Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
FXUS64 KFWD 230453
Area Forecast Discussion
National Weather Service Fort Worth TX
1153 PM CDT Wed Mar 22 2017
Clear skies will prevail for the next few hours, but the first
rivulets of nocturnal stratus are beginning to appear on
satellite imagery across the Hill Country. Area wind profilers
reveal the low-level jet is strengthening, with 40 kts indicated
around 1500 feet. This jet will quickly usher low-MVFR cigs
across the Waco airfield near 23/08Z, and near 23/10Z at the
Metroplex terminals. Upstream surface observations reveal
dewpoints are only in the lower to middle 60s at this hour,
which, from a climatological standpoint, is not supportive of an
IFR signal based on anticipated temperature-dewpoint spreads.
This, combined with stout 35-45 kt winds just off the surface,
mean we`ll continue to carry cigs near and just above 1 kft. There
may be a brief window at the onset of stratus for IFR cigs, but
we`ll monitor trends.
Cigs will rapidly improve and scatter around mid-morning Thursday
as drier air begins to push in and the effects of daytime mixing
are felt. At the same time, strong south winds will materialize.
Some wind gusts in excess of 30 kts appear possible, especially
Thursday afternoon. These winds will be slow to subside and will
remain elevated Thursday night.
A potent low pressure system will approach the region late
Thursday night. At this time, the threat for thunder appears too
low to warrant mention in the DFW extended TAF, but did add a
mention of VCSH after 24/11Z as the strongest forcing arrives.
With such a potent system, thunder is not out of the question, but
will allow future shifts to fine tune these details.
The only significant change to the previous forecast is
to increase wind speeds on Thursday. As the lee side trough
deepens, the pressure gradient will tighten across North and
Central Texas. This pressure gradient should support southerly
winds of 15 to 25 mph by late morning across most of the forecast
area. Some gusts of 30 to 35 mph will be possible along and west
of the I-35 corridor. A Wind Advisory may be necessary for parts
of North and Central Texas Thursday. Wind speeds will probably not
immediately decrease as sunset approaches, so have also increased
wind speeds for Thursday night.
.PREV DISCUSSION... /ISSUED 316 PM CDT Wed Mar 22 2017/
An upper ridge currently parked over the Southern Plains will
shift east tonight through Friday as a West Coast upper trough
heads east. Return flow will be on the increase tonight and
tomorrow as lee-side troughing intensifies and the pressure
gradient narrows. A 40 KT low level jet will develop in advance of
the system this evening after winds decouple. These strong 925 MB
winds will mix to the surface mid to late morning Thursday,
creating warm and breezy conditions. At this time, it appears that
relative humidity values will remain too high to create
significant wildfire concerns.
Thursday night: forcing for ascent should become strong enough to
generate scattered showers and storms over West TX and the Texas
Panhandle. Convection will likely initiate along a dry line, which
will be followed closely by a Pacific front. Storms will spread
east into western counties of North Texas as the Pacific front
overtakes the dry line overnight, likely developing into a QLCS as
the system moves into the I-35 corridor Friday morning. Early on,
there could be a few strong to possibly severe storms with a low-
end damaging wind threat. A better chance for severe storms (with
both a damaging wind and large hail threat) will occur east of
I-35 where the atmosphere will have time to destabilize late
Friday morning and Friday afternoon. Rain chances will end from
west to east Friday afternoon, with just about all precipitation
exiting the easternmost locales by sunset.
Cooler and drier conditions are expected Saturday following the
passage of the cold front. This will be short-lived, however, as
a second upper trough will quickly induce return flow late
Saturday into Sunday. There is quite a bit of energy with this
system, but the lack of appreciable moisture may limit convective
development for much of the area. The most likely scenario is that
there will be scattered storms Sunday afternoon and evening
initially developing near the Red River where the coldest air
aloft and steepest lapse rates will be. This activity would
develop farther south with time while spreading east, so the
highest POPs will be across the northeastern counties, with
generally lower POPs the farther south you go. Shear and
instability will be sufficient for a few strong to possibly
severe storms, with large hail and damaging winds equal threats.
The upper level pattern looks to remain active and fairly
progressive as we move through next week. All models are
advertising a deep upper low right over the middle of the
country a week from now, with subtle differences in timing and
intensity. The time of year alone is enough justification to keep
in mind that there will at least be some possibility of severe
weather, with better details becoming realized with time.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 63 85 65 82 57 / 0 5 40 70 5
Waco 64 83 65 81 55 / 5 5 30 70 5
Paris 57 82 60 72 55 / 5 10 10 70 20
Denton 62 84 63 81 54 / 0 5 40 60 5
McKinney 61 83 62 75 55 / 0 5 30 70 5
Dallas 63 85 65 79 57 / 0 5 40 70 5
Terrell 61 84 63 74 57 / 5 5 20 70 10
Corsicana 62 85 63 75 58 / 5 5 20 70 20
Temple 63 84 63 81 56 / 5 5 30 70 5
Mineral Wells 61 85 60 83 53 / 0 5 50 40 5