textproduct: Cleveland

WHAT HAS CHANGED

Forecast remains on track. Overnight convection should taper off over the next few hours. Locally heavy rainfall possible this afternoon and evening in showers and thunderstorms.

KEY MESSAGES

1) Showers and thunderstorms likely this afternoon with heavy rain possible in thunderstorms.

2) Temperatures begin to trend warmer starting early next week.

DISCUSSION

KEY MESSAGE 1... A stationary boundary will drift south into the Ohio Valley through this evening bringing increased precipitation chances to the region with the support of an upper level vort max. Showers and thunderstorms should fire along the boundary this afternoon as the atmosphere begins to destabilize. Severe weather parameters are generally on the lower end, so not anticipating any widespread impacts. Though a strong thunderstorm wouldn't be out of the realm of possibilities with MLCAPE near 1000-1500 J/kg and low level lapse rates near 7-8 C/km supporting strong wind gusts from those storms. Additionally, heavy rain will be a concern with slow storm motion (10-15 mph) and high PW values (~1.7 in) across the region. The southeastern counties would be the most probable to see any flooding concerns though will be dependent on the location of the boundary and where storms initiate. WPC has include that area in a slight risk (level 2 out of 4) for excessive rainfall for today and will need to be monitored as storms begin to fire off this afternoon. Precipitation chances will decrease into the evening as the boundary drifts to the south and upper level forcing moves off to the east.

On Saturday, another vort max will moves to the east of the region that afternoon into the evening. This will bring a low end chance for precipitation to mainly the southern and eastern counties up into Pennsylvania Saturday afternoon. Dry weather is expected starting Sunday as ridging builds into the region.

KEY MESSAGE 2... Upper level ridging will begin to build into the region on Sunday. Generally, flow will be weak as the ridge sets up overhead through Monday. Highs will be in the mid 80s on Sunday, increasing to the upper 80s on Monday. Overnight lows will be in the mid 60s. On Tuesday, the surface high will drift to the east and westerly flow will take hold across the region. This will increase temperatures for the middle of the week onwards with confidence increasing in above average temperatures. An upper level trough across Eastern Canada and Northeastern CONUS may keep temperatures a touch cooler for those in far Eastern Ohio and Northwestern Pennsylvania. Though, those finer details will be worked out over the coming days.

AVIATION /12Z Friday THROUGH Tuesday/

Scattered showers and thunderstorms continues across some portions of the area, including far northeast Ohio, northwest Pennsylvania, and parts of central Ohio. There is a very low chance that it continues east towards KCLE/KCAK/KYNG with embedded isolated lightning. Visibility down to 2 SM is possible with thunderstorms.

This afternoon, additional scattered showers and thunderstorms are expected at all TAF sites, except KERI. At KCLE, they may develop a bit earlier around mid to late morning. Heavy rain is likely within thunderstorms with visibility down to 2 SM or lower. Gusty winds to around 30 knots could be possible but scattered nature and low confidence in occurrence prevents a mention in the TAF.

Patchy FG/BR is possible late tonight into early Saturday morning, especially at our southern sites, such as KMFD, KCAK, and KYNG.

Outlook...Non-VFR possible with scattered thunderstorms through Saturday afternoon.

MARINE

Light and variable winds are expected through today. Northeast winds develop tonight following the passage of a cold front and high pressure building in from the north. Those northeast winds gradually increase from 5-10 knots tonight to around 15 knots Saturday afternoon. Waves increase to around 2-3 feet Saturday afternoon, with greatest wave heights expected in the central basin. Northeast winds back off Saturday night before returning Sunday afternoon with winds around 15 knots and waves around 2-3 feet.

Light and variable winds are expected Monday as high pressure moves overhead. Winds become southwest Tuesday and Wednesday as high pressure departs to the southeast. Waves generally expected to be less than 1 foot.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...None.