NWS FWD Area Forecast Discussion at 115 PM CDT Sat Apr 20 2024

by Ted Ryan

838 
FXUS64 KFWD 201815
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
115 PM CDT Sat Apr 20 2024

...New Short Term, Aviation... 

.SHORT TERM... /NEW/
/This afternoon through Sunday/

Waves of rain and storms have continued over North Texas today as
strong isentropic lift prevails behind the cold front and brings
elevated parcels to their level of free convection. Temperatures
have already reached their highs today, with near steady or
falling temps in the 50s are expected this afternoon. Now that the
cold front has pushed through the entire CWA, surface based 
instability is shunted to our south, but an axis of modest 
elevated instability/MUCAPE still exists south of I-20. This will 
provide the fuel for another round of storms starting early this
afternoon over the western zones and progressing eastward into 
the evening hours for the remainder of the region. This round of
convection is in response to forcing from an upper level 
disturbance as it moves across. The evidence of this disturbance 
is confirmed by the batch of storms currently organizing across 
the Big Country. PoPs are near 100 percent for all of North Texas
this afternoon and/or this evening. Additional rainfall amounts 
of 1-2 inches are expected with this activity. Isolated (10% of 
the area) will have storm totals of 3-4 inches. While the rain 
will be widespread, and occasionally heavy, we think the pace and 
rain rates will be spaced out enough to avoid flash flooding 
issues, thus no flood watch will be issued. Still minor flooding 
of low-lying and flood prone locations is a concern. The severe 
weather threat is non-zero, but is highest south of I-20, better 
still in Central Texas, where hail up to quarter size is a threat.

Rain will end/clear the region from NW to SE this evening and
overnight. Clouds will be more stubborn, but eventually drier air
in the low levels will work to erode them Sunday afternoon.
Temperatures will be seasonably cool in the upper 40s and low 
50s for lows tonight, while highs will only reach the low to mid 
60s.

TR.92

-----

And now a personal note, this is my last forecast shift. I've 
worked at this office just shy of 20 years as both a forecaster 
and the Science and Operations Officer. I have enjoyed serving the
people of our region, hopefully bringing a little more 
predictability to our chaotic atmosphere and teaching others some 
meteorology along the way. I am moving on to a new opportunity 
behind the front lines of operational forecasting at the regional
office where I will help advance the NWS in what will likely be a
period of unprecedented change brought about by artificial 
intelligence being used for traditional weather forecasting 
purposes. I'm in awe where numerical modeling is today compared to
the start of my career 25 years ago. Where we'll be in 10 years 
is probably going to be even more incredible. Before you get too 
excited about having that perfect forecast of a rain shower down 
to the minute, I want to use this AFD for my last "Ted talk" to 
explain why we're hitting a wall in the quest to create that 
perfect accurate forecast, and why those lame jokes about 
meteorologists getting paid to be wrong aren't going to go away 
anytime soon.

The atmosphere is a nonlinear system, meaning that our ability to 
forecast it is extremely sensitive to knowing the exact 
condition of every single breath of air. We crudely sample the 
atmosphere directly with instruments that aren't precise or 
numerous enough, and make even more approximations with remote 
sensing like satellites. And while computing power will no longer
become the bottleneck in forecast information (AI represents an 
order of magnitude leap of cheap computing power for weather 
prediction purposes!), the technology and ability to know the 
initial state of the atmosphere will continue to hold forecast 
accuracy back. So while we may never get the perfectly accurate
hyper-detailed computer model, we are now getting something very 
valuable...the probabilities of different outcomes based on the 
guesstimates of what the current state of the atmosphere may look 
like. In other words, if weather prediction were a game of 
Blackjack, we learned the rules of the game in the 20th century 
(discovery of meteorology as a science), figured out the best ways
to play a hand to win during the last few decades (numerical 
modeling), and now we are entering the phase where we're able to 
count cards and know our exact odds with every move (probabilistic
forecasting). Notice that even counting cards in a game of 
Blackjack with a computer means we don't know the outcome of every
single hand. There's still the element of random chance at play 
(or in the weather business we call that chaos theory). But over
many hands (or forecasts), we'll be able to make better decisions
knowing those probabilities. 

