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FXUS63 KIND 210635

Area Forecast Discussion
National Weather Service Indianapolis IN
234 AM EDT Sun Jul 21 2019 

The SYNOPSIS, NEAR TERM, and SHORT TERM sections have been updated 

Issued at 234 AM EDT Sun Jul 21 2019

A cold front will move through central Indiana this afternoon and 
tonight. The front will interact with a hot and humid airmass and 
result in widespread thunderstorms late this afternoon and tonight. 
Much cooler and less humid conditions will follow next week, in the 
wake of the front, as Canadian high pressure builds in. 


.NEAR TERM /Today/...
Issued at 234 AM EDT Sun Jul 21 2019

An upper wave, currently across Montana, per H20 vapor imagery, will 
pivot southeast across the Dakotas today. This will bring the jet 
stream further south, which will shunt the upper ridge to the south 
and allow a cold front to drop south into northern sections of 
central Indiana this afternoon, per model blend. The synoptic scale 
front and outflow boundaries will interact with the hot, moist and 
unstable atmosphere and result in scattered to numerous 
thunderstorms today, especially during the afternoon and over 
northern sections. Will carry the highest PoPs there. Current radar 
trends and High Resolution Rapid Refresh suggests any convection 
will hold off until 12z or later over the forecast area.

Models are suggesting moderate to strong instability during the 
afternoon. However, shear will be marginal at best. Still, SPC has 
issued a Marginal Risk of severe weather for all of the forecast 
area for Day1. Damaging winds will be the main severe threat.  

The high heat and humidity will continue to be a threat today, 
although not sure the heat index will hit 105 at all locales. Still, 
with this being going on for the last few days, will allow the 
Excessive Heat Warning continue at least for now. That said, there 
is a good chance it could be cancelled a few hours earlier than the 
current 8 PM expiration time. 


.SHORT TERM /Tonight through Tuesday night/...
Issued at 234 AM EDT Sun Jul 21 2019

High Resolution Rapid Refresh and blend favor likely or higher PoPs 
tonight as the cold front drops southeast across the area. Models 
agree that the front will slow up enough to keep high PoPs in south 
on Monday. But by Monday night, the convection should end frond 
northwest to southeast as the upper trough pivots through, the front 
moves further to the south and Canadian high pressures builds in. 

Temperatures and humidity levels will be much more comfortable next 
week and especially Tuesday. High confidence in the below to well 
below normal National Blend trends.


.LONG TERM /Tuesday Night through Saturday/...
Issued at 310 PM EDT Sat Jul 20 2019

Fantastic weather is expected throughout the extended period next
week. Broad high pressure at the surface will expand into the 
area for much of next week with upper level heights cooling as the
strong ridge aloft shifts west into the Rockies and Intermountain
West. This will result in several days with dry and seasonable 
weather...highlighted by mainly sunny pleasant days and clear 
comfortable nights. Dewpoints will nosedive into the 50s by 
Tuesday evening and Wednesday before slowly climbing back into 
the lower 60s by next weekend. Highs will slip back to the low 80s
before gradually warming into the mid 80s by Friday and Saturday.

Extended models hinting of a cold front impacting the region at
some point next weekend which will once again bring in a cooler
airmass for the beginning of the last week of July. Storm impacts
with this front likely to be just outside the 7 day forecast.


.AVIATION (Discussion for the 210600Z TAF Issuance)...
Issued at 1139 PM EDT Sat Jul 20 2019 

VFR conditions are expected through most of the period.

Overnight there will be a few mid clouds as well as some high clouds 
from convection to the west (convection will remain west).

As a front moves into the area Sunday, scattered lower level clouds 
will develop as well as some convection. Short term models appear to 
be slowing the more widespread convection, so delayed the 
predominant rain until later afternoon and into the evening. 

Expect conditions to lower near 06Z Mon or later.


Excessive Heat Warning until 8 PM EDT Sunday for INZ021-028>031-



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