textproduct: Cleveland

WHAT HAS CHANGED

No changes to the general messaging. Monitoring for shower and storm potential (along with accompanying severe weather/heavy rain risks) late this afternoon/evening, late Friday afternoon/evening, and again late Saturday into Saturday night.

KEY MESSAGES

1) Scattered showers/thunder lift northeast across the area through midday today, followed by a significant warming trend this afternoon. Additional shower/thunder potential moves in from the west late today and tonight, with a minimal severe weather risk.

2) Continued shower and thunder potential Friday and Friday night as a front pushes into the area and then stalls on Friday, before lifting north into Saturday. Some uncertainty exists regarding the placement of the stalled front and favored location for shower and storm potential late Friday into Friday night. Locally heavy rainfall may accompany some storms.

3) A strong cold front sweeps through late Saturday and Saturday night. A band of showers/storms with at least a low severe weather and heavy rain risk likely accompanies the front, with warm and breezy conditions continuing ahead of it.

4) Much cooler and generally low impact weather is expected from Sunday through the first half of next week.

DISCUSSION

KEY MESSAGE #1:

Scattered showers and perhaps a bit of thunder will lift east- northeast across the area through about midday along and ahead of a warm front. Not expecting any severe weather or a substantial enough amount of rain to re-aggravate any ongoing flooding. Some patchy dense fog is developing early this morning, and may not completely until the front clears a given location. It will remain chilly ahead of the front, with temperatures quickly surging this afternoon once the front lifts through. Outside of perhaps Erie, much of the area will push well into the 70s today. Parts of North Central and Northeast OH, which should see the strongest warming this afternoon, will push into the upper 70s to close to 80. With dew points in the upper 50s/lower 60s behind the warm front, it will feel warm and humid for early April. Wind gusts of 25-35 MPH are likely this afternoon and early evening, especially west of I-77.

There will be renewed convective potential later this afternoon through tonight ahead of a cold front approaching from the west. Some guidance suggests loosely organized showers/storms firing from eastern OH into PA late this afternoon or evening, likely along the leading edge of a surge of higher theta-e air. Sufficient instability and deep-layer shear are expected for a marginal wind/hail threat with convection in our eastern counties late today or this evening, though confidence in this convection occurring is low-medium in such a weakly forced regime.

Attention then turns to the west ahead of an approaching cold front this evening through tonight. Showers/storms are expected to develop and organize well to our west this afternoon, with whatever is left of the activity pushing into our area this evening and tonight. The environment is supportive of organized convection and severe potential to our west this afternoon and early evening. Decreasing instability overnight, the surface front not even approaching Toledo until Friday morning, and greater large scale forcing only grazing us (stronger forcing stays to our west/northwest) all argue against robust convection spreading across our area. While a Marginal Risk (level 1 of 5) for severe weather from the SPC does get into our Northwest OH counties with damaging winds and perhaps a brief tornado possible, this should be a lower-end threat for our area and should not carry well east overnight. In fact, confidence in substantial rain occurring decreases east across the area overnight tonight. The main window for any severe weather in our Northwest OH counties appears to be between 8 PM and Midnight. While the area can not take much rain at the moment, area-average QPF tonight is under a quarter- inch with guidance suggesting localized peak amounts will remain under an inch. This suggests we should not re-new flooding issues through tonight. It will be quite mild tonight with lows in the 60s.

KEY MESSAGE #2:

The cold front that approaches tonight should push into at least Northwest OH and over Lake Erie Friday morning, though will be losing momentum as low-mid level heights begin rising behind the shortwave that tracks through the Great Lakes tonight. The front will likely push into and then stall across northern Ohio on Friday, remain nearly stationary Friday night as increasing south-southwest flow south of the front tries to counteract a push of cooler air from the north, and then start lifting back north by early Saturday.

Some lingering showers may be ongoing from eastern OH into PA Friday morning, with a general minimum in rain potential otherwise expected Friday morning. The forecast for Friday afternoon-night is deceptively tricky. It will remain warm and humid with potential for showers and storms along and south of the front, with cooler and drier weather north of the front. Some models stall the front over far northern portions of the area, which makes sense given the height rises that will be ongoing on Friday...however, other models show the front continuing to move through before stalling across our southern counties towards Route 30 Friday evening. Gut feeling is that the front will stall farther north given the height rises, but if we do see a greater push of north-northeast winds off the lake the height rises may not matter as that would push the front south.

Where this becomes critical is in evaluating shower and storm potential Friday afternoon through Friday night. Models that are more progressive with the front, such as the HRRR/ARW/RRFS, have more limited shower and storm potential that is focused across our southern and southeastern counties Friday afternoon into Friday night. Models that stall the front farther north, such as the NAM/RGEM/ECMWF, are more generally aggressive/widespread with shower and storm potential late Friday afternoon through Friday night. Even with weak forcing, am expecting the warm/humid and uncapped airmass to allow convection to start developing Friday afternoon. Activity is likely to continue through the night as the front becomes better- defined and as a modest southwesterly low-level jet develops. Again though, exact placement and coverage are question marks. The environment (weak to moderate instability with about 30kt of deep- layer shear) can support a marginal wind/hail risk with more robust storms Friday afternoon/early evening, covered by an SPC Marginal Risk (level 1/5) for a good portion of our area. Instability profiles get skinny Friday night with precipitable water values climbing over 1.25" (well above 90th percentile of climatology for this time of year), supporting increasingly efficient rain rates within any convection. The stalled/tightening front should continue to act as a trigger for convection through much of Friday night, with the warm and moist southwesterly low-level jet perhaps allowing for localized back-building and training. So, if we do end up seeing greater coverage of convection, flooding/flash flooding can become a greater concern on top of soils that will still be fairly saturated.

