textproduct: Cleveland

WHAT HAS CHANGED

Showers should be a bit slower to move into the area today than previously forecast, keeping the bulk of today dry. Widespread showers are now expected Friday into Saturday.

KEY MESSAGES

1) Multiple weak disturbances are expected to impact the area into next week as a broad upper level trough remains in place. Near average temperatures will persist.

DISCUSSION

KEY MESSAGE 1... As high pressure becomes nearly stationary off the Mid-Atlantic Coast, the area will be impacted by multiple shortwaves moving along a broader upper level trough into next week. Currently, a weak cold front is slowly meandering east towards the area, however is expected to stall just west of the CWA today. This should allow for the bulk of the area to remain dry, although some afternoon, diurnally driven showers are possible given the increased moisture flow and daytime instability. The better forcing looks to arrive late tonight into Friday as a mid-level shortwave helps to sag the cold front closer to the area and allow for additional support for showers. More widespread shower and thunderstorm potential will increase in the afternoon with additional support from daytime heating, but given weak shear not expecting any severe storms. Some of these showers will linger into Saturday. Locally heavy rainfall remains the primary concern with showers that develop given a near parallel mean flow, expected slow storm motion, and increasing moisture with dewpoints in the upper 60s to low 70s and PWAT values climbing to 1.5" or more.

Late Saturday into Sunday, there should be a notable break in precipitation chances as the area falls under a weak ridge briefly, but it will be short lived as another shortwave moves along the broad trough and moves another weak boundary toward/through the area. Widespread shower and thunderstorm chances once again increase Sunday evening into Monday. This shortwave will quickly be followed by an additional one late Monday into Tuesday. With these general unsettled pattern expected to persist into mid-week next week, expect numerous rounds of showers across the area. Showers into next week will continue to have the heavy rain potential. In areas impacted by multiple rounds, localized flooding will be possible. To highlight the hydrology concern, WPC has at least a portion of the area in a Marginal ERO through Day 5. With the weak convective elements, SPC has only highlighted the area in general thunder.

Temperatures through this entire period will linger near normal with highs in the 80s and overnight lows in the 60s. With very muggy conditions expected, apparent temperatures may climb closer to 90 during peak heating.

AVIATION /12Z Thursday THROUGH Monday/

A mix of fog and low stratus remains over eastern Ohio and Northwest Pennsylvania this morning. Expect IFR/LIFR conditions at KCAK and KYNG and MVFR at KERI for the next hour or so until diurnal mixing allows for this fog and low stratus to dissipate.

For later today, very low confidence remains in the shower and storm activity over the immediate airspace. Overall, believe that activity will be both east and west of the area but not overhead. Some of the western activity may get to KTOL and have a PROB30 for MVFR and thunder. Otherwise, the main impacts may just be a mix of low-to-mid level clouds that will spread across the region. For overnight into Friday, suspect that some larger coverage of rain will develop and spread into northern Ohio overnight and have introduced VCSH to the end of most of the TAFs. Winds will be light through the period and generally south to southwest.

Outlook...Scattered showers and thunderstorms expected through Monday, especially during the afternoon and evening hours for each day.

MARINE

The lake will remain in the warm sector of a trough moving through the Great Lakes region. Light southwest winds will continue across the lake today with low waves in offshore flow. Another weak low will enter the region for Friday and Saturday and allow southwest flow to continue. A weak cold front will swing through on Saturday night, bringing brief northwest flow. A stronger low pressure system will enter the Midwest on Sunday and extend a warm front across the lake allowing southwest flow to return. This low will get closer to the lake on Monday and enhance the southwest flow, potentially getting to 20 kts. There is potential for brief marine headlines with this system early next week, but there is still time to iron out details.

CLE WATCHES/WARNINGS/ADVISORIES

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