Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 160313
Area Forecast Discussion
National Weather Service Wilmington OH
1013 PM EST Wed Feb 15 2017
Weak high pressure will briefly build into the area late
tonight into Thursday. A warm front will develop across the
region Thursday night and lift north of the area Friday. This
will mark the beginning of an extended period of very warm
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --Radar is showing a little flurry activity dropping south thru
the srn portion of Central Ohio. Expect these to be out of the
region by midnight.
Meanwhile despite some neutral to caa advection at H8, the sc
have been eroding some. So backed off on the sc building down
into the tri-state. However, mid clouds are expected to swing
down into the region.
Lows will drop down to the lower to mid 20s overnight.
-- End Changed Discussion --
.SHORT TERM /THURSDAY NIGHT/...
Weak high pressure will build into the area on Thursday and low
level temperature advection will turn warm. This should result
in stratocumulus diminishing during the day. However, a short
wave dropping into the region in northwest flow will bring a
mid deck across the region Thursday afternoon into Thursday
night, with these clouds moving out late Thursday night. Highs
will be a few degrees higher than today. Lows will likely be
reached Thursday evening with steady or even slowly rising
temperatures late Thursday night.
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Very high confidence that this period begins an anomalous stretch of
warmth that becomes impressive by all February measures in terms of
magnitude and duration. Also high confidence in weekend rainfall
potential being insignificant /amounts/ focusing along and south of
the Ohio River /Saturday/...and that appreciable threat of any more
significant sensible weather holds off until Tuesday
night/Wednesday. But all the talk will most definitely revolve
around the stretch of late February warmth which begins Friday and
likely goes all the way through next Friday /Day 9/.
In the details...at 12Z on Friday there is strong deterministic and
ensemble agreement in a deep longwave trough over Nova Scotia and
compact/closed low in the active southern stream over Texas...which
will be in the process of opening up/shearing northeastward into a
generally unfavorable regime to support it /confluent flow/.
Residual cold air with the departing longwave trough over the
northeast will have long since vacated the Ohio Valley...with large
pool of above normal temps set to push in as heights rise over the
eastern U.S. downstream of the aforementioned trough in TX. By
Saturday...agreement remains strong in the data that TX trough
continues to open up/weaken as it shifts through the middle/lower MS
valley...while even deeper/sharper srn stream energy digs thru
southern California and old Mexico. Heights will continue to rise
into Saturday morning before the remnants of the rapidly weakening
upper trough reverse that trend...which will induce a threat of
light rain/showers along and south of the Ohio River /nearest the
maximum of pv advection aloft and height fall center/ Saturday and
Saturday evening as these weak dynamics /and rather anemic moisture
transport/ shift through.
By 12Z Sunday...wave continues to significantly deamplify as it
shifts through the Mid-Atlantic...with no sense of appreciable cold
advection in its wake given srn stream origin. Attention then turns
to very deep/sharp/anomalous mid/upper level trough shifting through
Mexico...with impressive /climatologically significant/ height rises
downstream into the Ohio Valley Sunday thru Tuesday. All manner of
climo-based tools /including NAEFS standardized anomalies...NAEFS
climate percentiles...etc/ suggest the mid/upper level ridge will be
in the 95-99%ile in magnitude...if not outside the 30 year analysis
used in these products. Not surprisingly...GEFS/ECMWF temp anomalies
are running 1.5 to 2.0 sigma above climo at 925/850mb. This is a
strong signal which has been duplicated over many days of ECMWF/GFS
A long-duration period of February warmth is expected...rivaling
similar Feb. warm stretches from 2000...1976...1930...and 1880.
Starting on Friday...a 5 to 7 day stretch of high temperatures
averaging out in the upper 50s /central Ohio/ to lower 60s /Ohio
River/ is highly likely. The warmth will peak on Monday/Tuesday
before clouds with approaching moisture ahead of the now-ejecting
srn stream trough temper things a little bit by Wednesday. Monday
and/or Tuesday may feature a 70F reading or two along and south of
the Ohio River. Latest ILN forecast is already forecasting a record
high minimum temp at CVG for Tuesday /Day 6 - 51 degrees/ which is
indicative of the confidence/magnitude of this warm stretch. But it
is worth mentioning that upcoming warmth does not appear `record
breaking` in magnitude over multiple days or with the more-often
higher visibility max temperature -- as daily max temp records are
near/above 70. Instead...the upcoming period appears more
significant in terms of length/duration of anomalous Feb warmth.
Noting that 2000 was the last /and perhaps most significant of all
Feb warm spells/ it was not at all surprising to see the 15.12Z CIPS
analogs suggesting the GFS-forecast pattern for late this weekend
has high correlation to the pattern of late Feb/early Mar 2000.
Lower confidence is noted in precipitation chances Tues/Wed of next
week given speed /not so much depth/ of the srn stream trough as it
ejects out of deep south TX into the wrn Gulf. All NWP solutions
have a deep system...but speed /longitude/ of the trough axis is
highly variable by Day 7...suggesting a general increase in rain
chances is warranted in the forecast...but far too early to
Given this is a strong srn stream system...with further energy again
digging into the western CONUS...the warmth will likely continue
well past mid-week into early next weekend.
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
An area of scattered flurries will affect Central Ohio TAFS for
the first couple of hours of the taf period. Don`t expect any
reduction in visibility, but covered the pcpn with a VCSH.
H8 CAA this evening should push the SC deck southward. Have the
SC reaching CVG/LUK around 06Z. For the rest of the TAFS,
ceilings should remain VFR. Some of the guidance is trying to
indicate the MVFR cigs will be possible in the nrn tafs around
12Z, but right now it looks like the chance is low enough to
leave out of the forecast.
WAA will begin after 12Z Thursday, and there should be an
erosion of the SC from sw to ne as this happens. have the lower
VFR SC going scattered all all tafs by 21Z.
OUTLOOK...No significant weather is expected.