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fxus64 kfwd 231137 aaa 
afdfwd

Area forecast discussion...updated
National Weather Service Fort Worth Texas
637 am CDT Sat Jun 23 2018



Aviation...
/12z tafs/

An outflow boundary stalled across the dfw metroplex overnight but
is already losing its identity. The winds in the metroplex will
continue turning to the south by mid morning and will increase to 15-20
kts with gusts up to 25 kts. Similar winds are expected at kact
today. Stratus clouds cover kact this morning and are also
occurring along the stalled outflow boundary through the
metroplex, impacting a few of the airports. VFR conditions are
expected at all the taf sites by 15z, but MVFR cigs are expected
to return as early as 06-07z tonight with continued breezy south
winds.

A complex of storms is expected to develop across northwest Texas late
this afternoon and this evening, eventually moving south and/or
southeast. At this time the complex is expected to remain west of
the taf sites, but we will be closely monitoring this complex and
any associated outflow boundaries for impacts to the airports
overnight tonight. Air traffic to our west will likely be impacted
by these storms.

Jldunn

&&

Short term... /issued 311 am CDT Sat Jun 23 2018/
/today and tonight/

An mesoscale convective system moving across Oklahoma tonight is pushing a fast moving
outflow boundary south into North Texas. Some showers or storms
will be possible north of a Jacksboro to Emory line early this
morning but the majority of this complex is remaining north of the
Red River. Where the outflow boundary stalls today may have
implications on the afternoon forecast. Hi-res model guidance is
not tracking this feature very well, but based on its speed,
believe this boundary may reach the I-20/I-30 corridors before
stalling...and it may possibly advance south of that. We will have
to keep an eye on the boundary but at this time I believe the
boundary will fade out and/or retreat north later this morning as
surface winds increase from the south in response to a surface
cyclone to our west.

Breezy winds of 10-20 mph are expected again today with hot
temperatures ranging from the mid 90s in the east to around 103
degrees in the west. The breezy winds will help reduce heat stress
again and will forego issuing a heat advisory at this time. Heat
index values will range up to 106 degrees today and tomorrow at
scattered locations, but calculations of wet bulb Globe
temperatures, which take into account the wind factor, are
several degrees below recommended values. However, it will still
be a hot day where outdoor enthusiasts can be overcome by the heat
in the direct sunlight if they do not take precautions to protect
themselves.

Late this afternoon/early this evening, as the cap weakens near a
stalled front just outside our northwestern border, thunderstorms
are expected to fire where triple digit temperatures will result
in high instability nearing 3000-4000 j/kg. Hi-res guidance is in
good agreement these storms will merge into a complex that travels
south and southeast. Corfidi vectors suggest a southeastward
movement is possible and have hedged pops a little farther east
than guidance. Shear values will be stronger today with 0-6 km
values around 40 kts, supporting a severe storm threat. Initially,
large hail and damaging winds will be the main threats, but as
the storms merge into a complex, the threat will largely become
damaging winds. The large hail threat may exist outside of our
area depending on where the stalled front is and storms initiate,
but the complex should become cold pool driven resulting in a
damaging wind threat. For this evening and tonight, have the
highest pops up to 50% west of Interstate 35. The complex will
likely have dissipated or moved out of our area by daybreak
Sunday.

Jldunn

&&

Long term... /issued 311 am CDT Sat Jun 23 2018/
/Sunday through next weekend/

Most of the Saturday night convection will be gone by daybreak
Sunday as the low level jet wanes and increased subsidence is
encountered. Will keep slight chance pops for any lingering
precipitation in the northeast counties Sunday morning, otherwise
hot and dry weather will quickly return. Highs will climb into the
mid and upper 90s along and east of I-35 with triple digits again
possible across the west. Temperatures and dewpoints alone yield
apparent temperatures at or above 105 in several spots, but strong
southerly gradient winds should once again lessen the heat index
values by a couple degrees.

Meanwhile, an upper low will be moving east into the plains with
a surface front stretching from northwest Texas into Missouri. A
shortwave rounding the base of the low will generate another round
of strong to severe convection Sunday afternoon and evening,
though this time it will initiate farther north than the Saturday
evening activity. There is an outside chance that some of this
activity will enter our northern-most counties late Sunday night
or Monday morning before dissipating. The chance of this occurring
seems pretty remote right now based on the location of the upper
level system, and the most recent guidance supports this idea.
Will show some below-20 pops along the Red River and forego the
mention of any weather at this time. A similar scenario is set for
Monday night as another shortwave swings around the slow-moving
upper low, with below-20 pops again in place along the Red River.
That said, conditions will need to be monitored each night, and
some slight chances for storms for the northern counties might
eventually be needed if models or developing convective complexes
trend farther south.

By Tuesday, the upper low will be located over the Midwest and
upper level ridging will extend farther north into the Southern
Plains. The only chances for precipitation from Tuesday through
next weekend may be if seabreeze showers reach far enough inland.
Otherwise, continued hot and dry weather can be expected without
the benefit of short-term relief via the occasional nocturnal mesoscale convective system.

30

&&

Preliminary point temps/pops...
Dallas-ft. Worth 100 78 98 78 97 / 10 40 10 5 5
Waco 100 77 98 78 97 / 5 30 5 5 5
Paris 94 76 93 76 93 / 30 20 20 10 5
Denton 100 76 98 78 97 / 20 40 10 10 5
McKinney 98 77 96 76 94 / 20 30 20 5 5
Dallas 100 78 98 79 97 / 10 30 5 5 5
Terrell 97 76 98 78 97 / 10 20 5 5 5
Corsicana 99 77 96 77 95 / 5 20 10 5 5
Temple 98 76 97 77 95 / 5 30 10 5 5
Mineral Wells 101 76 100 76 98 / 20 50 5 5 5

&&

Forward watches/warnings/advisories...
none.
&&

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