Plains/Arkansas/Louisiana Major Flood Sept 22-29 during major drought

[Ed, snow and hurricane fan]

This seems regional thread worthy.  Euro 12Z ensembles were scary.  Today's op Euro is a disaster, op GFS not as bad.  Not enough rain to end the drought, but enough to cause possibly disastrous creek and urban flooding.  Pictures below.  PW multi-day over 2 inches.  Remanant PTC moisture and an impressive (for August) slow moving front.  For non-direct tropical flooding, this could be a Donald Sutherland worthy flood event.

[Ed, snow and hurricane fan]

.LONG TERM... /NEW/
/Sunday Night Onward/

Ingredients are continuing to come together for a heavy rain event
Sunday and Monday across most of North and Central Texas. As
mentioned in the Short Term discussion, while drought usually
means soils are readily able to absorb plentiful rain...the
severity of the current drought has dried out and compacted the
surface soil, making it at least initially resistant to water
inundation. This will result in most of the initial rainfall
running off, increasing the risk of flooding. Meteorologically...a
squeeze play between a remnant tropical system moving in from the
south, a mid-level trough moving in from the west, and a weak
front moving in from the north will converge over North Texas late
Sunday into Monday. Plentiful warm and humid air over the region
is supporting warm-cloud depths between 12-16 kft, so any storm
that develops will be a very efficient rainfall producer.

Due to all of the above factors, we have issued a flood watch for
all of North Texas starting Sunday morning that currently runs
through Sunday evening. This watch will likely need to be extended
through Sunday night into Monday...but since we are uncertain of
how far southeast to expand the watch and how long into Monday the
watch needs to go, we will reserve expansions and extensions of
the watch until later tonight or tomorrow morning.

Expect an increase of precipitation coverage over North Texas
Sunday evening as low level inflow ramps up and moves overtop of
the warm front. Over the course of the night, strengthening
convergence ahead of a developing surface low should provide
enough ascent to develop thunderstorms further south into Western
Central Texas by daybreak. As the low and its attendant fronts
slowly advances east over the course of the day, expect a general
eastward movement of the heavy rain axis. Precip will start to
trend down across North Texas late Monday as drier air filters
into the region around the same time as the front starts to exit
to the southeast. The front is then expected to stall over
Southeast Texas, with daily precip chances continuing for the rest
of the week.

[Ed, snow and hurricane fan]

Flood watches and warnings already up for today, 3-5 inches just today per SHV/OUN/FWD watch text.  And that won't be all.

 

In addition, GOES East DMV and RAP analysis data showed a 60-70 kt
jet streak at 250 mb over northeastern OK, forecast to shift ESE
over the next 6 hours. The right entrance region of this jet
streak along with diffluent flow around an upper ridge over
southwestern TX will aid in increasing vertical motions along the
Red River Valley into southern AR/northern LA. In the lower
levels, convergent and confluent flow in the 925-850 mb is
forecast to set up which should act as a focus for future
convective development.

Periods of slow moving, training and repeating rounds of heavy
rain are likely to form east of the ongoing axis of rain west if
I-35 in the next 3-6 hours. Despite significantly dry soil
moisture, with the most recent (Aug 21) 0-40 cm soil moisture
showing less than the 10th percentile from northern TX into
southern OK, the increasing potential for 2-3 in/hr rates and
possible 6-hr totals over 4-5 inches are expected to lead to a
likely flash flood risk later this morning.

Otto

ATTN...WFO...FWD...LZK...OUN...SHV...TSA...

[Powerball]

Nothing more than sprinkles in the Metroplex thus far. We'll see what the next few hours bring.

[cstrunk]

It was modeled /forecast as 8"+ for a pretty big area of N/NE TX as of yesterday and now it's 4-6"+.

I would bet it ends up being more like 2-4"+ for most of the area based on model trends and what we've seen so far. A few isolated 6"+ totals. 

Still very welcome moisture but it's not going to be the drought-buster it was pegged as... For most. 

[cheese007]

Tornado warning for Hill amd Ellis counties in TX!

[cstrunk]

17 hours ago, cstrunk said:

It was modeled /forecast as 8"+ for a pretty big area of N/NE TX as of yesterday and now it's 4-6"+.

I would bet it ends up being more like 2-4"+ for most of the area based on model trends and what we've seen so far. A few isolated 6"+ totals. 

Still very welcome moisture but it's not going to be the drought-buster it was pegged as... For most. 

4.66" at my house in Longview so far. Moderate rain continuing. Looks like 6"+ is going to be likely before the event is over.

DFW got hit hard overnight with more on the way, too.

