Forecast Discussion for ILN NWS Office
543
FXUS61 KILN 210615
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
115 AM EST Thu Nov 21 2024
.SYNOPSIS...
Multiple disturbances will progress through the region as we
head toward the end of the work week bringing much cooler
temperatures, gusty winds, and periods of rain and snow showers.
Dry conditions return to the region for the weekend before
precipitation chances return on Monday. Weekend temperatures
return to seasonable normals.
&&
.NEAR TERM /THROUGH TODAY/...
The main cold front has moved well east of the area, but
observations are indicating a secondary front (or trough axis)
is crossing east into the area. The main impact from this
secondary front is a wind shift from SW to W, along with gusts
in the 20-30 knot range. KDAY recorded a peak wind of 29kts at
0147Z. Gusts will subside slightly behind the front, but the
region will eventually settle into a breezy scenario through the
rest of the overnight hours -- with occasional gusts to around
20kts on westerly flow.
No significant changes to the overall thinking for the snow
showers and banded snow in the morning. 00Z runs have
highlighted the greatest accumulation potential with these bands
more in the west-central Ohio to central Ohio corridor, likely
as there is a greater chance for repeated bands of snow. Further
south, such as in the Cincinnati area, the heavier snow showers
may only impact the area for a couple hours. Regardless,
accumulation potential for this initial shot of snow showers
still looks to be rather limited for roadways, with impacts
from the briefly reduced visibilities as perhaps a greater
factor -- and perhaps some accumulations on roads if repeated or
heavier snow showers occur at a given point.
Previous discussion!! >
Continued complicated forecast in store for the next couple of
days. Synoptically, the 500H closed low located over Minnesota
has begun the process of wrapping a speed max around its base.
This will be the forcing needed to rapidly strengthen and
intensify a developing surface low located across the eastern
Great Lakes and into Appalachia. The isallobaric response will
greatly increase our pressure gradient and enhance the thermal
response with another push of strong CAA.
So, sensible weather wise... Given the tight pressure gradient
in place, wind speeds will remain somewhat elevated during the
overnight hours, sustained around 10-15 MPH with some gusts
possible. Additionally, the enhanced CAA moving into the region
will plummet our temperatures and we`ll quickly fall into the
30s overnight. However, with the wind, it will feel like we`re
in the 20s (remember, even though NWS has changed its cold
weather products (visit:
https:/www.weather.gov/images/iln/2024WinterColdCriteria.png
for more information) wind chill is not going away!!).
As the upper level low progresses toward the Ohio Valley, a vort
max wrapping around the western side and base of the low will
promote ascent coupled with steep low level lapse rates within
the DGZ. This, combined with a fairly saturated column, will
result in banded snow showers moving through the region during
the early morning hours on Thursday. This initial round of
precipitation will be limited in coverage but has the potential
to result in heavier bursts of rapidly accumulating snow coupled
with quick reductions in visibility. AM rush hour pavement
temperatures are forecast to be well above freezing, however, it
is not unheard of for a quick burst of heavy snow to overcome
warm-ish pavement temps (think
NWS ILN Office Area Forecast Discussion
