FXUS63 KIWX 190759

Area Forecast Discussion
National Weather Service Northern Indiana
359 AM EDT Thu Sep 19 2019

Issued at 348 PM EDT Wed Sep 18 2019

Dry and warm conditions will persist into Friday. Clouds will
begin to increase on Saturday, with showers and thunderstorms
becoming likely Saturday night through Monday morning. Some
locally heavy rainfall is possible during this period. High
temperatures will reach into the lower to middle 80s today.


.SHORT TERM...(Today and Tonight)
Issued at 311 AM EDT Thu Sep 19 2019

Upper ridge will continue to prolong warm conditions across the area
today as a weak shortwave crests the ridge this afternoon. High
temperatures are expected to reach into the lower to mid-80s. This
afternoon and into the tonight period, southerly return flow will
help bring a weak warm front from southern IN northwards across the
area. With the increased low level moisture, overnight lows will
only drop into the low 60s.


.LONG TERM...(Friday through Wednesday)
Issued at 311 AM EDT Thu Sep 19 2019

Forecast for Friday continues to look warm and dry. The 00Z NAM/GFS
do generate QPF within the return flow regime, but will lean the
forecast towards the dry ECMWF as it has a better run-to-run
consistency. High temperatures are expected to reach into the
lower to mid-80s Friday afternoon.

Saturday night through Monday continues to be the focus of the

An upper trough is forecast to eject out of the central High
Plains and into the upper Midwest Saturday into Sunday morning. As
the trough moves into the upper Midwest, the associated upper jet
is shown to strengthen to 110-120kt. Southwesterly winds aloft
will help to transport a tropical moisture plume from the
remnants of Tropical Depression Imelda into the Midwest. Models
show PWATs increasing into the 1.75" to 2" range by Saturday
evening. Lift provided by the entrance region of the upper jet
will help to initiate convection across IL Saturday afternoon
before drifting eastwards into the western zones Saturday night
into Sunday morning with the progression of the trough. On Sunday
afternoon, the trough axis is forecast to take on a more neutral
to slightly negative tilt as it moves over the western Great
Lakes. At the surface, a SW to NE oriented cold front is forecast
to approach the area during the same timeframe. This will cause
precip to expand eastwards to encompass the entire area until the
cold front moves east of the area by midday Monday.

For this forecast issuance, the GFS has come closer to the
consistent ECMWF/CMC concerning the onset of precip. Will continue
to lean the forecast towards the ECMWF which has lower to mid 80s
for highs area wide on Saturday and across NW Ohio on Sunday.
There is still the possibility for locally heavy rainfall with
this system, primarily across NW IN and SE lower MI given the
forecast climatologically high to near record PWATs and initial
slow movement of the cold front. Models show the potential for
storm total rainfall amounts of 1 to 2 inches of rain across the
NW half of the CWA with lower amounts across the SE half.

Weather turns dry with near average temperatures Tuesday and


.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1240 AM EDT Thu Sep 19 2019

Ridging sfc and aloft yield VFR through the period.





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