textproduct: Cleveland

SYNOPSIS

A low pressure system will deepen over the mid-Mississippi Valley and move east dragging a strong cold front through the region early on Monday. Troughing will linger behind the front over eastern Lake Erie through mid-week. Another low pressure will move through the region on Wednesday.

NEAR TERM /THROUGH MONDAY/

Plenty of changes this forecast package to include an upgrade to the High Wind Watch as well as the issuance of a Winter Storm Watch (will discuss in the short term section). Starting with the upgrade winds, the majority of the High Wind Watch has been upgraded to a High Wind Warning for early Monday morning through Monday night as winds with a strong cold front will be 35-40 mph with gusts up to 60 mph expected. Additionally, a Wind Advisory has been issued for the two tiers of southern counties in the CWA as winds will be 20-30 mph with gusts up to 55 mph.

A strong upper level trough is deepening across the northern Great Plains today that will progress eastward throughout the day and move into southern Ontario by Monday afternoon. This trough will continue to deepen as it moves into the Great Lakes region, strengthening as it does and supporting a surface low that will bottom out at around 975mb. The main impact with this system will be the winds associated with the cold front and the CAA advection being ushered in behind it. There will be a low level jet of 45-55 kts moving through the region with and behind the front and given the mixing levels being around 5kft, this will allow for gusts of 50-60 mph to mix down with the higher end gusts being within the warning. Winds will begin to subside late Monday afternoon into the evening, though will still stay elevated at around 20 mph with gusts around 30 mph. Areas along the eastern lake shore from Cuyahoga eastward may stay elevated through late Monday evening with the northwesterly winds off the lake.

The secondary threat of this system will be the rain and potential severe thunderstorms. For the rain, guidance has been trending total QPF down over the past few runs across the CWA as the bulk of the rainfall has shifted off to the north into Michigan and Canada. HREF probabilities have low probabilities of less than 20% for the majority of the area to receive at least an inch of rainfall with higher totals near northwest Ohio and northeast Pennsylvania. Those areas will still need to be monitor for any flooding that may occur. The downward trend of rainfall can be attributed to a large dry slot moving into the region behind the warm front this afternoon where most of the area will receiving minimal precipitation during. There is also a low risk of severe weather with the cold front passage early Monday morning. Instability will be low (100-150 J/kg MUCAPE), though there will be plenty of shear given the strong wind fields associated with the low. Given this, the primary impact with the cold front will be damaging winds as there will be greater potential for the stronger winds to reach the surface.

Temperatures today will be fairly warm with the passing warm front and highs will reach into the upper 50s to low 60s. Highs will be within a few degrees of records at most climate sites today. Overnight into Monday morning temperatures will begin to plummet behind the cold front. High temperatures for Monday will be just around midnight in the upper 50s and fall to the mid 20s by Monday afternoon.

SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/

Behind the cold front, cold air will sweep in from the northwest with 850mb temperatures dropping down to -14C to -16C across the region. This, with the northwesterly flow will generate lake effect snow across the snowbelts through the short term period. The main focus point for this will be in northwestern Pennsylvania as they will be near a possible Lake Huron connection and have been placed in a Winter Storm Watch as a result. Snow totals will be around 6-12 inches in Pennsylvania and up to 3-6 inches across the snowbelts with elsewhere expecting less. With the elevated winds behind the cold front, blowing snow and snow squalls are a possibility that could reduce visibilites and cause commutes to become hazardous. Troughing will linger over the lake through Tuesday afternoon when flow will shift to become more westerly across the region. The lake effect snow showers will briefly weaken until a shortwave and accompanying surface low moves southeastward across the Great Lakes that will reinvigorate the lake effect snow machine early Wednesday morning.

Temperatures will remain cold through the short term with highs in the 20s to low 30s and overnight lows in the teens.

LONG TERM /THURSDAY THROUGH SATURDAY/

Lake effect snow showers will continue through Thursday and then begin to wane as surface high pressure and ridging starts to build in from the west. Through Saturday morning, temperatures will still remain fairly cold with highs only into the mid 20s and overnight lows down in the low teens to single digits. Additionally, wind chill values could reach single digits each night. With high pressure building in late in the week, temperatures on Saturday could reach above freezing for some areas in the southern portion of the CWA.

