121
FXUS63 KIWX 280515
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
115 AM EDT Fri Jun 28 2024

.KEY MESSAGES...

- A few rounds of storms possible, one late Friday night into
  Saturday AM, with scattered storms also possible later
  Saturday afternoon into early evening. Some locally heavy
  rainfall is possible with Round 1, and an isolated severe
  weather potential may exist for Saturday afternoon/evening.

- After a warm Saturday, cooler for Sunday behind cold front.
  Temperatures warm back into the 80s by Tuesday.

- Dangerous swimming conditions for southeast Lake Michigan
  beaches are expected again Sunday and Sunday evening.

&&

.UPDATE...
Issued at 906 PM EDT Thu Jun 27 2024

No significant changes are anticipated to the going forecast
this evening. Progressive, low amplitude flow will allow short
wave trough across Central Plains/Iowa to shift across the
southern Great Lakes overnight. Backing of mid low level winds
will result in continued increase in mid level positive theta-e
advection and eastward expansion of extensive mid level clouds
across Mid MS Valley. A few sprinkles/light rain showers are
being reported across far eastern Iowa/northwest Illinois, but
very dry low level downstream airmass evident on KILX 00Z RAOB
suggests dry forecast still reasonable. Increase in clouds and
warm advection overnight will allow temperatures to become
steady overnight in the lower 60s.

&&

.DISCUSSION...
Issued at 218 PM EDT Thu Jun 27 2024

Surface high pressure centered over Lake Michigan is keeping the
area cool and dry today under northerly winds. Highs are only in
the 70s this afternoon. Skies have been mostly clear, and the
few fair weather cumulus that have developed with daytime
heating will fade away this evening. Therefore, radiational
cooling will bring overnight lows down to around 60 degrees.
Dry weather will persist on Friday, but moisture and clouds and
heat will increase as the flow swings southerly. Rainfall
chances then also increase on Friday night with a series of
shortwaves in progressive westerly flow aloft.

Showers and thunderstorms remain possible on Saturday, and SPC
has the area in a Marginal Risk for severe storms. Bulk shear
will be increasing to around 40 kts, and there is sufficient
CAPE ahead of and along the cold front that will be sinking down
through the region Saturday afternoon to warrant this
assessment. Details will become more clear as we get closer to
that time.

Cooler and drier weather return behind the front for Sunday. It
will stay dry on Monday, but warm slightly as the upper ridge
builds. The next chance for storms will be late Tuesday into
Tuesday night as another front moves in. But models show this
front stalling over the area on Wednesday and temperatures
warming into the upper 80s. This seems a bit warm given cloud
cover and rain, but will leave the NBM forecast for now.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 115 AM EDT Fri Jun 28 2024

Elevated warm/moist air advection will support ample midlevel
clouds and perhaps a few sprinkles at times but low levels
remain very dry and VFR conditions will persist through the
period. Chances for thunderstorms and MVFR conditions increase
just after 06Z Saturday as deeper trough moves into the Great
Lakes and low level moisture increases. Will likely add a
thunder/MVFR mention with the 12Z TAF`s.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

UPDATE...Marsili
DISCUSSION...Cobb
AVIATION...AGD