Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Fort Worth Texas
347 am CDT Wednesday Jul 27 2016
Hot and humid conditions along with scattered showers and
thunderstorms will continue for a couple more days across North
Texas before upper ridging builds back in across the Southern
Water vapor imagery shows a weak upper trough centered over
Louisiana this morning. This feature is expected to continue to
slowly move north today. To the northwest of the upper
trough...there is a band of moisture associated with a mid level
deformation axis which extends from southwest Missouri into
central Oklahoma and into North Texas. 00z upper air analysis at
700mb indicated the presence of rich moisture from near Midland
into North Texas and extending into the Ozarks. Latest rap
analysis indicates precipitable water values in excess of 2 inches along this axis
and across a good chunk of North Texas. At the surface...there is
some weak troughing noted from south of Lubbock to near Wichita
Falls and into southern Oklahoma. Given these features...think a
good portion of North Texas...especially across the northern half
of the County Warning Area...will see convection develop later this morning into
the afternoon hours...so we have raised pops to 40-50%. South of
the I-20 corridor there may be a relative minimum in convective
coverage with the exception of our far southern counties. This
area may see some activity spread north from southeast Texas. All
of this activity should again be diurnally driven with a peak in
coverage late this afternoon and diminishing after sunset.
Conditions will be favorable for isolated strong downburst winds
and locally heavy rainfall.
Later tonight...a second shortwave trough will swing through the
Central Plains and into northern Oklahoma with northerly flow at
500 and 700mb increasing. There is some potential for a complex of
thunderstorms to develop and move south late overnight although
the latest high resolution guidance is less bullish on this
scenario. Nonetheless...will have some 20% pops late tonight
mainly along and north of I-20.
The more likely scenario is that this passing shortwave sends a
weak boundary down into North Texas for Thursday. With rich
moisture still in the region...scattered showers and thunderstorms
would likely develop along this boundary during the day Thursday.
Will continue with 30-40% pops during this time across much of
Beyond Thursday...upper ridging begins to nudge back eastward into
the area. This will confine pops on Friday mainly to the eastern
half of the County Warning Area and only across the far northeast by Saturday.
Temperatures will slowly nudge upwards back to near 100 degrees
during this time with rain chances diminishing to near zero by the
latter half of the weekend. A pair of strong shortwave troughs
will move through the northwest U.S. Sunday and Monday which
should help deepen a surface low east of The Rockies. This will
keep wind speeds up a bit across North Texas so it won't feel too
oppressive across the region.
/issued 1145 PM CDT Tuesday Jul 26 2016/
earlier convection has ceased as the atmosphere has nocturnally
stabilized across north central Texas. The rest of the overnight
hours should be quiet at the taf sites with easterly winds
gradually veering to a southeasterly direction at less than 10
kts. Outside of convection, VFR conditions will prevail through
A pretty tricky forecast appears to be in store for Wednesday.
There are some indications from high-resolution guidance that
elevated showers and storms may develop near the Red River during
the morning hours, likely in response to ongoing isentropic
ascent/warm advection. There's been enough of a signal in recent
guidance to add in vcsh at the metroplex sites after 14z. Any
activity that does develop will move slowly towards the southwest.
As far as the thunder potential goes: a vorticity lobe pivoting
towards the arklatex and subtle surface convergence around a
pressure trough may be the impetus for convective development on
Wednesday afternoon. For the 06z taf issuance, opted to prevail
thunderstorms in the vicinity at the metroplex sites from 19-23z, and 21-00z at Waco.
Thereafter, activity should once again nocturnally wane with the
loss of daytime heating.
Preliminary point temps/pops...
Dallas-ft. Worth 96 77 96 77 97 / 40 30 30 10 20
Waco 96 77 97 75 99 / 30 20 30 10 20
Paris 96 74 93 73 94 / 40 30 40 20 30
Denton 94 73 94 74 96 / 50 30 30 10 20
McKinney 94 75 94 75 95 / 50 30 30 20 20
Dallas 96 78 96 76 98 / 40 30 30 10 20
Terrell 95 75 94 75 96 / 30 20 40 20 20
Corsicana 95 76 96 76 96 / 30 20 40 20 20
Temple 94 75 96 75 97 / 30 20 30 10 20
Mineral Wells 95 72 95 72 97 / 50 20 30 5 10