A slow-moving/stalled frontal boundary lingering across the Ohio Valley into the Northeast will bring multiple rounds of rain and thunderstorms. As multiple waves of low pressure travel along this boundary, we’ll see several rounds of rain spread across multiple days, pretty much until the end of the week. During this stretch, because of the cloud cover and rain, temperatures will range slightly below average in the upper-70s.
Rest of today – mostly cloudy with rain arriving later in the day. HRRR (high resolution rapid refresh) simulated radar suggests the onset time of the first round of rain sometime between 5-7PM. This first round of rain isn’t expected to last too long. Overnight, around 1AM, we could see more substantial rain. Temperatures during the day peaking in the upper-70s and overnight lows in the mid-60s.
High resolution rapid refresh simulated radar for 5:30PM
High resolution rapid refresh simulated radar for 1AM Tuesday
Tuesday – high temperatures in the mid-70s with mostly cloudy skies again. Rain chances more likely in the morning. Overnight lows in the mid-60s.
Wednesday – chance for showers and thunderstorms continues, with high temperatures in the mid-70s and overnight lows in the mid-60s.
Weather Prediction Center surface forecast for 8AM Wednesday
Thursday – yet more chances for rain and cloudy skies with high temperatures in the mid-70s, and overnight lows again in the mid-60s.
A cold front that pushed through overnight leaves us with some cool, crisp air to start the weekend. The first half of the weekend will be characterized by plenty of sun before a slow moving frontal system approaches later in the weekend. This will bring back chances for showers and thunderstorms going into next week when it appears an active weather pattern could take root.
Rest of today – mostly sunny with high temperatures in the mid-70s. A post-frontal trough may touch off a few isolated storms later in the afternoon. Overnight lows in the low-60s.
Weather Prediction Center surface forecast for 8AM Saturday, showing high pressure off the coast of NC
Saturday – mostly sunny with highs in the low-80s. High pressure takes hold off the Southeast US coast, with clockwise return flow bringing some warmer air this way. Overnight lows in the low-60s.
Sunday – with a frontal boundary approaching from the northwest, clouds increase and chances for showers and thunderstorms do also. High temperatures should still be mild in the low-80s. As the Overnight lows in the mid-60s with rain chances continuing.
NAM output of 1000-500 mb thickness, surface pressure and precipitation for 8PM Sunday.
Monday – the frontal boundary that approaches from the northwest weakens and stalls out. This is partly due to flow at the upper levels flattening out/becoming somewhat parallel to the front’s orientation, and partly due to the high pressure that by this time will become anchored over Bermuda. Multiple waves of low pressure are forecast to move along this stalled front bringing another day that holds chances for showers and thunderstorms. Prolonged southwest/westerly flow ahead of the cold front which really slows down should allow temperatures to reach the mid-80s despite more cloud cover and precipitation. Overnight lows in the upper-60s with yet more rain possible.
After a rainy start to the week, high pressure takes over during the mid-week period. Another storm system moves in Thursday. Behind this next bout of rain, a dry and mostly sunny weekend should await us.
Rest of today – skies clearing as a cold front pushing. Winds picking up with some subsidence (sinking air, since air mass behind the cold front is cooler and drier). High temperatures reaching into the upper-70s with this subsidence and some downsloping from the northwest. Overnight lows in the mid-60s.
Weather Prediction Center surface forecast for 8AM Wednesday
Wednesday – high pressure remains firmly rooted over the area. High temperatures in the mid-70s with mostly sunny skies. Overnight lows in the low-60s.
Thursday – a developing low closer to the coast and another one further inland over the Great Lakes will bring showers and thunderstorms to the area. First, like Monday, a warm front will lift through earlier in the day, then a cold front is expected to follow later on. High temperatures in the low-70s due to rain and cloud cover. Overnight lows in the upper-50s.
NAM model for 1000-500 mb thickness and surface reflectivity at 8AM Thursday, showing a distinct area of rain associated to a low emerging off the coast of the Delmarva Peninsula
Friday – with a cool start, temperatures top out in the mid-70s. Mostly sunny in the wake of the cold front Thursday. Overnight lows in the low-60s.
High pressure will build over southwestern Quebec this weekend, and this will be the predominant influence on sensible weather in the area. This should result in the first rain-free weekend in quite a while, so get out and enjoy it if you can. By the beginning of next week, rain comes back into the picture. Temperatures through the period will be at or slightly above average in the upper-70s.
Rest of today – filtered sun through a deck of higher clouds appears to be on the order of the day with a cold front stalling out and becoming stationary to our south. No rain though! High temperatures around 80°F. Overnight lows in the mid-60s.
