128
FXUS64 KFWD 171054
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
554 AM CDT Sat May 17 2025

...New Aviation, Short Term...

.KEY MESSAGES...

- More widespread severe thunderstorms are expected across much
  of the forecast area this afternoon with threats primarily for
  damaging winds and hail.

- Scattered storms will be possible again on Sunday and Monday
  afternoons. A few storms may be severe (15-30% chance), with
  greater chances on Monday.

- A cold front on Tuesday will knock temperatures back down to
  near or slightly below normal for the middle of next work week,
  with afternoon highs ranging from the mid 70s to the mid 80s.

&&

.SHORT TERM... /NEW/
Update:
Overnight guidance continues to support this afternoon`s
anticipated convective trends outlined in the previous forecast
below, with initiation along and east of the dryline expected by
mid afternoon. While extreme instability would be favorable for
large hail initially with discrete cells, fairly quick upscale
growth into one or more linear segments should occur which would
lessen the hail threat to an extent (as compared to a discrete
supercellular mode) but could significantly increase the damaging
wind threat in parts of North Texas. Sunday`s forecast still
remains rather uncertain, and will maintain low broad-brushed
PoPs with at least a low potential for isolated severe storms.
This will be a more weakly forced setup with the dryline being the
only lifting mechanism, so despite another day of remarkable
instability, thunderstorm initiation may struggle to overcome weak
afternoon capping.

-Stalley

Previous Discussion:
/Through Sunday/

Another round of strong/severe thunderstorms is forecast this
afternoon and evening which will affect much of the forecast area.
Depending on the evolution of convection, a potentially
significant damaging wind event could materialize in parts of
North Texas.

For the rest of the early morning hours, weak large-scale ascent
and steep lapse rates may continue to support elevated convection
rooted in the mid-levels similar to the isolated ongoing cells
within the DFW Metroplex as of 1 AM. However, a relative lull in
convection is expected through much of the morning with an
intrusion of low stratus and perhaps some patchy fog to begin the
day.

An incredibly volatile and unstable airmass will be in place later
today as the stalled frontal boundary responsible for Friday
evening`s storms pivots northward in response to strengthening
southerly low-level flow. The buoyant sector will be bounded by
this frontal zone draped to our north, and a sharpening dryline
to our west across the Big Country. As a compact vort max rippling
through southwest flow aloft interacts with these boundaries and
significant warm sector instability, rapid convective development
will occur across the Big Country and western North Texas. Due to
the quick erosion of capping and likely widespread thunderstorm
development, isolated supercells are unlikely today, at least for
any prolonged length of time. Instead, rapid upscale growth into
one or more convective clusters or line segments will likely
become the primary storm mode just an hour or two after
thunderstorm initiation, with dry mid-level air promoting strong
cold pool generation. With remarkable surface-based instability
of 5000-6000 J/kg for such a complex to feast upon, this setup
could result in a potentially significant damaging wind event in
parts of North Texas, should a forward-propagating linear complex
materialize. To the south in Central Texas, convection may remain
slightly more isolated given perhaps some weak residual capping
being farther removed from the mid-level ascent that will be more
prominent across North Texas. This may favor cells remaining
discrete, at least for a longer time period, and therefore
significant hail may be the primary hazard. In terms of the
tornado threat, modest low-level flow and poor hodographs should
limit this potential to an extent, although any time surface-based
convection exists with extreme instability this potential is
certainly non-zero. Embedded circulations within a line are also
possible, but once again may be limited by the modest 15-20 kt of
0-3 km shear. The main time window of concern will be roughly from
1 PM to 8 PM, with the greatest threat area roughly along and
north of the I-20 corridor.

Sunday`s convective forecast is a bit more uncertain at this
time. It is possible that a cluster of thunderstorms could
initiate near the leading edge of greater moisture return on
Sunday morning in parts of North Texas or southern Oklahoma, with
additional storms developing along a renewed dryline boundary just
west of the CWA during the afternoon. However, unlike Saturday,
the dryline will really be the only forcing mechanism present,
and convective initiation may struggle to overcome capping during
peak heating. We`ll keep lower PoPs of 20-30% in North Texas for
Sunday afternoon, and it is possible that little in the way of
deep convection is able to become established. Even if just one or
two storms are able to develop, they could easily become severe
in the presence of extreme instability and sufficient deep-layer
shear.

-Stalley

&&

.LONG TERM... /Issued 318 AM CDT Sat May 17 2025/
/Monday through Friday/

...Monday and Monday Night...

By Monday, the axis of an upper-level trough and corresponding
vort max will pivot out into the Great Plains. This will induce
surface cyclogenesis somewhere in the central High Plains, with a
dryline extending south into northern and central Texas. A cold
front will also dive south across the Plains behind the low-
pressure center, but is not expected to reach our area until
Tuesday. Ahead of the dryline, an extremely unstable airmass is
expected. Surface dewpoints in the low to mid 70s, highs in the
80s and mid-level lapse rates of 7 to 8.5 C/km will result in
SBCAPE ranging from 3500 to 5000 J/kg. With the approach of height
falls and strong forcing for ascent associated with the upper-
level disturbance, scattered thunderstorms (40 to 60% chance) are
expected to develop along and just ahead of the dryline Monday
afternoon north of I-20. Coverage will be increasingly sparse
with southward extent (20 to 40% chance south of I-20), as
convective inhibition will be more robust in the absence of lift
further to the north near the Red River. With sufficient deep
layer shear (bulk shear on the order of 50-60 knots) in
conjunction with the warm unstable airmass east of the dryline,
initial storm modes appear to be a mix of discrete supercells and
semi-discrete clusters, with large hail and damaging winds the
primary hazards. A tornado or two Monday afternoon/evening cannot
be ruled out, particularly between I-20 and the Red River.

