textproduct: Cleveland

WHAT HAS CHANGED

While widespread rain is still expected Sunday night and Monday, the qpf forecast for Sunday night and Monday has started to trend lower.

KEY MESSAGES

1) Scattered showers and thunderstorms are expected this afternoon.

2) Widespread rain of 1-1.5 inches is forecast for Sunday night into Monday. Rises on area rivers are likely with the potential for a couple to approach minor flood levels. Ponding of water on roadways is also likely.

DISCUSSION

KEY MESSAGE 1...

Scattered showers are noted upstream across Michigan ahead of a shortwave crossing northern Lake Michigan. In addition, a few thunderstorms are also ongoing early this morning south of Lake Michigan where moisture advection is focused. Expecting to see a few showers near Lake Erie this morning moving southeast. Both coverage of showers and potential for scattered thunderstorms are expected to increase as these move inland across Northeast Ohio and Northwest Pennsylvania, generally between noon and 4 PM. Instability will be a limiting factor today with surface based CAPE of only 500-700J/kg. Some shear is present but dry air in the mid-levels will likely limit storm intensity. A couple wind gusts of 30-40 mph are possible with thunderstorms.

KEY MESSAGE 2...

The next rain making system arrives Sunday night as a shortwave races east across the Plains towards the local area. Surface low pressure of 1006 mb will approach from the west ahead of the shortwave late Sunday night. Rain is expected to expand west to east across the area Sunday night with a 40-45 knot low level jet providing a good focus for isentropic ascent. Deep moisture and efficient rainfall will contribute to several hours of steady rain. Thunderstorms are more likely to arrive early Monday morning as the warm front lifts north into Central Ohio. Occasional showers are expected to continue on the northern flank of the low through the day on Monday.

Overall the rainfall forecast has trended slightly lower with this system over the last 24-48 hours. We are looking for rainfall ranging from 0.75" towards Erie Pennsylvania with locally around 1.5" closer to Central Ohio. Uncertainty in the forecast is a result of how upstream convection will influence moisture transport and coverage/duration of rain across the local area. Convection is expected to fire from Indiana southwest into Missouri on Sunday and build southward with time. This area to our southwest is highlighted for both a Slight Risk of severe weather and a Moderate Risk of excessive rainfall. The Excessive Rainfall Outlook for the local area has trended down with just a few of our southwestern counties included in the Slight Risk of Excessive Rainfall(level 2 of 5) while the rest of the area is in a Marginal Risk of Excessive Rainfall (level 1 of 5). In addition, dry air in the mid-levels now looks to arrive overhead early Monday. Still expect rises on area rivers, especially where rainfall exceeds an inch. This could be enough to push a river or two to action stage but confidence is lower in a couple of the southern rivers reaching minor flooding. Ground conditions will certainly get soggy with ponding of water likely during higher rates. Will monitor for localized flooding in poor drainage areas or if training of thunderstorms occurs. Temperatures continue to trend down for Monday with cloudy skies and lingering showers. Temperatures are forecast to remain slightly below normal through next week.

AVIATION /12Z Saturday THROUGH Wednesday/

A few showers are being observed on radar this morning, but dry air is not allowing these to reach the ground, so kept all terminals dry and VFR this morning. A better potential for scattered showers will occur this afternoon as the mid/upper shortwave and associated cold front pass across the region. Confidence remains low on any cells impacting a terminal, but the best potential is at KMFD, KCAK, and KYNG, so kept VCSH there. Any briefly heavy downpour could drop cigs and vis to MVFR or lower, but for the most part, VFR will continue this afternoon and through tonight.

Light W winds early this morning will increase to 10-15 knots this afternoon, gusting up to 25 knots at times. W winds will become light again tonight.

Outlook...Showers and thunderstorms are possible Sunday afternoon through Tuesday morning with the potential for non-VFR coverage.

MARINE

Quiet conditions are expected on Lake Erie today and most of Sunday, with W winds of 5-10 knots this morning increasing to 10-15 knots this afternoon before turning light and variable tonight into Sunday afternoon. Conditions will start to change Sunday evening as low pressure moving out of the Mississippi Valley lifts a warm front to just south of the lakeshore Sunday night. This will support E winds increasing to 15-25 knots Sunday night, turning NE at 15-25 knots Monday behind the trailing cold front as the low progresses toward the Mid Atlantic. NNE winds will then gradually decrease Monday night, turning NNW at 5-10 knots Tuesday through Wednesday as high pressure builds down across the Great Lakes. Small Craft Advisories are likely Sunday night and Monday, with the highest winds and waves expected in the western and central basins.

CLE WATCHES/WARNINGS/ADVISORIES

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