textproduct: Cleveland

WHAT HAS CHANGED

Overall, no major changes needed with this forecast. There are some concerns of decaying convection moving into the area tonight, although confidence remains low at this point.

KEY MESSAGES

1) Unsettled weather likely as early as tonight and on Tuesday afternoon into Tuesday night. Some storms may be strong to severe late Tuesday into Tuesday night.

2) An active weather pattern will present multiple chances for rain and thunderstorms for mid to late week.

3) Above average temperatures are expected to persist for the next several days.

DISCUSSION

KEY MESSAGE 1... Unsettled weather is expected through late Tuesday. There's some potential for isolated strong storms tonight, although a greater risk exists for Tuesday afternoon into Tuesday night.

Warm/moist southwest flow is expected across the area over the next couple of days as a warm front continues to lift away from the CWA and settles over the Upper Midwest/Great Lakes. Scattered/periodic light rain showers are likely across the area through the daytime hours today. It will also be quite gusty with southwest wind gusts to 25 to 35 mph likely this morning through this afternoon. By this evening, a weakening complex of storms may approach from the west or northwest, although there is very low confidence in the timing, placement, and coverage of convection due to weak forcing and uncertainty in instability this far southeast. The best coverage of showers/storms will be closer to a frontal boundary to the north/northwest of the CWA. Nonetheless, if storms do manage to move into the area overnight, elevated instability and a LLJ over the region support low-end threat of some isolated gusty winds and hail, primarily across NW OH which is clipped by a Marginal Risk (level 1 of 5) of severe weather.

Attention then turns to Tuesday afternoon into Tuesday night as somewhat better upper level support arrives from the west in response to a deepening trough over the Plains. The local area will remain in the warm sector throughout the day Tuesday and expect MLCAPE values of 1500 to as high as 2500 J/kg across much of the area with a strong LLJ will moving into the region late in the day and into the night. Effective bulk shear and 0-6 km shear values will reach about 30 to 40 knots in the northern half of the area as better winds aloft move into the region Tuesday evening, which would support a line or broken line of strong thunderstorms. All hazards will be on the table, although damaging winds and large hail will be the primary concerns. There is a Slight Risk (level 2 of 5) for severe weather across northern Ohio with a Marginal Risk (level 1 of 5) across the remainder of the CWA. There are several limiting factors that could throw a wrench into things, however. First, any scattered showers or storms early in the day or convective debris from Monday night showers/storms could keep clouds around and limit destabilization. Second, forcing will be somewhat weak with the best forcing to the north of the local area. Third, a capping inversion will likely be in place and this will need to be broken for any stronger convection to develop. And fourth, the evening/night timing of convection would be diurnally unfavorable, resulting in a more stable atmosphere (or perhaps more elevated instability) by the time convection moves into the CWA. Long story short, there's high confidence in scattered showers and thunderstorms Tuesday into Tuesday night, although confidence in the timing and likelihood of severe weather is quite low at this point and will likely rely on mesoscale features that have not yet been resolved.

KEY MESSAGE 2... Periodic showers and thunderstorms will continue throughout the majority of the week as a frontal boundary wavers over the Upper Great Lakes and Upper Midwest and the local area remains in the warm sector. The timing of any showers/storms will rely on the timing of weak disturbances that ripple across the frontal boundary, but as of now it appears that PoPs will peak on Wednesday as low pressure lifts northeast into the Upper Midwest. Confidence in any stronger convection is low at the moment. Precipitable water values will be unseasonably high at 1.2 to 1.5 inches Wednesday into Thursday and there may be a brief period with a swath of higher PWATs across the northern part of the area on Wednesday. This could result in periods of moderate to heavy rainfall rates in showers/storms which could lead to isolated instances of flooding and rises on the most responsive creeks and streams. Fortunately, the recent stretch of drier weather has allowed antecedent conditions to trend a bit drier, which will help mitigate the onset of flooding unless repeated rounds of heavy rain move over the same locations/basins. A brief period of drier weather is likely as the aforementioned frontal boundary finally pushes south of the area, but rain chances will quickly return as the next system approaches from the west late Friday into Saturday.

KEY MESSAGE 3... Persistent warm air advection will result in temperatures that are well above normal through the first half of the weekend. Widespread highs in the 70s are expected through Saturday with periods of lower 80s likely across portions of the area. Lows will also be well above normal in the 50s and 60s. For reference, average high temperatures for this time of year are generally in the upper 50s and lower 60s.

AVIATION /12Z Monday THROUGH Friday/

Gusty southwest winds will persist across terminals through this evening. Highest wind gusts of 30-35 knots will likely occur this morning into early this afternoon. Winds briefly diminish this evening, but anticipate another period of elevated westerly to southwesterly winds Tuesday morning. In terms of rain chances, expecting isolated to scattered showers to push across terminals throughout the day today. Anticipate for cigs/vis to remain VFR though slightly higher probabilities of MVFR ceilings remain at terminals along the I-75 corridor.

The confidence in the forecast decreases substantially as we head into the evening hours tonight. Current suite of hi-res guidance hint at remnant convection entering western terminals ~00Z/Tue from Lower Michigan/Indiana. However, there remains a lot of uncertainty with exact timing and intensity of this area of thunderstorms by the time they enter Ohio late this evening. For now, have timed out with PROB30 groups any TSRA impacts to terminals from west to east. Future TAF packages will fine tune this timeframe as the forecast becomes clearer.

Outlook...Occasional non-VFR conditions are expected in periodic showers and thunderstorms through Thursday.

MARINE

Southwest winds remain elevated at 20-25 knots early this morning before wind speeds diminish from west to east through this afternoon. Small Craft Advisory for the western basin will expire at 10 AM this morning with the remainder of the lake expiring at 4 PM this afternoon. Southerly to southwesterly winds 12-18 knots will remain in place through the end of the week as multiple systems move across the region. Periodic shower and thunderstorm chances will be present through Thursday.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory until 10 AM EDT this morning for LEZ142>145. Small Craft Advisory until 4 PM EDT this afternoon for LEZ146>149.