Absolute Vorticity

tron777 wrote: ↑Fri May 20, 2022 2:30 pm Euro has Tues dry now next week but very active Wed and Thurs. Wow.,.. buckle up folks! What a roll we've been on. May need to create threads to bring the domes back. Of course Mike wouldn't be too thrilled with me so...

Hey watch it now!

Not sure what to expect guys for the long Memorial Day weekend... we will likely try and get that hashed out next week. I've seen anything from warm and humid with the upper 80s to a cut off low and 60s / 70s on the models the last few days. We need to get past tomorrow and Wed / Thurs of next week first of course. Hope to see some dry time for bbq'ing and smoking prospects.

If you think our weather is nutty... try Denver, CO. They had 88 yesterday and they are under a winter storm warning for tonight and Saturday as 8"+ of snow is expected. Then back into the 80s sometime next week. Summer > Winter > Summer Now Denver and the Front Range of the Rockies are no strangers to drastic weather changes but even this for so late in the cold season is impressive. check out these stats... Tim will appreciate this.

If Denver gets more than 3.8", it will be their 3rd largest snowstorm on record for so late in the season. They had 10.7" on May 25-26, 1950 and 5.6" on 5/29/1975! Wow! Their latest measurable snow was 0.5" on 6/5/1953. Dang!!!!

This maybe even more impressive - if the temp drops below 30 this weekend, it will be the coldest ever for so late in the season. It was 30 on 6/2/1951, but has never been colder than 30 after May 19th.

Records go back 150 years, to 1872.

Bgoney wrote: ↑Fri May 20, 2022 7:56 am

Angelika wrote: ↑Fri May 20, 2022 7:41 am Does anyone know how much it rained? Our house is taking on water. I don't have time for this.

Radar estimates look like there were some isolated 3-4" amounts

Screenshot_20220520-075420_Chrome.jpg

Looks about right. We got smoked in Blue Ash and Montgomery.

Sitting at 88 here at my house.

I am sitting at 86 here currently. CVG had 85 at the 5pm observation.

EDIT: CVG ended up with 86 also.

Current AFD for this weekend from the boys:

There will be a dry start Saturday under mostly sunny skies and a
persistent south to southwest low level flow. This will help
temperatures reach the mid 80s to around 90 by mid afternoon
Saturday.

For late Saturday through Saturday night, clouds will thicken in
advance of a cold front extending from southwest to northeast.
As moisture convergence and lift increase when the front moves
into a favorably unstable regime, the threat for thunderstorms
will spread from northwest to southeast late Saturday afternoon
through Saturday night. Out of an environment containing
1500-3000 J/KG CAPE, and relatively potent low to mid level wind
fields, some thunderstorms may reach severe limits for damaging
winds and hail, and a tornado or two cannot be ruled out.

A cooler airmass will begin to arrive by Sunday morning, with
lows ranging from the upper 50s northwest to the upper 60s
southeast.

The cold front will finally push east across the region during the
day on Sunday. This will generally result in a decreasing chance of
showers and a few thunderstorms from the northwest through the day.
In the developing CAA, highs on Sunday will range from the mid 60s
in the northwest to the mid 70s in the southeast.

tron777 wrote: ↑Fri May 20, 2022 3:27 pm If you think our weather is nutty... try Denver, CO. They had 88 yesterday and they are under a winter storm warning for tonight and Saturday as 8"+ of snow is expected. Then back into the 80s sometime next week. Summer > Winter > Summer Now Denver and the Front Range of the Rockies are no strangers to drastic weather changes but even this for so late in the cold season is impressive. check out these stats... Tim will appreciate this.

If Denver gets more than 3.8", it will be their 3rd largest snowstorm on record for so late in the season. They had 10.7" on May 25-26, 1950 and 5.6" on 5/29/1975! Wow! Their latest measurable snow was 0.5" on 6/5/1953. Dang!!!!

This maybe even more impressive - if the temp drops below 30 this weekend, it will be the coldest ever for so late in the season. It was 30 on 6/2/1951, but has never been colder than 30 after May 19th.

Records go back 150 years, to 1872.

I have a cousin named Tom whom he and his wife live in Colorado Springs!

Got to 87 here this afternoon.

CVG 86, DAY 88 and CMH 85.

