Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
422 am EDT Friday Aug 28 2015
the center of high pressure will slip into the Appalachians
today...but will provide another dry day. A weak upper level
disturbance will result in the chance for a few showers and
thunderstorms...primarily Saturday night into Sunday. Seasonable
temperatures are expected through the weekend.
Near term /until 6 am this morning/...
high pressure currently over the region will continue to push off
to the east today. Skies should be mostly sunny as some upper
level moisture works in from the convection out over the plains.
Return flow on the back side of the high will help push
temperatures up into the upper 70s to lower 80s today.
Short term /6 am this morning through Sunday/...
even though the high will be centered off the East Coast
tonight...it will provide another dry night.
On Saturday a 500 mb will swing out of the the upper MS valley into
the Great Lakes. The GFS has become the quickest with this
system...pushing precipitation into the region quickly on Saturday.
Meanwhile the European model (ecmwf)...holds precipitation back until Sunday...as it is on
the slower side of guidance. The NAM is in the middle of these two
solutions and is the preferred solution for this run. Delayed
precipitation chance until late Saturday afternoon and kept them limited to
the NE counties. As the system pushes in Saturday night it is
weakening so kept slight chance probability of precipitation in for Saturday night across
the entire region.
On Sunday...lingering lift and moisture across the region will
act as a focus for scattered showers and thunderstorms.
Highs over the weekend will be in the lower to middle 80s...with lows
60 to 65 Saturday morning and the middle to upper 60s Sunday morning.
Long term /Sunday night through Thursday/...
the 27.12z models are starting to come into a little better
agreement with upper level flow patterns for at least the first half
of the extended period. Given the continued significant spread
amongst the gefs members however...confidence is still below normal
so have generally used a blend of the GFS/European model (ecmwf) and wpc guidance.
Have therefore gone with broad brushed slight chance probability of precipitation for
much of the County Warning Area on Monday. The remainder of the extended period
looks generally dry at this time.
There is general agreement on a developing upper ridge over the
plains early next week that will broaden as it shifts eastward over
the eastern Continental U.S.. this will lend itself to warmer than normal
temperatures given gefs 850mb temperature and 500mb height anomalies
are around 1 to 2 Standard deviations above normal for parts of the
area. Expect high temperatures to warm by a degree or two each day
Monday through Wednesday with highs generally in the middle to upper
80s. Would not be surprised by some 90s near and south of the Ohio
Aviation /07z Friday through Tuesday/...
high pressure over the area will slide east and winds will shift
to the east-southeast and remain on the light side <5kt. Low
pressure in the plains will track to the upper Midwest and cirrus
cloud deck is expected to stream into the region this morning and
last through the day...lowering to a deck around 15kft at the tail
end of the valid period.
Outlook...no significant weather expected.