AFTERNOON-OVERNIGHT: Clouds and some rain showers continue to move across the forecast area this morning. These are thanks to an upper-level and surface low that are continuing to move out of the forecast area today.
While the upper-level low will be moving to the southeast of the region today, some clouds and showers will stick around. However, with some dry air working into the area some sunshine will likely get through too.
While the main upper-level low will exit, some remaining disturbances will be moving across zones 1 and 5 this afternoon. By 2-3 PM this could cause some isolated to widely scattered showers to get going across Indiana and Ohio.
Through the early to mid-afternoon hours today the weather will likely feature more clouds than sun across zones 1 and 5. However, by late afternoon into the evening the models are pretty persistent with thinning clouds and clearing skies.
Through the overnight the area of high pressure will continue to ridge into the zones. As it does, dry air will move in with it allowing the rain to end totally and causing skies to become mostly clear.
Overnight lows will be around 40 north to the upper 40’s south.
FRIDAY: With high pressure in control of the weather on Friday the weather to end the work week will be very nice. Skies will remain sunny to mostly sunny through the day with light westerly winds of 5-15 mph.
With an upper-level ridge of high pressure building into the Midwest from the Great Plains region, this will allow for temperatures to rebound some on Friday as well.
Highs on Friday will be in the upper 60’s east to mid 70’s west.
Friday evening into the overnight clear to mostly clear skies will remain in place. Lows will be in the upper 40’s to mid 50’s.
SATURDAY: A cold front will be in place to the north of the forecast zones on Saturday morning. As this works southward through the day clouds and precipitation chances will be on the increase across zones 1 and 5.
Highs on Saturday will be in the mid 70’s north to low 80’s south.
As the front moves southward through the day on Saturday rain and storms will develop along it. By 4-5 PM at least some isolated storms will become possible across zone 1 in Indiana and Ohio.
Through the evening the front and associated storms will continue south and southeast. Isolated to scattered storms will be possible across the cold front in zone 1 across Indiana and Ohio. However, to the west across portions of Illinois a MCS (mesoscale Convective System) or cluster of strong to possibly severe storms may be developing.
The NAM 12 km does show what looks to be an MCS type event moving into and across Indiana around 10 PM and after Saturday evening.
Through the overnight the front will continue its movement southward through the forecast area. The cluster of storms would continue to the southeast or south south east along the front. Possibly impacting places from Indianapolis to Cincinnati. By 2 AM the NAM does show the possibility for storms in the Cincinnati metro area.
I do think by late Saturday afternoon through the evening strong to severe storms could be possible. Strong flow aloft will be present as winds at 500 mb will be around 55-70 mph. At lower-level 850 mb winds will be moving in at 40-50 mph.
Instability could end up being a bigger factor on Saturday as well in determining if storms will be strong to severe. The current run of the NAM shows a small ribbon of 1000-1250 J/Kg of CAPE right along the cold front. While this would be enough to get strong to possibly severe storms to form, much lower values and the threat would be greatly decreased.
Overall, the threat for strong to severe storms is there and worth mentioning. However, there are still some details that will need fine-tuned as we get closer to the forecast period. If a severe weather threat should materialize hail and damaging winds would be the primary threats, along with the threat of the previouldy mentioned MCS.
Saturday night into Sunday the cold front will continue to the south across zone 5. While rain and some t’storms will remain possible along the front, the strong to severe threat will likely be fading as we lose better instability and dynamics.
SUNDAY: The cold front that moves south Sunday will slow down and likely become stationary across central to northern Kentucky and possibly across southern Indiana.
This front will allow more clouds to stick around across zone 5 and possibly southern zone 1 Sunday. With the front remaining in place to the south of the region some isolated to widely scattered rain/storm chances will emerge Sunday afternoon, especially across zone 5.
Highs on Sunday will be in the mid 60’s north to right around 80 south, closer to the front.
New rainfall totals through the end of the weekend will average .20-.40” in many places. However, higher amounts will be possible under some of the stronger storms. IF a cluster of storms should emerge Saturday evening then a swath of heavier totals would be possible. The NAM shows this potential very well as swath of .60-1.20” of rain is placed right across the I-74 corridor from Illinois to southern Ohio.
MONDAY – TUESDAY: An area of low pressure will be developing across the Great Plains by late in the weekend. On Monday this will lift northward across the Plains and into the western Midwest. As it does, the stationary front that is in place across the region will begin to lift back northward as a warm front.
While some rain and storms will be possible across the warm front and even into the warm sector of the system on Monday. However, with the warm front lifting northward earlier in the day there will be no real lifting mechanism to get storms to fire in the afternoon.
While it is possible for storms to develop in the afternoon, warm sector clouds and the lack of sufficient instability may prohibit a greater threat for storms on Monday.
Highs on Monday will be in the 70’s.
Tuesday there are some differences in the model guidance regarding frontal placement and timing. Regardless, a low pressure looks to move to the north of the forecast area on Tuesday. As it does, an attendant cold front will move across the forecast area through the day.
One of two scenarios could play out Tuesday along the front. The first being rain and storms are ongoing along the front through most of the day. Or the second being, as we build instability in through the afternoon and evening storms will develop along the front.
Winds aloft also look pretty impressive with this system. Given the setup I do think that severe weather could be a threat as the front moves through Tuesday. However, timing/placement/impacts are still very fuzzy and need worked out.