textproduct: Cleveland

WHAT HAS CHANGED

Areas of dense fog will impact portions of the forecast area through late this morning. A Dense Fog Advisory has been issued until 10 AM for the southern half of the forecast area.

KEY MESSAGES

1) Areas of dense fog across the region through this morning. Low visibility could impact the Thursday morning commute, primarily across southern zones.

2) Unsettled weather continues with multiple rounds of showers and thunderstorms through Saturday. Strong to severe storms are possible on Saturday. Showers and storms return by the middle of next week.

3) Above normal temperatures anticipated through the middle of next week.

DISCUSSION

KEY MESSAGE 1... Patchy dense fog has developed across much of the western half of the forecast area early this morning as rain showers exit to the east and leave behind saturated low levels. Expect for fairly widespread visibility reductions to one-quarter mile or less through late this morning, especially across western zones. Fog/low stratus will eventually dissipate around mid-day. A Dense Fog Advisory is in effect through 10 AM this morning for southwestern zones. Will continue to monitor visibility observations for any possible expansions to the advisory.

KEY MESSAGE 2... early this morning. A more significant push of rain showers enters from the west this morning through this evening as surface low pressure glides east across the forecast area today. Still can't rule out some embedded thunderstorms this afternoon and evening, primarily south of US-30 where CAPE values increase to 100-200 J/kg. Total QPF amounts now through Friday morning range between 0.50 to 0.75 inches areawide. Locally higher amounts of 0.75 to 1 inch will be possible across the extreme southern portion of the forecast area where HREF probabilities of 1 inch or more of precipitation range between 40-60%.

These showers and storms will exit to the east leading to a brief dry window tonight into early Friday morning. Some scattered showers expected again on Friday as a warm front lifts northeast across the local area. By Saturday, low pressure moving across the Great Lakes region will drag a cold front east through the local area. This timeframe looks to be the most favorable for strong to severe thunderstorms to develop as CAPE values increase to 400-700 J/kg ahead of the cold front. With the most recent SWODY3 Update SPC has added the entire area to a Marginal Risk (Level 1 of 5) with the eastern half of the area in a Slight Risk (Level 2 of 5). Stay tuned for more updates regarding this

Expect another window of primarily dry weather late Saturday night behind the cold front through late Monday night. More unsettled weather expected through midweek as another system moves through the Great Lakes and Ohio Valley regions Tuesday into Wednesday.

KEY MESSAGE 3...

Given the placement of the surface boundary, temperatures will once again range drastically between southern and northern zones. Highs will primarily remain in the mid 40s to low 50s along the lakeshore whereas highs in the low 60s will be possible across the southern two-thrids of counties. As the warm front finally pushes north of the local area on Friday highs will rise into the mid 60s to low 70s with widespread upper 60s to low 70s ahead of the cold front on Saturday. We'll cool into the upper 50s on Sunday behind the cold front before returning into the upper 60s Monday through midweek. For context, average highs for early/mid March generally top out in the mid 40s.

AVIATION /18Z Thursday THROUGH Tuesday/

As a near stationary boundary lingers across northern Ohio through much of this period, conditions are expected to remain IFR/LIFR at all terminals. Through this evening, light rain showers across the area will continue with visibilities being reduced to generally 2-4SM with locally worse conditions in the heaviest showers. Ceilings are widespread between 300-800 ft and will persist. Tonight, showers should diminish from west to east, but with that boundary lingering, plenty of moisture and warmer temperatures will once again result in widespread fog developing. By 06Z, all terminals should be socked in with fog with persistent visibilities below 1SM. The exception may be terminals immediately along the lakeshore that may remain north of the boundary, but either way IFR/LIFR ceilings will still reduce conditions. On Friday, that aforementioned boundary will begin to lift north as a warm front, gradually improving conditions. Most terminals will not see non-IFR conditions until after this period, unless the boundary speeds up.

Winds will generally be light and variable through this period, becoming southwest at 5-10 knots Friday afternoon.

Outlook...Occasional periods of rain through Saturday will bring additional non-VFR conditions.

MARINE

Northeast winds of 10-15 knots across Lake Erie today will persist through much of Friday before a warm front lifts north late Friday into Saturday. Behind the warm front, winds will veer to become southwesterly, increasing to 15-20 knots through Saturday evening. As a surface ridge builds over the area late Saturday, winds will weaken to 5-10 knots before ramping back up Sunday night to 15-20 knots. The active pattern will continue to bring elevated wind speeds periodically across Lake Erie this week. Although the lake remains mostly ice covered, where there are breaks in ice, waves will periodically increase to 2-4 feet. These breaks are primarily observed in the western basin. As temperatures remain above average the next couple of days, the ice thickness and coverage will continue to slowly decrease.

CLE WATCHES/WARNINGS/ADVISORIES

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