Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 251754
Area Forecast Discussion
National Weather Service Wilmington OH
154 PM EDT Sat Mar 25 2017
A southerly flow ahead of low pressure will provide warm
temperatures and mainly dry weather today. Showers and a few
thunderstorms will develop tonight through Sunday when the low is
forecasted to travel to the Western Great Lakes. Another upper
level disturbance will then move across the area Monday
afternoon into Tuesday providing a continued chance of showers
and thunderstorms for the area.
.NEAR TERM /THROUGH TONIGHT/...
A vertically stacked low pressure can be seen rotating across
the midwestern United States this morning on WV with a stalled
boundary located in northern Ohio. This low pressure will slowly
pull northeast today with the stalled boundary across northern
Ohio pulling north as a warm front. As the low approaches the
forecast area this afternoon weak PV will move across the area
along with weak WAA. This mornings KILN sounding revealed a PWAT
of 0.83" (which is slightly above the 75th percentile for this
time of year) with an 850mb temperature of 10 degrees C.
Forecast soundings for this afternoon show PWATs continuing to
slowly rise but a stubborn CAP slow to erode. Given this CAP it
is not surprising that high res models don`t show much
precipitation for this afternoon. Not until late this evening
does a band of precip from the upper level low arrive across our
far western zones. Given the mentioned above have delayed onset
of precipitation a couple of hours later.
A vertically stacked low pressure system will move slowly to
Missouri today. Moisture will increase gradually in the
southerly flow ahead of the low, producing mainly mid and high
clouds. However, a few showers and thunderstorms may develop
primarily over western counties this afternoon in a modestly
unstable regime containing under 200 J/KG CAPE. Have backed off
PoPs from previous forecasts due to slower progression of the
High temperatures in the low to mid 70s will be close to 20
degrees above normal.
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Low pressure system will be lifting from Missouri to Chicago
tonight through Sunday. Even though the system will be weakening
as it moves into a broad upper ridge, a large swath of moisture
and lift ahead of the low will impact the ILN area. Showers will
become widespread tonight through Sunday, and thunderstorms
will also be possible. Severe weather threat appears to be
limited by marginal CAPE of around 500 J/KG.
High temperatures will be reduced by clouds and precip, with
highs in the 60s expected.
.LONG TERM /MONDAY THROUGH SATURDAY/...
An active weather pattern for the upcoming week. Initial upper level
and surface low to lift northeast across the Great Lakes Sunday
night. Precipitation to come to a temporary end Sunday night into
Monday, as ridging builds in ahead of next upper level trof.
Monday starts out dry early with pcpn overspreading the region, as
next shortwave and surface low tracks northeast from the southern
plains into the Great Lakes Monday night. In the warm moist
environment temperatures on Monday to rise to highs from the upper
60s north to the lower 70s south.
As this system pushes off to the east the pcpn to end Tuesday, as
surface high begins to builds into the Great Lakes. Temperatures
will remain above normal, with Tuesday`s highs ranging from the
lower 60s north to the upper 60s south.
Surface high to slide east across the Great Lakes Wednesday. This
will provide dry weather with temperatures closer to normal. Highs
on Wednesday to range from the upper 50s northwest to the mid 60s
Model solutions diverge on handling late week weather system. GFS
showing an open wave in split flow pattern, while the more
consistent ECMWF and Canadian solutions show a closed low. Will
trend the forecast toward the ECMWF/Canadian. Will bring chance pops
in Thursday and increase these pops to likely Thursday night into
Friday, as the upper low and associated surface low lift northeast
from the mid MS Vly into the Great Lakes. As instby increases will
include a chance of thunder Friday afternoon into Friday evening.
Highs Thursday and Friday generally 60 to 65.
Precipitation is expected to end early Saturday as weak high pressure
builds into the region.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
All TAF sites currently VFR this afternoon as a surface low over
the Midwest slowly pulls northeast. Latest runs of high res
models continue to show precipitation moving in from the west
around 6z Sunday morning. The showers and isolated thunder
Sunday morning will move into the area in the form of a band and
will likely loose cohesion as it progresses eastwards.
Sunday afternoon forecast soundings begin to destabilize with
ceilings lowering towards MVFR as the upper level low moves over
central Indiana. As forecast soundings destabilize showers and
thunderstorms will develop across the forecast area with higher
coverage across our eastern TAF sites. Thunder will be likely in
any storms that develop Sunday afternoon into evening. The
chance of precipitation will continue into Sunday evening as the
upper level low moves overhead.
OUTLOOK...MVFR ceilings and visibilities will be possible late
Monday into Tuesday morning.