AFTERNOON-OVERNIGHT: High pressure continues to build into the forecast zones this morning. However, with some leftover low-level moisture, clouds and mist did stick around as was mentioned in yesterday’s forecast. However, the good news is we are clearing out and sunshine is getting through!
Through the morning clouds will continue clearing out, but as they do heating will take place and some instability will build. Once temperatures at the surface rise they will create a dramatic temperature difference through the environment, this can be measured in lapse rates. Anything above a 6.5-7° drop is pretty high, this afternoon forecasts call for a 9-10° drop, so there will be some decent instability present.
While no thunderstorms will be in the forecast, some afternoon instability showers may get going across the area by 12-1 PM this afternoon.
Through the afternoon isolated to widely scattered showers will be possible across western and southern Indiana and southern Ohio where better instability/lapse rates occur. However, better chances look to be across Illinois. By 5-6 PM the HRRR picks up on those showers that will be ongoing.
Through the evening into the overnight we will lose daytime heating and instability. As that occurs any remaining showers across Indiana and Ohio will being to fade out. By 10-11 PM tonight most of the rain will be over, with only a couple of showers remaining.
Overnight a couple stray showers may remain, but overall it will be dry. With the high pressure in place clouds will fade as well, giving way to a clear to mostly clear skies overnight.
New rainfall totals this afternoon through late tonight will be pretty minimal. Most places will see less than .10”. However, a few locations could see .10-.20” of new rainfall.
Lows tonight will be in the low 40’s north to around 50 south.
THURSDAY: High pressure will continue to control the weather across zones 1 and 5 on Thursday. With dry, sinking air in place mostly sunny conditions will be likely across both zones.
Highs on Thursday will be in the mid 60’s north to around 70 south.
Thursday evening the area of high pressure will start to move to the east and northeast. To the southwest a developing storm system will be moving closer to the forecast area. As it does, clouds will thicken up from southwest to northeast across the forecast zones later in the evening through the overnight.
While clouds will stream in through the overnight Thursday into Friday, I don’t expect any rain chances to arrive until very late into the overnight/early Friday morning.
Lows Thursday night will be in the upper 40’s north to mid 50’s south.
FRIDAY: Friday morning some isolated showers may be moving into very southern Indiana near the Ohio River across zone 5. The NAM model does show some showers entering southern Indiana around 8-9 AM Friday morning.
Through the day on Friday the low will continue to track to the south of the forecast zones. As it does, isolated to scattered rain and a couple t’storms will be possible from I-70 southward across Indiana and Ohio, with the better chances farther south closer to the Ohio River.
By late evening into the overnight the low will move away from the forecast area. While some isolated showers may remain through midnight or so across southern Ohio, rain will come to an end by Saturday morning.
Highs on Friday will be in the upper 50’s to mid 60’s.
I will add, while models seem to be in pretty good agreement with the placement of the low/rainfall we will be watching for any changes in the model data. If the low were to go farther north or farther south, rain chances could be increased or decreased over the forecast zones.
WEEKEND: Behind that system an area of high pressure will move back into the forecast area. This will allow for dry, sinking air to move in, clearing out most of the clouds. With the high in place mostly sunny conditions are expected through at least early afternoon on Saturday.
However, temperatures aloft will be very cold once again on Saturday. With cooler air aloft instability will build through the afternoon hours. With that in mind, clouds will develop and some isolated afternoon rain showers are not totally out of the question. Although, I think rain coverage will be pretty limited due to the area of high pressure.
Highs on Saturday will be in the mid 60’s to low 70’s.
Sunday high pressure will remain in control of the weather, so yet another nice day will be in-store for the area. Sunny to mostly sunny skies will be in place across the region with perhaps some more clouds building through the afternoon.
On Sunday the upper-level trough that brought cool temperatures aloft on Saturday will be moving off to the east. However, it does appear that it will still have enough influence on our weather that cool air will remain at the upper-levels. This may allow for enough instability for a couple isolated showers to develop, but right now it’s really not enough coverage to mention specifics.
Temperatures on Sunday will continue to moderate with highs in the low to mid 70’s.
LONG-RANGE (NEXT WEEK): At the surface an area of high pressure will remain in control of the weather. This will allow for a very nice start to the work week with sunshine and very little chance of rain.
At the upper-levels the trough will eject off of the East Coast. Behind it a ridge of high pressure will start to build in over the region. This ridge will not only reinforce the calm and dry conditions; it will also allow warmer air to overspread the forecast zones. By early next week above average temperatures will be in place with highs in the 80’s!
Looking a little longer down the road into mid to late next week a larger storm system is forecast to take shape. Right now timing, threats, and location are still in question, this is something we will have to fine tune as the forecast period draws closer.