Weather Prediction Center surface forecast for 8AM Saturday. That big area of high pressure over Quebec will be bringing us some sunny skies for a change.
Saturday – this will be the best day of the weekend with sunny skies as high be pressure builds north and high temperatures staying in the low-80s. Overnight lows again in the mid-60s.
Sunday – still a good day for being outside with more clouds expected and becoming mostly cloudy late. High temperatures in the upper-70s with overnight lows in the low-60s.
NAM output for 2PM Monday, by this time, it appears that a cold front bringing showers along with it will be nearing the area.
Monday – the next storm system comes through with a cold front forecast to pass Monday into Tuesday. Rain chances look to be sometime in the afternoon at this point. High temperature in the mid-70s with mostly cloudy skies and overnight lows in the low-60s.
This week starts off right around average for this time of year, with pleasant, sunny conditions. High pressure remains in control for a good part of the week and temperatures start creeping up as the high pressure continues moving east and offshore. Clockwise flow around this exiting high pressure from the southwest and west will help warm temperatures up before the next chance for rain comes in Wednesday and Thursday.
Rest of today – clear skies with high temperatures in the low-70s. Overnight lows in the mid-50s.
Weather Prediction Center surface forecast for 8AM Tuesday
Tuesday – high pressure still in control, temperatures again in the low-70s with plenty of sun. Overnight lows warming up into the low-60s.
Wednesday – the high pressure center will be southeast of us and a warm front will push through. This should allow temperatures to reach into the low-80s with partly sunny skies. We could see an afternoon shower or thunderstorm as a result of increased instability. Overnight, a prefrontal trough and cold front is forecast to push through and lead to more chances for showers and thunderstorms with low temperatures in the mid-60s.
Pivotal Weather rendering of GFS model output for 1000-500 mb thickness and precipitation, 2AM Thursday
Thursday – partly sunny skies again with continuing chances for shower and thunderstorms later in the day. High temperatures in the low-80s. Overnight lows in the mid-60s.
We’ll get a much needed respite from deluging rains at least for part of the weekend as high pressure initially takes hold of the weather. This should give us two days to start with slightly above average warmth and mostly sunny skies. By Sunday, the next storm system to affect the region will be closing in and we can expect more rain and thunderstorm chances. Timing of this system now appears to clear the area by Monday and result in cooler but sunny conditions starting next week.
Rest of today – early fog has burned off and we’re in line to have a nice day with sunny skies and high temperatures topping out in the low-80s except at the immediate coast where a sea breeze is expected to develop with onshore flow forecast later in the day. Overnight lows in the low-60s.
Weather Prediction Center surface forecast for 8AM Saturday
Saturday – another great day with temperatures in the low-80s (except again at the coasts with sea breezes) and mostly sunny skies. Clouds on the increase late and overnight with lows again in the low-60s.
NAM (North American Model) output for 500 mb vorticity and heights on Sunday 8PM showing a pronounced upper low over James Bay in Canada with a trough extending into the Ohio Valley. This will provide upper level divergence and instability to spur storms on Sunday.
Sunday – a warm front is forecast to push through overnight into Sunday and set the stage for rain and thunderstorms later in the day as a cold front approaches from the west. Temps probably topping out a touch cooler in the upper-70s with more clouds hanging around. Overnight lows around 60°F.
Monday – at this time, expecting the aforementioned cold front to sweep through the region before the day Monday. That should result in cooler highs in the low-70s with mostly sunny skies. Overnight lows in the upper-50s.
Temperatures cool off after a warm holiday weekend. A frontal boundary will linger in the area this week allowing multiple disturbances to move along it. This will result in multiple chances for rain but with generally mild temperatures except today. Looking into the weekend, it does appear that high pressure takes over and gives us a nice Saturday at the least.
Rest of today – mostly cloudy, temperatures cool, in the upper-60s. Showers early should give way to a period of dry weather, however, stronger showers and thunderstorms could hit later this evening around 8PM ahead of an approaching low sliding along a warm front just to our south. We are just outside Storm Prediction Center’s slight risk area for severe thunderstorms, and these storms should weaken as they near the more stable marine layer, in particular if clouds hold and no sun peaks through. Overnight lows staying steady in the upper-60s.
Weather Prediction Center surface forecast for 8PM Tuesday
Wednesday – a cold front is forecast to push through and allow for some drying out on Wednesday with partly sunny skies. High temperatures should rise into the upper-70s. Dry weather doesn’t last because yet another warm front pushes through later in the evening with more showers and thunderstorms possible. Overnight lows in the low-60s.