[cheese007]

14 minutes ago, cstrunk said:

4.66" at my house in Longview so far. Moderate rain continuing. Looks like 6"+ is going to be likely before the event is over.

DFW got hit hard overnight with more on the way, too.

7.17 inches since 3pm yesterday per FWD

[Calderon]

Major comms issue with FTW has OHX (Nashville) issuing the warnings for their CWA. Trying to look at stream gauges as well and nothing has updated since at least midnight-1am.

[radarman]

More than a foot of rain ESE of Dallas.  Seemingly the jackpot so far.

Johnson county also putting up very big numbers.  And Tarrant co, though behind by several inches, is getting hit very hard again as we speak as convective processeses commence with heating.

 

[donsutherland1]

Through 10:00 am CDT, Dallas-Fort Worth has picked up 4.36" of rain. That smashes the daily record of 2.47" for August 22nd, which was set in 1916. It also surpasses the August daily record of 4.28", which was set on August 28, 1946. The 2-day total of 7.89” also surpasses the 2- and 3-day records for August.

[radarman]

From NWS chat below (for KDFW)... earlier they said that 3pm yesterday to 3pm today will be the period to watch: 
(10:17 AM) nws-bianca.garcia: Yes, it looks like we are at #4 for the greatest 24 hour period precip totals. For the top 3 stats: The all time highest is 9.57" (September 4-5, 1932), #2 is 8.81" (April 24-25, 1922), and #3 is 8.11" (Sept 21-22, 2018).

[donsutherland1]

Earlier, an hourly record 3.01” of rain fell at Dallas-Fort Worth. Hourly records go back to 1953.

[radarman]

8 minutes ago, radarman said:

From NWS chat below (for KDFW)... earlier they said that 3pm yesterday to 3pm today will be the period to watch: 
(10:17 AM) nws-bianca.garcia: Yes, it looks like we are at #4 for the greatest 24 hour period precip totals. For the top 3 stats: The all time highest is 9.57" (September 4-5, 1932), #2 is 8.81" (April 24-25, 1922), and #3 is 8.11" (Sept 21-22, 2018).

last hour update... now 8.4" (passes 2018)  

for the month now 9.36" and goes to #2 all time (1915)

[cstrunk]

Confirmed tornado in Winona, TX within the last hour.

[Witness Protection Program]

Someone contact FEMA.

[Powerball]

Not to discount how extreme this event is, but there's definitelty a decent gradient with the rainfall across the Metroplex.

The activity and amounts drop off drastically in NE Dallas and the NE suburbs ( I.E. Collin County).

[Powerball]

21 hours ago, cstrunk said:

It was modeled /forecast as 8"+ for a pretty big area of N/NE TX as of yesterday and now it's 4-6"+.

I would bet it ends up being more like 2-4"+ for most of the area based on model trends and what we've seen so far. A few isolated 6"+ totals. 

Still very welcome moisture but it's not going to be the drought-buster it was pegged as... For most. 

While much of the activity was delayed yesterday, the amounts that were pegged still ended up coming to fruition.

[Ed, snow and hurricane fan]

Has its own Wiki Page  

https://en.wikipedia.org/wiki/2022_Dallas_floods

 

[canderson]

Parents outside Longview just clocked it at 7" rain. They've not had power since midday Sunday. 

[cstrunk]

16 minutes ago, canderson said:

Parents outside Longview just clocked it at 7" rain. They've not had power since midday Sunday. 

6.72" so far at my house in Longview.

[radarman]

appears that this event will likely be #2 all time at DFW for 24hr rainfall

[donsutherland1]

Some statistics from Dallas-Fort Worth's extreme rain event:

- One-day total: 5.66" (new August record & 5th highest daily figure)

- Two-day total: 9.19" (new August 2- and 3-day record; 4th highest 2-day total)

- Hourly rainfall: 3.01" (new hourly record)

[Ed, snow and hurricane fan]

Drought isn't officially over, but a 2011 thousands (yes, almost 2,000 homes in rural Bastrop County E of Austin) of homes burning isn't happening.  Almost all of Texas I-35 and E is now not likely, IMO, to see big fires.  Still exceptional drought per drought monitor AUS/I-35 corridor, but I suspect it is now more reservoir levels being abnormally low, which isn't good, but isn't month long wildfires bad.  

 

Drinking water supply (underground  and karstic Cretaceous Edwards Limestone) in San Marcos and San Antonio are still low but CPC short-medium outlook is now normal to above normal rainfall.

https://www.sanmarcosrecord.com/news/edwards-aquifer-authority-declares-stage-4-permit-reductions