Absolute Vorticity

Sargent51 wrote: ↑Mon Apr 19, 2021 9:03 pm No snow. No thank you. That’s the post. Good night.

Trevor would agree 24 / 7 with this post.

Anyway, good morning folks! Overnight models still showing 1-2" for CVG actually being possible. Will up my call a tad with the new data. Will still go with a 2-4" type of snow fall North and West of our coverage area.

I-70 Crew: 1-2"
Cincy Metro / CVG: Up to 1"
SE Crew: Dusting / covering possible

tron777 wrote: ↑Tue Apr 20, 2021 6:44 am

dce wrote: ↑Mon Apr 19, 2021 8:45 pm

tron777 wrote: ↑Mon Apr 19, 2021 7:44 pm

tpweather wrote: ↑Mon Apr 19, 2021 6:24 pm Good Evening and beautiful down here in SC though I know the heat will be here before you know it. Concerning snowfall and still sticking with a dusting locally and from Indy to Toledo a 1-2 inch snowfall is possible and maybe a touch more towards Toledo but that area will be getting the snow a tad earlier when there is still some daylight so that would tend to hold down accumulations. Years ago when Rich A. was alive we always had the argument about how much snow falls and what we count as accumulations. I was always on the side of snowfall on the ground not melted snow and this will be one of those situations when yes we could get .25 inches liquid but snow on the ground is a dusting. Late April and the ground is warm even at night but yes heavy enough snow may be able to overtake all the negatives. My guess is models will have problems and overestimate by at least twice the amount.

The bulk of the snow at least for us locally will be at night after midnight so that is favorable. We will need heavy precip rates for accumulations since it is after mid April now, but there will be a narrow band of backside snowfall. I think someone could get 4" or more out of it. Not in our forecast area though.

If there are areas that truly end up with 3-4" totals I would be really concerned about downed tree limbs and power lines. The leaves have really begun to pop over the last week. If this snow falls when the sun is down and it has a chance to accumulate on trees I would be kind of concerned.

That could certainly become a problem for folks north and west of our CWA. I think we'll be fine. Even if you get 1-2" up your way, it'll melt fairly quickly.

Should not be a problem for I-70. 1-2" would probably not cause limbs to come down. You start to get 2 1/2 -3 inches building up on limbs that may be a different story. Indiana and the northern Miami Valley would be most at risk for a power outage, in my opinion. But again, that is only if accumulation builds up. If 3-4 inches falls and only 1-2" is the most on the ground or trees at any one time then my entire post is meaningless. If it does, however, not melt then I do think it is a legitimate concern.

dce wrote: ↑Tue Apr 20, 2021 8:34 am Should not be a problem for I-70. 1-2" would probably not cause limbs to come down. You start to get 2 1/2 -3 inches building up on limbs that may be a different story. Indiana and the northern Miami Valley would be most at risk for a power outage, in my opinion. But again, that is only if accumulation builds up. If 3-4 inches falls and only 1-2" is the most on the ground or trees at any one time then my entire post is meaningless. If it does, however, not melt then I do think it is a legitimate concern.

We're on the same page here Doug!

SnowTalk! https://www.wave3.com/2021/04/20/snowtalk-weather-blog/

12Z NAM showing 2" now at CVG. I'd cut it in half since it's mid April so that goes along with my up to 1" call for the Metro. 9Z SREF Mean is now up to 1.6" for CVG. 1.7" for CMH and a whopping 2.6" for DAY!

12z 3km NAM and HRRR hinting at possible rain/snow squalls tomorrow afternoon.

cloudy72 wrote: ↑Tue Apr 20, 2021 10:49 am 12z 3km NAM and HRRR hinting at possible rain/snow squalls tomorrow afternoon.

Forgot to mention tomorrow afternoon. Graupel also a possibility too.

12Z GFS is in line with my ideas.

12Z GEFS continues to show 1-3" for many people with 4"+ north of I-70 and our CWA.

Mid 50s here... 41 at Indy right now. 30s over W IN and ILL with snow presently falling from the St. Louis area back across Central and N ILL into NW IN. This is all headed our way behind the front tonight. SPC Meso page shows near and behind the front, Fantastic forcing in the 850 MB and 700 MB areas in the atmosphere. This means tremendous lift and forcing to create the band of rain and snow for tonight. Most of it will be post frontal.