Thursday – another impulse of low pressure and warm front moves through the area bringing continued chances for rain. High temperatures in the upper-70s under mostly cloudy skies. Overnight lows again in the low-60s and with more chances for rain.
GFS model output for surface pressure, precipitation, 500 mb thickness at 6AM Friday
Friday – cold front sweeps through and allows for sunny skies to return, this should be a really nice day with high temperatures in the upper-70s. Overnight lows about 60°F.
I’m at my college for reunion weekend, and offered to do a detailed forecast for one of the days I’m here. Saturday is shaping up to be a bit of a mixed bag. Temperatures should be summer-like in the mid to upper-80s, but the downside is a risk for possibly strong to severe thunderstorms especially in the early evening hours. These thunderstorm chances are far from being certain though, and there’s a chance we may miss out entirely on any precipitation. In other words, it’s another good day for a precipitation forecast bust!
My Forecast High: 87°F | Low: 62°F | Max sustained winds: 21 mph | Total precipitation: 0.28″ – verification will come from METAR data for the period between 2AM Saturday and 2AM Sunday (06Z Saturday to 06Z Sunday) at LPR (Lorain County Regional Airport).
Verification High: 90°F | Low: 61°F | Max sustained winds: 25 mph | Total precipitation: 0.00″ – on high temperatures, hedging up towards the higher end of guidance turned out to be a good idea. It’s yet more evidence that MOS guidance tends to be too cool for breezy warm sectors. If anything, I could have been a touch more aggressive on the high here. Did well on the low temperature, and from what I could see, did decently on max winds too. Like I’d mentioned in the forecast, the bust potential for precipitation on this day was significant. That ended up being the case – KLPR and Oberlin missed out on the heaviest rain and more serious convective activity, leading to barely a trace of measurable precipitation. In retrospect, I probably could have gone even drier with my forecast, but I would still have not felt comfortable going with zeros.
Weather Prediction Center surface forecast for 2PM Saturday
Synoptic Set Up A stationary front eventually lifts through Ohio overnight as a warm front. We’ll spend the day in the warm sector of a surface low centered over central Ontario. At the 850 mb level, winds will not be strong enough to qualify as a low-level jet and relative humidity values likewise do not appear particularly high. At 500 mb, a robust shortwave trough is forecast to push through later in the day, bringing some decent vorticity and upper-level lift. Further up at the 300 mb level, there’s not much evidence of enhanced divergence and lift since we’ll be south of a 300 mb jet streak.
GFS model output for 500 mb vorticity and winds valid at 8PM Saturday. Note the strong cyclonic vorticity values over Northeastern Ohio at this time (bright oranges). This will provide some synoptic scale lift for initiating storms via upper-level divergence.
High Temperatures GFS and NAM MOS and NBM all show Saturday to be a warm day. GFS is the warmest with 87ºF while NBM is coolest with 83ºF. EKDMOS (ensemble MOS) 50th percentile matches comes close to GFS MOS at 86ºF. Because forecast soundings show we’ll be in a well-mixed warm sector with decent though not ideal conditions for warm advection, I am tending towards thinking that a high of 87ºF is in fact possible. We could be even warmer if enough sun breaks out between possible earlier showers and rain later in the day.
GFS 2-meter temperature contours and winds at 2PM Saturday showing decent, though not ideal conditions for warm advection (southwesterly winds of 15 knots at a somewhat sharp angle across closely packed temperature contours). If surface winds were forecast to be stronger, we’d be looking at better chances for robust warm advection and hence warmer temperatures.
Low Temperatures NAM and GFS MOS are again in close agreement with 61ºF and 63ºF lows respectively. NBM is a touch cooler at 59ºF. Although both NAM and GFS show evidence of a nocturnal inversion forming, and calm winds at the surface, both models also show extensive cloudiness or even precipitation ongoing overnight. Because the boundary layer starts out with plenty of moisture, there shouldn’t be much in the way of evaporational cooling. Thus, clouds will actually serve to stave off any radiational cooling, which leads me to believe overnight lows will be on the warmer side of guidance. I’ll go with 62ºF here.
NAM MOS guidance for KLPR
GFS MOS guidance for KLPR
Max Sustained Winds NAM, GFS MOS have maximum synoptic winds averaging about 16 knots. I see no clear reasons to go much higher than 18 knots for a max sustained wind tomorrow, unless we happen have a thunderstorm roll through with sustained winds that are much higher. EKDMOS’ 50th percentile lies right around this figure. Even with well-mixed boundary layer forecast to form tomorrow afternoon, winds above the surface up to 850 mb do not appear to be that strong, only around 20-25 knots. Layer mean wind analysis of the NAM sounding only showed winds of about 16 knots.
