FXUS63 KIWX 202308

Area Forecast Discussion
National Weather Service Northern Indiana
708 PM EDT Mon May 20 2019

Issued at 707 PM EDT Mon May 19 2019

Some breaks in the clouds will occur this evening, but will
quickly fill in over night ahead of the next system. Temperatures
will fall into the upper 30s to lower 40s with just an outside
chance for some patchy frost in low areas. One more cool day will
be seen Tuesday with highs in the lower 60s before a dramatic warm
up arrives for the remainder of the week and into the holiday
weekend with periodic shower and thunderstorm chances.


.SHORT TERM...(This Evening through Tuesday)
Issued at 248 PM EDT Mon May 20 2019

Persistent cloud cover and cold air advection has limited our
warming across the northern Indiana, southern Lower Michigan, and
northwestern Ohio as highs have struggled to reach the mid-50s. As
skies clear overnight there is a chance for temperatures to
quickly drop into the lower 40s with a possibility of reaching
38 degrees; primarily along and north of Interstate 80. This could
allow for some patchy frost to develop. With that being said,
this window for frost development will be quickly closing after
midnight. This is due to increasing clouds as an elongated
shortwave slowly lifts northwards across the area. This will
help temperatures to warm slightly during the later half of the
overnight hours. Light showers are also possible in association to
this lifting shortwave as it interacts the now stalled cold front
across central IN. These showers are expected to persist into the
daytime hours before the shortwave lifts north into Lower
Michigan. Given the increase in cloud coverage during the day,
high temperatures will struggle to warm into the 60s.


.LONG TERM...(Tuesday Night through Monday)
Issued at 248 PM EDT Mon May 20 2019

Late Tuesday night, an upper low over the Central Plains is
forecast to lift northwards into the northern Plains. This will
send a cold front eastwards into eastern IL by sunrise Wednesday.
Convection is expected to be ongoing along the front as it moves
across IL and into western IN. As this convection moves into the
CWA, storms will be losing synoptic forcing as the axis of the
ridge lifts across Lower Michigan. This should result in a gradual
weakening trend through the late morning hours. The front is
forecast to stall across the southeastern CWA and be a focus for
convection to develop on throughout the day. With PWATS forecast
in the 1.25-1.5" range, the rainfall could result in localized
flooding; especially in areas of saturated soils. As a sub-
tropical high strengthens over the southeastern US, this area of
showers should diminish.

Persistent high pressure over the southeastern US will result in
above average high temperatures Thursday through the weekend.
Models show the center of the high being a bit to far south to
keep the area dry for this time period. This could result in a
prolonged period of rain chances as perturbations round the top
of the high. Its far to early to be able to time these
perturbations out each day so have stuck close a blended


.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 707 PM EDT Mon May 20 2019

Lingering cu field at SBN has brought brief return to MVFR cigs.
Will go for first few hours MVFR with winds holding up before
decoupling occurs and clouds mix out leaving behind mainly high
clouds into tomorrow. Next system arrives and may bring a light
shower to KSBN in the morning, but not worth a mention given low
chance. KFWA should remain VFR through the period.





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