Absolute Vorticity

tron777 wrote: ↑Thu Mar 23, 2023 10:47 am Wonder if the HRRR isn't correct at least for this afternoon? Storms have already developed over ILL and have now pushed into Western IN. Need to keep an eye on those.

Wonderful post and that was another reason yesterday I had temps lower today. With storms forming west of here those cloud tops get blown east as well. Still probably going to hit 70 but a close call. The system that develops over the southern plains on Friday is one that will strengthen as it heads northeast. Looks to pass just to our northwest but there is tons of moisture even coming up from the GOM. This piece of energy was able to promote a Tornado in the L.A. area on Wednesday and said to be the strongest one since 1983. This tells me plenty of energy to work with and plenty of wind energy and though the main item has been about the heavy rain but I can see some of those winds getting up there with gusts over 40 at times. Hopefully models will narrow down the area of heavy rain but again with this dynamic system still expecting some wavering back and forth.

tpweather wrote: ↑Thu Mar 23, 2023 11:08 am

tron777 wrote: ↑Thu Mar 23, 2023 10:47 am Wonder if the HRRR isn't correct at least for this afternoon? Storms have already developed over ILL and have now pushed into Western IN. Need to keep an eye on those.

Wonderful post and that was another reason yesterday I had temps lower today. With storms forming west of here those cloud tops get blown east as well. Still probably going to hit 70 but a close call. The system that develops over the southern plains on Friday is one that will strengthen as it heads northeast. Looks to pass just to our northwest but there is tons of moisture even coming up from the GOM. This piece of energy was able to promote a Tornado in the L.A. area on Wednesday and said to be the strongest one since 1983. This tells me plenty of energy to work with and plenty of wind energy and though the main item has been about the heavy rain but I can see some of those winds getting up there with gusts over 40 at times. Hopefully models will narrow down the area of heavy rain but again with this dynamic system still expecting some wavering back and forth.

Definitely one of the more interesting non-wintry systems we've had so far this year. Storms, heavy rain, just a little bit of everything.

The front moving in is rather nice for this time of year and we are seeing 15-20 degree difference in just a few miles. Where that front decides to stop and take a break is still key as warm moist air later tonight will flow over that front and steady moderate to heavy rain at times will fall. Watch out for the 4a-9a time Friday morning as this period of time could really lay down some nice totals in that 5 hour period.

Had a nice thundershower move through. Up to 0.39" of rain. New rain gauge just arrived so have time to put out for the main event!

Up to 68 degrees as of 1pm at CVG. Myself and CVG up to 0.03" for the day. That rain sure has fallen apart that was headed this way. 70 has a chance.

One trend today is the cold front is being held up as it has remained just northwest of Indy all morning. Lets see over the next 3-6 hours how far south and east the front moves. You get these waves associated with the front and once a wave moves by the front then usually moves but this morning and early afternoon the front still has moved very little.

Up to 66 in my hood after the storm departed.

Let's hope the 12z GFS is wrong in terms of rainfall over the next 16 days. Parts of NKY get over 10" rain if this run is correct. Looks like 4 events - first one is the upcoming one for tonight thru Sat morning, Event 2 is next Thursday night into Friday and event 3 is around April 4th with final one on its heels around the 6th.

cloudy72 wrote: ↑Thu Mar 23, 2023 1:38 pm Let's hope the 12z GFS is wrong in terms of rainfall over the next 16 days. Parts of NKY get over 10" rain if this run is correct. Looks like 4 events - first one is the upcoming one for tonight thru Sat morning, Event 2 is next Thursday night into Friday and event 3 is around April 4th with final one on its heels around the 6th.

Yeah... we could see some bad river flooding if this pattern keeps up. I see the MJO diving into the COD then coming back into Phase 7 by early April. So this pattern of big troughs coming into the West and sending out pieces of energy and popping a SE ridge should continue. Could be a violent spring with severe wx should this pattern continue deeper into Spring.

tron777 wrote: ↑Thu Mar 23, 2023 1:58 pm

cloudy72 wrote: ↑Thu Mar 23, 2023 1:38 pm Let's hope the 12z GFS is wrong in terms of rainfall over the next 16 days. Parts of NKY get over 10" rain if this run is correct. Looks like 4 events - first one is the upcoming one for tonight thru Sat morning, Event 2 is next Thursday night into Friday and event 3 is around April 4th with final one on its heels around the 6th.

