Severe Wx / Flooding Rain Event Combo: April 2-6, 2025

[MVWxObserver]

I have some cousins and their families in southwest IN in the Moderate risk.

[tron777]

18Z HRRR and NAM soundings near CVG valid for Wed evening:

hrrr_2025040118_033_39.05--84.51.png

nam_2025040118_033_38.98--84.69.png

[tron777]

Latest call from the WPC:

WPC Call.jpg

[Bgoney]

Here are the totals for Ohio back in 97s two day event. Notice Areas to the west of 71 were only in the 1-2” range , and nearly nothing for the northern half of Ohio

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[tron777]

Here are the totals for Ohio back in 97s two day event. Notice Areas to the west of 71 were only in the 1-2” range , and nearly nothing for the northern half of Ohio



IMG_3373.jpeg

'97 was impressive for its localized nature as well as the quick 2 day hefty totals! This upcoming event, if some guidance is right, is a much longer event with similar totals but the rain shield with each system should be much, much greater. The aerial coverage should be significant with this one. The Met. or weather weenie in all of us will be in awe of this event. Just hope the low lying areas don't get hit too hard.

[tpweather]

Good Evening and some great posts earlier. Still believe the severe threat is rather large Wednesday evening. Does that mean tornado's and no but very strong winds are very likely which can cause damage. How much rain do we get with the first round late Wednesday and early Thursday will depend on the front putting on the brakes. That could be anywhere in southeast Indiana to eastern Kentucky. Some areas with this first round alone may be over 3 inches with no problems. Then we need to see where the next round decides to take shape the remaining days of this event


Not many silver linings with this event and the only one I can think is we will some breaks in the action over the 4 days. Some of the rain will soak in but its not late spring or summer where you have tons of vegetation that loves to take in water. My guess is most of the streams,lakes,rivers are probably running about normal for this time of year so helps somewhat.

Again with an event that we don't see very often there is a lot of guessing at this point and with each passage hopefully we can start to see where the heaviest rain falls the next day and what problems that may occur. If the same location gets hit every time with the heaviest amounts that will be a big problem.

I did notice they sort of extended some of the heavy rains further to the northeast and this is not good news because some of that will make its way to the Ohio River.

[Bgoney]

Great post TIM, soil moisture through the profile is currently at 80-90% saturated in and around Cvgland, so maybe a half inch or so will get ground saturated fully. Anything after that is going to be strictly runoff

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[tpweather]

Great info Bgoney and some of the heaviest rains are expected where the ground is almost fully saturated like you mentioned. I was not sure if this is normal this time of year and really just basing if off the amount of precip so far this year which is near normal. I know other factors are involved but not sure exactly what those other factors entailed. Thanks for the above info.

[Bgoney]

Latest HRRR. 850 winds are expected to be higher than a few days ago, in the range of of 70-80mph , so might see more of straight line winds along with spin ups in that line.

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[MVWxObserver]

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[tpweather]

Good Morning getting ready for a busy period. Good news sort of is the round of storms later Friday and early Saturday my be further to the northwest. One reason to get a big time rain event is a strong high to the east and sometimes this builds back west and the models are starting to see this happen. I mentioned earlier this week heaviest rains tend to fall in southern Indiana and western Kentucky with these setups.

One of the problems in forecasting is will the models be correct or will your memory of these patterns be correct. Many times its a combo and there is the problem when trying to forecast in advance.

Still going to be plenty of rainfall but maybe spread out more so not one area gets hit with the heaviest rain everyday. Sticking with the 6-8 but my gut is telling me that may be too high. After the Friday morning rains end we may get a break until Saturday and miss the rains Friday night and if that is the case you can take off an inch or two for overall totals. If we get that drier period Friday two things happen and we could really end up with a very warm day Friday and yes maybe some sun but this also will help in getting that atmosphere primed for the last wave later Saturday afternoon and early Sunday which could enhance the storms during that period.

Stay tune because my guess is plenty of changes coming and after each wave passes and the atmosphere sort of regroups and decides where to hit for the next round.

[tron777]

Good morning all! SPC still has us in an enhanced risk but the moderate risk is closer just to our SW. A high risk is now out for West KY and Western TN. Wow! Click here to see those SPC maps:

https://www.spc.noaa.gov/products/outlook/day1otlk.html

The warm front managed to spark off a couple of storms near Cincy this morning near and just N of the river. Once that action moves out of the way, then the destabilization process can begin. Also to note... we will need to watch for the potential of isolated cells, or supercells that may try and fire up ahead of the main line this evening. Otherwise the big line that comes thru tonight with the big wind, spin up TOR threat etc, may not come until midnight. Nighttime events are the worst but this one may indeed do just that. Keep your phones charged, turned on and Wx radio handy tonight!

