Indianapolis, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

448
FXUS63 KIND 031322
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
822 AM EST Tue Dec 3 2024

.KEY MESSAGES...

- Unseasonably cold conditions will continue through Friday.

- A warming trend will commence this weekend into next week.

&&

.FORECAST UPDATE...
Issued at 819 AM EST Tue Dec 3 2024

On the latest update, cloud cover has been kept over southern
portions of Indiana through most of the daytime hours. a 1038mb
surface high is currently being analyzed, most of which is collocated
with a low stratus layer. Within this area of high pressure,
subsidence and weak winds will act to reinforce the stratus layer,
keeping it around until later this evening when greater mixing
occurs on the periphery of the high.

With the stratus layer lingering at around 1000ft, any weak lift
could lead lead to a stray flurry over southern Indiana, but no
accumulation is expected. Also, increased cloud cover will likely
lead to a dampened diurnal curve this afternoon, with slightly
suppressed afternoon highs.

Grid updates are out.

&&

.SHORT TERM (Today and tonight)...
Issued at 317 AM EST Tue Dec 3 2024

Another cold December day expected across Central Indiana. Latest
satellite imagery shows low stratus along and south of the I-70
corridor slowly moving southward early this morning. ACARs soundings
from around the region confirm the presence dry air advection
through the column and weak subsidence with a shallow saturated
layer around 1400ft agl. High pressure sliding southeast across the
Mid Mississippi valley will continue to advect dry air into the
state resulting in clearing skies through the rest of the morning.
Despite ample sunshine today and weak low level ridging pushing in
aloft, surface temperatures will be very slow to respond. Dense
arctic airmasses at the surface typically are stubborn to retreat,
with model guidance normally pushing them out too fast despite weak
warm air advection aloft. Therefore, lowering highs toward the
NBM25th percentile in the upper 20s to 32 degree range. Areas with
any snowpack will likely remain a few degrees colder, particularly
across South Central Indiana. With such cold temperatures, watch out
for slick spots on roadways due to leftover moisture from snow
showers yesterday.

While the weather today will be cold and relatively quiet, focus
turns toward the next weather system to approach the region from the
northwest. Surface high pressure and low level ridging push south
and east resulting in continued warm air advection just above the
surface. As mentioned above, surface temperatures will be slow to
respond, so expect a developing inversion layer overnight tonight
and into Wednesday morning as surface temperatures fall into the low
20s. A few models continue to show the presence of a saturated layer
within the lowest 1 km developing towards dawn on Wednesday morning.
While the threat is quite low, weak lift ahead of the approaching
system may be able to squeeze out a few sprinkles or drizzle across
portions of Western and South Central Indiana. This saturated layer
appears too warm to support the formation of dendrites, so anything
that does fall from the sky will likely be super cooled
droplets...or freezing drizzle. With surface temperatures well below
freezing, anything that does fall would freeze on contact. The
threat is low, but with the past few systems overachieving, it is
definitely worth mentioning as any freezing drizzle can result in
major travel impacts.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 317 AM EST Tue Dec 3 2024

The broad persistent eastern Canadian and U.S. trough will gradually
settle further east with time but not before sending more waves our
way in the northwest flow aloft around the base of the broad trough.
This will keep it cold through Friday. However, the pattern will
late this weekend into next week, when a southern system will head
our way, and in its wake, the upper flow will become southwest,
ahead of another low pressure system.

Wednesday and Wednesday night...

There is some potential for freezing drizzle Monday morning based on
model soundings. That said, a tight surface pressure gradient, in
between a northern Ontario low pressure system and a southeastern
high will result breezy or windy southwest low level flow which will
quickly warm the boundary layer to above freezing. So, any impacts
will likely be confined to the morning hours. There is some concern
this could impact the morning commute to work. Later in the day,
soundings suggest any precip will be mostly rain with the freezing
level approaching 3K feet. However, as the boundary layer cools in
the wake of the associated cold front, snow could mix in Wednesday
night. Either way, soundings are showing moisture limited to a layer
from 2-5K feet, which suggests low coverage and QPF. With breezy
northwest winds in the wake of the front, wind chills could fall
below zero over at least northern sections overnight.

Thursday through Monday night...

Canadian Rockies high pressure will settle southeast to the Mid
South by Friday. The result will be dry but cold weather with
temperatures once again some 15 or so degrees below normal Thursday
but a quick warm up for the start of the weekend as low level flow
becomes southwest overtop the southeastward moving high. Would not
rule out light rain and snow Saturday as a wave moves through in the
fast northwest flow aloft, otherwise temperatures will climb to
several degrees above normal by Sunday and the aforementioned
southern system will bring chances for rain in

&&

.AVIATION (12Z TAF Issuance)...
Issued at 552 AM EST Tue Dec 3 2024

Impacts:

- MVFR cigs clearing out from north to south at KHUF and KBMG

Discussion:

Latest satellite imagery shows MVFR stratus clouds very slowly
pushing south of the I-70 corridor. The northern edge of the cloud
deck has somewhat stalled along a line from Terre Haute to
Cincinnati over the past few hours. Confidence is lower in the speed
of the southward progression of this stratus deck; however it is
looking more likely that at least KBMG will be stuck under the low
clouds for much of the morning. Terre Haute is right at the northern
edge of the clouds and should begin to clear out over the next hour
or two.

Once clouds clear, expect VFR conditions for the remainder of the
day today. WNW winds around 10 kts will gradually become SW this
afternoon and then southerly tonight, increasing to 10-15 kts by
early tomorrow morning.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Updike
SHORT TERM...CM
LONG TERM...MK
AVIATION...CM