The role of the meteorologist of the future will become one that 
communicates the probability outcomes that are important to the 
people they serve. Some of the kinds of forecasts I think we'll 
have in 10 years are the chance of: a strong tornado hitting your 
city in 6 hours, a nearby river flooding your house next week, a 
record cold snap or heat wave in 2 weeks, and so on. Monitoring 
and communicating these kind of probability predictions will help
prepare society to be ready for whatever Mother Nature throws at 
us. Take note young weather enthusiasts...don't get into this 
field just because you think weather is interesting, make weather 
a career if you're passionate about helping people prepare for the
worst of it!

TR.92

&&

.LONG TERM... /Issued 246 AM CDT Sat Apr 20 2024/
/Sunday Night Onward/

A surface ridge will build southward from the Plains into North 
and Central Texas on Sunday as a weak mid level ridge develops 
aloft. This will set the stage for a cool and dry start to next 
week, with below-normal temperatures expected both Sunday and 
Monday. Sunday night should be the coolest night as a good 
radiative cooling scenario allows temperatures to fall into the 
lower and mid 40s. Conditions will remain dry while becoming 
slightly warmer Monday and Monday night, though temperatures will
still be 5 to 10 degrees below normal.

A general warming trend will continue through the midweek period 
as the mid level ridge strengthens overhead. A shortwave rounding 
the northeast periphery of the ridge will push a cold front 
southward towards the Red River late Tuesday, beginning a period 
of unsettled weather mid to late next week. The front will likely 
stall somewhere between the Red River and the I-20 corridor, 
providing a focus for isolated showers and storms Tuesday night 
and Wednesday. POPs will initially be low, however, as subsidence 
from the ridge works against convective development, and will keep
rain chances in the slight chance range.

The ridge will begin to break down on Thursday as the next
shortwave trough approaches from the west, bringing somewhat
better chances for rain Thursday into Friday. Convection may
initiate along the dryline as it enters the Big Country, and we 
may need to monitor the potential for a few severe storms late 
Thursday into Friday. As the shortwave exits to the east, a larger
scale upper trough will be entering the Rockies and will provide 
even better rain chances as it emerges in the Plains. There may be
a lull in precipitation late Friday into next Saturday, but 
convection will redevelop by late next Saturday into next Sunday 
as the upper trough approaches and storms develop along an 
attendant Pacific front. A few severe storms may again be in play,
which is typical for April, and we will know a lot more the 
further into next week we get.

30

&&

.AVIATION... /NEW/
/18z TAFs/

Waves of showers and thunderstorms continue to develop and track
across the Metroplex TAF sites. After this current batch moves
through the TAF sites through 18z, the amount of instability for 
thunder will be somewhat limited, so expect showers to dominate
but have VCTS to cover the occasional lightning strike. However, 
stronger upper level lift will arrive late this afternoon, likely 
yielding another round of storms on station between 22z and 00z. 
This wave will wind down with a widespread shield of rain and 
occasional rumbles of thunder this evening -- with all convective 
activity finally clearing the Metroplex from NW to SE around 3z. 
In the meantime IFR to MVFR CIGs will prevail, and visibility 
outside of precipitation should range around 5-7SM. IFR CIGs 
should persist overnight, with gradual lifting to MVFR expected 
Sunday morning as drier air moves in. N/NE winds at 10-15kt will 
persist through the period.

For Waco, similar trends, expect the convective window will mainly
be between 0z and 5z. 

TR.92

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    58  50  66  48  72 / 100  90   5   0   0 
Waco                64  50  63  45  69 /  90 100   0   0   0 
Paris               57  48  64  42  70 / 100  90   5   0   0 
Denton              57  46  64  42  71 / 100  80   5   0   0 
McKinney            55  49  64  44  71 / 100  90   5   0   0 
Dallas              57  50  65  47  73 / 100 100   5   0   0 
Terrell             57  49  63  44  71 / 100 100   5   0   0 
Corsicana           60  50  65  46  70 /  90 100   5   0   0 
Temple              65  49  63  45  70 /  80 100   0   0   0 
Mineral Wells       58  46  65  44  72 / 100  80   5   0   0 

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$