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000
FXUS63 KIND 191314
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
914 AM EDT Fri Apr 19 2024

.KEY MESSAGES...

- Cooler but dry through Monday. Some frost potential mainly north
Sunday morning, more widespread frost possible Monday morning.

- Increasing rain chances next Tuesday, low chance for
  thunderstorms

&&

.FORECAST UPDATE...
Issued at 914 AM EDT Fri Apr 19 2024

- Becoming Mostly Sunny, but Cool.

Surface analysis late this morning shows Low pressure over Lake Erie
with a cold front that extended southwest across western OH and
Central KY to Central TN.  Strong high pressure was found over the
Dakotas, with surface ridge axis extending southeast across IA, IL
and into northern Indiana. GOES16 shows the back edge of clouds
associated with the cold front found along a line stretching from
near Ft. Wayne to Vincennes. Higher clouds were found upstream over
MO and KS. Cool northerly surface flow was in place across Central
Indiana due to the arriving area of high pressure.

Today, models show the back edge of cloud cover across the southeast
half of Indiana will make steady progress east through the late
morning and early afternoon, bringing Mostly Sunny skies to our area
by this afternoon. Some of the previously mentioned high clouds may
streak across Indiana this afternoon. Forecast soundings do show a
few moments of upper level saturation, but keep the lower levels dry
with unreachable convective temperatures. Thus with the departure of
the low clouds combined with arrival of a few high clouds, skies are
expected to become mostly sunny.

Cold air advection is in play today, with 850mb temps falling to
near 0c by 00Z. Thus we will look for slow and minimal rises in
temperatures this afternoon, with highs generally in the middle 50s.

&&

.SHORT TERM (Today and tonight)...
Issued at 304 AM EDT Fri Apr 19 2024

A broad/deep low over Canada forced a cold front through Indiana
overnight. MSLP gradient between the low over Quebec and high east
of the Rockies will be enough for breezy conditions today. Once
lingering PBL moisture and stratus depart, some midlevel stratus and
cirrus may remain peripheral to aforementioned departing low. Raw
model blend and higher resolution models may capture cold advection
regime better than biased corrected guidance given recent warm
pattern. Post-frontal continental air will be about 15 degrees
cooler than 24-hours prior.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 304 AM EDT Fri Apr 19 2024

Saturday through Monday...

Pattern shift arrive this weekend with much cooler yet drier air.
After an extended period of well above normal temperatures for
April, temperatures dip below normal this weekend and through mid
next week as upper troughing sets up over Eastern North America with
multiple reinforcing shots of cooler air. Will have to watch for the
potential for a few frosty mornings as well, especially for North
Central Indiana in the coming days.

Surface high pressure centered over Southern Alberta and Northern
Montana Saturday slides southward into the Southern Plains by Monday
morning keeping Indiana within a northwesterly flow pattern in the
lower levels. Cold air advection through the weekend will keep
temperatures below average with highs struggling to reach the 60
degree mark despite drier air and sunshine. Watching Sunday night
and Monday night for the potential for frost; however with the
center of the surface high well to the west, winds should remain
elevated enough to prevent widespread frost. Temps at 850mb drop to
0 to -4C Sunday and Monday morning. With such a cold airmass aloft,
lows still will likely drop into the mid to upper 30s, with any wind
sheltered area susceptible to colder temperatures and frost.
Greatest threat for frost will likely be Monday morning as the
pressure gradient and winds relax, leading to better conditions for
radiational cooling.

Other that potnetial for frost, no other hazards expected through
Monday.

Tuesday through Friday...

Brief ridging builds in Tuesday ahead of another upper trough diving
into the Great Lakes region from the northwest.  Warm air advection
ahead of the associated surface low tracking through Michigan should
lead to temperatures near average in the mid 60s, but with the
threat for rain. Sufficient moisture return combined with increasing
dynamics supports likely POPs on Tuesday. There is still timing
discrepancies between models regarding the speed of the front and
time of arrival for rainfall with the GFS being a good 6 hours
faster than the Euro or Canadian. Still think the highest PoPs will
be midday Tuesday, but will watch model trends closely and adjust
the timing of the expected rain in future forecast packages.

Cold air advection and surface high pressure building in behind the
departing low will allow for quiet weather conditions to return
briefly before another system approaches late next week.Another
chance for frost returns Thursday morning as high pressure becomes
centered over the Great Lakes. Watching North Central Indiana for
the best chance for frost. high pressure quickly pushes east with
numerous systems setting up for the end of the week and into the
weekend into the Great Plains. Expect a gradual moderating pattern
for temperatures late week and into next week with no chances for
frost after Thursday morning.

One thing to note, Indianapolis is already in the top 13 for wettest
April`s on record. Numerous chances for rainfall Tuesday, and then
again the weekend of April 27-28th will likely push Indianapolis at
least into the top 10 for wettest April`s on record.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 634 AM EDT Fri Apr 19 2024

Impacts:

- MVFR or briefly worse ceilings through early morning, improving
after 13z

- Winds gusting to 20 kt today, diminishing this evening

Discussion:

Latest satellite imagery shows low stratus across Central Indiana
bringing MVFR to IFR cigs to the TAF sites. Low stratus will slowly
improve from NW to SE from 12-14z with mainly clear skies expected
by mid to late morning. Wind gusts to near 20 kts expected through
early this afternoon. Winds will diminish later this afternoon and
into the evening.


&&

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

$$

UPDATE...Puma
SHORT TERM...BRB
LONG TERM...CM
AVIATION...CM