textproduct: Cleveland

WHAT HAS CHANGED

Confidence is increasing in a period of showers and thunderstorms Saturday afternoon/evening, with PoPs increasing to the 70/80% range. The latest forecast data is also trending towards a low potential for severe weather Saturday afternoon.

KEY MESSAGES

1) Dry conditions continue with temperatures gradually warming through Friday.

2) The weather pattern will change for the weekend, allowing for showers and storm chances for Saturday through Sunday. There is low potential for severe weather Saturday afternoon.

DISCUSSION

KEY MESSAGE 1... High pressure over the Great Lakes region will allow for continued dry and seasonable weather. As high pressure departs to the southeast, southwest flow will allow for temperatures in the 70s today to increase into the 80s Thursday and Friday.

KEY MESSAGE 2... An upper-level trough and cold front move southeast across the Great Lakes region Saturday and Sunday. Southwest low-level flow and continued building of humidity will allow for a broad favorable region for scattered showers and thunderstorms early Saturday morning through Sunday afternoon, though there is focused period of better forcing Saturday afternoon/evening, with a period of 70-80% PoPs (an increase from the previous forecast).

Latest model guidance has been trending towards a slightly more favorable solution for a marginal severe weather threat Saturday afternoon. All three major model ensembles (GEFS/ENS/CMC), have stronger flow aloft compared to the last few cycles (resulting in better forcing and deep-layer shear). Uncertainty is primarily with timing of synoptic-scale features, and with run-to-run consistency with model guidance.

Consequently, the risk for flooding has decreased somewhat. Stronger flow should yield faster storm motions, reducing the residence time of thunderstorms over any one particular location. The high-end QPF signal in the NBM, particularly in the 90-95 percentile range, has decreased compared to previous cycles, further limiting the flood risk. However, high PWATs and other moisture indicators still support efficient rainfall rates within thunderstorms, which could result in minor, localized flooding in flood-prone locations.

AVIATION /12Z Wednesday THROUGH Sunday/

VFR across the TAF sites this morning with VFR to persist through the TAF period. Winds will increase out of the north to northeast this morning into the afternoon, enhanced by a lake breeze, 4 to 7 knots. Winds will gradually become light and variable and may favor a slight southerly direction at times late this evening and overnight.

Outlook...Non-VFR becoming more likely in showers and thunderstorms on Saturday.

MARINE

Mainly quiet marine conditions are expected through the week and through the weekend as high pressure persists across the region. Overall flow will generally remain light through much of the week, before shifting to the southwest late Friday through Saturday, 10 to 15 knots, ahead of a low pressure system and cold front. Winds will shift towards the northwest behind the front on Sunday, around 10 knots. Some thunderstorms are possible with the cold front Saturday afternoon and evening which could pose a strong wind threat.

CLE WATCHES/WARNINGS/ADVISORIES

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