Terre Haute, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

911
FXUS63 KLOT 021124
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
624 AM CDT Fri May 2 2025

.KEY MESSAGES...

- Additional rounds of showers are possible at times later today
  through early next week, with the highest forecast confidence
  on Sunday.

- Expect cooler-than-normal conditions this weekend followed by
  a mild stretch during the middle of next week. Cooler
  conditions will prevail along the lakeshore next week with
  persistent onshore flow.

&&

.DISCUSSION...
Issued at 324 AM CDT Fri May 2 2025

Through Saturday:

Early morning surface analysis depicts a weak low pressure wave
roughly between KMLI and KSQI in northwest IL, with a west-east
nearly stationary front extending eastward along the I-80
corridor into northern IN. This wave appears to be a reflection
of a mid- level short wave trough axis evident near the
Mississippi River in GOES vapor imagery. Relatively weak forcing
associated with this wave has generated isolated to widely-
scattered showers across eastern IA and parts of northern IL
since last evening, as well as a few isolated thunderstorms
within a region of weak elevated MUCAPE mainly south of the cwa.
Overall, coverage of showers has been significantly lower than
much of the guidance has indicated, and have maintained only
slight chance (~20%) eastward-moving pops across the area
through about 14Z/9 AM CDT until the mid-level short wave axis
moves east of the area. Weak subsidence develops in the wake of
this disturbance from mid-morning through mid-afternoon, which
should allow for dry conditions for most of the day.

Farther to our west, another mid-level short wave was noted
digging south-southeast across the Plains. This wave is progged
to help deepen and amplify a long-wave upper trough from the
northern Lakes to the lower Missouri Valley region by this
evening, which will again result in height falls developing
across the forecast area later this afternoon and tonight, and a
return of low (20-30%) chance pops especially across our
western cwa by late this afternoon. Scattered showers will
likely persist across a good portion of the area tonight into
Saturday as the upper trough continues slowly moving across the
area and deepen, eventually forming a closed low over downstate
IL by Saturday afternoon. Greatest shower coverage (40-50%) is
expected to be across western and southern parts of the forecast
area, in the vicinity of the trough axis and developing mid-
level low. Drier northeast low level flow looks to result in
decreasing shower coverage north by Saturday afternoon.

Northeast winds and onshore flow was already developing north
of the aforementioned stationary front, and will increase across
the area as the surface wave moves off to the east this
morning. Combined with mostly cloudy conditions especially
across the northern cwa, this will result in cooler temperatures
today ranging from the 50s near the lake to the low-mid 60s
farther inland. South of I-80, temps may approach 70 degrees.
Most areas are expected to only be in the 50s to low 60s
Saturday, with breezy northeast winds, cloud cover and scattered
showers.

Ratzer


Saturday Night through Thursday:

This weekend, the base of an upper trough will swing into the
Tennessee Valley before breaking off from the Polar Jet late
Saturday and becoming a cutoff upper low with core focused
directly over the Midwest. The system will meander over the
region during the day on Sunday before getting shunted northward
into the Great Lakes Monday into Tuesday by a deep, encroaching
upper low swinging into the Desert Southwest. This system is
expected to bring us intermittent bouts of rain during the early
part of next week.

The forecast in the long term picks up Saturday evening when we
could maybe see a few showers in our south, although better
chances will be well south of the CWA. But, as moisture and
forcing gets wrapped around to the northern flank of the upper
low, scattered showers are anticipated to fall on our area
Saturday night and Sunday. Additional periods of showers are
likely Sunday night and Monday as the low begins to work
northward across the region. Despite an unimpressive kinematic
field around the low, guidance is resolving decent lift on the
northern periphery of the low via DPVA. However, profiles are
expected to dry out from the top-down as the center of the low
nears overhead, which will likely keep coverage rather scattered
and intensity largely on the lighter side, especially Sunday
night and Monday, although some pockets of more moderate to
heavy rain will be possible amid the deep forcing. No
thunderstorms are expected with this low as all of the
instability looks to remain east of the system out into the Ohio
Valley. The generally better rain chances and higher coverage
is anticipated across the eastern half of our CWA nearer to the
track of the low level circulation. By the time the core of the
low is positioned over the CWA Monday evening, precip chances
should be off to our northeast and Tuesday looks to be rain-
free.

Temperatures on Sunday will be similar to Saturday`s, in the 50s
and lower 60s. Monday looks to be a few degrees warmer
followed by a pleasantly mild middle of the week. Highs Tuesday
through Friday are forecast in the upper 60s and lower 70s,
likely stuck in the 50s along the lake though with persistent
onshore flow through the week. That other aforementioned upper
low moving into the Desert Southwest this weekend will get
sheared off across the central CONUS next week. Its remnants may
push a disorganized system of scattered showers across the
region during the day on Wednesday. A second wave of showers
also associated with this weakening upper low may impact the
area late in the week. Thunder chances next week are generally
low for now as models have just about all instability staying
away from the area.

Doom

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 624 AM CDT Fri May 2 2025

The main aviation weather concerns for the 12Z TAF period
include:

* MVFR to IFR cigs this morning

* Additional MVFR/IFR cigs possible Friday evening and night
  with scattered showers likely

An IFR deck with MVFR vsbys mixed in moved inland off the lake
late last night and is parked over the Chicago sites early
this morning. GYY may get caught beneath this deck yet, but DPA
and RFD can

Light scattered showers will spread over the area from the west
late this afternoon into early evening. Confidence in shower
coverage is on the lower side, although at least isolated
pockets of rain look to be moving in the vicinity of the
airfields for the better part of this evening and tonight as
well as Saturday morning. Additional MVFR, or even IFR cigs will
be possible, especially after dusk, although there is low
confidence in cig trends late today at this time.

Meanwhile, expect E or NE winds below largely below 10 kt
through tonight, building closer to 12 to 14 kt Saturday
morning.

Doom

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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