GFS forecast sounding for 5PM Saturday
NAM forecast sounding for 5PM Saturday
Total Precipitation There’s a large spread between NAM and GFS on forecast totals tomorrow. This will be the trickiest part of the forecast because there’s clear signs that convective precipitation, with a couple rounds of possibly strong to severe thunderstorms could materialize. Any strong thunderstorm passing overhead could quickly dump a few tenths of an inch of rain. However, if we miss out on any significant thunderstorm action, we could see just a trace of rain instead. It’s still too early to tell the finer details of where storms will initiate at this point. Based on forecast soundings above, the best chance for thunderstorms to roll through would be during the late afternoon and early evening, maybe 5-8PM when moisture is best and instability is maximized from daytime heating. Strong, mostly unidirectional shear profiles with westerly winds increasing from 10 knots at the surface to 50 knots at 500 mb suggest the potential for damaging winds as the biggest severe weather threat.
NAM forecast for 850 mb winds and relative humidity at 2PM Saturday
GFS forecast for 850 mb winds and relative humidity at 2PM Saturday
Going against the potential for significant precipitation, neither GFS nor NAM really show strong signals of low-level jet support. Winds at the 850 mb level don’t look to be particularly strong, and moisture support isn’t looking great either. What’s more, while there’s mention in the local forecast office discussion of a right entrance region of an upper-level jet that would provide some dynamic lift, I’m not seeing that myself. They did also mention that a trough would pass through and provide a focus for some lift. This would be a necessary trigger since there’s no clear frontal boundaries that would provide the convergence and lift necessary to generate showers and thunderstorms. Given the hit or miss nature of thunderstorms, less than ideal conditions for heavy precipitation, and disagreement between GFS and NAM MOS at this time, I find it prudent to hedge down with a forecast for 0.28″ of total precipitation despite MOS guidance averages at 0.48″.
The long holiday weekend appears to be mainly dry, and even features a day that could make for a good beach getaway. We do have a chance for rain overnight Saturday into Sunday but this shouldn’t be a damper on anyone’s plans. Sunday’s shaping up to be the warmest day of the weekend although Memorial Day itself may end up being the nicest all around day.
Rest of today – breezy and sunny with high temperatures in the mid-70s. The strong pressure gradient between a departing surface low and a high pressure center moving east from the Great Lakes is what’s causing these breezy conditions. Winds should die down overnight as the high moves overhead and the pressure gradient relaxes. Overnight lows in the upper-50s.
Weather Prediction Center surface forecast for 8PM Friday
Saturday – as the high pressure continues moving east, clouds will increase due to the influence of an advancing warm front. This frontal boundary may serve as the focus for some showers and thunderstorms overnight Saturday into Sunday. High temperatures Saturday expected to be in the low-70s due to increasing cloud cover. Overnight lows in low-60s.
GFS model output for surface pressure, precipitation, 500 mb thickness valid 4PM Sunday
Sunday – we’ll be in the warm sector this day. Clouds and rain are expected to subside early and allow for temperatures to warm into the mid-80s and possibly higher. This will be the best day of the weekend to hit the beach though it’s not a lock for sunny weather all day. Overnight lows in the mid-60s.
Monday (Memorial Day) – anticipating this will be the best day of the weekend with sunny skies and mild temperatures in the upper-70s. Overnight lows in the low-60s.
This week kicked off with high temperatures yesterday that were more typical of the mid-summer. Things have cooled off noticeably this morning in the wake of a cold front that brought some showers and thunderstorms to parts of the region last night. The remainder of the week should see temperatures around normal for this time of year, with the next chance for rain Thursday. Looking ahead to Memorial Day weekend, it seems there could be some rain chances especially late Saturday into Sunday.
Rest of today – sunny conditions with high pressure in control today. Fresh northwesterly breezes calming down later in the afternoon. High temperatures in the low-70s. Overnight lows in the mid-50s.
Weather Prediction Center surface forecast for 8AM Wednesday
Wednesday – high pressure remains in place, yielding another great day with lots of sun and seasonable high temperatures in the low-70s. Overnight lows in the upper-50s as a warm front approaches from the southwest.
Thursday – chance for showers, on the light side developing ahead of this approaching warm front. High temperatures in the low-70s with partly sunny skies. Rain chances increase going into the overnight hours as the parent low of the warm front nears, lows in the low-60s.
GFS model output fro surface pressure, 500 mb temperature and height valid 10PM Thursday
Friday – mostly sunny behind Thursday’s quick-moving storm. High temperatures in the mid-70s. Overnight lows around 60°F
