textproduct: Cleveland

WHAT HAS CHANGED

The bulk of the forecast remains unchanged regarding the upcoming systems. It is worth noting that confidence in any severe potential remains low, but is expected to increase with future model runs.

KEY MESSAGES

1) Multiple rounds of convection possible in the next 48 hours, but there remains a high level uncertainty in the potential across the area.

2) A strong low pressure system is expected to impact the area late week into the weekend.

3) Above average temperatures are expected to persist through Saturday.

DISCUSSION

KEY MESSAGE 1... A boundary slowly sagging south today should stall just north of the area. Multiple low pressure system are expected to travel along this boundary through Thursday, resulting in multiple chances for precipitation and thunderstorms. There are two notable periods of potential strong to severe storms in the next 48 hours, but there remains little confidence in the evolution of either system.

The first push of storms is expected late tonight into Tuesday morning as decaying convection from the northern Great Lakes moves into the area. Given the timing, limited instability will be present, however a strong LLJ of 35-45 knots will assist in maintaining some storms. Cannot rule out a couple strong to severe thunderstorms, but highest confidence in this occurring would be across the northwestern portion of the area. Primary threat will be wind, although hail is not out of the question. Right now, SPC highlights this potential over the area with a D1 Marginal Risk.

The tricky part of this forecast is figuring out how quickly this morning convection pushes east and allows the atmosphere to rebound ahead of the next system. Some hi-res guidance, including the HRRR, suggest that there will be two lines of convection in the morning which would result in storms lingering much longer. On the flip side, models such as the ARW having convection moving east of the area by late morning. If the HRRR is correct, thunderstorms will likely still occur overnight but much of the severe potential will remain limited. If the ARW is correct, then strong to severe thunderstorms across the area is possible late Tuesday evening into the overnight hours. With convection departing earlier in the day, ample WAA and deep layer moisture will be able to surge across the area, enhance by daytime heating and increasing instability. This should provide a decent environment for strong to severe storms to occur with the primary concern being strong to damaging winds. The only common thing amongst the spread in models is that the convection that does push into the area will likely be decaying remnants of severe weather expected across the upper Midwest tomorrow. SPC currently has a D2 Slight Risk to highlight this potential threat.

Stay tuned for the latest forecast as this system continues to evolve and models hopefully get into a better agreement in handling what will happen in the next 48 hours.

KEY MESSAGE 2... A deepening upper level trough is expected to push south across the central CONUS on Friday into the weekend, moving a strongest low pressure system and associated boundaries through the area. This system may once again pose a severe weather risk, although confidence is fairly low this far out. There is high confidence that areawide showers will occur this weekend as a strong cold front moves east. On the backside of that boundary, temperatures will once again dip, although this time to near normal, with highs falling into the 50s by Sunday.

KEY MESSAGE 3... Temperatures are expected to remain above normal for the bulk of this week with highs consistently in the 70s, possibly touching 80 at times. Overnight lows will remain mild with temperatures only falling into the 60s. CPC has highlighted the area in a potential for prolonged above average temperatures for the next two week. It is worth noting that after the cold front Saturday, temperatures will briefly fall back to near normal (in the 50s) before once again increasing next week.

AVIATION /00Z Tuesday THROUGH Saturday/

The main aviation concerns for this evening TAF update is with the ongoing strong convection that is moving across northern Ohio and NWPA. We have mainly VFR conditions for most of the area outside of the areas being impacted by the showers and storms. There are TEMPO groups through late evening highlighting the potential for a short term impacts for TAF sites due to the scattered convection through 06z ending from west to east during the overnight. Brief MVFR to IFR conditions may be possible with any heavier showers and storms over the airfield. Ceilings will remain VFR to possible MVFR later tonight through late Tuesday morning. Ceilings will lift by midday into the afternoon to VFR on Tuesday. The TAF forecast is somewhat uncertain Tuesday morning through the end of the period as model guidance varies quite a bit on timing and location of the next 1 or 2 rounds of possible convection that may move close or over portions of our area on Tuesday. We will maintain a generic VFR forecast in the TAFs for now until we have better confidence. Southwest winds will remain elevated 10 to 20 knots over the next 18 to 24 hours with gusts 25 to 30 knots likely, especially during the daytime heating mixing down winds on Tuesday.

Outlook...Occasional non-VFR conditions are expected in periodic showers and thunderstorms through Thursday.

MARINE

Southwest winds remain elevated at 20-25 knots early this morning before wind speeds diminish from west to east through this afternoon. Small Craft Advisory for the western basin will expire at 10 AM this morning with the remainder of the lake expiring at 4 PM this afternoon. Southerly to southwesterly winds 12-18 knots will remain in place through the end of the week as multiple systems move across the region. Periodic shower and thunderstorm chances will be present through Thursday.

CLE WATCHES/WARNINGS/ADVISORIES

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