textproduct: Cleveland

WHAT HAS CHANGED

PoPs, QPF, and snow amounts have trended up slightly through Thursday evening downwind of Lake Erie in Northeast Ohio and Northwest Pennsylvania. Impact should be limited with no more than 1 to 2 inches of snow through the next couple days. Additionally, a Cold Weather Advisory was issued for portions of north central, northeast, and northwest Ohio from 7 PM this evening to 11 AM Thursday.

KEY MESSAGES

1) Extended cold weather, including the potential for record low temperatures, will continue through the weekend, allowing for elevated risks for cold exposure and damage to infrastructure.

2) Periodic light snow may impact parts of Northeast Ohio and Northwest Pennsylvania through the end of the week.

DISCUSSION

KEY MESSAGE 1... The main message for this week continues to be the prolonged cold spell that we are in the middle of. Wind chills this morning are still projected to get down to around -15 across most of the forecast area, though lake clouds from Lake Michigan has kept temperatures a bit warmer along and near the I-75 corridor in Northwest Ohio. A Cold Weather Advisory remains in effect areawide through 11 AM this morning.

While wind speeds will be fairly similar tonight, temperatures are expected to be a bit milder compared to this morning, contributing to milder wind chills. Even so, a Cold Weather Advisory was issued from 7 PM this evening to 11 AM Thursday for portions of north central, northeast, and northwest Ohio from 7 PM this evening to 11 AM Thursday. This is a lower confidence advisory compared to the last few cold weather headlines, mainly due to a slightly warmer airmass and the potential for lake effect clouds keeping temperatures a bit warmer than forecast. Even so, was fairly generous with areal extent of this advisory mainly due to the duration of cold weather, and the increased levels of impacts that it can pose.

The coldest air temperatures of the forecast are expected Thursday night into Friday morning and again Friday night into Saturday morning when lows are in the -5 to -10 range. Forecast minimum temperatures are near record lows for each of these dates. Record lows would require clear skies and calm conditions for favorable radiational cooling; however, there is a lot of uncertainty in the cloud cover forecast, mainly because low-level moisture and lake effect clouds are difficult to forecast, especially given ice development on the lakes. Lower wind speeds are forecast, though should still contribute to wind chills at or below -15 each of these days for most of the area.

Temperatures remain cold and below normal through early next week, though a warming trend to contribute to improving conditions.

This extended period of cold temperatures will bring increased risk of infrastructure impacts due to the cold, including burst pipes, water main breaks, and dead batteries. The prolonged nature of the cold will also pose a continued risk of exposure to more vulnerable populations. These impacts will continue through at least Monday.

KEY MESSAGE 2... A broader upper-level trough remains over much of the eastern CONUS with northwest flow of cold air aloft continuing through the week. Subtle mid-level shortwave troughs will swing through at various points, producing increased chances of light snow showers at various points this week. Even though Lake Erie is mostly ice-covered, cracks in the Lake Erie ice (along with added low-level moisture from upstream Great Lakes) continues to contribute to low-level moisture downwind of Lake Erie. The best chance at some light snow will be Wednesday afternoon when deeper moisture up to 700 mb will accompany one of the aforementioned shortwave troughs, with a better shot at light snow accumulations in the snowbelt of Northeast Ohio and Northwest Pennsylvania. At this point, only an inch of additional snow accumulation is expected, but wouldn't be surprised to see some highly localized amounts of 2 or 3 inches in the higher of Erie, PA. Impacts to travel should be minimal.

AVIATION /12Z Wednesday THROUGH Sunday/

Mainly VFR is found across the region this morning, with some low clouds hanging around KCAK bringing a small area of MVFR/IFR. Clouds will fill in across most of the region this afternoon through tonight, bringing periods of MVFR. NW Ohio may avoid the bulk of this, so kept KTOL and KFDY more frequently VFR, but it will be quite frequent farther east. This is in response to a mid/upper trough and associated cold front crossing the region later this afternoon and evening. Lake Erie is about 100% ice covered, but there is still enough latent heat transport through the ice for some light lake enhanced snow showers ahead of the front this afternoon followed by pockets of light lake-effect snow showers in its wake tonight. This will mainly occur in NE Ohio and NW PA, so have periods of VCSH and SHSN at those sites this afternoon and tonight corresponding with the longer periods of MVFR. The snow will be most frequent at KERI, but the timing of the snow showers is the lowest confidence there since these types of situations produce frequent, difficult to time, snow showers across NW PA.

SW winds of 5-10 knots this morning will increase to 10-20 knots this afternoon, with gusts up to 25 knots possible. This could lead to minor visibility reductions from blowing snow. Winds will veer more W and decrease to 5-15 knots this evening and tonight.

Outlook...Additional periods of non-VFR with low clouds and snow showers are expected through this weekend. Greatest chances exist in NE OH and NW PA, where periodic lake-effect snow downwind of mainly ice-covered Lake Erie should occur.

MARINE

Winds on Lake Erie will quickly turn SW again this morning and increase to 15-20 knots through the day as another cold front approaches the lake. As the front passes across the lake tonight, winds will veer to W and decrease to 10-15 knots, with W winds of 10- 15 knots continuing Thursday before turning NW at 5-10 knots Thursday night through Friday night. Winds will veer to NNW and increase to 10-15 knots Saturday, backing to W again by late Sunday with 10-15 knot speeds continuing.

The deep arctic airmass entrenched across the Great Lakes region will allow ice on Lake Erie to further expand and thicken through the weekend. This will help to anchor the ice in place, effectively reducing the movement of the ice despite the changes in wind speed and direction.

CLIMATE

Record low temperatures are possible on Friday and Saturday. Here are the daily record low minimum temperatures for January 30 and 31:

Date Toledo Mansfield Cleveland Akron Youngstown Erie 01-30 -10(2019) -10(2019) -4(1873) -6(1965) -8(1965) -4(2019) 01-31 -10(2019) -7(2019) -5(1971) -5(1948) -9(1948) -6(1899)

CLE WATCHES/WARNINGS/ADVISORIES

OH...Cold Weather Advisory until 11 AM EST this morning for OHZ003- 006>014-017>023-027>033-036>038-047-089. Cold Weather Advisory from 7 PM this evening to 11 AM EST Thursday for OHZ006-008-009-017>019-027>033-036>038-047. PA...Cold Weather Advisory until 11 AM EST this morning for PAZ001>003. MARINE...None.