Marine Weather and Tide Forecast for Mansfield, OH

KEY MESSAGES
1) Multiple rounds of severe weather are possible through Thursday with an additional potential on Saturday as the active pattern continues. All hazards are at play.

2) There is increasing concern about the potential for flooding across the area. A Flood Watch has been issued for portions Northwest Ohio.

3) Above normal temperatures will continue through Saturday before cooler temperatures return Sunday into early next week.

DISCUSSION
KEY MESSAGE 1...
A very active pattern will bring the potential for multiple rounds of severe weather today, Wednesday, Thursday and again on Saturday.
Focusing on the remainder of today/tonight first, there is currently a Slight Risk across much of the area (Marginal risk in NWPA) for the potential of strong to severe storms producing strong winds, large hail, and non-zero potential for tornadoes. The atmosphere appears to be destabilizing quickly this afternoon after the morning round of convection moved east. Dewpoints have climbed into the 60s with strong southwest WAA. Patches of clearly skies are also being observed, further enhancing the daytime heating. As a result, SBCAPE has already climbed to 1000 to 2000 J/kg across the western counties, allowing for an area of storms to develop. These storms may continue to ride the theta-e gradient towards the northeast, but are expected to weaken as the environment becomes less conducive.
With that being said, these pop up showers will likely be possible through much of the afternoon, even with an overall lack of large scale support.

The larger concern for severe weather across northern Ohio will be tonight as a LLJ and mid-level shortwave traverse the region. These components should enhance ongoing convection upstream of the area, which will ultimately push east. Best thought on timing at this point is onset near Toledo between 3-5Z Wednesday, gradually spreading east. The path of the system should closely mirror the warm front that will be established north of the area, keeping the greatest severe potential along and north of US30. With that being said, strong outflow colliding with an unstable atmosphere further south will have the potential for additional convection to develop along those boundaries, which is the primary reason SPC has shifted the Day 1 Severe Outlook further south. Through tonight there will be many moving parts that will have to be monitored, making this forecast extremely tricky and maintaining rather low confidence at this point. All hazards will be at play, although the tornado threat should be isolated to any storms that develop ahead of the main MCS.

Now shifting to the remainder of the week. Multiple shortwaves and surface low pressures are expected to traverse the region, bringing the potential for additional severe weather on both Wednesday and Thursday. Both days, the severe potential will be highly dependent on how well the atmosphere recovers after overnight/early morning convection. On Wednesday, right now the best timing looks to be in the afternoon and evening with the primary hazard being strong winds, although large hail and a tornado or two cannot be ruled out.
SPC has highlighted much of the area in a Day 2 Slight Risk. On Thursday, a slightly more defined, yet still weak cold front will push east early in the day. This frontal boundary would likely be the focus of any convection and to highlight this SPC has pus the western portion of the area in a Marginal Risk.

Last but not least, there is also a severe weather potential on Saturday as a deepening upper level trough pushes into the region with strong synoptic support and a strong cold front pushing east.
Given this is rather far out, not going to dive into the details as they will likely change, but to highlight this risk SPC has highlight much of the CWA in a 15% probability of severe weather on Day 5.

TLDR: There are multiple chances of severe weather through Thursday with all hazards at play. Timing and intensity remain uncertain at this point. A potent trough will push east this weekend, moving a strong cold front east on Saturday and resulting in another potential round of severe weather. SPC has highlighted all of these concerns in the various severe weather outlooks.

KEY MESSAGE 2...
With this very warm and moist airmass, similar more to late spring/early summer conditions, heavy rainfall associated with convection is likely. Modeled PWAT values of 1.25-2" are expected to persist into Thursday as sustain southwesterly flow continues to stream deep layer moisture across the region. Although QPF totals remain very uncertain, especially given the uncertainty in the various rounds of convection, there is a good chance of very efficient rainfall rates of 1-2" per hour in the strongest storms.
These rates are supported by a deepening warm cloud layer and periods where a skinny CAPE profile are predominant in modeled soundings. In addition, some of the convection should be enhanced by a strengthening LLJ that nudges northeast into the region, which will further enhance heavy rainfall potential. These conditions combined with recent heavy precipitation across the area may result in localized flooding and rises in streams and rivers, especially in areas that receive multiple rounds of convection. Given the increasing confidence in the heavy rainfall potential, a Flood Watch has been issued for portions of NW OH beginning at 00Z Wednesday through 12Z Thursday. Will have to continue to monitor the evolution of storms over the next 48 hours to determine any additional hydrologic headline needed.

KEY MESSAGE 3...
As recently discussed in most of the AFDs, northern Ohio and northwest Pennsylvania continue to reside in a pattern of above average temperatures with daily highs into the 70s and overnight lows in the 60s. These temperatures will persist through Saturday before a strong cold front pushes east and cools temperatures back to near average for this time of year. High temperatures on Sunday and into early next week will only climb into the 50s with overnight lows dropping into the 30s. Given the prolonged warmth the area has seen this week, the growing season has officially begun for all of the Ohio Counties in the CWA With the cool down expected, will have to monitor for any frost potential early next week.

AVIATION /18Z Tuesday THROUGH Sunday/
There are thunderstorms moving through central Ohio this currently that are bringing visibility down to IFR and LIFR in the heaviest portions. This line should continue eastward and impact KMFD,KCAK, and KYNG over the next few hours. It will be fairly quick moving so non-VFR conditions won't last long.
Thunderstorms may impact KCLE as the top portion of the line moves through, though conditions should not deteriorate as much that far north. Winds with the line have gusted up to 35 knots out of the west-southwest though up to 40 knots is possible as well. After this line moves through, VFR conditions are expected until 05-08Z tomorrow morning when a line of thunderstorms will move in from the north. There is some uncertainty as to the spatial extent and when the line will reach the area, so opted for a PROB30 at this time. This will need to be refined in the coming TAF package this evening.

Winds are currently 10-15 knots sustained gusting around 20-30 knots out of the southwest. Winds at the surface will diminish tonight by 00-02Z down around 12 knots. There may be some turbulent air in the lower levels, but LLWS concerns should be minimal with lower level winds at around 30 knots. By early tomorrow morning, winds will start gusting up to 20 knots and continue through the end of the TAF period.

Outlook...Periods of non-VFR conditions are expected in showers and thunderstorms through Thursday.

MARINE
Winds across Lake Erie remain between 10-20 knots out of the south to southwest today. As with previous days, the resultant waves of 3-5 feet will be higher in the open waters and towards Canada. Generally, winds will remain out of the southwest at 10-15 knots across the lake through Friday. High pressure will build into the region on Friday and winds will become light at around 5 knots and variable. By Saturday, winds will increase again out of the south to 15-20 knots as a warm front moves north across the lake.

CLE WATCHES/WARNINGS/ADVISORIES
OH...Flood Watch from 8 PM EDT this evening through Thursday morning for OHZ003-006>009-018-019.
PA...None.
MARINE...None.