Road temperatures are above freezing.

Southerly flow will allow for temperatures to continue to
increase this morning. Have allowed a little lag for Road
temperatures to warm up above freezing across the Scioto valley.

Precipitation chances to continue 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 as pressure
gradient increases. 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 /18z Thursday through Tuesday/...
middle level short wave trough to move through the Great Lakes today/tonight. Associated
surface low over lower Michigan to lift NE with southward trailing cold front
over Indiana sweeping east through the taf sites this afternoon. MVFR ceilings will
develop with this frontal passage of this front. The development
of a few showers will also be possible. Due to lack of widespread coverage
have limited mention to vcsh. Have ceilings drop to IFR for a period late
this afternoon at kday. Expect MVFR ceilings through the night with a few snow
showers possible off Lake Michigan. These snow showers could
affect the western taf sites but due to limited coverage have
omitted the mention at this time. Ceilings to improve to VFR by Friday
afternoon as surface high pressure builds in.

Southwest winds will gust up to 28kts and veer to the west this
afternoon. These west winds will continue to gust up to 24 kts and veer
northwest tonight.

Outlook...IFR ceilings and visibilities likely Sunday into Sunday
night with MVFR conditions possibly continuing into Monday.


Iln watches/warnings/advisories...


near term...Arkansas
short term...Novak
long term...

National Weather Service Glossary of Abbreviations