textproduct: Cleveland

WHAT HAS CHANGED

Increased POP's slightly early this evening through overnight tonight since, for example, weak CAPE, including elevated CAPE, and at least moderate effective bulk shear should allow upstream organized showers and thunderstorms, over the Mid MS Valley and vicinity as of 9:45 AM EDT, to persist generally NE'ward or ENE'ward and overspread our CWA beginning early this evening, between 5 PM and 8 PM. In addition, increased forecast high temperatures slightly for this late afternoon in the Erie, PA area. Here, expect the combination of daytime heating amidst 850 mb temperatures moderating to near 10C by this late afternoon and persistent downslope surface winds to allow highs to easily reach the lower 70's despite an increase in primarily mid/upper-level cloud cover from the west this afternoon as subtle shortwave trough axes aloft are preceded by moist isentropic ascent.

KEY MESSAGES

1) Decaying storms will push into the area ahead of a cold front tonight, bringing the potential for gusty winds across the area.

2) A cooler weather pattern returns midweek into early May. There will be multiple overnight periods when the potential for frost will arise as temperatures approach freezing.

DISCUSSION

KEY MESSAGE 1... A potent low pressure system is expected to impact parts of the Midwest today, bringing the potential for widespread convection upstream of the area ahead of a cold front. This cold front is expected to slowly push east through the day and into the evening hours, pushing the aforementioned showers and storms east as well. This robust low is expected to remain intact, however given the diurnally unfavorable timing of storms reaching the area, there will be limited concern for severe potential today. These storms should be significantly weakening as they move into the CWA as the bulk of forcing and the axis of greatest instability should remain south of the area. With that being said, there is a strong LLJ of 50-60 knots that is expected to push east ahead of the aforementioned cold front. Mixing layer heights should remain fairly elevated given the ongoing convection, which may allow some of these showers and thunderstorms to mix some of the LLJ down to the surface. These gusts should remain fairly isolated in nature and likely associated with the most well developed storms. In the Day 1 outlook by SPC, the area is highlighted in general thunder, further messaging the isolated potential for any severe threat as the decaying storms push east, but still worth noting the wind threat.

In addition to gusty winds, periods of heavy rainfall, especially across the southern tier of counties may lead to localized reductions in visibilities and ponding on roadways. The overall flooding concern however is minimal given the progressive nature of the system. Will continue to monitor upstream convection today and destabilization over the CWA for any shift in the severe potential.

KEY MESSAGE 2... After this robust system early in the week, a strong cold front will act to usher in a Canadian high with much cooler characteristics. This will lead to a roller coast of temperatures with highs today climbing into the mid to upper 70s, but only reaching into the 50s by Wednesday. Overnight lows will follow a similar trend with overnight lows Wednesday night dropping into the 30s to low 40s. These overnight temperatures are expected to continue to cool, with some areas reaching into the low the mid 30s at times, especially on nights when skies are clear and radiational cooling can be enhanced. These temperatures will likely lead to local frost and possible freeze concerns, impacting vegetation that has already begun to grow given the early spring warm up. Will continue to monitor for extent and magnitude of this potential and the need for any headlines. These below average temperatures look to stick around with the entire area highlight in the CPC Day 6-10 outlook for below normal temperatures (this outlook covers May2 to 6).

AVIATION /12Z Monday THROUGH Friday/

Winds will be on the increase today out of the southeast 15-20kts, then increasing to 20-30kts after 18Z ahead of a cold front that will be moving into the region from the west. After 03Z Tuesday, winds will become more southerly. Expecting MVFR visibilities in -SHRA, and eventually MVFR ceilings once the showers saturate the lower levels of the atmosphere which will be an hour or two after beginning. Leaving -TSRA out of the prevailing forecast in the TAF, but isolated thunder is expected.

Outlook...Non-VFR likely in showers and low ceilings Tuesday. Non-VFR likely again in showers and thunderstorms on Wednesday.

MARINE

Southeasterly winds 10-20kts today become southerly 20-30kts ahead of a cold front tonight with wave heights increasing away from shore at 1-3ft and 3-5ft in the open water zones. Behind the cold front, winds become onshore eventually late Tuesday around 10-15kts with nearshore wave heights 1-3ft Wednesday through Friday.

CLE WATCHES/WARNINGS/ADVISORIES

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