AFTERNOON – OVERNIGHT: An area of low pressure continues to spin off to the regions west today. However, through the evening and overnight this low will move to the north of the forecast zones. As it does, a cold front will sweep through zones 1 and 5 tonight.
This afternoon we will be in the warm sector of the storm. This will keep conditions warm and sunny through the day. Highs will be topping out in the upper 60’s to mid 70’s this afternoon!
However, the sunshine will also allow instability to build into the atmosphere this afternoon and evening. Later this evening CAPE values will be from 1000-2000 J/kg. This is plenty enough instability to support t’storms and even strong to severe t’storms.
While there will be plenty of instability models have trended slower with storm progression and moved the center of low pressure farther south. What this will do for our forecast is shift the severe weather threat farther north and northwest, closer to the low. Here is the latest severe weather outlook showing the greatest risk or severe weather across northwestern Indiana.
Tonight the cold front will sweep eastward across Illinois. As it does a broken line of rain and thunderstorms will develop along it and move eastward. By 12 Am the cold front and storms will be entering western Indiana.
Storms look to quickly move eastward across Indiana impacting the central portions of the state and the Indy metro around 1-2 AM.
Through the overnight storms will continue to the east across Indiana and into Ohio. I think as they do they will start to lose better instability and dynamics, so they will start to weaken.
By 7-8 AM Wednesday morning the cold front and rain will be moving out of western Ohio and the forecast zones.
Regarding the storms tonight, the NAM model isn’t very aggressive developing storms, in fact you could say it’s likely a little conservative. I do think there will be more scattered storms than what the model is depicting.
Although the overall severe weather risk has shifted farther northwest I still think some strong to severe storms will be possible, especially across zone 1 and northern zone 5. The main risks will be damaging winds, hail, and perhaps an isolated tornado.
Overnight rainfall totals look to be around .20-.40” in places where there is rain. However, if you get under a strong to severe t’storm .50-1” of rain locally can’t be ruled out.
WEDNESDAY: Wednesday morning the cold front will swing off to the east of zones 1 and 5 taking the rain and clouds with it.
However, the area of low pressure will start to stall out and occlude to the north of the area Wednesday. As it does the pressure gradient will really start to tighten and winds will become strong. Sustained winds out of the west at 10-20 mph are likely, with gusts of 35-45 mph possible!
Highs on Wednesday will be in the upper 50’s north to mid 60’s south.
By 7 PM Wednesday evening an upper level disturbance will move through Indiana. As it does it will prove enough to create some isolated to scattered evening rain showers with possibly an isolated t’storm mixed in.
As we lose daytime heating and the disturbance moves through, any precipitation will come to an end by midnight.
THURSDAY – FRIDAY: The low pressure to the north will finally move off to the east of the region on Thursday. However, it will still influence our weather as winds will remain strong with gusts up to 40 mph possible.
Highs on Thursday will be in the low 50’s north to mid 60’s south.
Thursday evening yet another 500 mb vorticity max will spread southward across the zones.
As it does another round of isolated showers will develop across the zones. With lows dropping into low 30’s north to low 40’s south, if showers should stick around through the overnight a changeover to some light snow showers would be possible north.
Friday an area of high pressure will start to ridge in from the northwest. As it does much cooler air will spill into the forecast area. Highs on Friday will only top out in the mid 40’s north to mid 50’s south.
Friday evening an upper level low will start to move closer to the region from the northwest. As it does an associated piece of upper level energy will move into the Midwest. With this in place some isolated rain showers will be possible Friday evening, but as of right now these look very isolated in nature.
WEEKEND: The upper level low/trough that will be to the northwest Friday will work into the region for the weekend. This will keep slight chances of precipitation in the forecast both Saturday in Sunday.
In fact, Friday night into Saturday and Saturday night into Sunday temperatures do look cold enough to support some snow showers in locations. This will be overnight as daytime temperatures will be warm enough to support rain.
Highs this weekend will be cool with temperatures topping out in the upper 30’s to low 50’s.
7 DAY FORECAST
WEDNESDAY: AM CLOUDS, THEN MOSTLY SUNNY. 20% CHANCE OF RAIN OR T’STORM LATE. HIGHS IN THE UPPER 50’S NORTH TO MID 60’S SOUTH. WESTERLY WINDS AT 10-20 MPH, GUSTING TO 35-45 MPH.
WEDNESDAY NIGHT: MOSTLY CLEAR WITH LOWS IN THE 40’S.
THURSDAY: MOSTLY SUNNY TO PARTLY CLOUDY WITH 20% CHANCE OF PM SHOWERS. HIGHS IN THE LOW 50’S NORTH TO MID 60’S SOUTH. WINDS FROM THE WEST AT 10-20 MPH, WITH GUSTS UP TO 40 MPH.
THURSDAY NIGHT: PARTLY CLOUDY WITH A 20% CHANCE OF RAIN AND/OR SNOW SHOWERS. LOWS IN THE LOW 30’S NORTH TO AROUND 40 SOUTH.
FRIDAY: PARTLY TO MOSTLY CLOUDY, WITH A 10% CHANCE OF SHOWERS. HIGHS IN THE MID 40’S NORTH TO MID 50’S SOUTH. WEST TO NORTHWEST WINDS AT 6-12 MPH, GUSTING TO 25 MPH.
FRIDAY NIGHT: INCREASING CLOUDS CHANCE OF RAIN AND/OR SNOW. LOWS IN THE LOW TO UPPER 30’S.
SATURDAY: MOSTLY CLOUDY, AM SNOW SHOWERS TO RAIN, 30% CHANCE OF PRECIPITATION. HIGHS IN THE LOW 40’S NORTH TO LOW 50’S SOUTH. VARIABLE WINDS AT 5-15 MPH.
SATURDAY NIGHT: PARTLY TO MOSTLY CLOUDY, 20% CHANCE OF SNOW SHOWERS. LOWS IN THE UPPER 20’S NORTH TO UPPER 30’S SOUTH.
SUNDAY: PARTLY CLOUDY, 20% CHANCE OF AM SNOW SHOWER TO RAIN SHOWERS. HIGHS IN THE UPPER 30’S NORTH TO UPPER 40’S SOUTH.
SUNDAY NIGHT: PARTLY CLOUDY WITH LOWS IN THE UPPER 20’S TO MID 30’S.
MONDAY: 30% CHANCE OF AM SNOW TO RAIN.HIGHS IN THE MID 40’S EAST TO MID 50’S WEST.
MONDAY NIGHT: PARTLY TO MOSTLY CLOUDY WITH 20% CHANCE OF SNOW/RAIN SHOWERS. LOWS IN THE UPPER 20’S NORTH TO LOW 40’S SOUTH.
TUESDAY: MIX OF SUN AND CLOUDS, 20% CHANCE OF RAIN. HIGHS IN THE MID 50’S TO MID 60’S.
TUESDAY NIGHT: PARTLY CLOUDY WITH LOWS IN THE MID 40’S TO MID 50’S.