After sundown, severe thunderstorms south of I-20 should gradually
weaken as CIN increases with the development of the nocturnal
boundary layer. Along and north of the I-20 corridor, synoptic
forcing for ascent may be enough to allow severe storms to persist
through the early overnight hours. Storms should generally grow
upscale into clusters/bowing segments, transitioning to primarily
a damaging wind threat. However, any storms that are able to
remain discrete will have an increased tornado threat owing to the
development of the low-level jet. Forecast soundings show 0-1km
SRH increasing to the 200-300 m2/s2 range in the Texoma region,
and around 150-200 m2/s2 for northern parts of the metroplex,
which is all sufficient for tornadic storms. As stated above, the
realization of the late evening/early night tornado threat Monday
night will depend on storm evolution during that afternoon and
evening, of which the exact details remain unclear at this time.
Regardless, thunderstorms should weaken and exit our area to the
east sometime around or just after midnight.


...Tuesday...

A cold front is expected to reach the Red River and quickly push
south/southeast across north Texas during the morning hours. A
dryline is still expected to extend south from the cold front,
roughly along the I-35 corridor as synoptic forces will prevent
its retrograde out west overnight Monday night. Over the course
of the morning, diurnal heating and a very moist boundary layer
will result in quick destabilization of the warm sector airmass
across eastern Texas into the southern Mississippi River Valley.
There is substantial uncertainty with how far west any
thunderstorm and severe potential will extend, as this will depend
on the speed of the cold front and how quick destabilization
ahead of the front is able to happen. The most likely area to see
scattered strong to severe thunderstorms would be along and east
of a line from Paris to Killeen during the early afternoon hours.
Here, the primary hazards would be large hail and damaging winds.
Though a tornado or two can`t be ruled out, the tornado threat
should generally be low with linear convection being the preferred
convective mode. Storms should clear the region by late afternoon
as cool, dry air funnels in from up north. This will finally give
a reprieve from the stretch of above average temperatures, with
nighttime lows Tuesday night dropping into the upper 50s/low 60s.

...Wednesday through Friday...

Upper-level ridging and surface high pressure will build into the
region mid-week next work week. This along with northerly flow at
the surface will keep us clear with slightly below normal
temperatures. Afternoon highs Wednesday and Thursday will range
from the mid 70s in northeast Texas to the mid 80s closer to the
Hill Country. Nighttime lows will drop into the 50s/low 60s.

On Friday, the ridge axis looks to shift east of the region,
allowing southerly flow to return to the area. This will bring the
return of moisture and warmth from the south, resulting in highs
by the end of next work week in the 80s along and east of the I-35
corridor, and low 90s west of the I-35 corridor.


Darrah

&&

.AVIATION... /NEW/
/12z TAFs/

Patchy mist and a swath of low stratus are accompanying a
northward-moving warm front into North Texas as of 11z, both of
which are reducing categories to MVFR at times. There is a small
chance that cloud bases could briefly dip below 1 kft around
daybreak, and this will be Tempo`d at Waco where it has a slightly
higher probability of occurrence. Scattering to VFR should occur
at all airports by midday. Convective development will be underway
west of the TAF sites early in the afternoon, with storms likely
congealing into one or more clusters or line segments before
moving east into all the TAF sites between 21-01z. These storms
are likely to be severe with hail/wind threats, and some
significant damaging wind gusts could occur if a more organized
line segment is able to materialize. The strongest storms should
vacate the airports to the east after 02z, although isolated
showers and perhaps a thunderstorm could linger in the vicinity of
the TAF sites as late as 04z. Outside of convective influences, a
southeast wind around 10-15 kts will prevail through the majority
of the period. Another round of low stratus at MVFR heights can
be expected heading into Sunday morning.

-Stalley

&&

.SPOTTER INFORMATION STATEMENT...
Spotter activation may be requested across North and Central Texas
this afternoon and evening. Even if activation is not locally
requested, any reports of hazardous weather to the National
Weather Service are appreciated.

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    91  72  89  72  86 /  80  40  30  20  60
Waco                93  72  92  72  90 /  50  40  10   5  30
Paris               88  68  85  69  83 /  80  50  40  20  60
Denton              90  68  89  70  86 /  80  30  30  20  60
McKinney            90  70  88  71  83 /  80  50  30  20  60
Dallas              92  72  89  72  85 /  80  50  30  20  60
Terrell             89  71  88  72  86 /  80  60  20  10  50
Corsicana           91  73  92  74  90 /  60  50  10   5  30
Temple              95  72  93  73  93 /  40  30  10   5  20
Mineral Wells       92  69  92  70  90 /  70  20  30  20  50

&&

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

$$