[House of Cards]

My back yard was already the Okee Fenokee Swamp on Sunday when I was outside looking for funnels, so I can't imagine there is much more room in there for soaking up any moisture. I'm nervous about this one, will my sump pump be able to keep pace with this much rain? Or worse than that, if we lose power my battery backup isn't as strong as the primary pump is. I'm hoping we stay as dry as possible thru tonight and the winds help "blow off" some of the surface moisture that is already there so whatever comes from this mess has a little extra room to go.

[House of Cards]

Noticed also the SPC has dropped a High Risk out for extreme Western KY and TN. Guessing that is where all the chasers will be, but those road networks are pretty lousy for chasing I believe. I really hate that our chances are coming well after dark. Night time nasty weather really sucks!

[tron777]

Noticed also the SPC has dropped a High Risk out for extreme Western KY and TN. Guessing that is where all the chasers will be, but those road networks are pretty lousy for chasing I believe. I really hate that our chances are coming well after dark. Night time nasty weather really sucks!

IMO Dave, most of the heaviest rains will be falling at night this week. Some folks will probably be losing some sleep this week as a result of the weather.

[tron777]

[tron777]

Visible is showing some clear skies just to our S in KY. That area of clearing should give us a little sunshine soon.

[tron777]

A very long, but good read from the boys: As of 6:30am:

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Low pressure currently deepening over the central plains will move
into the upper Midwest today, while a warm front in advance of the
low will arrive into our area early this afternoon. Meanwhile, a
strong low level jet will develop by around sunrise, causing showers
and elevated thunderstorms (likely some small hail too) through the
morning hours. The focus of the moisture convergence appears to be
north of Interstate 70, though can`t rule out a few storms to the
south as well.

Behind the warm front, precipitation will end and temperatures will
quickly rise into the middle to upper 70s, with a few locations south
of the Ohio River reaching into the lower 80s. Dewpoints will rise
quickly as well, likely into the lower 60s. With strong winds aloft
and surface heating, southerly winds may gust as high as 45-50 mph
at times during mid- afternoon.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Hazardous weather will affect the middle Ohio Valley this evening
into the overnight hours. Strong low pressure is likely to occlude
over Lake Superior while a cold front advances toward our area from
the west. Ahead of the front, long curved hodographs and lingering
modest instability will bring the risk of severe thunderstorms.
High-resolution models signal an onset of storms ranging from around
10PM in west-central Ohio (06Z HRRR) to around 2AM or even later (06Z
NAM Nest). This uncertainty continues with the subject of storm mode.
06Z HRRR and the WRF-NSSL show mainly linear mode, while the NAM Nest
conveys storm clusters. All told, the highest risk of discreet or
clustered supercells exists for our western Ohio, eastern Indiana,
and northern Kentucky counties, while upscale growth into a QLCS is
more likely further east.

For Thursday, the storms will have mostly moved off to the southeast
of the CWA... but the cold front itself will likely lag behind across
the Ohio and Tennessee valleys. Despite the high PoPs in the
forecast, strong storms and heavy rain are likely to be at a lull on
Thursday as another wave of low pressure organizes to our southwest.
Clouds and precipitation will hold highs in the upper 60s to lower
70s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A very active long term period is on tap for the area, continuing
from the near/short term periods. A prolonged, widespread, and
significant flood event is likely across the local area,
particularly through this weekend, as multiple rounds of storms and
heavy rain will lead to the challenging of historical 5-day rainfall
accumulations.

After the initial round of storms/heavy rain tonight into the day
Thursday, another round of storms/heavy rain will blossom into
Thursday night as tremendous forcing/lift develops amidst a quasi-
stationary LL baroclinic boundary stretched across the srn 1/3 of
the local area. Strong moisture/mass convergence is expected once
again Thursday night into early Friday along the boundary, which
should be draped nearly-parallel to, and in the vicinity of, the OH
Rvr. The axis of heaviest rain is likely to focus just on the cool
side of the front, suggesting the Tri-State through EC IN and N/NE
KY and south-central OH (essentially the srn half of the ILN FA)
will be the focus area for another widespread 1-2 inches of rain,
with locally higher amounts, just from Thursday night through Friday
morning. The best sfc-based instby should stay to the S of the local
area, but with the robust forcing and some elevated instby,
widespread thunder expected during this period before coverage
becomes a bit more ISO/SCT into the daytime Friday.

