textproduct: Cleveland

WHAT HAS CHANGED

Rainfall amounts have increased slightly Saturday night into Sunday associated with the remnants of Isaias.

KEY MESSAGES

1) 1) Periods of moderate to heavy rainfall and breezy conditions are expected Saturday night through Sunday associated with the remnants of Isaias.

2) A cold front will bring the next chance for showers and thunderstorms on Tuesday.

DISCUSSION

KEY MESSAGE 1... The remnants of Hurricane Isaias will move north into the Ohio Valley Saturday night through Sunday, resulting in periods of moderate to heavy rain across the region, especially late Saturday night into Sunday morning. Additional periods of moderate to heavy rain are possible Sunday morning and afternoon, mainly along and east of the I-71 corridor as the remnants of Isaias gradually move east towards the Mid-Atlantic Coast. Rainfall amounts have increased slightly in this forecast package, especially along and east of the I-71 corridor where totals may range between 1 to 2 inches. The latest REFS guidance, albeit somewhat aggressive, also indicates a low probability (20 to 30%) for a narrow swath of 3 inches of rain, though this is likely the "worst case" scenario. The overall threat for flooding is still considered to be low due to recent dry conditions and low stream/river levels.

In addition to the widespread rain, a potent southeast low-level jet will bring breezy conditions into the region, with wind gusts primarily in the 25 to 35 mph range, though can't rule out isolated higher gusts up to 40 mph, especially in the favored downsloping areas.

KEY MESSAGE 2... The next chance for precipitation will be on Tuesday as a cold front moves southeast through the Great Lakes. A narrow corridor of weak instability may form ahead of the front as surface dew points increase into the low 60s which could support a few thunderstorms. Can't rule out a few stronger storms given the ample mid-level shear in place, approaching 40 to 50 knots at times Tuesday afternoon.

AVIATION /00Z Saturday THROUGH Wednesday/

VFR conditions continue through the TAF period. Some mid to high-level clouds will move across the airspace at times. A dry airmass and light breeze is expected to preclude fog overnight tonight. Expect light and variable winds this evening to generally shift southeast tonight into Saturday, increasing to 7-12kt during the day Saturday. Winds may get close to crossing back over 150 degrees at times on Saturday at CLE, though most reliable guidance continues to insist that winds will remain in the 130-140 degree range and not cross 150 degrees.

Outlook...Moderate to heavy rain will bring a period of non-VFR overnight Saturday night into Sunday, with lower ceilings and showers lingering into Sunday night in Northeast OH/Northwest PA. Non-VFR possible due to showers and thunderstorms with a cold front around Tuesday.

MARINE

Generally quiet marine conditions are expected through Saturday with offshore flow of 10 to 15 knots. Southeast flow will increase into the 15 to 20 knot range on Sunday as the remnants of Isaias move north into the Ohio Valley, though not anticipating any marine headlines at this time. Winds will shift towards the northwest on Monday, 10 to 15 knots, as Isaias moves east of the Mid- Atlantic coast. Winds will again increase out of the southwest ahead of a cold front on Tuesday, 15 to 20 knots, shifting towards the northwest behind the front late Tuesday into Wednesday, 15 to 20 knots. A Small Craft Advisory will likely be needed behind the front.

CLE WATCHES/WARNINGS/ADVISORIES

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