textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the previous forecast.

KEY MESSAGES

1) Showers and thunderstorms will develop ahead of a cold front on Wednesday, and again on Thursday afternoon. A few strong to severe storms are possible, mainly across Northwest Ohio Wednesday afternoon and evening.

2) Temperatures will trend warmer by the end of the weekend into early next week with increasing shower and thunderstorm chances.

DISCUSSION

KEY MESSAGE 1... A mid-level shortwave (25-30 knots of WSW 700 mb flow) will traverse the base of an upper-level trough Wednesday into Thursday across the Great Lakes as a cold front sweeps east through the area on Thursday. Showers and thunderstorms will develop ahead of the front Wednesday afternoon and evening, primarily impacting portions of Northwest Ohio along the I-75 corridor, and again Thursday afternoon, generally east of the I-77 corridor. The greatest threat for organized thunderstorms on Wednesday will be west of the area across portions of north-central Indiana, though depending on the eastward extent of the instability gradient, a few of our counties along the I-75 corridor across Northwest Ohio could see some strong to severe storms as well, generally between 6 and 10 PM. Damaging wind gusts up to 60 mph appear to be the primary concern, though large hail up to 1 inch and a brief tornado also cannot be ruled out.

Showers and thunderstorms should largely diminish overnight as the shortwave swings east through the Ohio Valley, though redevelopment is possible again Thursday afternoon with the aid of diurnal heating, mainly east of the I-77 corridor. The latest guidance suggests a decreasing risk for strong to severe storms Thursday afternoon as the greatest coverage of storms continues to trend further east of the area into Pennsylvania and Southeast Ohio.

KEY MESSAGE 2.. After a brief stint of drier and seasonable weather, a large upper-level ridge will enter the region towards the end of the weekend into early next week with increasing temperatures and humidity. Highs will reach above average in the mid to upper 80s on Sunday, potentially touching 90 in some spots by Monday. In addition, we'll also have to continue to monitor the potential for showers and thunderstorms, especially Monday night through Tuesday as an upper-level trough swings east through the Upper Great Lakes.

AVIATION /06Z Wednesday THROUGH Sunday/

Patchy fog/mist will try to develop from far Northeast OH into Northwest PA early this morning. Confidence in impacts to TAF sites is marginal, though have TEMPOs for some MVFR BR at ERI and YNG early this morning. Otherwise, VFR (just FEW-SCT afternoon cumulus around 050) until showers/storms move in from the west this evening, reaching TOL as early as 22z. Confidence in TS impacts is fairly high at both TOL/FDY, where prevailing VCTS with TEMPOs are in the TAFs. Some storms in Northwest OH may be strong to severe with wind gusts of 40-50kt. Activity should weaken quickly as it spreads east and impacts quickly become more uncertain. Have a window of VCSH with PROB30 for TSRA at CLE and MFD, with VCSH at CAK. If activity reaches ERI/YNG it would be at or after the end of the current TAFs. Southeast winds at mainly <5kt early this morning will shift south-southwest at 7-12kt with a few gusts up to 20kt this afternoon. Winds remain south-southwest tonight. Outlook...Isolated to scattered thunderstorms possible across Northeast OH/Northwest PA Thursday afternoon. Non-VFR possible in low ceilings and a few showers moving off of Lake Erie Thursday night into early Friday.

MARINE

South-southwest winds will persist over the lake ahead of a cold front that will cross on Thursday, shifting winds more westerly. Winds will generally be 10-15kt through much of Thursday, perhaps briefly stronger late Wednesday night into Thursday morning as the cold front crosses. These winds will build 1 to 3 foot waves (largest in the open waters), perhaps briefly closer to 4 feet in the open waters of the central and eastern basin early Thursday. 1 to 3 foot waves will be pushed towards the shoreline northeast of Cleveland on Thursday as winds turn more westerly, though winds will quickly subside Thursday afternoon which should keep waves below small craft criteria. A period of slightly elevated winds in the 10-15kt range out of the north- northeast is expected Thursday night into early Friday, which will likely create another period of choppy conditions with 1 to 3 footers in the nearshore waters. Favorable marine conditions are expected Friday afternoon into the weekend with high pressure sliding through the region.

Thunderstorms will likely move over at least western Lake Erie this evening before weakening, with lower confidence in thunderstorms across the eastern half of the lake tonight. Thunderstorms may re-develop along the cold front over eastern Lake Erie late Thursday morning or early afternoon before pushing inland. Any storms can lead to briefly higher/erratic winds and waves. A few showers and perhaps a thunderstorm may occur Thursday night into early Friday morning as a trough crosses the lake, with a low risk for waterspouts.

CLE WATCHES/WARNINGS/ADVISORIES

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