textproduct: Cleveland

WHAT HAS CHANGED

Winter Storm Watch for all counties now. Cold Weather Advisory for all zones Friday morning through Saturday morning. For the winter storm this weekend, snow amounts have come up a bit area-wide. Timing remains the same.

KEY MESSAGES

1) Potent winter snow storm will affect the area Saturday night through approximately early Monday. Significant snow accumulations should be expected. A Winter Storm Watch is in effect for all counties.

2) Sub-zero wind chills Friday morning and actual air temperatures below zero Friday night into Saturday morning have prompted a Cold Weather Advisory for this period.

3) Continued cold through next week with temperatures not climbing above freezing at all in the 7 day forecast.

DISCUSSION

KEY MESSAGE 1...

Operational models now coming into better agreement as the trend northward with this system into northern Ohio and northwestern Pennsylvania appears more and more likely. As the system organizes over the southern plains region, surface low pressure will develop along the south Texas coast. This area of low pressure will track northeastward Saturday into Saturday night and into the middle/upper Ohio River Valley. On Sunday, a southern stream and northern stream 500mb trough axis will phase over the midwest, and a 700mb trough axis just east of that moves into the lower Ohio Valley. This should keep the surface low going through at least Sunday before it gets kicked eastward with the progression of the mid/upper level systems. Given the location and tracks of these various components, the axis of heavier snowfall will include much of our CWA, and the southern/southeastern/eastern zones will get the highest amounts. Our northwest Ohio counties should receive the least amount of snow, but that should still be a 5-7 inch range or so as of this forecast issuance. Still have a lot of details to unfold however, as this system is still two and a half days out. A quicker dissolving or exit to the aforementioned surface low would lessen snowfall amounts, especially in the northwestern zones. A stronger band of low level f-gen could lead to a refinement in the placement and areal coverage of the heaviest snowfall for our area. Also not being resolved well right now, and if it will even end up as a feature to explore in the forecast, is a possible TROWAL which could extent snowfall on the back end of the event. Also something to watch is the NAM and an amplified dry slot moving in from the southwest late Sunday into early Sunday night which could cut off the later end of the snowfall. These are all things to watch for as the system approaches.

KEY MESSAGE 2...

In the more immediate term, another cold front will come through tonight. Some light snow is possible with it, and the northeastern zones could end up with a quick inch or so, but the main story with it will be the plummeting temperatures and the increase in the winds in the wake of the cold front. Although it will be difficult to actually get to the -15 criteria for the Cold Weather Advisory, one has been issued for our entire area of responsibility from Friday morning through Saturday morning. Winds and temperatures bring sub zero wind chills Friday morning, while temperatures below zero but lighter winds warrant the advisory Friday night through Saturday morning.

KEY MESSAGE 3...

After the exit of the major winter storm Monday, temperatures will remain well below freezing through the end of the week as another cold front comes through Wednesday before any warm ups can occur. Cold Canadian high pressure from the Canadian prairies spills into the Great Lakes with another round of well-below normal temperatures for the region.

AVIATION /18Z Thursday THROUGH Tuesday/

VFR conditions are seen across the region as high pressure will briefly nudge in during the first part of the TAF period. There are mid level clouds moving west to east across northern Indiana that will move across the northern TAF sites this afternoon, though should stay VFR. A cold front will cross the region early tomorrow morning between 11-15Z that will bring non-VFR ceilings and scattered snow showers. There is higher confidence in snow showers from KCLE eastward, though lower confidence at KCAK. Only KERI could see prolonged lake enhanced snow showers through the end of the TAF period with non-VFR visibilities.

Winds will be gusting this afternoon and evening from 20-30 knots out of the west-southwest and will taper off around 22-23Z tonight. Overnight, winds will be out of the west at around 10 knots. Winds will shift to be out of the west- northwest after the cold front tomorrow night and start gusting to 20-30 knots through the end of the TAF period.

Outlook...Non-VFR possible in lake effect snow showers in NE OH and NW PA through Friday. Non-VFR likely late Saturday through early Monday in widespread snow showers. Possible non- VFR in NE OH and NW PA with lake effect snow showers early next week.

MARINE

Lake Erie is still mostly ice covered as seen by satellite passes this morning and throughout the day. Winds across the lake have been between 20-30 knots out of the west to southwest which has caused the ice to move eastward across the lake. There is some fastened ice just west of the islands in the open waters and that will continue in the near future. Winds will diminish through this afternoon into the evening down to 15-25 knots across much of the lake with higher winds near 30 knots possible in the far eastern basin of the lake. There is potential for winds to reach near gales in the eastern basin tonight after midnight though it will be brief and continue to diminish down to 10-20 knots by Friday evening. With the elevated winds, water levels near Toledo will be close to reaching the critical mark for safe navigation this evening, though should stay above as winds will diminish. Waves in the ice free zones will be around 6-8 feet through Friday evening before diminishing to less than 2 feet by Saturday afternoon.

A strong low pressure system will cross south of the Great Lakes region this weekend and arctic high pressure will build in behind. Winds will become lighter across the lake at less than 15 knots through Monday morning as another low traverses the region and winds increase to near 25 knots. There should be decent ice growth across Lake Erie this weekend as arctic air will remain in place over the region for at least the next week.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Cold Weather Advisory from 6 AM Friday to 7 AM EST Saturday for OHZ003-006>014-017>023-027>033-036>038-047-089. Winter Storm Watch from Saturday evening through Monday morning for OHZ003-006>009-017>019-027>029-036-037-047. Winter Storm Watch from Saturday evening through Monday afternoon for OHZ010>014-020>023-030>033-038-089. PA...Cold Weather Advisory from 6 AM Friday to 7 AM EST Saturday for PAZ001>003. Winter Storm Watch from Saturday evening through Monday afternoon for PAZ001>003. MARINE...None.