Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
405 PM EST sun Dec 28 2014
high pressure is forecast to provide dry weather through Thursday.
Temperatures will slip below normal as colder air arrives on a
northerly flow around the high. Complex low pressure may bring
precipitation next weekend.
Near term /until 6 PM this evening/...
kept low chance probability of precipitation early in far southeast for lingering rain
along departing boundary. Otherwise expect dry weather with a
broad expanse of high pressure starting to build in on a westerly
flow aloft. Clouds should show a decreasing trend
overnight...though perhaps not as quickly as suggested by a model
blend. Lows are forecast to range from the middle 20s northwest to
the lower 30s southeast.
Short term /6 PM this evening through Tuesday night/...
high pressure will continue to build in from the west. No precipitation
is expected under a dome of dry air and subsidence. The center of
the high will be far to the west...dropping from the northern
rockies to the Central High plains. The southward movement of the
high will allow cold advection over the Ohio Valley on a northerly
flow. Highs on Monday will be mainly in the middle and upper
30s...decreasing to average in the lower 30s for Tuesday.
Long term /Wednesday through Saturday/...
surface high pressure will move from the plains to the lower
Mississippi Valley at the start of the forecast period. This high
should keep dry conditions in place across the area Wednesday and
Thursday with generally below normal temperatures.
The main question for this period is the evolution of the southwest
Continental U.S. Upper level low and associated cyclogenesis east of The
Rockies. The 12z models have slowed the ejection of energy from the
southwest Thursday and Friday...and have also tended to track the
resulting surface low farther south. The eastern Pacific Ocean upper
level ridge almost takes on an Omega block appearance Wednesday
night...which would lend credibility to a slower progression of the
downstream system. This forecast leans toward the 12z GFS solution
as it is slower than the 06z GFS/00z European model (ecmwf)...but not as dramatically
slowed as the 12z European model (ecmwf). Given this scenario...Friday probability of precipitation have been
reduced relative to the previous forecast since the onset of
precipitation should be more toward Friday night. Snow or a mixture
of snow and rain will be in the forecast for this time. BUFKIT
soundings have some indications of freezing rain Friday night...but
too much uncertainty is still in play for inclusion in this package.
Snow and mixed precipitation should turn to rain on Saturday before
diminishing Saturday night.
Some chance for light snow and rain showers is maintained Sunday in
the wake of the departing system.
Aviation /20z Sunday through Friday/...
MVFR stratus deck behind the frontal boundary will linger into the
overnight period. This deck will be slow to push east-southeast...but will
lift to above 2k feet in the 03z-07z timeframe for the northern taf
sites. Rap/NAM 925 level seems to depict the low cloud level
fairly well...so am lingering an MVFR deck at kcvg/kluk the
longest...finally lifting in the 12-15z timeframe. VFR after that time.
Outlook...no significant weather is expected at this time.