textproduct: Wilmington

WHAT HAS CHANGED

No significant changes were made.

KEY MESSAGES

1) Showers and thunderstorms will occur ahead of a cold front that will move through the region tonight.

2) More showers and storms will occur Monday night into Tuesday ahead of the next cold front.

DISCUSSION

KEY MESSAGE 1) A mid level ridge over the area will keep most of the showers over the CWA at bay with the exception of the far northwest (Mercer County) this early afternoon. Dry lower levels will take some time to see an appreciable moisture increase, which should hold off any showers and thunderstorms until late day. By early evening, the area of showers will have crossed the IN/OH border as a surface low quickly tracked ene to the Toledo area in the late evening. These showers will be associated with a cold front that will stretch wsw- ene through Mercer, Auglaize, and Hardin counties a little before midnight. A secondary surface circulation is expected to settle over Mansfield after midnight, with the cold front stretching from there to the Cincy area. The front will move east and any rain ahead of it is expected to be exiting the southeastern CWA before daybreak.

Given the atmosphere the showers will need to overcome as an upper level s/w butts into the upper ridge that looks to be situated over the center of the CWA in the late day, severe threat looks to be weak, with diurnal heating creating minor instability a little before nightfall in the west, lingering through the evening in the east until precip begins towards midnight.

KEY MESSAGE 2) Short wave emerging from the central Rockies Sunday night will deepen as it heads east northeast into the Great Lakes by Tuesday. While overall pattern is pretty stable, there has been a trend towards a bit more spread in the mid levels with this system as it gets this far east, which may be more representative of some timing uncertainty compared to system strength. The mean has certainly become slightly slower with the progression.

Given this, the chance of seeing precipitation reaching our forecast area on Monday continues to wane. Bulk of the showers and thunderstorms may not even move across the area until later Monday night. The potential for strong to severe storms will be greatly diminished if this later timing continues as it heads towards the diurnal minimum of the typically lowest instby. It does appear a low level jet will push into the region on Monday night and weaken as it moves across the area. This may result in good moisture transport which could mean locally heavy rainfall would be of more concern. WPC pushes a marginal risk of excessive rain, west of the Scioto River Valley. Being day 4, there is plenty of time and room for meaningful changes in how this system impacts the area, and latest guidance continues to bring the front in later and later.

With the slower progression, the associated cold front is indicate to be in southeast CWA Tuesday morning. If it is slow enough, there may be a window for some instability to develop in southern CWA before the front clears the area. If that were to occur, then some stronger storms could not be ruled out.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

Cold front is pushing through the region, though losing intensity as we head into the evening hours. The Geostationary Lightning Mapper (GLM) still returning a handful of strikes on the southern edge of the line as it moves into the Tri-State. This, with weak instability profiled on ACARS, has prompted the addition of -TSRA into the prevailing TAF at CVG and LUK for the next hour or so. Confidence on there being enough instability for the line to produce lightning at these sites is medium at this time.

For all other sites, went with -SHRA timed in over the next several hours as the front moves through. VFR CIGs will drop to MVFR behind the front with some isolated periods of IFR possible. Confidence on any IFR is very low, so did not include in TAFs at this time. CIGs will improve back to a SCT/VFR deck Saturday afternoon hours.

Southwesterly winds ahead of the front this evening will continue to periodically gust to around 20 knots. As the front moves through, we'll see a wind shift. Winds behind the front will swing to out of the west then northwest, around 10 knots or so. Northwesterly winds continue on Saturday, with occasional gusts to 18 knots or so but not frequent enough to include in TAFs at this time.

OUTLOOK....Thunderstorms possible Monday night into Tuesday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...None. KY...None. IN...None.