FXUS64 KFWD 170810

Area Forecast Discussion
National Weather Service Fort Worth TX
310 AM CDT Wed Jul 17 2019

/Today and Tonight/

Another day of oppressive heat and humidity is expected today,
with rain chances near zero across North and Central Texas. A Heat
Advisory is in effect for areas generally along and east of
US-281, including the entirety of the Dallas/Fort Worth
Metropolitan Area, and Waco.

The upper-level ridge responsible for the hot temperatures
continues to strengthen. The 00Z RAOB showed a 500 mb height of
594 dam, which is an increase of 3 dam (30 m) since the same time
yesterday. Given the increasing strength of the ridge, and the
fact that yesterday's guidance ran a little low compared to actual
observed temperatures, opted to go a bit above guidance for
today's highs. The official forecast high at DFW is 98 F for
today, but a few locations could hit 100 F, as we saw on Tuesday.
Denton, Sherman, and Breckenridge all observed high temperatures
at or just above 100 F on Tuesday, so given that today will be a
repeat, or even a little warmer, do not be surprised if a few
locations hit the century mark again this afternoon.
Unfortunately, in addition to the heat, oppressive dewpoint
temperatures will persist with afternoon dewpoints forecast to be
in the upper 60s to lower 70s for most of our county warning area
(our far western counties may drop into the mid 60s however).
Because of this, heat index values this afternoon will once again
reach into advisory criteria (>= 105 F) for most locations along
and east of U.S. Highway 281.

Rain chances will be near zero for all of North and Central Texas
as the aforementioned ridge continues to suppress convective
activity. After sunset, dewpoint temperatures will rebound into
the low 70s as diurnal boundary layer mixing ceases, resulting in
low temperatures in the mid 70s for most locations, with lows
struggling to fall out of the 80s for the urban core of the
Dallas/Fort Worth Metropolitan Area.



/Thursday into Next Week/

Our streak of hot and humid weather, characterized by highs in the
mid to upper 90s, will continue into the weekend thanks to the
influence of an elongated mid-level ridge across the
southern/central US. The ridge may weaken slightly on Thursday and
Friday, though, as a weakness generated from southern Rockies
convection drifts east across the Plains. In turn, a degree or two
may be shaved off high temperatures, versus those of Tuesday and
Wednesday. Heat indices will still approach 105 near/east of the
I-35 corridor, given persistence of dew points in the upper 60s to
lower 70s. Pending greater confidence in more widespread 105+
heat indices, the heat advisory may need to be extended into

A weak easterly wave may approach our region late this weekend,
encouraging showers and sea-breeze activity to our southeast. At
this time, the wave appears quite weak/sheared, with little
convective focus apparent across North and Central Texas;
therefore, have maintained a dry forecast through the weekend.

A more substantive pattern shift is now appearing more likely
early next week, as the ridge focuses and amplifies over the
Rockies. Whereas slightly more model discrepancy existed over
prior days, most medium-range guidance now suggests that northerly
flow across the Plains and Midwest (on the eastern periphery of
the aforementioned ridge) should be adequate to drive a cold
front south across the region Monday night into Tuesday. The front
should be accompanied by a few showers and storms, although
timing uncertainty precludes boosting PoPs too high for any one
period. Regardless, it now appears more probable that cooler and
drier post-frontal air could infiltrate North and Central Texas
Tuesday into Wednesday. High temperatures may only be in the 80s
to lower 90s, which would be several degrees below normal.



.AVIATION... /Issued 1139 PM CDT Tue Jul 16 2019/
/06 UTC TAF Cycle/

Concerns---Wednesday morning MVFR potential at ACT...lower at
D/FW...DAL and GKY.

VFR is anticipated through most of the pre-dawn hours on Wednesday
at all TAF sites...with MVFR cigs overspreading Central Texas by
12 UTC. GOES imagery reveals some patchy MVFR stratus was already
ongoing across the upper Texas Coast. Regional radar VWP also
indicate unseasonably strong low-level flow in place with winds
between FL020 and FL030 around 25 knots. This should allow MVFR
stratus to invade KACT around 1100 UTC where a TEMPO group for
occasional cigs around FL018 has been included. The low level flow
should veer and keep most of the patchy MVFR stratus east of most
D10 airports, though depending on trends in overnight satellite
imagery a TEMPO group for MVFR may be necessary at D/FW...DAL
and/or GKY. At this time, it's more likely that these sites will
remain VFR and I'll omit any mention of MVFR for these sites.

VFR is anticipated at all sites by 1500 UTC Wednesday with VFR CU
around FL045 from late morning and into the afternoon. For
simplicity sake...will let future TAFs introduce the largely
diurnal CU. Southerly winds of 10 to 12 knots will continue with
occasional gusts in excess of 15 knots through Wednesday afternoon.
Little in the way of rain/storms is anticipated as mid-level
ridging should suppress most convection.



Dallas-Ft. Worth 98 78 98 78 98 / 0 0 0 0 0
Waco 98 76 98 76 98 / 0 0 0 0 0
Paris 94 75 92 75 92 / 0 0 0 0 0
Denton 97 76 98 77 97 / 0 0 0 0 0
McKinney 96 76 96 77 97 / 0 0 0 0 0
Dallas 98 78 98 79 98 / 0 0 0 0 0
Terrell 96 76 98 77 98 / 0 0 0 0 0
Corsicana 97 76 93 75 94 / 0 0 0 0 0
Temple 98 75 96 76 97 / 0 0 0 0 0
Mineral Wells 98 74 98 75 97 / 0 0 0 0 0


Heat Advisory until 7 PM CDT this evening for TXZ091>095-101>107-



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