Scientific Forecaster Discussion
fxus61 Kiln 220713
Area forecast discussion
National Weather Service Wilmington Ohio
313 am EDT Tue Oct 22 2019
a cold front is working through the area early this morning
brings isolated showers and gusty winds. Cooler and blustery
conditions will occur on Tuesday as strong low pressure persists
over Ontario. High pressure over the middle Tennessee Valley
will build in on Wednesday, offering dry weather and near
seasonable temperatures. Southerly flow will bring warmer
temperatures for Thursday.
Near term /through today/...
cold front continues to move eastward, keeping any showers contained
to eastern areas early this mornings. As of 2am, modest
clearing was already occurring across western area as the dry
conveyor belt provides much drier air behind the front. All
shower activity should be cleared and east of the area and hour
or two after sunrise. Mostly sunny skies to dominate the first
half of the day before cumulus begins to develop and spread,
especially along and north of I-70. Further south toward the
Ohio River, more abundant sunshine prevails as cold air
advection is rather weak with winds out of the southwest. With
the center area of low pressure slow to pull away into southeast
Canada, blustery winds are forecast once again today. Strongest
winds occur along and north of I-70 with winds gusting 30-35 mph at
times. A few isolated wind gusts to 40 mph are possible. South
of I-70, regular gusts of 20-25 mph are expected.
Overall, temperature advection is fairly neutral so temperatures
are forecast to rise into the low to mid 60s, especially along
the Ohio River. With cloud cover across the north, temperatures
may struggle a little but still think mid to upper 50s are
achievable today. Upper 30s and low 40s for most, but some mid
30s may be possible in sheltered areas.
Short term /Wednesday through Wednesday night/...
fairly benign Wednesday as surface high pressure builds over the
Tennessee Valley. Southwesterly flow and abundant sunshine helps
push temperatures a few degrees above normal as temps rise into
the mid and upper 60s. Nighttime low temperatures a few degrees
above normal with widespread mid 40s under clear skies.
Long term /Wednesday night through Monday night/...
although not too much in the way of active weather is expected to
start the long term period, it is not expected to be entirely quiet
either as a moisture-starved cold front progresses through the Ohio
Valley during the day on Thursday. And with southwesterly surface
flow well-established early on Thursday, expect what will likely be
the warmest day in the long term fcst period for at least the
southeastern half or so of the iln forecast area as highs reach into the lower
70s for most of the ahead of the aforementioned front. Further to
the north/west, clouds may keep temps a bit cooler across portions
of west-central Ohio and east-central Indiana.
It is important to mention, however, that even at this point,
forecast confidence tails off fairly quickly beyond Thursday owing
to uncertainties in exactly how digging short wave energy across the south-
Central Plains evolves for the end of the week. The GFS continues to
show a wetter solution for Thursday night into the day on Friday
while the European model (ecmwf) remains persistent in its depiction of a cutoff low
in the desert SW by late in the workweek opposed to the more
progressive GFS scenario. The European model (ecmwf) solution would support a drier
Thursday night into Friday but perhaps a wetter weekend as the
aforementioned low eventually ejects into the Southern Plains and
Mississippi River valley by Saturday into Sunday. This particular
evolution would spell a fairly wet Saturday night through Monday
morning scenario for much of the Ohio Valley -- and there is some
support for this even in the eps (with ensemble mean quantitative precipitation forecast > 1" for a
large portion of the region in the Saturday night into Sunday night
time period). However, conversely, the gefs is on the other end of
the spectrum with ensemble mean of only a tenth of an inch or so for
most of the area during the Saturday-Monday time frame. This, of
course, leads to uncertainty into exactly how to handle the late
week forecast, and did not have confidence to go with a dry forecast
for this weekend and handled the uncertainty with high chance pops
for now. However, should the longer-range guidance begin to trend
toward a closed low/European model (ecmwf) scenario (with seems most plausible at
this juncture), pops and quantitative precipitation forecast may need to be further increased with
future fcst cycle updates.
No matter how the weather pattern evolves for the end of the long
term period, temperatures will be near to slightly below normal for
the end of the week into this upcoming weekend, with lows in the
upper 30s and 40s and highs mainly in the upper 50s and 60s.
Aviation /07z Tuesday through Saturday/...
light showers still occurring over the eastern taf sites as the
cold front slowly moves through eastern Indiana. Observations
near the front indicate a brief shift to 250-270 with the
frontal passage before shifting back to 200-230 with the mean
flow. Ceilings are mainly MVFR but there have been a few
temporary improvements for some taf sites. After the frontal
passage, expecting more significant improvements to cloud cover
as dry air moves in tonight.
Winds will diminish some overnight to around 12 to 15 kts and
then gust up to 25 kts on Tuesday as the cold air filters into
the region. VFR ceilings around 5000 feet are likely Tuesday
aftn, especially across the northern taf sites.
Outlook...MVFR conditions possible again on Friday with the
next cold front.