FXUS64 KFWD 191756

Area Forecast Discussion
National Weather Service Fort Worth TX
1256 PM CDT Tue Jun 19 2018

The primary aviation weather concerns with this TAF package will
be cloud trends followed by precipitation chances.

Ceilings have generally lifted above 3000 ft across North and
Central Texas early this afternoon. However, some pockets of MVFR
will be possible through mid afternoon. By 20Z, ceilings should
all be between 3500 and 5000 ft and remain in this range until
late this evening. A 25 knot low level jet will result in MVFR
ceilings developing across the Hill Country late this evening.
These low clouds will spread northward and reach all TAF sites
overnight. Ceilings between 1000 and 2000 ft will be common
initially, but will likely fall below 1000 ft before sunrise
Wednesday and remain IFR until mid morning.

Showers and isolated thunderstorms will remain a possibility
through Wednesday morning. The best coverage of showers will be
across Central Texas, but even the Metroplex TAF sites may see a
brief shower, especially during the heat of the day. Impacts to
flight operations (if any) at the Metro Terminals should be brief
and minimal.


.SHORT TERM... /Issued 310 AM CDT Tue Jun 19 2018/
/Today and Tonight/

Broad ridging across the southern half of the CONUS continues to
be compromised by an easterly wave along the Texas Coast. This
feature is producing flooding rains along the Coastal Plains and
Southeast Texas, but coverage of precipitation and overall
rainfall totals drop off substantially the farther inland you go.
RADAR data early this morning indicates this persistent trend
as the moderate to heavy showers moving up the I-45 corridor
diminish considerably while approaching the southeastern counties.
POP and QPF grids for today and tonight will reflect this trend,
being highest across the southern and southeast counties, and will
peak this afternoon as diurnally driven convection occurs. As for
temperatures, clouds and precipitation will keep high temperatures
slightly below normal, but the forecast highs will go above
guidance based on overly cool model trends the past few days.

Southeast winds today could be a bit gusty at times as an
upstream shortwave over the northern Rockies instigates lee-side
troughing and the pressure gradient tightens. Otherwise, clouds
and an overall moist airmass will keep low temperatures tonight
well into the 70s.



.LONG TERM... /Issued 310 AM CDT Tue Jun 19 2018/
/Wednesday Through Monday/

The old tropical surface and weak mid level trough over South Texas
will continue to progress westward toward the Rio Grande Valley
on Wednesday. A strong longwave trough moving east over the
Central High Plains this same time frame will be amplified enough
to possibly begin absorbing the South Texas disturbance in
a"detached" manner through Wednesday evening. As this process
occurs, models are advertising mid level vorticity advection
across areas east of I-35 with still very moist airmass in place.
As such, will continue to carry 50%-60% coverage across our
eastern counties, with chances diminishing the further west you go
away from the better moisture and forcing. Later Wednesday night
into Thursday morning, it appears our focus will shift north
toward the strong mid level trough moving east across the Central
Plains, that begins to drag a weak surface cold front into West-
Central Oklahoma into Northwest Texas and stalls it Wednesday

Late day storms will develop off to our northwest as forcing from
this system and the right exit region of a cyclonically curved
upper level jet streak rotate across Southern Kansas and Oklahoma
by Wednesday evening. As the Central Plains mid level trough heads
toward the Ozarks/Mid Mississippi Valley late Wednesday and
Thursday, developing northwest flow aloft in it's wake should
possibly push a small MCS southeast toward our Red River counties
east of I-35 by sunrise Thursday morning and have increased POPs
into the chance category across our northeast counties for that
time frame. Though this system will likely be weakening, a few
strong storms and gusty outflow will certainly be possible with an
unstable environment in advance of the early morning storms.
Otherwise, the clouds and higher rain chances should allow for one
more day of lower high temperatures on Wednesday, especially our
eastern CWA.

The Central Plains/Mid Mississippi mid level trough looks to
deepen and slow down as a closed low Thursday and Friday, as we
continue on the southwest edge of this system and within northwest
flow aloft. Outflow from the morning MCS and support from that mid
level flow should allow the weak surface front to sag across the
Red River counties and possibly as far south as the I-20/30 corridors
late this week. Better forcing and moisture east of I-35 will
have me keeping low convective chances through that Thursday
night, before the front loses it's identity and mid level forcing
continues to shunt further east away from the area on Friday. With
some veering of low level flow and modest compressional warming
in advance of it, the heat will return with highs 95 to 100 and
heat indices Friday into Saturday ramping up to near or slightly
above 105 degrees in some place, as upper 60s and lower 70s dew
points linger around. Even Sunday will be pretty steamy with an
overall hot and humid forecast with little in the way of rain
chances, though a progressive shortwave in west-northwest flow
will track east over the Red River Valley Saturday night. I have
added in slight chances for thunder along and north of I-20, but
we'll have to see how our environment sets up for any future
adjustments as it will be a well-defined disturbance with large-
scale ascent. Otherwise, a check of records shows those are safe
with values 103-105 degrees.

By the end of the weekend into Monday, it appears our northwest
flow aloft regime will dampen with a more normal, broad mid level
ridge setting up over much of the state into the Gulf Coast
region. The stronger zonal flow aloft to our north "should" keep
most systems and convective chances to our north across the
Central Plains into Oklahoma and the Ozarks. At the surface,
strengthening southerly flow will mean an increase in occasionally
gusty south winds which should help with the heat somewhat with
dew points likely mixing out and heat indices remain below
advisory levels. Highs both Sunday and Monday will be in the mid-
upper 90s, with lows in the 70s, except around 80 within the
immediate urban heat island of the DFW Metroplex.



Dallas-Ft. Worth 86 74 91 76 93 / 40 20 40 20 20
Waco 88 73 90 74 94 / 60 40 50 20 20
Paris 87 72 85 72 89 / 30 20 60 50 50
Denton 89 73 91 74 93 / 30 20 30 30 20
McKinney 86 72 87 71 92 / 30 20 40 30 30
Dallas 86 75 91 76 93 / 40 20 40 20 20
Terrell 86 73 90 74 92 / 40 30 50 30 40
Corsicana 84 73 86 74 91 / 50 40 50 30 30
Temple 86 73 88 73 92 / 60 50 50 20 20
Mineral Wells 90 72 91 72 94 / 30 10 20 20 20




Back to Main Forecast Discussion Page