With the slower front, much of the area should push well into the 70s on Friday with dew points remaining in the low-mid 60s ahead of the front. Locations near the lakeshore may be in for a sudden temperature drop when/if the front pushes onshore off the lake Friday afternoon or early evening, with noted uncertainty regarding the timing and southward push of the front.

KEY MESSAGE #3:

A much deeper trough pushes into the Great Lakes Saturday and Sunday, driving stronger low pressure through the region. The approach of this stronger system will lift the front well north as a warm front into early Saturday. As the trough digs it will push a much stronger cold front across the area late Saturday or Saturday night.

We should briefly break into a mainly dry warm sector on Saturday, after perhaps some lingering showers/storms near the warm front across our northern counties early in the day. It will be warm and breezy on Saturday, with highs again well into the 70s with an 80 degree reading not ruled out if we see enough dry time/sun. There is high confidence in a band of rain/storms moving in along and just behind the front late Saturday and Saturday night.

While forcing will be strong, especially Saturday night, somewhat meager/skinny instability profiles to go along with the stronger deep-layer shear being displaced behind the front could limit severe potential. A narrow overlap of more favorable shear and some instability may play out near the front, especially Saturday night as forcing and flow aloft maximize over our area. Given that, the SPC has outlined much of our area in a Marginal Risk (level 1 of 5) for severe weather for later Saturday through Saturday night. It's worth noting that given increasing forcing at night, the setting of the sun will not make as large of a difference with severe potential. Overall, feel this is a lower-end threat for locally damaging winds as things currently stand. While forcing increases Saturday night the front will keep moving, with average QPF values generally in the 0.30-0.70" range (highest east) and locally up to 1" or so possible in more robust convection. The amount of rain on its own is not that concerning from a flooding perspective, though the rain with the cold front Saturday night could worsen any still ongoing flooding.

KEY MESSAGE #4:

A period of much cooler weather with lighter precipitation chances settles in Sunday through the first half of next week. A few showers may linger on Sunday. A re-enforcing shortwave and cold front are expected Monday into Monday night, with 850mb temperatures potentially dipping to -10C on Tuesday. Strong high pressure moves overhead Tuesday night before shifting east on Wednesday.

Scattered showers may accompany the cold front Monday afternoon into Monday night area-wide, with greater potential southeast of Lake Erie. Minor lake effect may linger into Tuesday before high pressure has a chance to really build in. Showers during the day Monday will largely fall as rain, though it will be cold enough aloft that showers can have a bit of a convective flavor and produce some graupel or very small hail (not sleet). Lingering lake effect behind the front late Monday night into Tuesday would likely fall as mainly snow...though the cold airmass is not deep or moist enough for a noteworthy amount of lake effect snow, meaning light accumulations at most. Unfortunately, the POPs outside of areas downwind of Lake Erie are too low to get a forecast mention in our point and click or zone forecast products Monday afternoon and evening, and we do not directly control those extended grids at the WFO level anymore.

Highs will return to the 40s and 50s Sunday through Wednesday, with overnight lows mainly in the 30s...and likely 20s Tuesday night across much of the area with high pressure overhead.

AVIATION /06Z Thursday THROUGH Monday/

IFR conditions are in place across most of the area with TOL holding just above IFR but likely to fall overnight. Several terminals will see low IFR conditions as a warm front lifts north with ceilings of 200-500 feet between 09-13Z. Patchy drizzle has been on going at CLE and scattered showers are expanding across Northwest Ohio. Can not rule out an isolated thunderstorm at FDY or TOL before 13Z but coverage is too low to include at this time. The chance of showers will be lower but extend east across Ohio through 14Z. After that time, conditions are expected to improve rapidly as winds veer from northeasterly around to the south behind the front. Winds will increase quickly between 15-18Z with south to southwest winds gusting to 25-30 knots. This will help to scatter out the low clouds and VFR is expected this afternoon into the evening. Showers with a chance of thunderstorms will spread west to east late tonight but for now have only included showers in the vicinity at TOL/FDY/CLE but thunder may also accompany these showers. A low level jet will arrive overnight and have included a brief period of low level wind sheer at terminals where winds may drop off after sunset.

Outlook...Additional periods of non-VFR conditions possible in showers and thunderstorms late tonight. Non-VFR possible Friday through Saturday night with rain and low ceilings with low ceiling continuing through Sunday.

MARINE

A Small Craft Advisory remains in effect for all nearshore waters except towards Maumee Bay for 3 to 5 foot waves with northeast winds of 15 to 20 knots through the morning. After that, a warm front will lift north across Lake Erie and winds will shift around to the south at 15-20 knots by tonight. The front will oscillate north and south across Lake Erie through Saturday before a stronger cold front finally pushes east across Lake Erie Saturday night Saturday night into Sunday. This will be accompanied by west winds of 15 to 25 knots and waves building to 4 to 6 feet in the nearshore waters east of Vermilion. Small Craft Advisories will likely be needed behind the front on Sunday. Conditions improve Monday as high pressure builds into the Ohio Valley.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory until 1 PM EDT this afternoon for LEZ143>149.