Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/13/22

Area Forecast Discussion

National Weather Service Indianapolis IN

 1114 PM EDT Thu May 12 2022

...Updated Aviation Discussion...

.Forecast Update...
Issued at 947 PM EDT Thu May 12 2022

Surface analysis this evening continues to show strong high pressure
in place over the northeastern states...extending SW into the Ohio
Valley. This was resulting in warm but dry SE surface flow across
Indiana. Aloft...water vapor showed strong high pressure in place
aloft from New England across Indiana to IL. This continued to
provide subsidence across Central Indiana as well as allow very dry
air to reach the surface. Dew point temps this afternoon fell to the
mid 40s but have recovered this evening slightly in to the upper
40s. The ridge of high pressure aloft was keeping any TSRA over the
upper midwest from making any progress east and the upper steering
flow was pushing any storms toward Ontario.

Little overall change is expected overnight as forecast soundings
and time heights continue to show a dry column with subsidence
overnight. Given the mostly clear skies on GOES16...have continued
with a mostly clear sky overnight. Lows in the lower to mid 60s are
expected given the drier air mass than the previous night.

&&

.Short Term...(This evening through Friday night)
Issued at 305 PM EDT Thu May 12 2022

High pressure aloft and dry weather will continue through the day
tomorrow. An upper low will be retrograding towards the Ohio Valley
during the time as well, allowing for SE winds through the short
term period. This will continue subsidence induced dry air advection
into tomorrow keeping dewpoints in the upper 40s to mid 50s. ACARS
soundings this afternoon show a low level layer of extremely dry air
that`s being mixed down to the surface so dew points are lower than
models previously predicted. Going to continue that dry trend
through the afternoon in the grids.

The upper low will continue towards the area tomorrow which will
help to erode the strong subsidence aloft. Because of this,
moisture and cloud coverage will start to increase from tomorrow
afternoon, on. In addition, an upper trough from the west will
return weak upper lift late tomorrow night and reintroduce PoPs
to the area after a week of dry and warm air.

Temperatures tonight will drop to near 60 degrees given the lower
dewpoints over the area. Tomorrow`s high will again be in the 80s
but tomorrow night`s lows will be slightly higher than tonight with
the anticipated higher moisture content.

&&

.Long Term...(Saturday through Thursday)
Issued at 305 PM EDT Thu May 12 2022

Highlights...

* Showers and thunderstorms expected Saturday and Sunday

* Near normal temperatures next week

* Active pattern setting up mid to late next week

...Saturday and Sunday...

After a hot and dry week for mid May, the overall pattern will
transition over the weekend and into next week. The remnants of a
narrowing ridge centered across the region diminish with the
approach of the closed off low currently drifting off the Southeast
coast. As this lifts north into the Ohio Valley Saturday, it will
become absorbed by the stronger jet stream tracking from the Pacific
coast into the Great Lakes. The interaction of the jet with the
closed low combined with a remnant frontal boundary tracking into
the region will bring a better threat for convection for both
Saturday and Sunday.

A warm, soupy atmosphere remains in place Saturday with highs in the
low 80s and dew points well into the 60s. A weak frontal boundary
will be the primary feature aiding in showers and storms Saturday
across the region; however overall forcing aloft is weak resulting
in disorganized convection driven by subtle levels of instability
and lift. With very little BL shear and winds aloft, expect slow
moving convection which could lead to locally heavy rainfall at
times Saturday evening. With the loss of heating and instability
over night, showers and storms will likely diminish after sunset.

Sunday`s pattern is a bit more favorable for stronger storms and
organized convection as forcing aloft and wind energy increases. The
left exit region of a 100kt jet streak rounds the base of the upper
low in South Central Canada and pushes into the lower Great Lakes
region by Sunday afternoon. Diffluence aloft resulting in large
scale ascent across the region should aid in convection developing
Sunday evening. Despite very weak surface flow, low to mid level
winds increase to 25 to 35 kts in response to the approaching
wave/trough axis. Drier air advecting in from the west northwest and
lower surface instability work against severe thunderstorm
potential; however this will probably not completely limit the
threat. Long and straight model hodographs Sunday evening suggest an
environment favorable for organized convection and discrete cells
with healthy outflow and storm top divergence. Will have to watch
for the potential for isolated strong winds, hail, and localized
flooding with the strongest storms. Despite an environment more
conducive for organized storms, there is still better model
agreement having more widespread activity on Saturday rather than
Sunday. Deterministic models still disagree with coverage and
timing of the Sunday convection; so overall confidence remains
lower. Outside of the thunderstorm potential, expect highs in the
lower 80s once again before a cooler airmass moves in from the
northwest early next week.

...Next Week...

As the upper ridge reorganizes over the Plains and deep troughing
settles over southeast Canada, a relatively cooler northwest flow
pattern set up across the region for the first few days of the week.
Surface high pressure drops south into the Ohio Valley Monday and
Tuesday keeping the threat for significant precipitation low through
midweek. Will have to keep an eye on any weak waves riding along the
jet stream that could increase clouds and possibly a shower during
this timeframe. Confidence remains low on any details of these minor
features.

The overall pattern becomes active again as a warm front pushes into
the Ohio Valley Tuesday night and Wednesday increasing chances for
broader and more organized showers and storms. With a warmer and
moist airmass approaching, the potential is there for more robust
convection to impact central Indiana, possibly lingering into
Thursday as well as the boundary oscillates over the region. Current
thinking is that this timeframe is worth monitoring for severe
weather potential.

Highs will slide back closer to normal in the extended with the loss
of the ridge but still seasonable for mid May. Expect lower 80s over
the weekend dropping back into the 70s through the middle of next
week.

&&

.Aviation...(06Z TAF Issuance)
Issued at 1114 PM EDT Thu May 12 2022

IMPACTS:
- VFR flying conditions are expected through the TAF period.
- SE winds from 5-10 kts

DISCUSSION:

Little change in the overall forecast.

High pressure over the northeastern states continues to provide a
dry NE surface flow to Central Indiana. Strong ridging in place
aloft stretching from the Lower Mississippi Valley to Southern
Ontario and new England continues to provide subsidence aloft.
Forecast soundings continue to show a dry column through the period
as Indiana remains under the influence of of these previously
mentioned weather features.

Convective temps in the mid 80s may be reached on Friday...leading
to some SCT CU...but any CIGs will be VFR and any CU development
should be limited.

&&

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

$$

Update...Puma
Short Term...KH
Long Term...CM
Aviation...Puma