textproduct: Cleveland

WHAT HAS CHANGED

Although precipitation chances linger, have opted to lower QPF totals over the next 36 hours to better reflect the dwindling chances for thunderstorms and associated heavy rain tonight. Some embedded thunderstorms are possible Sunday with the cold front. General totals should be between 0.3-0.8 inches in most places with the heaviest axis of precipitation now just to the southwest of the CWA.

KEY MESSAGES

1) Shower coverage should gradually increase this morning before becoming more widespread today. Isolated thunderstorms today may bring locally heavy rainfall which could result in isolated flooding concerns. The axis of heaviest precipitation extends from near Toledo towards Mount Vernon and areas west.

2) First taste of fall arrives this week with periodic rain chances, especially on Tuesday and Wednesday.

DISCUSSION

KEY MESSAGE 1... In previous forecasts, a warm front was expected to push north of the area late Saturday, however looking at recent surface analysis this boundary appears to have stayed south of the area. As a result, the bulk of heavy precipitation has remained out of the area with the highest totals reaching Toledo at almost 1" so far. This warm front may nudge a bit more north today as a low pressure system moves along it towards the CWA. This cold front will move a cold front across the area this afternoon. As a result, there remains an elevated potential for heavy rainfall, especially within any thunderstorms that develop, however the widespread heavy rain is no longer expected as the primary precipitation mode should remain more stratiform tonight. As a result, have opted to lower QPF with this forecast package to generally be 0.3-0.8 inches of precipitation with a higher axis around 1 inch extending from Toledo southeast towards Mount Vernon. Some of these areas have already received a decent bit of rain on Saturday which will result in saturated antecedent conditions. However, given recent low levels on area rivers and the more stratiform type of precipitation the area should mostly handle the additional rainfall. Overall, today will be quite a dreary day and will also mark the transition into a week of fall like conditions. Highs today will climb into the upper 60s across northern counties and into the mid to upper 70s across southern counties. Overnight lows should drop into the low to mid 50s with the exception of portions of NWPA which may even see temperatures fall into the 40s.

KEY MESSAGE 2... As the system today departs east, a Canadian high pressure will nudge south across much of the Great Lakes region while a surface trough linger across the Ohio Valley. The placement of these systems will leave the CWA right in the middle. This positioning will allow for a cooler airmass to arrive and high temperatures fall into the 60s this week with overnight lows in the 40s to 50s. Chances for precipitation on Monday should be isolated to the far southern counties, but shower potential ramps back up on Tuesday and Wednesday as an upper level shortwave trough moves east, nudging the surface high north and providing support for the potential development of additional showers. This high will push back south for the end of the work week. In addition, the positioning of the area on the gradient between the trough and high pressure will result in breezy conditions this week with the strongest winds expected along the I-75 corridor.

AVIATION /06Z Sunday THROUGH Thursday/

Broad low pressure with a stationary front is in place across the region. While ceilings range from VFR to IFR at 06Z, the trend will be towards IFR by dawn as the front pushes south. Scattered showers will cross the local area and be hard to time overnight. Rain will expand in coverage and spread west to east across the area between 10-19Z with moderate rain at times. There will be a chance of thunderstorms extending in an arc across FDY/MFD but could extend as far north as TOL/CLE/CAK. Brief heavy rain is possible with thunderstorms. IFR will be favored in NW Ohio while ceilings will try to lift to MVFR towards YNG/ERI this afternoon. Showers will tend to dissipate from north to south during the afternoon. Skies may try to scatter out at ERI after 00z Monday as high pressure strengthens to the north but confidence is low in that.

Winds will be variable overnight with the frontal boundary residing in the area. Most sites will eventually transition to a northwest then northerly wind as the front sags south today. Winds at TOL/CLE/ERI may exceed 10 knots with gusts possible this afternoon and evening with increasing flow on Lake Erie.

Outlook...Non-VFR possible with showers and occasional thunderstorms through Thursday.

MARINE

A low pressure system is expected to move northeast along a stalled boundary that remains south of Lake Erie. This will initially allow for winds to remain from the north-northeast at 5-10 knots through this afternoon. As this low shifts east and moves a cold front across the area, winds will begin to ramp up from the northeast to 20-25 knots in the western basin tonight. This will initially allow waves to build to 4-6 feet. On Monday morning, Lake Erie will fall under a gradient between a Canadian high to the north and a surface trough across the Ohio Valley. As a result, winds are expected to quickly ramp up on Monday to be sustained at 20-30 knots from the northeast. This increase in winds will result in waves building to 5- 7 feet, approaching 10 feet at times. These strong winds are expected to persist through at least Wednesday before the high is able to push further south on Thursday and allow for a transition to calmer conditions. As a result, a Small Craft Advisory has been issued for the southern lakeshore of Lake Erie beginning tonight through Wednesday evening. Given the elevated wave heights and strong winds, there is an increase in rip current potential so a Beach Hazards Statement has also been issued. These conditions are expected to be very dangerous and people should avoid going onto the lake for the start of this week.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Beach Hazards Statement from this evening through Wednesday evening for OHZ003-007-009>011. Beach Hazards Statement from late tonight through Wednesday evening for OHZ012-089. PA...Beach Hazards Statement from Monday morning through Wednesday evening for PAZ001. MARINE...Small Craft Advisory from 8 PM this evening to 10 PM EDT Wednesday for LEZ142>146. Small Craft Advisory from 2 AM Monday to 10 PM EDT Wednesday for LEZ147-148. Small Craft Advisory from 8 AM Monday to 8 PM EDT Tuesday for LEZ149.