Area Forecast Discussion

WHAT HAS CHANGED

Issued a Heat Advisory for our far north today.

KEY MESSAGES

1) Warm and humid conditions are expected again today. Isolated to scattered thunderstorms are possible this afternoon. Additional showers and thunderstorms can be expected again late this evening and into the overnight hours.

2) A drier and somewhat cooler airmass will move in behind the cold front for Friday afternoon and into Saturday. A secondary cold front will bring additional showers and thunderstorms on Sunday along with cooler temperatures for early next week.

DISCUSSION

KEY MESSAGE 1) Widespread showers and thunderstorms off to our west early this morning are forecast to gradually dissipate as they move east into our western areas through the pre-dawn hours. An outflow boundary is evident on radar out ahead of the initial areas of storms moving through northwest Indiana so this should help those dissipate. Will have to see how things transition though with the stronger convection back across central Illinois attm. The airmass to the south of the outflow boundary remains more unstable so this activity may linger a bit longer with its eastward push. Overall though, any severe threat should be low with any storms that are able to make it into our western areas through daybreak. The biggest threat will likely just be some gusty winds with any remnant outflow boundaries.

It looks like we will have another day with borderline Heat Advisory conditions. There is some of uncertainty though as we head through late morning with lingering clouds from the current MCS and what effect that will have on temperatures. Another concern is that most of the hi-res models are suggesting isolated to scattered thunderstorms redeveloping later this morning and into this afternoon, and then what effect those could have on temperatures. Will go ahead and continue with highs mostly in the upper 80s to near 90 degrees. This will result in heat indices in the 95 to 100 degree range. Will match up with neighboring office with a Heat Advisory across our far north for today, but handle the rest of the area with an SPS given some of the uncertainties.

Any daytime diurnally enhanced thunderstorms will dissipate heading into this evening. However, widespread thunderstorms will progress southeast into our area later tonight ahead of an approaching cold front. Some better deep layer shear will work in from the northwest overnight and this may allow for these storms to maintain their intensity more before they begin to weaken later tonight as they move southeast across our area. As a result, a few strong to severe storms will be possible tonight, especially across our northwestern areas. Damaging wind would be the primary concern.

KEY MESSAGE 2) The cold front should be just about east of our area by Friday morning so expect any lingering showers and storms across our southeast to taper off through the morning hours. A drier and somewhat cooler airmass will then settle into the area through Friday afternoon and continue into the day on Saturday.

A mid level short wave will move east across the Ohio Valley during the day on Sunday, helping to push a secondary cold front through our area. This will lead to fairly widespread showers and thunderstorms late Saturday night and into the day on Sunday. It will also usher in a cooler airmass for the first half of next week.

AVIATION /10Z THURSDAY THROUGH MONDAY/

A weakening area of showers and thunderstorms pushing east-southeast across southern Indiana should continue to weaken over the next few hours. However, they may hold together long enough to affect KCVG/KLUK for the first hour or so of the TAF period so will include a prob30 to cover the threat.

Otherwise, diurnally enhanced isolated to scattered thunderstorms will redevelop across the area through the afternoon hours. Any activity should taper off heading into this evening. However, more widespread showers and thunderstorms will drop southeast across the region later tonight ahead of an approaching cold front.

Generally expect VFR conditions to prevail outside of any showers or storms.

OUTLOOK... Thunderstorms possible Sunday.

ILN WATCHES / WARNINGS / ADVISORIES

OH...Heat Advisory from noon today to 8 PM EDT this evening for OHZ026- 034-035. KY...None. IN...None.