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afdfwd

Area forecast discussion
National Weather Service Fort Worth Texas
749 PM CDT sun may 28 2017



Discussion...

Scattered to numerous showers and thunderstorms continue across
mainly our far southern counties this evening. These storms appear
to be closely tied to a surface frontal boundary that is draped
across the same area, although some additional activity has
developed north of the front. Large scale forcing for ascent is
coming from a passing shortwave trough well to the north, although
the flow across most of Texas is generally zonal, so even weak
embedded impulses are providing sufficient lift. Over the last
hour, much of the southward push to the line has slowed
significantly. This may be in part due to the departing shortwave.
Nonetheless, sufficient lift for continued thunderstorm
development will come from persistent warm advection which is
expected to continue at least for the next several hours. The
850-700mb Theta-E axis will likely remain draped across our
southern counties all night and will be a focus for renewed
development. Given the slowing southward push of the convective
line, we are becoming a little more concerned with a localized
flash flood threat. The area near Highbank has picked up nearly 3
inches of rainfall, with 2.5" of that coming in 1 hour.

For the remainder of the night, we'll keep high pops confined
mainly along and south of a Goldthwaite to Waco to Palestine line.
This area will also be of greatest threat for localized flash
flooding. The severe potential appears to be waning a bit given
the amount of convective overturning that has already occurred.
Although, there does remain sufficient instability at least for
low end severe hail and wind gusts.

Aviation...
/00z tafs/

VFR conditions prevail across most of the area, outside of
convective areas. For the metroplex, there have been a few showers
approaching from the west, although these should continue to
diminish through the evening. VFR conditions should prevail
through the period with winds becoming more easterly toward
morning.

Farther south at Waco, scattered thunderstorms will continue for
the next several hours, and will tempo a thunderstorms and rain through 10pm for
now. IFR/MVFR cigs/vis will likely accompany any thunderstorms,
and Waco may have to deal with some MVFR cigs through the morning
hours in the vicinity of precipitation areas. VFR conditions
should return by late morning at Waco with northeast winds.
Additional precipitation chances will continue through Monday
night.

Dunn

&&

Aviation...

/issued 106 PM CDT sun may 28 2017/
18 UTC taf cycle

Concerns---IFR cessation at select metroplex taf sites, otherwise
MVFR through the afternoon and early evening with a potential for
-shra/ts at all taf sites. VFR this evening, with a low chance for
additional convection after 00 UTC.

For the metroplex taf sites---intermittent IFR cigs have persisted
at a few sites across the metroplex early this afternoon in the
presence of modest low level ascent. Some of these IFR cigs may be
perpetrated by the very shallow ascent, but this is expected to
end shortly. Most cigs should lift into the MVFR category (around
fl015) this afternoon as more robust convection likely helps in
overturning the boundary layer. The next challenge will be the
timing of this convection. At this time current lightning data
indicates the convection to the west is not overly impressive in
terms of its lightning production, so i'll simply prevail -shra
at all metroplex taf sites. If activity to the west starts showing
more signs of generating additional lightning, then a quick
amendment to include thunderstorms in the vicinity/ts may be necessary. VFR is expected to
return late this afternoon and into the early evening hours. There
is a potential for additional vcsh and perhaps thunderstorms in the vicinity around the
00-03 UTC time period, but confidence is too low to include in the
tafs at this time. Should convection occur, the main impacts
would be potentially small hail and perhaps gusty winds/turbulence
below the cloud base.

For the Waco taf site---MVFR will continue through the early
afternoon before the late may sun helps to erode cigs from the
south and east. With the front still located to the north of the
Waco terminal and increasing instability ahead of this feature,
there appears a reasonably high enough chance for ts at the
terminal. I have moved up the timing of thunderstorms in the vicinity by several hours
(closer to 22 utc) to account for this and it's possible that a
prevailing group for ts may be warranted in future amendments. The
chances for convection should dwindle this evening, but the
trends will need to be monitored. Main hazards with thunderstorms
will be hail and strong winds. Reductions to visibility and
ceilings will also be possible.

24-Bain



&&

Preliminary point temps/pops...
Dallas-ft. Worth 67 85 67 86 70 / 20 20 20 20 20
Waco 68 80 65 84 67 / 60 50 20 30 20
Paris 64 83 64 84 65 / 10 10 10 20 20
Denton 63 86 63 86 66 / 10 10 10 20 20
McKinney 64 84 64 85 66 / 10 10 10 20 20
Dallas 68 86 68 87 70 / 20 20 20 20 20
Terrell 67 81 66 84 67 / 20 20 20 20 20
Corsicana 68 79 67 84 68 / 40 50 20 20 20
Temple 68 80 65 84 67 / 70 60 20 30 20
Mineral Wells 63 85 62 86 66 / 20 10 20 20 20

&&

Forward watches/warnings/advisories...

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