textproduct: Cleveland

WHAT HAS CHANGED

Flooding in no longer expected to pose a threat this morning. Lowered high temperatures a degree or two today and Wednesday for areas with showers.

KEY MESSAGES

1) Below normal temperatures with occasional showers can be expected through Wednesday.

2) Dry conditions will return to end the week and will be accompanied by the coolest overnight low temperatures so far this season.

DISCUSSION

KEY MESSAGE 1... The local area resides between high pressure located north of the Great Lakes and low pressure over the Ohio Valley. Shallow cold advection continues this morning with northeasterly surface winds. While the heavier area of rain is exiting to the southeast, scattered showers continue in an arc from near Marion to Akron where lift continues along a tightly packed baroclinic zone at 850mb. This boundary remains in place through the day and lift is likely to increase through early afternoon as a shortwave passes aloft. Will continue with 60-70% pops today along this axis with additional rainfall generally around a quarter inch. Dry air continues to filter into northeast portions of the forecast area where pops will be low or dry towards the Ashtabula/Erie lakeshore. A brisk northeasterly flow will continue off Lake Erie with lakeshore areas and portions of Northwest Ohio seeing winds of 10-15 mph with gusts to 25+ mph.

Will continue with scattered showers into this evening with lift located to the north of an inverted surface trough that extends north up the Ohio/Pennsylvania border. Eventually mid-level dry air arrives and much of the area will be dry on Tuesday. Low chances of showers are focused downwind of Lake Erie in Northeast Ohio where good low level convergence and some lake enhancement may maintain scattered light showers. Will also allow for low 20-40 pops in the east where lift continues along that lingering frontal boundary in the 850-700mb layer.

Beginning late Tuesday night and continuing through Wednesday pops ramp up across central and eastern portions of the forecast area as an upper level trough arrives with a return of deeper moisture. The 00Z NAM is an outlier with the upper trough a little farther south and is therefore drier. Will lean the forecast towards the better model agreement which keeps scattered to numerous showers in our forecast area. With the better coverage of clouds and showers, lowered high temperatures by a degree or two across our interior counties where pops are greater than 60%. High temperatures will remain solidly in the 60s with the cool northeast flow and cloudy conditions.

KEY MESSAGE 2... The upper level trough moves southeast to the Mid- Atlantic on Thursday with surface high pressure strengthening across the eastern Great Lakes. Drier air arrives bringing an end to precipitation with gradual clearing. The cool and dry airmass will support the coolest lows we have seen so far this season beginning on Thursday night with inland lows solidly in the 40s with low 40s for interior portions of Nw Pennsylvania. This will repeat Friday night before trending just slightly warmer for Saturday night. Some of this will depend on winds and ability to decouple but can certainly expect a chill in the air.

AVIATION /12Z Monday THROUGH Friday/

Aviation conditions through this period have trended a bit more optimistic in recent hi-res guidance. Currently much of the area is experiencing VFR conditions with patchy MVFR where BKN ceilings have fallen to 2-3kft. These ceilings will likely bounce around today between VFR and MVFR for all inland terminals where the chance for persistent showers lingers. Given the uncertainty in the exact timing of these light showers at terminals, have opted to maintain using TEMPO/PROB30 to handle the periods of potential rain. Near the end of this TAF period, conditions at all terminals should see ceilings lowering to MVFR heights with isolated pockets of IFR possible.

Northeast winds of 5-10 knots this morning will ramp up to 10-15 knots by late morning. Gusts of 20-25 knots are possible, especially for lakeshore terminals and those along the I75 corridor. Wind gusts should weaken in intensity and frequency after sunset tonight.

Outlook...Non-VFR possible with showers and occasional thunderstorms through Thursday.

MARINE

Elevated northeast winds of 20-30 knots will continue on Lake Erie through Tuesday night as the local area resides between high pressure north of the Great Lakes and low pressure over the Ohio Valley. Small Craft Advisories and Beach Hazards are in effect for all Lake Erie nearshore zones and adjacent beach areas through at least Tuesday evening and continuing through Wednesday evening for all Ohio waters. Waves will tend to be 5-9 feet on the central basin. Although winds will be somewhat strong, there will also be a chance of waterspouts tonight into Tuesday and possibly again on Wednesday near the Lake Erie Islands where convergence is maximized in the northeast flow.

Winds become more easterly on Wednesday and decrease to 10-20 knots Wednesday night. Winds back to northeasterly again on Thursday ahead of strengthening high pressure and will maintain choppy conditions in the nearshore waters. Winds will remain out of the northeast but decrease over the weekend.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Beach Hazards Statement through Wednesday evening for OHZ003- 007-009>012-089. PA...Beach Hazards Statement through Tuesday evening for PAZ001. MARINE...Small Craft Advisory until 10 PM EDT Wednesday for LEZ142>148. Small Craft Advisory until 11 PM EDT Tuesday for LEZ149.