The baroclinic zone will pivot to the N into the day Friday, with
continued ISO/SCT coverage along the boundary as it shifts from near
the OH Rvr to near I-70 by the evening. As we progress into Friday
night into early Saturday morning, the heaviest rain/most widespread
storm activity should focus across far wrn/NW parts of the local
area (as well as to the W across IN) as weak sfc cyclogenesis
evolves, prompting the front to continue to be dragged to the N as
it lays out once again from SW to NE squarely across the OH Vly.
This will allow for a brief drier stretch to develop across the SE
third of the local area Friday night into Saturday, with mostly dry
conditions favored SE of I-71. However, steady shower/storm activity
is still favored from SE IN through WC OH, with another 1-1.5 inches
of rain possible in these areas during this time.

The final, and perhaps most concerning, round of heavy rain is
likely to evolve Saturday into Saturday night as the slow-moving
front drudges to the SE through the region amidst strong, sustained
forcing and PWATs in excess of 250% seasonal norms. The prolonged
maintenance of such anomalous/deep moisture in the environment is
very rare to see. PWATs may approach 2" at times through this
weekend, which would be well in excess of 300% of seasonal norms.
And to have this environment be sustained for such long periods of
time presents itself with a significant areal/flash flood and river
flood threat through this weekend. This evolution of
/repeated/ rounds of storms/heavy rain, some of which will contain
torrential downpours, is likely to yield multi-day rainfall
accumulations in the upper echelon of local historical records.

Very simply, those who live in low-lying and flood-prone areas
should make preparations for widespread, potentially significant,
issues. Multiple ensemble suites show over 90% probs for at least 4"
of rain through Sunday across a large portion of the local area,
with some probs of 10-20% of at least 8" of total rain extending
through the Tri-State into N KY, SE IN, and SW OH. And whatever
severe storm threat may evolve Friday or Saturday is likely to pale
in comparison to the flood threat during these time periods.

Drier conditions return by late Sunday as the front finally moves E
through the region and much cooler/drier conditions return by early
next week.

[tron777]

Wind is really picking up here now. Gusting to 35 now here. Warm front must have moved thru just now or is close to doing so.

[tpweather]

Good Morning Les and it looks like the NWS was looking at the same info I talked about this morning. Severe weather later today and then again later Saturday are the two periods to watch. Depending on where the low tracks later Saturday will determine who gets in on the very heavy and/or severe weather. That outbreak on Saturday could be just as strong as today imo. How much rain do we get tonight and Thursday night is the next question but glad to see we may get a decent break on Friday and Friday night but like I mentioned before getting that break may end up costing us on Saturday as the atmosphere should be primed once again and that last wave should be the strongest wave imo.

[tron777]

[tpweather]

I really like the 12z HRRR model output. Has the line of storms overnight and stalling out in eastern Kentucky. Then later Thursday the next wave is forming in Arkansas and heading northeast and this gives us a really nice dose of rainfall and though we may have a touch of severe weather I believe the Thursday night early Friday has a good shot of seeing the period with the heaviest rainfall and that could be in the 2-4 inch range for that period alone. The model only goes out 48 hours but I really like what I see.

[Thetis]

I really like the 12z HRRR model output. Has the line of storms overnight and stalling out in eastern Kentucky. Then later Thursday the next wave is forming in Arkansas and heading northeast and this gives us a really nice dose of rainfall and though we may have a touch of severe weather I believe the Thursday night early Friday has a good shot of seeing the period with the heaviest rainfall and that could be in the 2-4 inch range for that period alone. The model only goes out 48 hours but I really like what I see.

What is it about the 12z HRRR output that you like?

[tpweather]

I really like the 12z HRRR model output. Has the line of storms overnight and stalling out in eastern Kentucky. Then later Thursday the next wave is forming in Arkansas and heading northeast and this gives us a really nice dose of rainfall and though we may have a touch of severe weather I believe the Thursday night early Friday has a good shot of seeing the period with the heaviest rainfall and that could be in the 2-4 inch range for that period alone. The model only goes out 48 hours but I really like what I see.

What is it about the 12z HRRR output that you like?

Good Morning and I like how it shows the next 48 hours. Will it be perfect no but it shows the severe weather later this evening into the early morning hours then we get a break and then the next round comes in Thursday night and early Friday with storms that will be less severe but the heavy rain potential is greater imo.

[tpweather]

Always nice to make a forecast and then you see the professionals put out almost the same forecast and also the reasoning behind the forecast. This is not always the case and many times I have been 180 degrees away from their forecast but with the NWS locally and Brian in Louisville almost repeating what I mentioned this morning my confidence goes up. Again no forecast will be 100p/c correct everywhere but you hope to hit on the overall theme and give folks and ideal what the timeline may look like.