For tomorrow as Mike mentioned, we'll see some sun early in the day to steepen lapse rates. With cold 500 Mb temps above us, we will see small showers develop in the afternoon once convective temps are met. Rain, snow and graupel will all be possible. No accum expected with highs in the low to mid 40s but a nasty evening / overnight as well as Wed PM periods are ahead.

Frost / Freeze potential for tonight will be limited due to clouds and wind. Far NW areas would stand the best chance. All have a chance Thurs morning and eastern half of the area Fri morning.

A wet Saturday ahead in most areas followed by improving weather Sunday and heading into next week. Speaking of next week... much warmer air is expected with the 60s turning into the 70s ahead of a slow moving cold front scheduled for the second half of next week. Is it a strong front for a severe wx risk? Timing? Does the low occlude and become cut off? Lots of questions in the longer term.

Regional Radar Loop:

12Z UKIE has about a 1/2" S of the River, an inch north. I-70 on north looks good for a 2-4" type of event.

Auglaize and Mercer counties in the MV under a Winter Weather Advisory from 7 PM this evening to 7 AM Wed.

Currently 46 here in G'ville and progged for around 30 Wed morning.

12Z Euro in the ballpark as well with an inch or so down here... 2-4" I-70 on northbound.

Nice temp gradient across the OV. 62 at CVG... 30s in ILL.

Heavy snow in Lafayette, IN currently. Temp is 37!! Talk about dynamic cooling...

65 here last time I checked. 2-3 hours away to the west, it is snowing and middle 30s.

I'm up to 67 now... and it'll be snowing within the next 6-12 hours. Updated AFD from the boys:

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Weather map shows a slow moving front situated near the Ohio River,
with a deepening wave of low pressure traveling up the front from
the southwest. Enhanced by upper divergence under the right
entrance region of a jet streak, precipitation is certain with
this event, having already developed in an extensive band of
frontogenesis and deformation located from Detroit to St Louis.
A strong temperature gradient in place will become even more
drastic due to the frontogenesis. Precip moving from the
northwest will start as rain before mixing with snow as much
colder air arrives on a northerly low level flow. All snow may
be observed later tonight north of the Ohio River. Slushy snow
accumulations should be measured in most locations. We may see
around 3 inches over parts of West Central Ohio where a winter
weather advisory remains in effect. 1 to 2 inches will be
possible roughly along I-70, with under an inch south of I-70.
The slushy nature of the snow and warm road temps should limit
effects on travel. Still, this rare late April snow event may be
the latest date for such snow accumulations at Dayton.

Low temperatures dropping to the low and mid 30s will require
continuation of the freeze warning in effect for much of the
area.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Low pressure and wintry precip will be moving quickly east
Wednesday morning. Rain showers may develop for a few hours
Wednesday afternoon under a short wave rounding the west side of
an upper trough. Otherwise, we can expect mostly cloudy skies
and chilly temperatures with highs in the 40s.

For Wednesday night, surface high pressure will be moving toward
Kentucky behind the axis of the upper trough. Under reduced sky
cover and winds, temperatures are likely to plummet to the mid 20s
to low 30s, and a freeze watch remains in effect for the entire
area.

67 was my high... had a passing shower dropped 0.01". Temp now down to 58 degrees, A break in the action with a few scattered showers around ahead of the front. Rain will pick up in a few hours once the front passes and temps will fall quickly. Snowing in Indianapolis. Temp in the mid 30s.

Surface low looks to be developing SE of us late this afternoon. Greatest pressure falls are showing up from SE KY, SE, OH, and Western WV area so that is a good area for us. That will enhance the deformation zone that we are watching for us... by late this evening and esp after midnight.

EDIT: 58 now at CVG, 34 at IND with snow.

Had about an half hour of rain here. Two pretty good downpours. Caught me by surprise. Had sheets sitting outside to cover some flowers. Got them covered and a tarp over them.

CB put out a First Call Map this afternoon.

tron777 wrote: ↑Tue Apr 20, 2021 6:45 am

Sargent51 wrote: ↑Mon Apr 19, 2021 9:03 pm No snow. No thank you. That’s the post. Good night.

Trevor would agree 24 / 7 with this post.

Correct

But I’ll take it. Why not. Should rip pretty good out there for a while tonight. I’m off tomorrow so I’ll be up watching with beer(s) in hand!