AFTERNOON-EVENING: A stationary front remains in place across southern Indiana today. That is currently where rain and some thunderstorms are in place.
The area of rain across southwestern zone 5 and into Illinois has been weakening through the morning hours. While some models do have some upscale growth, the NAM 4 km shows them continuing to fade. By 1-2 PM only some scattered rain and storms will be in place across the forecast zones in Indiana.
Through the afternoon into early evening isolated to scattered storms will remain possible across zones 1 and 5 in Indiana and western Ohio, including Cincinnati.
Strong to severe storms will develop across Illinois this afternoon and evening. By 8-9 PM some of those storms look to be crossing the state line, especially across western zone 5.
Through the evening storms will continue to move eastward across Indiana. Eventually entering western Ohio and the Cincinnati area around 12-1 AM.
Through the overnight I do think storms will weaken across the area so the strong to severe storm threat will start to die out. By 4-5 AM Thursday morning most of the precipitation will be off to the regions east as the occluding front moves east of the region as well.
Strong to severe storms will be possible across portions of the forecast zones this afternoon into the evening hours.
While upper-level winds will not be overly impressive, CAPE values of 1000-1500 J/Kg will be possible across southwestern Indiana. This would be enough instability to allow severe storms forming in the better environment to the west to continue their strong to severe status as they move into Indiana. Especially if they can develop into more of a linear structure as the NAM 4 km would suggest.
The best chance for severe weather will be across southwestern Indiana this evening into tonight. However, some severe weather can’t be totally ruled out across southern zone 1 and zone 5 in Indiana with the stationary front in place.
Lows overnight will be around 50 north to around 60 south.
THURSDAY: I do think Thursday morning could start out foggy in some areas across zones 1 and 5. This will be as low-levels of the environment remain saturated, but a thermal inversion is in place aloft.
Through the daytime hours on Thursday there will be a disturbance rolling through the area along with a surface boundary. While it looks like most of the day will be dry, rain and some storms will develop near this boundary by 2-3 PM across southeastern Indiana and southwestern Ohio.
Through the afternoon rain and storm chances will continue across southeastern Indiana and into southern Ohio. However, by 4-5 PM more isolated to scattered areas of rain and perhaps a t’storms will develop farther north across zone 1 near a cold front.
Highs on Thursday will be in the upper 60’s north to upper 70’s south.
Some storms Thursday afternoon and evening across southeastern Indiana and into southern Ohio could be on the strong to severe side. While weak, westerly flow aloft will inhibit the possibility of a greater severe threat, daytime heating looks to allow 1500-2000 J/Kg of CAPE to develop.
With the boundary in place along with the higher instability low-end severe winds gusts and hail is not out of the question.
Through Thursday evening into the overnight the cold front to the north will push southward. As it does some isolated showers will remain through 1-2 Am Friday before fading overnight.
Regarding new rainfall totals, I think .50-1” of rainfall can be expected on average. However, I do think local accumulations of 2-3” will be possible where the strong to severe storms do occur through late Friday night.
While the NAM 4 km is a bit too aggressive with the rain totals, it does show those heavier pockets of rain nicely.
FRIDAY: The front will move out of the area early on Friday. This will set up for a mostly dry day across zones 1/5 with a mix of sun and clouds.
Highs on Friday will be on the cool side, with temperatures topping out in the low 60’s north to mid 70s south.
Friday evening into the overnight a warm front will be lifting to the north across southern portions of the forecast area. This will allow for scattered rain and perhaps a few t’storms to move back into zones 1/5 around 1-2 AM Saturday morning.
Through Friday night rain and some storms will continue to spread north across Indiana.
WEEKEND: Saturday morning the warm front will still be moving across zones 1 and 5. With this in place scattered rain and some storms will be ongoing across Indiana and Ohio.
Through the day the warm front will continue to lift northward as the low pressure center to the west gets closer. While I do think rain chances will continue throughout the day, the warm front looks to be far enough north by late afternoon that some dry time may be possible.
Highs on Saturday will be dependent on the front. If the front remains to the south then highs may only warm into the upper 50’s to upper 60’s. However, if the front moves farther north widespread 60’s would become more likely.
Sunday the area of low pressure that was across the Plains will move closer to the forecast region. Models are currently showing the low tracking south of the forecast area across Paducah, KY to eastern KY.
This track would greatly decrease severe weather chances across the forecast area Sunday that we had previously mentioned. However, rain and general thunderstorms would remain possible.
With that being said, that track is not written in stone yet, so we will watch models for any new data or trends.
Highs on Sunday will be in the upper 50’s to low 60’s north and along the front. South of the front upper 60’s to upper 70’s will be possible.
LONG-RANGE (NEXT WEEK): While some rain may stick around Monday as an upper-level trough moves through, next week looks calmer as a whole.
A northwesterly flow aloft will prevail for most of next week. While that will help ease any severe storm/heavy rain concerns, at least some rain chances will remain since the northwesterly flow usually proves to be an active one.