Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/17/22

Area Forecast Discussion

National Weather Service Indianapolis IN

 1147 PM EDT Wed Mar 16 2022

...Updated Aviation Discussion...

.Forecast Update...
Issued at 1014 PM EDT Wed Mar 16 2022

Minor changes made to the short term forecast during this update.
Optimal conditions for radiational cooling have allowed temperatures
to fall a bit faster than forecasted. Lowered min temperatures a few
degrees across Central Indiana with the lowest readings expected
around Bloomington.

Continuing to monitor the large distribution center fire in
Plainfield, just a few miles from the office and Indianapolis Intl
Airport. At 9 PM, MDCRS soundings from KIND depicted a low level
inversion already setting up around ~1400 feet agl. As the fire
continues to burn, smoke will become trapped under the inversion
tonight. However, light SE/S winds around 5 kt should continue to
push the smoke away from Indianapolis and the airport. Little to no
impacts from smoke have been reported so far. This evolving
situation will continue to be monitored through the night.

&&

.Short Term...(This evening through Friday night) Issued at 244
PM EDT Wed Mar 16 2022

Highlights:

-- Well above normal temperatures Wednesday and Thursday, although
no new records are expected.

-- Dry conditions will prevail through Thursday.

-- Low pressure system moving through Friday providing chances of
rain and thunderstorms.

Near zonal but weak ridging remains over much of the Ohio Valley
helping facilitate the ongoing quiet conditions. A low level
disturbance is moving along the Appalachian chain, with the northern
extent providing scattered cloud cover over southern central
Indiana. Mean flow remains out of the south west, originating over a
warm airmass, and therefor supplanting the above normal conditions.
Highs will raise a few more degrees this afternoon before topping
off in the low 70s. A few southern central Indiana locations could
see inhibited temperature gains given the incoming cloud layer.

With a deep PBL likely over the next few days, extended mixing will
likely drop surface moisture below projected levels. This will also
likely create occasional gusts in the afternoon. Without any
significant shift in the synoptic patter tomorrow, conditions will
be very similar with highs in the low 70s.

The next system will approach from the southwest late Thursday night
through Friday. Models are still slightly varied on surface low
track, but are coming to a consensus as the event nears. Current
trends are pushing the surface low to the NW of central Indiana, and
keeping the primary precipitation axis over northern IL/IN. For
central IN, a developing warm front will quickly push through Friday
morning, providing chances for showers. A brief break in coverage is
likely during the day on Friday as their near surface warms within
strong southerly flow.

By the afternoon, scattered to numerous showers will initiate along
a modest instability gradient. Isolated to scattered thunderstorms
will be possible in the warm sector, with greatest coverage over
southern portions of the region. As the cold front moves through
Friday evening, enough surface based lift should be present for the
potential of organized convection. Shear will be marginal for this
event given a fairly uniform wind direction, and magnitude in the
lowest 3km. Uncertainty on thunderstorm severity and extend still
exists. As CAMs ingest further data, a more clear look on severe
potential will be available, but overall expectations are for a low
risk with this event.
.

&&

.Long Term...(Saturday through Wednesday) Issued at 244 PM EDT
Wed Mar 16 2022

WEATHER HEADLINES
 ...Much cooler and dreary Saturday...
 ...Warming trend begins again Sunday...
 ...Inclement weather by Tuesday/Wednesday...

Saturday...

After low pressure and its associated cold front move through
central Indiana Friday night and early Saturday, much cooler air
will infiltrate across the region on Saturday, bringing a temporary
end to the well above normal high temps from late this week. Expect
a dreary day overall with low clouds, sporadic light rain or
drizzle, and a brisk breeze. Models suggest a bent-back look to
thickness lines, suggestive of a cool season TROWAL (trough of warm
air aloft) structure over northern IN early in the day, which could
lead to higher rain chances in that area. Some improvement in
conditions could occur late in the day or evening depending on
system speed. Expect highs mostly in the 40s during daylight hours.

Sunday and Monday...

As ridging aloft over the nations` midsection moves east into the
Ohio Valley, the surface reflection high pressure center will slide
east as well across the TN Valley and southeastern U.S. Low-level
flow on the backside of the high will result in warm air advection
and a return to above normal afternoon temps Sunday and Monday.
Expect max temps Sunday in the upper 50s to mid 60s, and well up in
the 60s to maybe lower 70s Monday. No rain is expected these 2 days.

Tuesday and Wednesday...

Next deep trough aloft is progged to take shape over the SW U.S.
early next week and begin lifting NE over the Plains on Tuesday.
Being several days out, there is bound to be some model
discrepancies on details and timing, but a clear signal of a
potentially significant system exists. In advance of this system and
on the backside of the high pressure off the SE U.S. coast, moisture
flux/transport should be quite efficient off the western Gulf of
Mexico and into the OH Valley during the day Tuesday. This could
lead to some heavy rain across the region. At this time, the swath
of heaviest rain (more than an inch or 2) associated with some
convection may be across southern IN on southward, but this axis
could easily change in later forecasts.

As the weather system advances eastward roughly in the Wednesday
time frame, deeper moisture transport should have moved off to our
east, but potentially steepening lapse rates aloft associated with
cool air advection with the trough aloft could lead to at least
scattered convective showers Wednesday. Still several days away to
better pin down specifics on this entire weather system, but
something to keep an eye on.

&&

.Aviation...(06Z TAF Issuance)
Issued at 1147 PM EDT Wed Mar 16 2022

IMPACTS:

-- No impacts.

-- Monitoring a large distribution center fire a few miles west of
KIND; however no impacts expected.

DISCUSSION:

VFR conditions will prevail through the period.

Main concern for tonight is the fire just west of KIND which has
been monitored closely. Most recent 0324z MCDRS soundings indicate
an inversion as low as 1100 ft agl; however smoke trapped under the
low level inversion should continue to be transported NW by weak SE
winds away from KIND. No concerns for the other terminals in the
region.

&&

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

$$

Update...CM
Short Term...Updike
Long Term...Funk
Aviation...CM