Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
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FXUS61 KILN 221048
Area Forecast Discussion
National Weather Service Wilmington OH
648 AM EDT Sat Oct 22 2016
The region will find itself under northerly flow today as it is
trapped between a strong low pressure system over New England and
building high pressure in the lower Mississippi Valley. This will
bring cool conditions today. By Sunday, the high will be over the
southeast U.S. which will turn the winds to the south bringing a
quick warm up. Another cold front will drop temperatures for the
beginning of the work week.
.NEAR TERM /THROUGH TONIGHT/...
With a closed H5 low located over the ne U.S., the region is under
a northerly CAA flow. This is bringing lake effect clouds down
across the area. However, the low level flow is beginning to back,
allowing breaks in the clouds. These breaks will work se into the
fa this morning. Unfortunately, H8 temperatures will remain below
0C today and as diurnal heating kicks in, lapse rates should kick
over and the sc will redevelop. Therefore increased the cloud
cover for the late morning into the afternoon.
Winds will pick up again today as mixing occurs. Gusts will range
from 10-15 in the Tri-state to 20-25 in Central OH.
With the cloud cover to help limit the solar insolation,
temperatures will be well below normal again, reaching the lower
to mid 50s. This will be 5-10 degrees below normal.
.SHORT TERM /SUNDAY THROUGH MONDAY/...
The upper level low will kick e tonight allowing the H5 heights to
rise. At the surface, high pressure will work from the lower MS
valley into the se U.S. Still expect some lingering clouds tonight
as this transition occurs. Temperatures aloft will be warming
tonight, but feel that there will be enuf decoupling of the
boundary layer that sfc temperatures will see a normal diurnal
By Sunday, sfc winds will have turned to the sw. This will bring
in warmer air and with a lack of cloud cover temperatures will
warm to near 70 in the Tri-state and mid to upper 60s elsewhere.
Models bring a H8 jet of 40 to 50 kts across the fa, so expect
some wind gusts to around 30 mph on Sunday.
Sunday night a cold front will drop down from Lake Erie. There is
enuf moisture will the system to produce some clouds with fropa,
but right now it is looking like the front will come through dry.
By sunrise Monday, the front will be south of the Ohio River,
leaving the fa mostly clear. Monday will be a little cooler under
northerly surface winds. Highs will range form the upper 50s in
Central and West Central OH to the mid 60s in nrn KY.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Tuesday morning surface high pressure will move in from the north
allowing winds to go mostly calm . Some high clouds may be moving
in from the west, but chances seem to be growing that frost may be
During the day Tuesday a shortwave will move over the midwest and
head east. At the same, the upper level trough axis over New England
will pull east. In response to the shortwave, a surface low will
form near the Nebraska/ Iowa border. During the day Wednesday the
shortwave will strengthen and start to wrap up. Both the GFS and
ECMWF are in pretty good agreement with this and have the shortwave
wrapping up into a low over Wisconsin Wednesday evening. Across
southwest Ohio low level flow will continue to increase ahead of the
low with strong upper level divergence. Divergence will come from
the RRQ of the upper level jet streak along with upper level
diffluence from the splitting of 250 mb winds. Instability at this
time looks limited but shear profiles are impressive (SFC-1km ~35kts
via GFS forecast soundings). Any change in the placement of the low
will easily change the values and orientation of the bulk shear
vectors though. Future model runs will help to continue to refine
this. Thursday afternoon into Friday the shortwave will push east
but the ECMWF and GFS differ on how the shortwave ejects. The ECMWF
picks up the shortwave in the main flow moving a cold front through
the area. The GFS on the other hand washes the shortwave out and
slowly pushes it southeast. The CMC has the shortwave diving into
southeast Texas and appears to be the outlier. For now have kept the
forecast trended towards ECMWF.
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --Sfc high pressure will settle into the Tennessee Valley through
the TAF period, providing quiet weather for the region.
Some MVFR clouds continue to stream southeast into the area and
are expected to linger through mid morning for the western
terminals. Otherwise, in the CAA pattern, expect Cu field to
develop into a VFR deck through the afternoon before shifting east
through the area through this evening.
Northwest winds of around 10 to 12 kts are expected during the
afternoon with a few gusts to 15-18 kts possible for eastern
sites of KCMH and KLCK where the pressure gradient will be the
tightest. Winds will become westerly and light after 00z Sunday.
OUTLOOK...No significant weather expected.
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