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FXUS63 KIWX 152338

Area Forecast Discussion
National Weather Service Northern Indiana
638 PM EST Fri Nov 15 2019

Issued at 354 PM EST Fri Nov 15 2019

Expect dry conditions through Saturday night, with partly to mostly 
cloudy skies. Lows will be in the teens and 20s. Highs will be in 
the 30s and low 40s. There are low chances for rain and snow showers 
Sunday, mainly west of Interstate 69. Dry conditions return Tuesday 
into Wednesday, with highs climbing into the 40s and low 50s. 


.SHORT TERM...(This Evening through Saturday)
Issued at 354 PM EST Fri Nov 15 2019

Surface high pressure centered over northern Ontario/Lake Superior 
this afternoon will continue eastward overnight, forcing the cold 
front currently located over southern Lower Michigan southward 
across the CWA. A shortwave will pass through nearly zonal flow 
aloft through early evening, but best forcing for any precipitation 
will remain north of our forecast area. Maintained dry forecast 
given the overall lack of moisture and increased mid/upper level 
ridging overnight, but have cloud cover lingering as the front 
descends into our CWA. Strong low level inversion will likely keep 
the clouds in place, but some of the guidance suggests it will 
diminish briefly this evening before filling back in later tonight. 
For now kept partly to mostly cloudy skies in for much of the CWA, 
with lows in the 20s. Should we see more clearing than currently 
forecast, will need to lower temperatures tonight in subsequent 


.LONG TERM...(Saturday Night through Friday)
Issued at 354 PM EST Fri Nov 15 2019

Temperatures will slowly begin to warm through the long term period, 
ranging from the mid-upper 30s and low 40s Sunday into Tuesday, then 
peaking in the mid 40s and low 50s Wednesday and Thursday. 
Otherwise, surface high pressure/upper level ridge keeps the 
forecast dry through late Sunday afternoon. Sunday into Monday a 
sharp upper level trough will shift from the plains into the Great 
Lakes. The occluding surface low will cross Lake Superior, then 
reach southern Ontario by Tuesday afternoon. The weakening front 
will shift into our western CWA late Sunday afternoon/evening with 
extremely limited moisture. Delayed start time a little bit from 
previous forecast as there is quite a bit of dry air to overcome 
initially. Forcing diminishes as the front continues eastward, thus 
have decreasing pops into early Monday morning (limited to areas 
west of I 69 for the most part). Expect a rain/snow mix, with snow 
more prevalent towards Monday morning. Another vort lobe will shift 
through the upper level trough Monday night before lifting off to 
the north, with northwest flow potentially leading to some slight 
lake response. Kept low chances for rain/snow mix Monday night, 
limited to Lake MI/north of I 80-90. 

Weak ridging aloft and surface high pressure will dry things out 
Tuesday into Wednesday, with 850mb temps rising to around 0C ahead 
of the next system. Expect mainly partly to mostly cloudy skies. 

The better chances for precipitation will be Wednesday night into 
Friday. We see an upper level low/deepening trough dive from the 
northern plains/Canadian prairie on Wednesday into the lower Great 
Lakes by Friday morning. Models disagree on the exact location, 
strength, and timing of the upper low/trough(and subsequent surface 
features)so maintained consensus blend pops. Best chances (capped at 
60 percent for now)look to be Thursday into Thursday evening. Warmer 
temperatures Thursday will keep precipitation as all rain, but into 
the overnight hours and Friday we will see more of a mix (or change 
to snow) as temperatures fall into the low 30s. Highs Friday will be 
in the mid to upper 30s, with brisk northwest winds and potential 
for lake enhanced rain/snow showers. 


.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 626 PM EST Fri Nov 15 2019

Cold front draped across northern Indiana will slowly drop 
southwards through the overnight hours. This will prolong MVFR 
conditions for KSBN and KFWA through the first several hours of 
this TAF cycle. Do think ceilings will be able to lift too near
4000ft at KSBN around the 04Z to 06Z hour, but improvement for 
KFWA will be delayed until after daybreak as winds round the dial
out of the northeast. There is some concern for MVFR ceilings to 
move back into the KFWA terminal around the 18Z hour tomorrow as 
low level moisture from Lake Eerie is advected westwards, but 
stayed optimistic this far out. 





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