April 2021 Weather Discussion

[tron777]

74 today imby... CVG 73 Look for some river valley fog in the morning otherwise a lovely day with sun and some clouds... Low 80s expected, Winds will be breezy out of the south at 10-20 mph with gusts to 30 possible.

[tron777]

Wed afternoon - Thurs night.... the following are rainfall amounts for that period at CVG from the overnight models.

NAM - 1.82"
GFS - 2.28"
Euro - 1.4"

[tron777]

Today… one more awesome day in the lower 80s before we get wet by tomorrow afternoon. A marginal risk of severe wx is also possible folks... FYI. This is for both Wed and Thurs.

[tpweather]

Wed afternoon - Thurs night.... the following are rainfall amounts for that period at CVG from the overnight models.

NAM - 1.82"
GFS - 2.28"
Euro - 1.4"

Good Morning Les and finally models getting higher with amounts compared to lately they would head south the nearer we got to an event. Much more in the way of moisture available for this system and a good call imo is 1-2 inches with locally higher if you get in a decent thunderstorm. Severe weather does not look likely though anytime you get a decent storm a period of heavier rains and winds are possible. Need the rainfall and 1-2 inches that is widespread really would be a blessing.

[tron777]

Good morning Tim! If models are right, this event should put us right around normal for rainfall if not a tad above, so we would be in fine shape after this system moves thru. May looks active at this time to kick off the new month so the long term looks good with regards to moisture.

[cloudy72]

Good morning!! Will try my turn at forecasting, I mostly bust but will give this system a go and see what happens! My low was 52 around 6:00 am this morning and already up to 58 so gonna be a warm one! Marginal risk for everyone tomorrow and for the I-71 corridor and SE Crew on Thursday. Rainfall looks plentiful for all based on all the main models (NAM, GFS, EURO). I'd say pretty much an inch is guaranteed by Thursday night for all. Models are differing on where the heaviest axis sets up and this is where you could see 2-3" local amounts in stronger storms. The NAM is most bullish with CAPE on Wednesday (1000-1500 j/kg), but as Tim and Les stated widespread severe not expected at this time but strong storms are possible.

[cloudy72]

Not certain how accurate these maps are, but you can see Wed afternoon could get busy per the Euro model with several clusters of thunderstorms around. Again, this is NOT depicting severe weather, just where the highest prob of lightning strikes will be located.

ecmwf-deterministic-indiana-lightning_density_inst-9640000.png

[tron777]

StormTalk! https://www.wave3.com/2021/04/27/goode- ... ther-blog/

[cloudy72]

12z NAM has lost the heavy rain threat for those from I-70 northward, but hammers CVG land pretty good through Thurs night (2-3"+). CAPE still pretty decent for Wed afternoon mainly along and south of the river.

[tron777]

Up to 75 here already... 82 should be a lock easy. After the rain, also want to mention a possible light frost threat for Sat morning. Could see U30s at CVG and cooler to our north and outside of town.

[MVWxObserver]

Had a load of dirt arrive for a Sugar Maple stump removal hole in our back yard yesterday that's been filled and nicely leveled off.

Hopefully not too much heavy intensity rainfall up this way for Wed - Thurs, as would hate to see any of that dirt get washed away.

Currently 73 here in Greenville and progged for 83 later this afternoon!

[tron777]

12Z GFS coming in just shy of 3" of rain at CVG now.

[tron777]

77 as of 1pm at CVG...

[MVWxObserver]

Currently 77 here in Greenville at 2 o'clock and 81 at KDAY.

[tron777]

1.32" at CVG on the Euro today. I like Tim's 1-2" call at this time. Can someone get 2 or 3"? Absolutely if training of storms occur over the same area.

[tron777]

I made it to 81 today. CVG also hit 81.

[MVWxObserver]

Currently 81 here in G'ville and has reached 82 at KDAY.