Yeah... we could see some bad river flooding if this pattern keeps up. I see the MJO diving into the COD then coming back into Phase 7 by early April. So this pattern of big troughs coming into the West and sending out pieces of energy and popping a SE ridge should continue. Could be a violent spring with severe wx should this pattern continue deeper into Spring.

Great Posts guys and it looks like an El Nino kind of pattern already.

tpweather wrote: ↑Thu Mar 23, 2023 1:23 pm One trend today is the cold front is being held up as it has remained just northwest of Indy all morning. Lets see over the next 3-6 hours how far south and east the front moves. You get these waves associated with the front and once a wave moves by the front then usually moves but this morning and early afternoon the front still has moved very little.

Seeing some nice CAPE Tim over S ILL. Even some weak CAPE working up into our area as well. Dews beginning to increase. PWATS are pretty nice for March 1.1 to 1.2" range. I think the stage is being set for the heavy rain event. Looks like the front is just NW of AV Country as you mentioned.

tpweather wrote: ↑Thu Mar 23, 2023 2:00 pm

tron777 wrote: ↑Thu Mar 23, 2023 1:58 pm

cloudy72 wrote: ↑Thu Mar 23, 2023 1:38 pm Let's hope the 12z GFS is wrong in terms of rainfall over the next 16 days. Parts of NKY get over 10" rain if this run is correct. Looks like 4 events - first one is the upcoming one for tonight thru Sat morning, Event 2 is next Thursday night into Friday and event 3 is around April 4th with final one on its heels around the 6th.

Yeah... we could see some bad river flooding if this pattern keeps up. I see the MJO diving into the COD then coming back into Phase 7 by early April. So this pattern of big troughs coming into the West and sending out pieces of energy and popping a SE ridge should continue. Could be a violent spring with severe wx should this pattern continue deeper into Spring.

Great Posts guys and it looks like an El Nino kind of pattern already.

A cool, wet summer is one option esp if El Nino comes on faster then expected. SOI is finally dropping off. Seeing some low positive days but many negative days strung together. Definitely a sign of the ENSO state changing.

tron777 wrote: ↑Thu Mar 23, 2023 2:02 pm

tpweather wrote: ↑Thu Mar 23, 2023 1:23 pm One trend today is the cold front is being held up as it has remained just northwest of Indy all morning. Lets see over the next 3-6 hours how far south and east the front moves. You get these waves associated with the front and once a wave moves by the front then usually moves but this morning and early afternoon the front still has moved very little.

Seeing some nice CAPE Tim over S ILL. Even some weak CAPE working up into our area as well. Dews beginning to increase. PWATS are pretty nice for March 1.1 to 1.2" range. I think the stage is being set for the heavy rain event. Looks like the front is just NW of AV Country as you mentioned.

Les the set up for heavy rain is starting to get in place. Just need to see where the front ends up stopping. Has moved little today and was expected to be near us by this time and its hanging up in the Indy area.

tpweather wrote: ↑Thu Mar 23, 2023 2:07 pm

tron777 wrote: ↑Thu Mar 23, 2023 2:02 pm

tpweather wrote: ↑Thu Mar 23, 2023 1:23 pm One trend today is the cold front is being held up as it has remained just northwest of Indy all morning. Lets see over the next 3-6 hours how far south and east the front moves. You get these waves associated with the front and once a wave moves by the front then usually moves but this morning and early afternoon the front still has moved very little.

Seeing some nice CAPE Tim over S ILL. Even some weak CAPE working up into our area as well. Dews beginning to increase. PWATS are pretty nice for March 1.1 to 1.2" range. I think the stage is being set for the heavy rain event. Looks like the front is just NW of AV Country as you mentioned.

