textproduct: Cleveland

WHAT HAS CHANGED

The forecast continues to trend warmer for Friday. Projected snow accumulations for Saturday night continue to trend upward, albeit slightly. Still expect the greatest snow accumulations from another round of snow to be focused just south of our region this Sunday night into Monday.

KEY MESSAGES

1.) Dry weather and overall moderation in air temperatures are expected through Saturday.

2.) Snow is expected Saturday night. Total snow accumulations should be mainly one inch or less.

3.) After a brief period of quiet weather during the day on Sunday, unsettled weather is expected to return Sunday night through this upcoming Thursday.

DISCUSSION

1.) Net low-level WAA continues to develop across our region today and then persists on Friday as a ridge axis at the surface and aloft continues to crest E'ward across our CWA today and then becomes located to our east on Friday. Lows in the upper teens to upper 20's are still expected around daybreak Friday. Late afternoon highs should then reach the mid 40's to lower 50's in NW PA and mainly the 50's in northern OH as abundant sunshine and daytime warming are complemented by somewhat breezy S'erly to SW'erly surface winds associated with the aforementioned WAA. For context, normal highs are near 40F and normal lows are near 25F this time of year in our CWA. Dry weather persists as stabilizing subsidence accompanies the ridge.

During Friday night through Saturday, the ridge continues to exit E'ward as cyclonic W'erly flow aloft becomes established over our region. In addition, a surface cold front starved of low-level moisture and exhibiting subtle slope should sweep SE'ward through our region Saturday morning. Behind the front, a weak surface ridge should nose into our region from the north-central United States and vicinity. Thus, dry weather should persist. Overnight lows should reach mainly the 30's Friday night. Saturday's late afternoon highs should reach the 40's to lower 50's amidst peeks of sunshine and very weak low- level CAA behind the front.

2.) During Saturday night, cyclonic W'erly flow aloft and embedded shortwave disturbances affect our region as the aforementioned surface ridge continues to nose into our region. The cold air mass deepens as the upper-reaches of the aforementioned cold front sweep SE'ward through our region, which should be accompanied by a frontogenetical deformation zone. Moist isentropic ascent ahead of the shortwave trough axes and associated with the frontogenetical convergence zone should trigger a fairly brief period of snow across our region. In addition, a sufficiently cold/moist low/mid-level atmospheric column and NNW'erly mean low-level flow over/downwind of the ~1C ice-free waters of Lake Erie, weak lake-induced CAPE, and the seeder-feeder process should permit a period of lake- enhanced snow (LEnS) to occur generally south of Lake Erie, especially the central and eastern portions of the lake. Total snow accumulations are still expected to be mainly 1" or less in our CWA, but localized totals of 2-3" are not out of the question due to the LEnS. Overnight lows should reach the upper teens to mid 20's around daybreak Sunday.

3.) Stabilizing subsidence and dry weather should impact our region on Sunday as W'erly flow aloft becomes anticyclonic briefly as a shortwave ridge moves E'ward across our region and the surface ridge continues to build from the Upper Midwest and vicinity. Late afternoon highs should reach the 20's in NW PA and mainly the mid 20's to mid 30's in northern OH amidst continued low-level CAA. During Sunday night through Monday night, primarily cyclonic W'erly flow aloft and embedded shortwave disturbances should affect our region as we remain within the cold sector, the aforementioned surface ridge continues to affect our CWA, and the embedded high pressure center should move from near the central Great Lakes toward the Gulf of Maine. Moist isentropic ascent ahead of a stronger shortwave trough axis should allow periods of primarily light snow to impact our region Sunday night into Monday. NWP model guidance continues to suggest the axis of greatest snow amounts will be located south of our CWA and near the I-70 corridor. Based on latest model trends, a coating to 2" of widespread snow accumulation is possible in our CWA from this round of snow. Stay tuned to forecast updates. Stabilizing subsidence behind the stronger shortwave trough axis should contribute to dry weather Monday night. Below-normal temperatures are expected Sunday night through Monday night as we remain in the cold sector.

Weather pattern evolution at the surface and aloft is less certain Tuesday through Thursday given sizable spread in NWP model guidance. In general, cyclonic W'erly to SW'erly flow aloft and embedded shortwave disturbances should affect northern OH and NW PA. A warm front should sweep generally N'ward through our region on Tuesday and allow near-normal high temperatures to return. Near-normal or above-normal temperatures should then affect our region Tuesday night through Thursday as the aforementioned front potentially wavers between the southern Great Lakes and OH Valley as multiple mid-latitude cyclones develop and move generally E'ward along the front, yet primarily WAA at the surface and aloft affects our region. Periods of precip, mainly in the form of rain, are expected Tuesday through Thursday due, in part to moist isentropic ascent along the upper-reaches of the front and ahead of shortwave trough axes. However, wet snow may mix with rain at times during the early morning hours of Tuesday through Thursday.

AVIATION /00Z Friday THROUGH Tuesday/

VFR is ongoing across the entire area and is expected to continue through the TAF period. For this update, maintained a brief TEMPO for BKN035 at all sites early Friday, though confidence in this has diminished. If trends continue, will likely remove it as needed with the 6z set of TAFs. Light and variable winds will be the story tonight into Friday morning, outside of CLE and ERI were a slightly more defined SSE wind (at less than 10 knots) will likely develop overnight. Winds turn more south-southwest at 10-15kt with a gust 20-25kt gusts later Friday morning and afternoon.

Outlook...Non-VFR becoming more likely in snow Saturday night into Sunday in snow. Non-VFR possible again in snow Sunday night into Monday, mainly along and south of US-30.

MARINE

Mainly quiet marine conditions are expected into early next week as much of the nearshore waters remain ice-covered. The main concern for elevated winds will be late Friday into Saturday when southwest winds of 20 to 25 knots develop ahead of a cold front which could result in additional shifting of ice across Lake Erie. As the cold front moves east across the lake on Saturday, winds will shift towards the north, 10 to 15 knots. Onshore flow of 10 to 15 knots will then persist through Monday, before gradually favoring a more southeast direction by Tuesday, around 10 knots.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...None.