AVIATION /18Z Sunday THROUGH Friday/

A warm front continues to lift north of the area this afternoon with some lingering light precipitation still occurring across Northeast Ohio and Northwest Pennsylvania. As the warm air behind the front pushes north, areas of fog have developed with visibilities as low as 1/4 being reported. As a result, the bulk of terminals are experiencing IFR to LIFR conditions with the only MVFR conditions lingering near the immediate lakeshore. Diminished conditions will continue ahead of an approaching strong cold front which will push east late this evening into the overnight hours. Additional IFR to LIFR conditions are possible, especially in the heaviest showers, but as the front departs to the east, ceilings and visibilities should gradually rebound to MVFR for much of tonight. On Monday morning, the upper trough axis will pivot across the area, ushering in snow showers from the northwest. These snow showers should remain primarily light other than in some heavier bands that may develop. The additional concern will be BLSN at terminals reducing conditions.

South to southwest winds of 10-12 knots, gusting up to 20 knots will gradually ramp up ahead of the cold front to be sustained at 15-20 knots with gusts of 25-35 knots this evening into tonight. The strong winds will be for western terminals. As the cold front passes and winds back to be from the west-northwest at 20-25 knots with gusts up to 40 knots possible at all terminals, with local gusts up to 50 knots possible across the northern terminals. Confidence is high in very strong gusts at all terminals.

Outlook...Non-VFR conditions will continue through Monday as rain transitions to snow along and behind the strong cold front. Non-VFR conditions across Northeast Ohio and Northwest Pennsylvania in lingering lake effect snow showers through at least Thursday.

MARINE

Morning Update... A Low Water Advisory has been issued for the western basin beginning tonight into Monday night.

Previous Discussion.. Low pressure will lift a warm front across the lake during the afternoon and evening today. Southeasterly winds 10-15 knots during the day today will turn southwesterly and increase to 15-25 knots behind the warm front tonight. The low will exit to the northeast tonight while dragging a strong cold front east across Lake Erie late tonight through Monday morning. Given strong CAA behind the front, southwesterly to westerly winds will quickly increase to gale to storm force by Monday morning. Gale and Storm Warnings have now been issued across the entirety of Lake Erie late tonight through Tuesday. Given strong southwesterly flow on Monday water levels in the western basin are expected to fall to 4 feet below low water datum, where the water level model bottoms out. A Low Water Advisory will likely be needed, but will allow future shifts to issue this to better nail down timing of greatest impacts.

Storm force winds across the central and eastern basins decrease to gale force Monday evening where subsequent Gale Warnings will be needed through much of Tuesday. A surface trough will linger across Lake Erie Tuesday through Thursday with elevated northwesterly to westerly winds 20-30 knots persisting through Wednesday evening.

CLE WATCHES/WARNINGS/ADVISORIES

OH...High Wind Warning from 1 AM to 10 PM EST Monday for OHZ003- 006>009-017>019. High Wind Warning from 4 AM Monday to 1 AM EST Tuesday for OHZ010>014-089. Wind Advisory from 4 AM Monday to 1 AM EST Tuesday for OHZ020>023-030>033-038. Wind Advisory from 1 AM to 10 PM EST Monday for OHZ027>029-036- 037-047. PA...High Wind Warning from 4 AM Monday to 1 AM EST Tuesday for PAZ001-002. Wind Advisory from 4 AM Monday to 1 AM EST Tuesday for PAZ003. Winter Storm Watch from Monday afternoon through Wednesday morning for PAZ002-003. MARINE...Gale Warning from 1 AM Monday to 7 AM EST Tuesday for LEZ142>144-162>164. Low Water Advisory from 1 AM Monday to 1 AM EST Tuesday for LEZ142>144-162>164. Gale Warning from 1 AM to 8 AM EST Monday for LEZ145>147- 165>167. Storm Warning from 8 AM to 7 PM EST Monday for LEZ145>147- 165>167. Gale Warning from 3 AM to 10 AM EST Monday for LEZ148-149-168- 169. Storm Warning from 10 AM to 9 PM EST Monday for LEZ148-149-168- 169.