[Bgoney]

Tractors, tractors, tractors everywhere. Dust is flying, farmers are hitting it hard this week, getting that corn in

[tron777]

Nice AFD from the boys this afternoon toying with the Flash Flood Watch idea:

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
PWATs continue increasing during the day on Wednesday thanks to
persistent southwesterly flow out of the Mississippi River Valley
and Gulf of Mexico. Eventually PWATs are expected to climb to 1.75 +
inches by the afternoon, which is near or at record values for late
April.

In terms of shower and thunderstorm activity for Wednesday, the
forecast gets fairly tricky. To start off the day, there could be
some scattered light shower activity before noon due to a weak low
passing north of the region. After 12PM, shower coverage diminishes
and surface based instability grows to low/moderate values (1500-
2000 J/kg). However, the lack of a clear forcing mechanism much of
the afternoon leads to only slight chance/chance PoPs for most of
the area. Any thunderstorms that do form in the afternoon could
produce heavy rain and gusty winds. Forecast highs are near 80.

Shower/thunderstorm chances then start increasing in the late
afternoon/early evening into the overnight with the arrival of a
shortwave and LLJ. The location of the heaviest rainfall axis for
Wednesday night is expected to be near/along the Ohio River
according to latest CAM and ensemble guidance. A Flash Flood watch
was considered on the day shift for southern Ohio and northern
Kentucky starting Wednesday night for a few main reasons: 1) near
record/record PWATs are likely 2) training convection is expected
due to boundary parallel winds (cold front to the northwest) 3)
efficient warm rain processes thanks to an above freezing layer over
10000 ft thick. However, a Flash Flood Watch was not issued since
the exact axis of heavy rainfall has not yet been determined with
any confidence and main flooding threat is still over 36 hours out.
Any thunderstorms Wednesday night could produce a very low end
severe threat with gusty winds being the primary threat.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
A cold front will sag slowly southeast across the region Thursday
into Thursday night with widespread showers and embedded
thunderstorms continuing along and ahead of the boundary. The ongoing
pcpn/clouds may help limit the instability across our area on
Thursday with daytime temperatures ranging from the mid 60s in the
northwest to the lower 70s across the southeast. Thus, the severe
threat looks somewhat limited for Thursday with the best chance for
any stronger storms to be across our southeast. Bigger threat will
likely be a continued heavy rain threat across our south given the
potential for some training storms and higher PWs. Depending on
exactly where this lines up, we may eventually need a flood watch
across potions of our southwest/southern counties. Pcpn will taper
off from the northwest Thursday night as the cold front moves off to
our southeast by Friday morning.

The upper level trough will shift east across the region through the
day on Friday. Suppose we could see a few light afternoon showers
across our northeast on Friday, but we should be mostly dry and
cooler. Highs on Friday will range from the upper 50s in the north
to the lower/mid 60s across the south

EDIT: LOU does have one issued for portions of their CWA, mainly IN counties and LOU Metro.

[tron777]

18Z NAM is going bonkers showing 3.64" of rain at CVG from multiple rounds of heavy rainfall. 18Z GFS is coming in with 2.25"

[Angelika]

When will the rain start?

[Bgoney]

Still like the 1-2" call as a rule . Always a.chance for heavier amounts if an area gets 2 or 3 rounds of storms. On either side of that heavier rain axis that ILN mentioned, rain amounts will be less .25"-.75". We're certainly due for at least some garden variety t-storms. MBY hasn't seen one for all of 2021. Dud of a severe season continues.

[MJSun]

Gorgeous day today

[Bgoney]

No changes in amountsfrom yesterday for today and tomorrow. Severe threat very low for event. However , the OV's first legit severe threat of 2021 may be taking shape for early next week , higher DPs and substantial shear look to be in the offing for that time period.

[cloudy72]

My low so far has been 69 - so quite summerlike out there! Has the feel of a stormy evening ahead so we shall see! I agree with the general 1-2" call. Any heavy training bands will have to be watched via mesoscale analysis as the models are still not certain where this will be placed. And of course if you are a lucky soul who is under several of these bands then 3"+ not out of the question.