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https://www.whio.com/news/trending/torn ... YORQ7DZA4/

1 dead and 44 injured after a tornado tore through Gaylord, MI on Fri afternoon.

Shear will be weaker this go round later today compared to Thursday so any severe cells should be more isolated than the organized severe of Thursday

Good Morning and a nice muggy one to start. Hit the mid-80's yesterday and can we hit 90 today. I believe so as we start at 70 and with plenty of sun and strong southwest wind I see 85 by noon or so and then see what happens. The one thing hindering us from getting to 90 is the dew points may still be rather high and usually you need a little drop in the afternoon to get those last few degrees that would bring us to 90. Going to be a close call. I agree with Bgoney on the severe chance and believe they will be more isolated. Next week we continue the stormy pattern.

I think debris clouds from ongoing t-storms to our NW will stop us from hitting 90. I like mid to U80s. Also like our storm prospects too esp western half of the area. Severe wx should be more isolated in the East. Second... we should see two rounds. I like between 4-6pm for the Metro with the pre frontal trough, then after midnight... probably 2..3, 4am range with the cold front beginning to head our way and get closer. Morning showers on Sunday then we are cloudy and cool and probably remain in the 60s for highs.

UPDATE from the boys... and they may also be agreeing.

650 AM Update >
As mentioned in the discussion this morning, monitoring upstream
convection will be very important with regards to the
thunderstorm forecast today. There are currently two clusters of
elevated storms off to the west -- one over NW Indiana, and one
over SW Illinois. The Indiana cluster is on a trajectory to
largely miss the ILN CWA, though it is possible it could clip
Mercer County OH at around 14Z-15Z. The Illinois cluster is on a
trajectory to move toward the western ILN CWA border by around
16Z, although the environment ahead of it -- likely capped --
does not appear favorable for it to strengthen or make a
transition to being surface-based in the near term. However
these storm clusters behave as they approach or enter the area,
any outflow or boundaries associated with them could serve as a
focus for additional development once SBCAPE develops later in
the day.

Some slight changes to PoPs were made to slightly increase
chances in the western ILN CWA in the 15Z-18Z time frame.

12Z OP NAM has nothing until this evening. The 3KM 12Z N AM has the prefrontal pop up stuff early this afternoon, a break, then action this evening. 12Z HRRR waits until late this afternoon then the main push is well after midnight. So a lot of model differences here. I gave my thoughts earlier. We shall see as always.

Mesoscale analysis already shows plenty of fuel for severe t-storms in the form of some nice CAPE already! Lapse rates are decent too. What we are missing is the wind shear and the trigger which is of course, still off to the West.

ALERT: MD Issued for a 40% chance of watch issuance over S ILL and S IN.

https://www.spc.noaa.gov/products/md/md0848.html

Late morning update from the boys:

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Morning update: made slight adjustments to PoPs based on time-
lapsed HRRR and RAP for late this morning into early afternoon.
Radar trends still show the weakening cluster of showers and
storms arriving east-central Indiana and west-central Ohio
around or just before noon. Based on this morning`s cluster
over-performing... that is, producing 45-55 knot gusts just
northwest of our CWA... will need to watch closely for gusts
along and immediately behind the initial gust front associated
with the midday showers.

Beyond this, chances of storm development heading into the mid-
afternoon hours will pick up considerably along and northwest of
Interstate 71. CAMs showing 2000-3000 J/kg MLCAPE along with
25-30 knots of effective bulk shear should lead to multicellular
organization with perhaps a few supercells. Relatively weak
low-level flow and little directional shear keep tornado threat
on the low side... however will still need to watch based on
storm- to- storm interactions and the moderate instability.

CAPE is now up to 4000 J/KG over NKY. The better shear and forcing is still NW of us closer to the front so not much is going to happen until we can get some sort of a trigger.

While the main line is still back in South Central ILL, watch the radar trends closer to us as showers are now starting to bubble up. So far, the forecast is in good shape.

