textproduct: Cleveland

WHAT HAS CHANGED

The forecast remains on track with sustained cold weather through Sunday night. There will be intermittent low chances for light snow through Saturday night. There is increasing confidence in a slight pattern shift to allow for less frigid, but still below normal temperatures, next week.

KEY MESSAGES

1) Very cold weather persists through Sunday night with nightly air temperatures below zero and wind chills of 10 degrees below zero or colder. The air temperatures may approach record low values on Friday and Saturday mornings. The cold weather will continue to pose a significant risk of exposure to people and animals and damage to infrastructure.

2) There are intermittent snow chances through Saturday night, mainly today, Friday night, and Saturday, with lake effect snow and the Arctic high pressure enter the region. There may be some low end travel impacts with any repetitive shower activity.

DISCUSSION

KEY MESSAGE 1... While a surface trough remains in the region today, a strong Arctic high pressure system will begin advancing southward today, reaching the US/Canada boarder in the Upper Midwest by Friday morning. This surface high will continue to expand south and east through the weekend and allow for a reinforcing shot of colder air through the region. High temperatures will stay below 20 degrees through Sunday and low temperatures will be near to below zero nightly through Sunday night.

For this morning, a mix of clouds from the trough and upstream lake effect has covered a large portion of the area. This has allowed for slightly "milder" air temperatures staying above zero. These clouds will push south through daybreak and there may be a brief drop below zero and combined with 10 kts of wind, there will be a short window for wind chills of -15F or so. Therefore, will maintain the Cold Weather Advisory through 11 AM for a portion of Northeast Ohio.

For tonight into Friday, less clouds and colder air advecting into the region will allow for more widespread and longer lasting temperatures below zero. However, with the advancement of the surface high, winds will calm in the decoupling atmosphere and the ambient temperature and wind chill will likely be the same. Therefore, while the air temperatures may be colder, the wind chills may be less frigid than recent days. Therefore, have not issued a Cold Weather Advisory for tonight into Friday. If some slightly stronger winds can develop on the higher elevations of northern Ohio and NW PA, there could be a portion of the area that could briefly hit advisory levels, but confidence is low on the headline need at this time.

For Friday night into Saturday, this period will be the coldest of the entire stretch with potential record-breaking low temperatures in the -5 to -15F range for the forecast area. However, these values are going to be achieved only if high pressure allows for a a fully decoupled atmosphere and there can be a brief period without clouds or snow showers to interrupt the temperature drop. This seems likely to happen for most of the forecast area with some waning confidence in NW PA and far NE OH. If the surface high does allow for these temperatures to drop, there will be very little wind across the region until closer to daybreak on Saturday as the upper trough axis crosses the region. Overall, there continues to be support for at least another Cold Weather Advisory for Friday night. If winds pick up more than currently anticipated, there is an outside chance for an Extreme Cold headline.

With 4 additional days of temperatures of 20 degrees or colder expected, the strain from the cold will increase daily. This prolonged stretch of cold conditions will result in increased infrastructure problems, including burst pipes and dead car batteries. There will be additional stress on people and animals, as well. Folks should continue to limit time outdoors and wear protective clothing to prevent frostbite and other impacts from cold exposure, including hypothermia. Pets and other animals should have limited time outdoors.

There will be a slight "pattern break" behind the high pressure system next week. High temperatures in the 20s are currently expected with a warm front behind the system and low temperatures will rise above zero. However, temperatures are not expected above freezing any time soon.

KEY MESSAGE 2... There will be several low chances for snow for portions of the area through Saturday night with lake effect snow continuing to flare across the region and several waves of energy moving through ahead of the Arctic surface high. Snow early this morning through today will be a function of a surface trough remaining across the area and some lake enhancement through some of the small remaining cracks in Lake Erie and upstream connections to Lakes Michigan and Superior. Only expecting a few tenths of snow in the worst case scenario. Overall, the aggregate air mass across the region is very dry and not expecting efficient snows at this time.

The main upper trough axis will push through on Friday night into Saturday and allow for flow to shift northerly. The trough itself may flare up some snow showers across the region. More importantly, this trough will allow for the Lake Huron fetch to enter the forecast area more fully. With that, have some low PoPs to address the snow potential. Will need to see if coverage/persistent of snow will increase and if PoPs need to be pushed to chance for portions of Saturday. Again, the overall air mass is dry with this Arctic pattern, so not expecting too much snow.

AVIATION /12Z Thursday THROUGH Monday/

Light lake-effect snow showers will bring periods of MVFR cigs and visibilities to KCLE, KCAK, KYNG, and KERI this morning, with conditions expected to improve from late morning through early afternoon. This will take the longest to completely end at KERI. Otherwise, arctic high pressure starting to build in from the Upper Midwest will allow for mainly VFR today through most of tonight. Confidence is increasing that some stratus clouds may bring MVFR cigs late tonight, so introduced that in the end of the TAFs.

SW winds of 5-10 knots this morning will turn NW this afternoon and further decrease, becoming light and variable tonight.

Outlook...Mainly VFR expected through this weekend with the exception of diurnal low-end VFR or MVFR ceilings and transient light snow showers. A more widespread non-VFR threat may arrive on Monday in snow showers with a clipper.

MARINE

Generally quiet conditions will continue on Lake Erie through early next week as a strong arctic high builds overhead. W winds this morning will slowly veer NW this afternoon and decrease to 5-10 knots, with winds becoming light and variable tonight and NNW Friday. NNW winds will slightly increase to 10-15 knots Saturday into Saturday night before turning WNW and decreasing to 5-10 knots Sunday. Winds will turn SW and increase to 10-15 knots Monday ahead of a trough progressing through the Great Lakes.

The arctic airmass and relatively light wind field across the region will allow ice on Lake Erie to further expand and thicken through the weekend.

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 OHZ006- 008-009-017>019-027>033-036>038-047. PA...None. MARINE...None.