textproduct: Cleveland

WHAT HAS CHANGED

The forecast remains generally on track with widespread rain late Saturday night into Sunday. We continue to get a handle on timing of the remnants of Isaias which have trended slightly faster with this cycle. Pops for Saturday night are about 20 percent higher.

KEY MESSAGES

1) Dry weather and warming temperatures continue through Saturday.

2) Widespread rain and breezy conditions associated with the remnants of Hurricane Isaias will move through the area late Saturday night through Sunday. Rainfall with this system will generally range from a half inch to an inch and a quarter. The potential for flooding is low.

3) The next cold front will bring a chance of showers and possibly a few thunderstorms on Tuesday.

DISCUSSION

KEY MESSAGE 1... Temperatures will trend warmer through Saturday as an upper level ridge builds overhead in the wake of a departing trough today. After a cool start this morning, temperatures will peak near normal in the mid 60s to low 70s this afternoon. Some mid and high cloud will arrive this afternoon from remnant convection ongoing over Iowa this morning. Southerly flow increases on Saturday as surface high pressure shifts to the east with a warm afternoon and temperatures solidly in the 70s.

KEY MESSAGE 2... Hurricane Isaias is forecast to make landfall Friday evening along the Alabama and Florida Panhandle Coast. The tropical system merges with a weak upper trough over the western Gulf with deep southerly flow providing good moisture transport north through the day on Saturday. The system is expected to weaken to a tropical depression within 24 hours, with the remnant low forecast over Central Tennessee by Sunday morning. The overall track has trended just slightly faster with rain still expected to reach northern Ohio after midnight Saturday night. Rain will tend to be moderate but could briefly be heavy at times. Breaks in the rain are expected to develop by Sunday afternoon as the deep moisture axis starts to shift northeast and a substantial dry-slot wraps north ahead of the closed low. Precipitation still looks to range from about a half inch to an inch and a quarter with locally higher amounts possible, mainly across the southeastern counties. The threat for flooding is still considered to be low due to recent dry conditions and low stream/river levels.

As for winds, the stronger wind field with speeds of 30-40 knots at 850mb moves overhead between 06-18Z Sunday. Depending on the surface pressure gradient, we could see some gusts of 20-30 mph ahead of or with the rain as it arrives Saturday night. Could also see some higher gusts with downsloping enhancement towards Erie Pennsylvania and will need to monitor trends as gusts could peak closer to 35-45 mph towards the city. After the rain moves in, it is less likely to see strong gusts with the rain stabilizing the boundary layer but will need to continue to monitor the track and strength of the low as it tracks through the Ohio Valley on Sunday. There is a low chance of thunderstorms, mainly across southern portions of the forecast area. Additional shower activity will fill back in across Northeast Ohio and Northwest Pennsylvania Sunday afternoon/evening. The remnant low will quickly exit to the east Sunday night.

KEY MESSAGE 3... After warming temperatures and dry conditions on Monday, the next cold front is poised to settle south across the region on Tuesday. This brings the potential for additional showers and possibly a few thunderstorms. Temperatures will settle back towards normal behind the front on Wednesday.

AVIATION /06Z Friday THROUGH Tuesday/

VFR conditions are expected through the TAF period today. Some scattered mid to upper level clouds are possible this afternoon into the evening, but nothing under 5k. Winds will be light and variable, though should be predominantly out of the south- southwest at less than 5 knots.

Outlook...Non-VFR is possible with rain showers on Sunday.

MARINE

Early this morning, north winds of 10-15 knots on Central and Eastern Lake Erie will result in choppy conditions. Conditions will improve this morning as high pressure builds overhead and winds back to westerly.

From Saturday night through Sunday, the remnants of Hurricane Isaias will move through the Tennessee and Ohio Valleys. We will be monitoring the strength and track of the low for possible adjustments to the forecast. At this time it looks like easterly winds will increase to 15-20 knots on the western basin of Lake Erie and may approach Small Craft criteria. Winds back to northerly on the back side of the system Sunday night but are expected to decrease quickly. The next winds of concern on Lake Erie will be Tuesday afternoon and night as southwest winds increase to 15-20 knots then veer to northerly behind the cold front. A Small Craft Advisory will likely be needed for central and eastern nearshore waters.

CLE WATCHES/WARNINGS/ADVISORIES

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