Area Forecast Discussion
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FXUS61 KILN 010831
Area Forecast Discussion
National Weather Service Wilmington OH
431 AM EDT Sat Oct 1 2016
A large upper level low will drift slowly north through the Great
Lakes this weekend. Under the influence of this upper low expect
cool temperatures and a chance for rain today and Sunday. A
warmer and drier airmass will build into the region through the
middle part of next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Upper level low evident on water vapor imagery centered over
southeast Indiana this morning. Model solns generally similar with
this upper low drifting a little north toward the Indiana/ Michigan
border by evening. Best lift/moisture to lift north out of ILN/s fa
around the periphery of this upper low. Weak forcing in the form of
low level convergence rotates around this low into ILN/s fa this
afternoon. Therefore, will continue likely pops over the western
counties. With marginal instability will continue to limit thunder
chances to slight chance. Temperatures will continue to be cool
with highs ranging from mid/upper 60s west under the low to around
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
With the upper low track ene across southern lower Michigan, rain
chances will diminish tonight. lows look close to normal and
generally in the lower and middle 50s.
As the lower drifts ene into srn Ontario Sunday expect to see more
in the way of sunshine. In the broad cyclonic flow around the
periphery of this low can not rule out afternoon showers. The best
threat for showers will occur across the ne counties. Expect highs
on Sunday to range from the upper 60s north to the lower 70s south.
The upper low finally loses it`s grip on the region and surface
high pressure builds in from the west. Expect dry conditions with
temperatures near normal Monday. Highs to range from around 70
north to the lower/middle 70s south.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The long term will open up with a closed low ejecting off to the
east over New England with weak mid level ridging building into
the region. The latest 30.12Z CMC, GFS, and ECMWF have come into
pretty good agreement with the timing of the low pushing off the
coast and away from the CWA. As the weak ridging forms over the
area another upper level system will be pushing into the Mountain
West which will push the next cold front into the area Friday.
Model discrepancy continues to be an issue for the second part of
the next work week though. The 30.12Z ECMWF and CMC both try to
linger some of the energy from the upper level low over New
England under weak ridging. This in turn helps to block
progression of Matthew and push the cold front through the area
Regarding more of the details, a general warming trend is expected
to commence starting Tuesday thanks to mid level ridging and a
warming low level thermal profile. 850 mb temperatures Monday are
forecasted to be around 9 degrees C and warm towards 13 degrees C by
Wednesday. This would support high temperatures in the upper 70s to
around 80 degrees, or about 10 degrees above normal for this time of
year. PWATs also fall below 1.00" so am expecting dry weather Monday
For the second half of the extended models begin to differ on the
timing of the passage of a surface cold front and the circulation of
Matthew. The ECMWF has a trough axis push through the area Friday
morning supporting a cold front passage Friday morning as well. The
GFS on the other hand supports the cold front passing through Friday
evening. In general, PWATS (~1.2") and upper level lift appear to be
sufficient for showers and thunderstorms with the frontal passage
but given low confidence in timing have kept PoPs in the chance
category for now. Have also kept grids reflecting more of the ECMWF
and CMC solution.
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
Slow moving upper low centered near the OH/IN border will
continue to affect TAF sites. While conditions are VFR to start,
MVFR ceilings, visibilities and showers may develop in persistent
low level moisture, and a few thunderstorms may occur this
afternoon in the vicinity of DAY, CVG and LUK as instability
increases. VFR is expected after 00z Sunday under decreasing
instability and forcing as the upper low lifts north to Michigan.
Winds are forecast to stay under 10 knots out of the south.
OUTLOOK...IFR ceilings possible Sunday near 12z.