Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Lincoln Illinois
658 am CDT Wednesday Oct 26 2016
Short term...(today and tonight)
issued at 328 am CDT Wed Oct 26 2016
An area of low pressure, currently over western Iowa, will
track eastward to northern Indiana by midnight tonight. The
trailing cold front is expected enter the by this afternoon, and
exit the forecast area to the east by shortly after midnight.
Showers and thunderstorms are likely along and ahead of the
frontal boundary, and will begin to push into the forecast area
from the west later this morning. Severe weather is not
anticipated with any of the storms given the very modest shear
profiles and instability anticipated. It will be a pretty nice day
ahead of the front with widespread 60s anticipated. Some readings
over 70 are likely south of I-70. On the down side, it will be
rather cloudy, and gusty southerly winds are expected. Drier
conditions will filter into the area overnight behind the front.
Overnight lows will be mild for late October, bottoming out in the
mid 40s to lower 50s.
Long term...(thursday through tuesday)
issued at 328 am CDT Wed Oct 26 2016
1011 mb low pressure over western Iowa will track eastward to
Western Lake Erie by 12z/Thu and over Lake Ontario by sunset Thu.
Showers will already be east of Illinois by sunrise Thu with clouds
decrease from the west during the day as 1024 mb high pressure
moves into Illinois/in with skies becoming partly to mostly sunny Thu
afternoon. Cooler highs in the upper 50s and lower 60s with
mildest reading SW County Warning Area. Lows Thu night in the low to mid 40s,
coolest over east central Illinois.
Cool down will be brief as breezy southerly winds develop on Friday
as surface high pressure ridges drifts off to the mid Atlantic
states and a cold front moves into central parts of Minnesota and Nebraska.
Some upper level ridging into Illinois on Friday as well with 500 mb
heights rising just above 582 dm. Highs Fri of 70-75f and warmest
over west central Illinois. Milder lows Fri night in the upper 50s to
near 60f. Even warmer on Saturday with highs in the mid to upper 70s
with partly to mostly sunny skies and SW breezes.
00z forecast models trending further south with some frontogenetic
forcing on Sat night with a chance of showers over northeast County Warning Area
by overnight Sat night especially from I-74 northeast. A frontal
boundary will press southward over central Illinois overnight Sat night
and into southeast Illinois on Sunday. Lows Sat night in the low to mid
50s. Highs Sunday range from the low to mid 60s from I-74 north to
the lower 70s south of I-70.
Temps warm back up on Monday (halloween) with increasing southerly
flow ahead of another approaching cold front moving into Minnesota and
eastern Nebraska by Monday afternoon. Also have upper level ridging
back into the Ohio River valley. Highs Monday back into the mid 70s.
The cold front will push southeast over central Illinois overnight Monday
night into Tue and currently appears to pass through dry with
limited moisture to work with. A bit cooler highs Tue over central
Illinois ranging from mid 60s by Galesburg and Lacon to near 75f by
Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 655 am CDT Wed Oct 26 2016
A cold front will track across central Illinois later today into
this evening. Showers and thunderstorms are likely at times ahead
of the front, and this precipitation should degrade cigs into the
MVFR category. More widespread MVFR conditions are likely tonight
in the wake of the front. Gusty southerly winds will develop this
morning, and should linger until frontal passage. Then, winds will swing
around to the northwest.