textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the forecast as it remains on track.

KEY MESSAGES

1) Scattered showers across Northwestern Pennsylvania tonight into Monday followed by high pressure to begin the week.

2) Unsettled weather begins mid week with rounds of precipitation followed by lake effect showers and cooler temperatures through the weekend.

DISCUSSION

KEY MESSAGE 1... Low pressure will move into the James Bay region this afternoon and begin to weaken through the evening. The associated cold front will move northwest to southeast across the region becoming less defined as it moves across Lake Erie. The front itself will be fairly dry outside of far Northeastern Ohio and Northwestern Pennsylvania. The majority of the precipitation that occurs will be lake effect driven as the lake is still relatively warm compared to the air moving in behind the cold front. 850mb temperatures across that portion of the area will drop down to near 0C during the day on Monday. Though, most of the moisture will exit to the east by midday Monday as the 925mb ridge begins to build in and dwindle the lake effect into the evening. Generally, not expecting much accumulation across Northwestern Pennsylvania, around a couple of tenths of an inch at most with all of it staying as rain with the warmer lower levels. A more widespread side effect to this system, will be the gusty winds into the evening today. Winds will generally be out of the west- southwest ahead of the cold front at 10-20 MPH with gusts around 25- 30 MPH and occasionally up to 30-35 MPH. Winds will subside this evening.

High pressure will build in across the Ohio Valley during the day Monday and persist into Tuesday before building off the east coast. Dry weather is expected during that time with relatively seasonable temperatures, if not a few degrees warmer than average.

KEY MESSAGE 2... As high pressure departs to the east on Wednesday, low pressure will begin to deepen to the west across the Mid-Mississippi Valley. There's still some discrepancies in the models on the exact track and magnitude of the low as it enters the southern Great Lakes region. Though confidence is high that there will be widespread precipitation beginning late Wednesday evening through Thursday night. The low pressure will depart off to the northeast Friday into Saturday and persistent north to northwesterly flow will set up across the region. There will be a much cooler air mass moving in behind the low as well dropping highs down into the mid to low 40s and overnight lows into the upper 20s to low 30s. With that, confidence is increasing in prolonged lake effect precipitation expected into the weekend. And with the colder air mass moving in, there is potential for a rain/snow mix this weekend across Northeast Ohio and Northwestern Pennsylvania.

It is still unknown how long the lake effect will persist as models disagree on how quickly the low exits and the oncoming ridge builds into the region. The AI models of the ECMWF and GFS are trending to hold onto the lake effect for longer, lasting into early next weeks. Whereas the non-AI version of those models move the precipitation out quicker. Depending on the solution will determine if there will be any rain/snow mix or if there will be mainly rain. At this point, confidence is low to say either way.

AVIATION /18Z Sunday THROUGH Friday/

VFR conditions are favored through the majority of the TAF period, although mid-level clouds will increase across NE OH/NW PA as a cold front pushes southeast across the area later tonight. Scattered showers are likely at KERI later tonight and possibly into early Monday morning which may briefly result in MVFR conditions in lower ceilings and reduced visibilities if a heavier shower moves over the terminal. Otherwise, lake effect clouds in the 3500 to 5000 ft AGL range will persist at NE OH/NW PA terminals through the end of the TAF period.

Winds will be quite breezy through 18Z Monday. Southwest surface winds of 10 to 20 knots with gusts to 25 to 30 knots are expected this afternoon with flow becoming more westerly and diminishing diminishing to 10 to 15 knots with gusts to 20 to 25 knots near 00Z tonight. Winds will likely remain elevated along the immediate lakeshore (including KERI) through Monday morning with periodic gusts to 25 to 30 knots likely. Northwest winds will develop behind the front Monday morning.

Outlook...Non-VFR likely in rain showers and low ceilings Wednesday night through Friday.

MARINE

The Small Craft Advisory for all of the nearshore zones remains in effect through this evening. Winds are currently out of the west- southwest at 15-25 knots with gusts around 30 knots. Waves are around 5 to 8 feet. They will slowly veer to be more out of the northwest by this evening and the winds and waves in the zones to the west of the Islands will begin to subside. The advisory will fall off for those zones tonight at 10PM. To the east of the Islands, winds will continue to be 15-25 knots with waves 5 to 9 feet through midday Monday before they begin to subside. The Small Craft Advisory currently runs through 10AM Monday for the Islands through Avon Point and to 3PM for the rest of the eastern zones. There is potential that waves could be slow to subside Monday afternoon and the small craft will need to be extended for the those eastern zones. Additionally, with the westerly winds, the water level in the western basin will drop close to the critical mark this afternoon, though should stay above it. Water levels will begin to rise as the winds shift to be northwesterly.

Later in the week, winds and waves will begin to increase again on Tuesday as a low pressure system moves north of the Great Lakes. Those will subside late Tuesday into early Wednesday morning with high pressure building into the Ohio Valley. Low pressure will move through the Ohio Valley early Thursday with winds shifting from the east to the north by late Thursday night. Winds and waves will increase as they shift to the north and another round of Small Craft Advisories will be needed for the majority of the lake lasting into the weekend.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory until 10 PM EST this evening for LEZ142- 143. Small Craft Advisory until 10 AM EST Monday for LEZ144-145. Small Craft Advisory until 3 PM EST Monday for LEZ146>149.