614
FXUS63 KIND 250812
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
312 AM EST Sat Jan 25 2025

.KEY MESSAGES...

- Highs above freezing for the first time in a week for Central
Indiana today

- Overall breezy early next week, yet above normal Tuesday-Wednesday

- Next chances of organized precipitation next Friday and Saturday

&&

.SHORT TERM (Today and tonight)...
Issued at 312 AM EST Sat Jan 25 2025

Much of the United States will be coming out of an extensive deep
freeze this weekend and next week as a more progressive and milder
weather pattern sets up over the country. Central Indiana has
largely been below freezing for about a week straight and today will
be the first day for many that temperatures finally break the 32
degree mark. For today, low pressure exists over the Hudson bay with
a weak, moisture starved cold front extending southwestward into the
Midwest. A 30-40 kt low level jet ahead of the front and increasing
southerly winds are working to bring a more mild airmass northward
into the region today. Strong mid and upper level zonal flow from
the pacific will increase high level clouds through the day. Despite
increasing clouds, "warm" air advection to result in highs reaching
the mid 30s across the north and low 40s in South Central Indiana.

The cold front to the west passes through the region later tonight,
with a wind shift from southwest to westnorthwest and a slightly
colder airmass. Cross sectional views of the atmospheric profile
continue to indicate a lot of dry air in the low and mid levels,
preventing precipitation from forming along this front. While a few
snowflakes or flurries are possible across North  Central Indiana
later today and tonight, most areas should remain dry this weekend.
Main impacts from this front will be falling temperatures back into
the teens and 20s later tonight and increased cloud cover.

&&

.LONG TERM (Sunday through Friday)...
Issued at 312 AM EST Sat Jan 25 2025

A relatively quiet and significantly milder stretch of weather is
likely for the long term period, with minor exceptions.

A more progressive weather pattern sets up for much of the country
this next week as the polar jet retreats well to the north, keeping
the bulk of the arctic air in Canada. An subtropical jet remains
strong, yet quasi-zonal and should stay south of the Ohio Valley,
leaving much of the region in an area of upper level convergence and
sinking air. Broad surface high pressure will generally be in
control across the southeastern and central CONUS, while weak
systems traverse through the Great Lakes and Upper Midwest. This
will allow for mostly dry conditions over the weekend into mid week
next week, and for temperatures to moderate significantly, with
highs and lows much nearer to seasonal normals.

The coolest day of the long term period is likely to be Sunday due
to weak cold air advection behind the cold front, with highs in the
mid 20s to to lower 30s.

High pressure shifts south of the region for the first half of the
new week with warm air advection kicking out the colder airmass in
place allowing for temperatures to moderate into the 40s. Indiana
will be sandwiched in the middle of high pressure to the south and
low pressure across the northern CONUS, resulting in strong westerly
flow as the low level pressure gradient tightens. Most of the energy
and moisture with the northern stream systems will remain north of
the region with high pressure keeping a much drier airmass in place.
Deeper mixing and steeper low level lapse rates Monday will result
in winds 10-20 mph and gusts 25-30 mph Monday afternoon and highs
reaching the upper 30s to low 40s. A similar pattern remains in
place Tuesday and Wednesday with each day a few degrees warmer than
the previous.

A stronger area of low pressure, associated with the northern branch
of the jet, moves into the Great Lakes and Northeast Wednesday into
Thursday. While this system does swing a cold front through
Wednesday night, the progressive pattern in place will prevent the
"colder" air front sticking around long. A brief drop in
temperatures expected Thursday; however a moderating trend quickly
returns for the weekend. Cross sectional views and mid range
guidance shows the potnetial for very light precipitation with the
frontal passage Wednesday night. Chances look very low at this
point, so will keep the forecast dry for now, but may have to add
sprinkles or flurries in the coming days.

The next opportunity for precipitation will come toward the end of
the forecast period towards next Saturday, as a closed low, which
will slowly drift through California and the Desert Southwest next
week, begins to pull northeast toward the Great Lakes and be
reabsorbed into a larger longwave trough shifting eastward into the
central US. Guidance today has trended slower with this system
bringing precipitation closer to Indiana Saturday morning rather
than Friday. Will go ahead and lower PoPs Friday and increase them
for Saturday based on latest Ensemble and deterministic trends. P-
type is still a question; however the pattern supports more rain
than frozen precipitation at this point.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1245 AM EST Sat Jan 25 2025

Impacts:

- Non-convective low level wind shear from 06z-14z

Discussion:

Brief period of low level wind shear early this morning as a 40-45
kt southwesterly low level jet moves over the state. Surface winds
will be from 190-230 degrees around 10 kts with gusts upwards of 15-
20 kts during the afternoon. Mid and upper level cloud cover
increase today; however ceilings will remain VFR above 10000ft.


&&

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

$$

SHORT TERM...CM
LONG TERM...CM
AVIATION...CM