Area Forecast Discussion
Issued by NWS Central Illinois
FXUS63 KILX 091507
Area Forecast Discussion
National Weather Service Lincoln IL
1007 AM CDT Wed Jul 9 2014
ISSUED 1005 AM CDT Wed Jul 9 2014
Weak surface trough located roughly along I-70 at 10 am, with some
clouds recently developing along it. These will push east of the
forecast area in the next couple hours. Remainder of the forecast
area currently clear, although visible satellite imagery showing a
large area of smoke aloft streaming southeast from the northern
Plains, which has started to brush across western Illinois.
Moisture cross-sections from the RAP model showing some lingering
clouds into early afternoon in southeast Illinois, but subsidence
will keep the remainder of the forecast area mainly sunny.
Made some minor adjustments to the hourly temperatures, which
tweaked the highs by a degree or two. Updated grids have been
sent, but the zone forecasts still appear OK.
ISSUED 645 AM CDT Wed Jul 9 2014
Despite the passage of a weak surface trough today, VFR conditions
should prevail over the next 24 hours. A layer of moisture in the
4k ft level will develop into scattered cumulus during the heat of
the day. A couple of forecast models are indicating a few showers
could develop ahead of the trough, but better chances should
remain southeast of the terminal sites this afternoon.
Winds will start out westerly this morning, then veer to the NW
with the trough passage and increase to around 10kt. Winds will
weaken with sunset and continue veering to the N-NE overnight.
Any reductions to visibility tonight due to fog will be minor and
ISSUED 330 AM CDT Wed Jul 9 2014
SHORT TERM...Today through Sunday
00Z models are in fair agreement the rest of the work week and
show a more unsettled weather pattern taking shape from Friday
Quiet weather expected through Thu night across central IL with
mostly clear skies and more comfortable humidity levels with
dew points in the upper 50s and lower 60s. Lows in the upper 50s
and lower 60s tonight and Thu night. Highs in the lower 80s today
and Thu with a few upper 70s NE areas. Weak 1018 mb high pressure
over the Plains to settle into MI tonight/Thu bringing the fair
weather to IL. Scattered cumulus clouds to appear late morning and
afternoon and more prevalent in southeast IL.
High pressure strengthens as it shifts into the eastern Great
Lakes and New England Friday with a return southerly flow setting
up over IL. This to bring warmer and more humid air back into the
area especially by Saturday/Sunday. A short wave near the western
states to ridge over top of broad/flat upper level ridge over
central Plains/Rockies and move into WI/IL Friday. This to bring
next chance of showers and thunderstorms to mainly areas from I-57
west Friday and across area Friday night & Saturday. Highs Friday
in low to mid 80s and mid to upper 80s Saturday/Sunday. Dew points
elevate into the mid to upper 60s Friday afternoon (highest
western IL) and low to mid 70s Saturday/Sunday.
LONG TERM...Sunday night through Wednesday
A couple of short waves pass ESE through IL this weekend into
Monday and continue daily chances of showers and thunderstorms in
tropical air mass. Upper level trof digging southward into the
Midwest and Great Lakes region early next week to also drive a
cold front south through central IL Monday afternoon/Monday night.
Cooler temperatures expected behind it Tue/Wed with highs in the
70s and less humid air returning.