textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the previous forecast package.

KEY MESSAGES

1) Cold front bring showers/storms late Wednesday into Wednesday night with a potential for severe weather.

2) High pressure for the end of the week and into the weekend.

DISCUSSION

KEY MESSAGE 1... No major changes to the timing of convection associated with a cold front moving in form the northwest later Wednesday. Upper level/surface low to track eastward from northern Ontario through JAmes Bay and into northern Quebec with an extensive cold front cutting through the Great Lakes. Today marks a transition into higher dewpoints and increasing temperatures as return flow feeds the moisture into the region as high pressure that has been over the region shifts eastward. Instability should not be much of an issue given the higher dewpoints while a layer of drier/lower RH air around 625mb and 0-6km shear increasing to 40-50kts ahead of the cold front brings a wind gust potential in what will probably be line segments of storms forming and moving through the CWA beginning late Wednesday afternoon. PWAT values also very high over 2 inches, but storms should be progressive in terms of forward motion through the region, so while heavy downpours can be expected, they should be of relatively short duration. Storms exit to the southeast by around 06Z Wednesday night with clearing in the wake.

KEY MESSAGE 2... Models hinting at a developing and trailing trough axis aloft Thursday which could serve to hold up the forward progress of the cold front due to a weak surface low forming along the front as a result. The result is POPs hanging on in the southern zones into Thursday before finally exiting by roughly 18Z. High pressure will be building into the Great Lakes from the west at this time, and will return to dry conditions for the end of the week and heading into the weekend. Temperatures knocked back 10-15 degrees with the passage of the cold front will be slightly below normal for Friday before gradual warming also returns for the weekend. With high pressure now off the New England coast for Saturday and Sunday, southerly flow will reintroduce low end POPs for the area, but most locations likely staying dry during this period. Another frontal system approaches late Sunday into Sunday night.

AVIATION /12Z Tuesday THROUGH Saturday/

VFR across the TAF sites this morning with mainly VFR cirrus to persist through the TAF period. Low chance of a few isolated to scattered showers along the I-71 corridor this afternoon so have introduced a window of vcsh at MFD, though not anticipating any non-VFR concerns. Winds at most sites will increase out of the south to southeast later this morning and afternoon, 5 to 8 knots, while a lake breeze at CLE/ERI will usher in north to northeast flow of 6 to 8 knots this afternoon. Winds at all TAF sites will shift further towards the south overnight, 5 to 7 knots.

Outlook...Non-VFR possible in showers and thunderstorms Wednesday into Thursday. Some storms could contain gusty winds Wednesday afternoon and evening.

MARINE

Offshore winds this morning less than 10kts become east northeasterly this afternoon in a brief period of a lake breeze where wave heights will linger around the 1ft mark/light chop. Southerly winds increase to 15kts tonight, becoming west southwesterly ahead of a cold front Wednesday 15-25kts. Cleveland east will see wave heights 3-4ft parallel to the shoreline for the nearshore zones in these stronger west southwesterly winds, and a Small Craft Advisory may be needed. Storms expected ahead of the cold front as it moves through. Winds northwesterly in the wake of the cold front Wednesday night with wave heights 1-3ft Thursday and Thursday night.

CLE WATCHES/WARNINGS/ADVISORIES

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