ILN issues Area Forecast Discussion (AFD) at Feb 8, 12:42 PM EST526
FXUS61 KILN 081742
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
1242 PM EST Sat Feb 8 2025
.SYNOPSIS...
A low pressure system moving through the Ohio Valley will bring
rain to the region today, with a period of freezing rain
possible along and north of I-70. High pressure and a drier
airmass will build into the region for Sunday.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
Based on latest guidance, decided to add Union and Delaware
Counties in Ohio to the Winter Weather Advisory for freezing
rain potential this afternoon through this evening. Although
there will be a sharp cutoff to the freezing rain/rain
delineation, northern parts of both of these counties may see a
more prolonged period of freezing rain, leading to ice
accretion (especially on elevated surfaces, including
bridges/overpasses) of up to a tenth of an inch.
PREVIOUS DISCUSSION...The initial wave of more significant
precipitation is passing just off to our south early this
morning. Farther north across our area, weak isentropic lift is
resulting in spotty weak returns on radar, but not sure how much
of this is even reaching the ground. Temperatures along and
north of about a Connersville through Wilmington to Chillicothe
line are at or below freezing, so some spotty very light
freezing rain will be possible this morning across about the
northern half of our area.
A more significant wave of pcpn will overspread our area from
the west late this morning and into the afternoon as a surface
low pressure system rides east along the Ohio River. Temperatures
will slowly rise through the day as surface winds become more
southeasterly ahead of the approaching low. This should allow
for temperatures to push up above freezing across much of our
north by the time the better pcpn moves in. The exception may be
across our far northern counties, where the surface flow will
remain more easterly. In these area, temperatures may struggle
to get much above freezing through the day. As a result, some
more significant ice accumulations will be possible across
Mercer, Auglaize and Hardin Counties and perhaps northern
portions of Shelby and Logan Counties, so will go ahead and
issue a Winter Weather Advisory for those areas. To the south
of this, expect a briefer period of freezing rain at onset,
before transitioning over to all rain, and will cover those
areas with an SPS.
We will end up with a decent temperature gradient across our
area today. Daytime highs will range from the lower 30s in the
northwest to close to 60 degrees in our far southeast.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM SUNDAY/...
As the surface low moves off to the east, it will drag a cold
front southeast across our area tonight with pcpn tapering off
behind the front. Surface high pressure and a drier, seasonable
airmass will settle into the area for Sunday. Lows tonight will
be in the mid to upper 20s with highs on Sunday ranging from
the mid 30s north to lower 40s south.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
H5 zonal flow stretching across the eastern CONUS will be in place
to start the forecast period. Surface high pressure across the Upper
Midwest region will result in dry and seasonable weather through
Monday.
Come Monday night, a weak surface wave will traverse the southern
CONUS. The precipitation shield from this broad system will likely
result in some wintry precip for our southern counties. Trends in
deterministic and ensemble guidance suggest that precip chances are
trending notably lower for locations near and especially north of
the I-70 corridor Mon night/Tuesday. In fact, the northern edge of
this precip shield may only reach our far southern OH counties.
Thermal profiles would suggest that most (if not all) of the precip
will fall as snow with this particular system. QPF footprint
increases as you head southward, suggesting that the highest snow
accumulations will be in our northern KY counties. 1-2" of snow is
certainly possible late Mon night into Tuesday morning for these
counties, with lower amounts as you trend northwards. Still some
uncertainty in the northern extent of this snowfall.
Once this first wave moves out, a more dynamic system is expected to
impact the Ohio Valley Wednesday afternoon through early Thursday. A
stronger low pressure system will develop as a deep, longwave H5
trough tracks through the Central Plains and Midwest regions. With
this particular system, model trends have shifted the center of the
surface low further NW compared to previous runs. This is leading to
warmer air intruding in the lower levels, producing more rainfall as
the primary p-type. Additionally, snow appears to be more limited
with this system as any wintry precip would likely be sleet/freezing
rain, which is favored along/NW of I-71. However, note that we are
still several days away from the onset of this system, so changes in
p-type/impacts are certainly possible. Once this system clears out,
frigid lows are expected Thursday night, but temperatures rebound to
near normal on Friday.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SHRA continues to expand in coverage through the region and will
be most widespread between 20z-01z before tapering off from W to
E thereafter. With the moistening of the profile, CIGs will
gradually trend to IFR area-wide, with MVFR/IFR VSBYs expected
as well (especially from 20z-01z), before VSBYs return to VFR by
02z through the remainder of the period.
IFR CIGs may briefly go LIFR this evening before gradually
returning to MVFR area-wide between 06z-09z. Coverage should
become more BKN in nature after 12z, with conditions returning
to VFR once again by 18z Sunday.
Some brief SW LLWS on the order of 40-45kts is expected between
about 21z-01z for srn sites of KCVG/KLUK/KILN. Sfc winds will
go light/VRB during this window as the sfc low tracks through
the area. WNW winds of 12-15kts, with gusts to 25kts, are
expected in the post-frontal environment between 01z-08z or so,
slowly subsiding toward daybreak. NW winds at 10kts or less
will evolve during the daytime Sunday.
OUTLOOK...MVFR CIGs are expected into Sunday. MVFR to IFR
conditions with snow are possible Tuesday into Wednesday, mainly
for southern parts of the area.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Winter Weather Advisory until midnight EST tonight for OHZ026-
034-035-043>046.
KY...None.
IN...None.
&&
$$
SYNOPSIS...JGL
NEAR TERM...KC/JGL
SHORT TERM...JGL
LONG TERM...Clark
AVIATION...KC
Source:
ILN issues Area Forecast Discussion (AFD) at Feb 8, 12:42 PM EST---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