ALERT: A T-storm watch is likely to be issued for us soon.

https://www.spc.noaa.gov/products/md/md0851.html




Mesoscale Discussion 0851
NWS Storm Prediction Center Norman OK
1200 PM CDT Sat May 21 2022

Areas affected...Portions of far eastern IL into IN...western
OH...and far northern KY

Concerning...Severe potential...Severe Thunderstorm Watch likely

Valid 211700Z - 211900Z

Probability of Watch Issuance...80 percent

SUMMARY...Continuing to monitor a line of thunderstorms moving
across Illinois for signs of increasing intensity and damaging wind
potential. Watch issuance appears increasingly likely in the next
couple of hours.

DISCUSSION...A cluster of thunderstorms is present over parts of
southern/central IL at 17Z. This line has remained sub-severe so
far, with wind gusts generally in the 35-45 kt range. Still, the
airmass downstream into IN and northern KY continues to destabilize
along and south of a front. MLCAPE of 1500-2500 J/kg has become
common as temperatures warm into the 70s and 80s. Recent
high-resolution guidance suggests that this ongoing cluster will
intensify over the next couple of hours as it moves eastward across
IN, northern KY, and eventually parts of western OH. Gradually
strengthening southwesterly flow through mid levels is noted on
recent VWPs from KVWX/KIND, which should aid in thunderstorm
organization. Current expectations are for the cluster to pose a
gradually increasing threat for scattered damaging winds as it
encounters a more unstable airmass in IN and vicinity. Some hail may
also occur with the strongest updrafts. Accordingly, Severe
Thunderstorm Watch issuance appears likely in the next hour or two.

CAPE now approaching 4500 over NKY and an LI of -8 Lapse rates are around 7.0C to 7.5C (wish that was a little higher) and we are missing the wind shear. If we had more of that, this could have been an explosive event. Currently only at 25 knots. Would like it about 40. Anyway... plenty of warmth and humidity though for sure. I'd expect loud booming thunder and nice cloud to ground lightning with these cells. DCAPE values are at 1100 so damaging winds are likely with any cells that can get strong enough. Could see a bit of hail with hail values around the same but a lot of warm air aloft so you'd want some strong updrafts there for assistance. We would want higher lapse rates for that so severe hail is isolated IMO while smaller non severe hail would be more likely. Not seeing much spin for tornadic storms at this point but you've always got to keep an isolated thereat in the forecast. You just never know. To me, wind is the primary severe threat right now with heavy rains, big thunder and big lightning as previously mentioned.

Line of storms to the West getting ready to cross the Wabash river into IN as the afternoon wears on. Isolated storms continue to pop and mature in our area out ahead of the main line. Nothing severe yet but it's worth monitoring. Still expecting a t-storm watch to go up within the next hour.

A nice cell near Rising Sun, IN crossing over into Boone Co now. Seeing the darkening skies and hearing the thunder now from that one. It should move in my direction in time.

EDIT: Along the I-71 corridor we are seeing a broken line of storms developing.

ALERT: T-storm Watch #254 just issued until 7pm EDT.

https://www.spc.noaa.gov/products/watch/ww0254.html

INZ075-080-KYZ091>093-OHZ077-211815-
Switzerland IN-Ohio IN-Boone KY-Kenton KY-Campbell KY-Hamilton OH-
138 PM EDT Sat May 21 2022

...A RAPIDLY DEVELOPING THUNDERSTORM WILL IMPACT PORTIONS OF OHIO,
NORTHEASTERN SWITZERLAND, NORTHERN KENTON, NORTHERN CAMPBELL, BOONE
AND WESTERN HAMILTON COUNTIES THROUGH 215 PM EDT...

At 138 PM EDT, a rapidly developing thunderstorm was located over
Rising Sun, moving northeast at 35 mph.

HAZARD...Wind gusts up to 40 mph, half inch hail, and very heavy
rain.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Hail may cause minor damage to outdoor
objects. Visibility will be poor and hydroplaning is
possible.

Locations impacted include...
Cincinnati, Covington, Florence, Erlanger, Fort Thomas, Newport,
Edgewood, Elsmere, Cheviot, Fort Mitchell, Villa Hills, Bellevue,
Fort Wright, Dayton, Ludlow, Crescent Springs, Crestview Hills, Park
Hills, Lakeside Park and Rising Sun.

This includes the following Interstates...
I-71 in Ohio between mile markers 0 and 3.
I-74 in Ohio between mile markers 6 and 19.
I-75 in Kentucky between mile markers 180 and 191.
I-75 in Ohio between mile markers 0 and 5.