Area Forecast Discussion
Issued by NWS Indianapolis, IN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KIND 150540
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
140 AM EDT Fri Mar 15 2024

.KEY MESSAGES...

- Breezy during daytime Saturday through Monday

- Much colder early week with freezing temperatures Sunday night

- Hard freeze Monday night

&&

.SHORT TERM (Today and tonight)...
Issued at 140 AM EDT Fri Mar 15 2024

Low-amplitude shortwave passage has displaced warm conveyor belt
and associated deep moisture plume southeast of the area, and has
nudged modest cP air mass into Indiana. Noticeably cooler and
drier post-frontal air mass will occur today. There could be deep
enough mixing and momentum transfer for some gusts in the 15-20
mph range this afternoon and this would be more likely if the
stratus layer breaks early enough in the day. As of now, it
appears enough PBL moisture will be present to maintain a stratus
deck into at least mid-afternoon.

Our model blend starting point for temperatures has had a cool
bias that we`ve adjusted for the last few days, but with a shift
to a cold advection regime, it should perform reasonable well.
Near to slightly above normal temperatures are expected (mid-50s
for maximum temperatures).

Subsident end of upper jet and associated high MSLP should
enhance radiative conditions and 1. with moist ground lead to some
patchy fog potentially, and 2. justify use of 25th percentile
blended guidance. The colder option is in line with statistical
and high-res guidance which handle these situations better,
typically.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 140 AM EDT Fri Mar 15 2024

The synoptic-scale pattern this weekend will become much more
amplified with brief blocking in the west and high-latitude ridging
in western Canada helping to force deepening troughing over the
Great Lakes region. This is a configuration that should be
effective at dislodging Arctic air over central Canada and
bringing it southward in a modified state into our region. As a
consequence, by early next week we`ll likely be dealing with a
frost/freeze situation.

By mid week GEFS-weighted clusters are less amplified and lags
troughing some, and the Canadian ensemble-weighted cluster is
quicker and more amplified with ridging building in by the end of
the week. The sensible weather implications are a gradual warming
trend with greater chances of exceeding currently forecasted
temperatures than having to trend the forecast cooler. Throughout
this period, although there are some transient minor shortwave
perturbations and periods of ascent, increased cloud cover should
be the extent of the impacts. Meaningful moisture remains
confined to low latitudes until the very end of the week. Until
then, we don`t expect precipitation and chances, and only low
chances are anticipated by the end of the week.

Day 8-14: Ensemble clusters are largely out of phase with the
synoptic-scale trough/ridge pattern, and there is no discernible
signal for anomalous temperatures or precipitation at this time.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1250 AM EDT Fri Mar 15 2024

Impacts:

- IFR ceilings trending MVFR and gradually improving later today

 Discussion:

Post frontal northern winds will arrive by or shortly after the
start of the 06z TAFs. These could reach ~12-14 knots with brief
gusts during the afternoon but will diminish by evening. IFR/MVFR
stratus should gradually improve during the day and we have moderate
forecast confidence for the end times for each category indicated in
the TAFs. There is a low probability for patchy fog tonight.


&&

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

$$

SHORT TERM...BRB
LONG TERM...BRB
AVIATION...BRB


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.