DFW FORECAST DISCUSSION
000
FXUS64 KFWD 242342
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
642 PM CDT Sun May 24 2020


.SHORT TERM... /NEW/
/Through Monday evening/

Convection from earlier today has left a large cold pool across
North and Central Texas. A few thunderstorms are still ongoing
along a Stephenville to Waco line, but these storms have been on a
weakening trend. Furthermore, an early look at the just-released
00Z RAOB shows that capping has built back into the region. These
observations suggest that the atmosphere is thoroughly turned
over, which introduces a bit of uncertainty into the overnight
forecast.

Thunderstorms are ongoing well to our west across the Llano
Estacado and into the Concho River Valley and Big Bend Region.
These thunderstorms should continue a eastward trek through the
evening hours. These storms could begin to weaken as they enter
our western counties and encounter the more stable air. Still,
confidence is high enough on at least some convective coverage to
maintain Likely PoPs. That being said, the severe weather
potential looks quite low. Where thunderstorms do occur however,
large precipitable water values and near saturated profiles will
mean thunderstorms will be capable of heavy rainfall rates.

Heading into Memorial Day, some thunderstorms will likely be
ongoing in the morning, but should start to exit the area by later
in the morning. Afternoon heating will likely be limited with
lingering cloud cover, with highs only forecast to get into the
low 80s. A few showers and thunderstorms could develop in the
humid environment across North and Central Texas, but with the
lack of any significant surface boundaries, will keep PoPs in the
Chance range for Monday afternoon. Shower and thunderstorm chances
will increase into Monday night however as another upper-level
shortwave trough passes through the region. Shear and instability
look limited, but with precipitable water values remaining at or
above 1.50 inches, heavy rain will be the primary concern.

Godwin

&&

.LONG TERM... /Issued 311 PM CDT Sun May 24 2020/
/Tuesday through Next Weekend/

Unfortunately, the challenges continue in the long term forecast
period as it pertains to the placement of the greatest PoPs. What
appears certain is that most areas across the region will receive
some rain. Temperatures will be below normal by 5 to 10 degrees
through the entirety of the long term forecast period.

The synoptic picture is becoming a little clearer as we start the
period and a diffuse frontal boundary is expected to ooze south
of the Red River. Deep troughing across the Permian Basin will
result in largely southwest flow aloft. Synoptic scale shortwave
troughs and mesoscale convective vortices will convoy toward
toward the Ozarks as a result. It appears probable that a good
cluster of convection will already be ongoing across the Concho
Valley late Monday evening. At present time, the most likely area
to be impacted will be locations along and west of the US HWY 281
corridor between 00-06Z Tuesday (Monday evening). There will be a
modest severe weather risk given that deep layer shear values will
be near 30 knots...700-500mb lapse rates approach 7 C/km and
MLCAPE values will top out in the 1500-2000 J/kg range. Convective
modes will likely be in the form of line segments/bows thus
facilitating a damaging wind risk. The multicellular nature of
activity will also support a marginally severe hail risk.

Through the pre-dawn hours on Tuesday, storm activity should
track eastward but may begin to slow as mean flow starts to become
more meridional. In fact, both upshear and downshear Corfidi
Vectors become increasing orthogonal to the line of convection and
this may suggest that the activity will slow, thereby increasing
the flooding risk. Exactly where this occurs is a little hard to
say and model QPF varies significantly spatially. Moreover, this
batch of convection that moves out of the Concho Valley could
impact what happens farther upstream along the surface frontal
boundary. There should be enough large scale ascent, however, to
overcome any subsidence induced on the northern fringe (the Big
Country and North Texas) of the Concho Valley complex. 0-6km flow
along the front suggest that any convective type activity will
likely train across areas near and northwest of an Eastland to
Mineral Wells to Sherman/Denison line. The exact coverage of the
heaviest precipitation, however, remains unknown. Given this
uncertainty and after coordination with WFOs Norman and Tulsa,
we`ve elected to hold off on any Flash Flood/Flood Watches. If
higher resolution guidance can focus QPF totals a bit better over
the next few model iterations, we`ll need to consider one,
especially given the antecedent conditions.

Showers and thunderstorms should continue to push eastward
through the day on Tuesday with the greatest rain/storm threat
shifting into East Texas. The severe weather threat does not look
overly favorable, given the very narrow CAPE profile and largely
unidirectional wind profile. However, a severe wet downburst
threat may materialize in some of the more robust convective
elements. The skinny CAPE profile combined with the unidirectional
wind profile coupled with PWATs in excess of 1.5" will support
very efficient warm-rain processes and thus a persistent
flood/flash flood risk...especially for locations along the Red
River.

Mid-week through the end of the weekend looks to remain unsettled
as the main upper low remains across the area. PoPs are largely
broad-brushed given that there is some model disagreement with the
positioning of the upper low. The latest ECMWF remains the
farthest to the east and southeast with the position of the upper
low (across the Brazos Valley) with the rest of the model
consensus lagging back towards the northwest across the northern
Big Country. What is certain is that the best chance for rain
during the calendar day should be during the daylight hours with a
relative lull in rain/storms during the nocturnal periods
Wednesday through next weekend.

Bain

&&

.AVIATION... /NEW/
/00Z TAFs/

Convection has dissipated within the D10 TRACON, with VFR and
south flow prevailing. Another round of TS should approach from
the west late tonight, reaching the TRACON area by 06Z. Some
uncertainty exists with regards to timing/coverage, but 06Z-09Z
appears to be the most likely time for impacts. CIGs may drop to
MVFR within TS, but should generally remain VFR outside of TS. At
KACT, MVFR CIGs even outside of TS appear more certain during the
overnight and morning hours. TS should exit by late morning,
giving way to VFR at all terminals by 18Z.

Godwin

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    67  80  67  74  63 /  70  40  80  80  30
Waco                67  82  65  77  61 /  80  40  90  80  20
Paris               66  77  65  75  64 /  60  40  80  80  40
Denton              64  79  65  73  61 /  70  40  80  70  30
McKinney            66  80  65  75  62 /  60  40  80  80  30
Dallas              68  82  68  76  64 /  60  40  80  80  30
Terrell             68  81  66  78  63 /  70  40  70  80  30
Corsicana           66  81  67  75  63 /  80  40  60  90  30
Temple              66  82  65  76  61 /  80  40  90  90  20
Mineral Wells       65  78  62  71  60 /  70  40  80  70  30

&&

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

$$

37/26

NWS FWD Office Area Forecast Discussion