Les the set up for heavy rain is starting to get in place. Just need to see where the front ends up stopping. Has moved little today and was expected to be near us by this time and its hanging up in the Indy area.

60 degree dews are here in NKY. Definitely a more sticky feel to the air for the first tine in a while. Pretty breezy though so not as warm feeling as it otherwise might be. We have some really good wind shear, in excess of 75 knots about 5000 to 10,000 feet up. Once that low level jet kicks in tonight, wherever that front is on either side of it, will be where the heaviest rains occur. Probably like a 50-60 mile wind band of extremely heavy rainfall. Moisture is already feeding in from TX, OK and MO. Gulf is open for business too.

Frontal position is so key as you mentioned. The more north it hangs, the better chance for severe wx I might add.

3.16" at CVG from the 12Z Euro.

69 now at CVG / here as of 4pm.

Update from the boys:

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A frontal boundary has started to work into the region. While
currently only isolated showers are present, expect a line of
showers and some thunderstorms to develop near the frontal
boundary this afternoon into this evening. This line will
develop near the Interstate 71 corridor and start to push into
southeastern portions of the region. Cannot rule out a strong
to severe storm with this line. In addition gusty winds can be
expected in advance and along the frontal boundary. The frontal
boundary will begin to stall out and another wave of rainfall
will move into the region overnight. Will have to watch for some
flooding concerns overnight and the flood watch begins this
evening. Low temperatures will range from the 30s north to low
50s south closer to the boundary.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
The widespread rain will push southward closer to the Ohio River
as the morning progresses to around the middle of the day on
Friday. As the boundary fluctuates the rain will start to then
move back northward. The area of low pressure will move near
the northwest corner of the forecast area overnight Friday
night. Very heavy rain and thunderstorms will move into the
region Friday night bringing with it the potential for flooding
and isolated severe weather. Expanded the flood watch further
north to cover this surge in moisture Friday night. Winds will
start to pick up at the end of the short term period.

High temperatures during the day on Friday will only be in the
40s and 50s with extensive cloud cover. Temperatures will then
rise into the nighttime hours as warmer moist air surges
northward.

&&

.LONG TERM /SATURDAY/...
Deepening surface low to eject northeast thru the Great Lakes
Saturday. A few thunderstorms will be possible early Saturday in the
east prior to a surface cold front passage. Southwesterly low level
jet of 50 to 60+ KTs to rotate thru the area Saturday. Expect
widespread windy conditions developing Saturday morning with wind
gusts up to 50 MPH due to the tight pressure gradient and the strong
low level jet. The area will likely require a wind advisory
for these strong winds.

Starting to see the beginnings of the line developing to our west.

CAPE values of 500 J/KG exist just to our West as well.

Starting to see some decent storms fire up in Oklahoma near the front. Things are really developing nicely and the models have been on this for days which always gives you more confidence with a forecast.

tpweather wrote: ↑Thu Mar 23, 2023 4:47 pm Starting to see some decent storms fire up in Oklahoma near the front. Things are really developing nicely and the models have been on this for days which always gives you more confidence with a forecast.

The rain train is developing nicely Tim! It'll be a wet night ahead. We have a couple more hours though before the front sinks further south.

At CVG:

18Z NAM - 2.83" - event total
18Z HRRR - 4.5" of rain ending at 8am Sat morning.

Will be back on later tonight and give out last minute thoughts.

70 at 4:38pm was my high today! I did it. Did CVG so it is official? 69 as of the 5pm climate report. I was close with my forecast. My dew is up to 61. Watching radar and awaiting the boundary to sink more to the SE.

Visible Satellite shows the position nicely. See brighter white band of clouds to our NW.


70 knot shear with 500 J/KG of CAPE currently for folks S of I-70. Watch for isolated severe this evening. T-storm watch over AR and MO at this time.I checked lapse rates, they are moderate so watch for some possible hail as well in stronger cells. I think any severe activity will become more isolated as the night wears on and turn into a flash flooding event where the front lays down.

You can see where the dews are pooling ahead of the front. PWATS as well. I think we are pegged for heavy rain - I-71 OH river corridor.