Marine Weather and Tide Forecast for Powell, OH

NEAR TERM /THROUGH TONIGHT/
Surface high pressure remains the primary weather influence today, keeping conditions dry. This system will begin to shift eastward throughout the day as it drifts towards the Atlantic coast. Return flow on the backside of the surface high will result in an influx of seasonably warm air, along with a gradual increase in humidity values. With the WAA and plenty of insolation, highs will climb back into the middle 70s to near 80 in our far south.

SHORT TERM /TUESDAY/
Skies will remain clear for the majority of the night before clouds build in from the west ahead of the next system. However, a tightening pressure gradient will lead to a response in surface winds, increasing southerly flow overnight. This will result in mild overnight lows in the 60s across our CWA

The main focus remains on the severe potential for Tuesday. CAMs now offer a little more insight on timing and storm mode. Models continue to highlight moderate instability developing during the day, but there does seem to be a trend towards an earlier onset of storms.
SBCAPE values of 1500-2000+ J/kg still seem probable, with the highest values expected near the Tristate. Wind shear profiles still appear to be marginal, but sufficient enough to lead to organized convection (especially with the forcing of a cold front).

By late morning, isolated cells may begin to develop across eastern IN/far western OH with a pre-frontal trough. Large hail would likely be the primary threat with any of these discrete cells earlier in the day, but given that some supercells could develop, an isolated tornado cannot be ruled out (but tornadoes do not appear to be a primary threat). As we progress into the early to mid afternoon, additional storm development occurs with the moderate levels of instability and increased forcing ahead of a cold front. This will likely result in more clustering of storms, perhaps forming a QLCS during the afternoon. Complex of storms would continue to move eastward with the progression of the cold front, with damaging straight-line winds now becoming the primary threat (although large hail and a spin-up tornado are still at play). It appears that the severe threat would likely diminish by the early to mid evening hours given the latest hi-res model trends showing a fast progression of these storms.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
While initial line of convection may already have cleared the area before the start of the period, the cold front will still be moving through the region on Tuesday night. This combined with a trailing short wave moving up the Ohio Valley will result in more showers and thunderstorms, mainly in the evening. It is unclear whether the atmosphere can recover sufficiently in the wake of the initial line for this additional activity to pose any threat. More than likely, instability will have waned enough to limit the strength of any storms, but will have to keep an eye on how this evolves.

The front will get through the entire forecast area before stalling across Kentucky. It will start to move back north on Wednesday afternoon, likely getting back into southern counties and then lifting across the entire area on Wednesday night. This will result in continuing chances of showers and thunderstorms.

A more robust, but weakening, short wave will lift out of the mid South on Thursday and track across the region Thursday night. This will be just in advance of a digging short wave from the northern stream that will swing through Friday night. Showers and thunderstorms will increase in coverage as we head through Thursday with a cold front pushing through Thursday night. At least scattered showers will continue on Friday with a secondary trough moving through.

Ridging at the surface and aloft will build in for the weekend.

Temperatures will remain above normal until the cold front passes.
There will be a brief cool down, for a day or two, with readings rebounding back above normal for Sunday.

AVIATION /12Z MONDAY THROUGH FRIDAY/
VFR conditions persist through the taf period. Mid level clouds continue to expand eastward this morning, but will eventually begin to break apart as we progress through the day.

Winds will shift to the south by late morning, increasing to around 10 kts. Continue to highlight increasing surface winds and gusts tonight ahead of the next low pressure system, along with LLWS tonight, mainly after 06z. Wind gusts could increase to 25-30 kts Tuesday morning before shower/storm chances increase.

OUTLOOK...Thunderstorms likely Tuesday into Tuesday night and possible again on Thursday. MVFR ceilings are possible on Wednesday.

ILN WATCHES/WARNINGS/ADVISORIES
OH...None.
KY...None.
IN...None.