Area Forecast Discussion Issued by NWS Dallas/Fort Worth, TX
000
FXUS64 KFWD 180554
AFDFWD
Area Forecast Discussion
National Weather Service Fort Worth TX
1254 AM CDT Thu Apr 18 2024
...New Short Term, Aviation...
.SHORT TERM... /NEW/
/Through Friday/
A dominant upper low can be seen on IR imagery spiraling over
southern Manitoba tonight, with a shortwave extending from the low
southwest through the U.S Rockies. The shortwave will swing
through the Plains on Thursday, sending a cold front south into
North and Central Texas and bringing the next chance of
thunderstorms to the region. The stronger lift associated with the
upper level system will be focused well north of the forecast
area from the Central Plains to the Ohio Valley, which may limit
the coverage of thunderstorms locally. Will hence keep POPs in the
chance to slight chance range and focused along the surface
boundary.
The latest timing based on recent runs of convection allowing
models still looks like storm initiation around 4 or 5 PM
somewhere along a line from Sherman to the DFW Metroplex to
Goldthwaite. With good instability and decent shear in place, any
storm which develops would have the potential to become severe
with large hail being the primary threat. Damaging wind gusts
would be the secondary threat, with the better wind potential
being in the evening when cell mergers and subsequent clusters or
lines may contain bowing segments. The tornado potential appears
low based on unimpressive amounts of low level helicity, though a
spin-up tornado or two cannot be ruled out.
The overall severe threat will continue as storms push through
the southeast third of the region Thursday night out ahead of the
front, with all activity exiting by midnight. Cooler and drier air
will enter Thursday night and Friday as the front pushes into
Southeast Texas. Temperatures will switch from 10 degrees above
normal on Thursday to 5 to 10 degrees below normal on Friday, with
Friday afternoon highs ranging from the mid 60s in the northwest
to the upper 70s in the southeast.
30
&&
.LONG TERM... /Issued 300 PM CDT Wed Apr 17 2024/
/Friday Through Mid Next Week/
By daybreak Friday, the aforementioned cold front is expected to
be slowly drifting or stalled near or just north of the Hill
Country as it becomes oriented parallel to the upper-level flow.
Moisture advection overtop of the shallow frontal surface should
quickly yield widespread dense cloud cover early Friday. By the
afternoon, an approaching weak shortwave trough embedded within
the zonal flow aloft...in combination with the established
isentropic ascent regime...will lead to isolated to scattered
showers and thunderstorms developing in the vicinity of the 850mb
front, which is expected to still be draped across North Texas
(near the Red River). Rain/thunderstorm chances will increase
Friday night in response to increasing large scale lift associated
with another weak shortwave shifting across Central/South Texas.
While buoyancy will be somewhat limited, there should be
sufficient elevated instability for convective elements/embedded
thunderstorms capable of producing small hail late Friday into
early Saturday. With PWAT values near or exceeding the 90th
percentile of the daily climatological mean, locally heavy
rainfall may lead to flooding impacts on Saturday, especially
wherever higher convective rain rates materialize. The prevailing
drought and drier antecedent conditions in the southwest portions
of our forecast area will likely limit most flood concerns in this
area. However, ponding or minor nuisance flooding cannot be
completely ruled out. Conversely, given the degree of soil
saturation in areas east of the I-35 corridor and current
reservoir conditions, rapid surface runoff and minor river
flooding issues are likely to emerge this weekend. In general, 1.5
to 2.5 inches of rainfall is expected with isolated higher totals
possible. There is a 30-40% chance that total accumulated
rainfall exceeds 3 inches in a few different areas across North
and Central Texas.
Increasing subsidence in the wake of the departing shortwave
should bring an end to rain chances by Sunday afternoon with drier
conditions prevailing through early next week. In contrast to the
unseasonably hot temperatures in the short term period,
temperatures will fall from near/slightly below normal to as much
as 15-20 degrees cooler than 1991-2020 averages by Sunday. This is
due to weak cold air advection behind the cold front in
combination with rain chances and extensive cloud cover. The
surface high will shift east over the Lower Mississippi Valley
Monday, allowing for onshore flow to return. The return of
southerly winds and ample sunshine early next week will lead to a
quick warm up with highs back into the 70s and lower 80s by
Tuesday.
12
&&
.AVIATION... /NEW/
/06Z TAFs/
MVFR ceilings will develop area-wide over the next couple of
hours, with cigs scattering by midday Thursday. Isolated
thunderstorms will be possible in the DFW Metroplex starting
Thursday afternoon at 21Z, and KACT at 23Z, as a cold front
approaches. Will stick with around 4 hours of VCTS at all
airports, but if future guidance hints at higher coverage than
currently expected, a TEMPO group may become needed. Convection
will end 01-03Z as the front pushes south of the region. North
winds around 15kt can be expected Thursday night through Friday
behind the front.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 58 70 60 66 51 / 20 10 60 90 100
Waco 63 74 65 75 52 / 40 10 30 90 100
Paris 57 66 55 59 49 / 30 20 60 90 90
Denton 54 68 56 63 48 / 10 10 70 100 90
McKinney 56 67 58 64 49 / 20 10 70 90 90
Dallas 59 71 62 66 52 / 30 10 60 90 100
Terrell 59 70 61 67 50 / 40 10 50 90 100
Corsicana 63 74 65 75 53 / 40 10 40 80 100
Temple 63 75 64 77 53 / 40 10 30 80 100
Mineral Wells 55 69 58 66 49 / 5 10 70 100 100
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$