Scientific Forecaster Discussion
fxus64 kfwd 220813
Area forecast discussion
National Weather Service Fort Worth Texas
313 am CDT Mon Jul 22 2019
/today and tonight/
Our much advertised late July cold front is on the way! Latest
radar imagery and surface observations indicate that the actual
boundary is just south of Oklahoma City and making steady
southward progress. An area of showers and thunderstorms is
ongoing across parts of eastern Oklahoma extending off to the
northeast but most of this activity will remain well off to the
northeast of our area.
Water vapor imagery shows the amplifying ridging over the western
U.S. And troughing over the Great Lakes which is allowing for
fairly modest northerly flow through the plains and ultimately
sending this front southward. Given that the parent trough is well
removed from our area, strong forcing for ascent will be lacking
as the front heads southward later today. The ongoing showers and
thunderstorms to the northeast are associated with a weaker pv
anomaly which is spreading through the Ozarks and this should also
remain east of our area later today. So as we go through the
morning, there may be little if any convection along the front
itself, except perhaps for a thinly forced line of showers right
along the boundary where mesoscale forcing is strongest. The front
should come through the metroplex around midday and spread
southward through the remainder of the County Warning Area through the afternoon.
We'll likely see an increase in scattered showers and perhaps a
few storms south of I-20 this afternoon during peak heating.
Forecast soundings for Waco by mid afternoon where temperatures
should be in the mid/upper 90s show a well mixed boundary layer
which could support an isolated damaging wind gust with the
strongest storms. The front will continue southward out of our
area by early evening with rain chances spreading south into
central Texas tonight.
High temperatures will likely only make it into the lower/mid 90s
along and north of I-20 where the front will make steady progress
through midday. To the south, it will be another hot day with
highs in the mid/upper 90s to near 100 degrees. Cooler and drier
air will spread into the region tonight with overnight lows
falling into the lower 70s with dewpoints in the lower 60s.
Manual 500 mb analysis this morning shows that a mid-tropospheric
trough is beginning to amplify across the eastern two-thirds of
the U.S. And Canada. The amplification of this trough is helping
to drive a surface cold front south. Surface analysis at midnight
CDT showed this cold front roughly along a line from Joplin to
Oklahoma City to Lubbock. This cold front should pass through
north and central Texas on Monday (see short-term forecast section
By Tuesday morning, most showers and thunderstorms associated with
the cold front passage should be south of our County Warning Area.
That being said, we may still have some lingering showers south of
a Killeen to Athens line in the morning. Rain chances should come
to an end by Tuesday afternoon however. Temperatures on Tuesday
will be substantially milder than the past few days, with highs
likely struggling to reach the 90s in many locations. Perhaps more
notably, steady north to northeasterly winds will usher in drier
air, allowing dewpoints to drop into the low 60s by late Tuesday,
and into the 50s for Wednesday and Thursday. With high
temperatures in the upper 80s to around 90 on Wednesday and
Thursday, and dewpoints in the low to mid 50s, it will feel quite
nice for late July, so make sure to get outside and enjoy it while
it lasts, because it won't stick around for long.
By late week, high pressure will move off to the south, allowing
temperatures and dewpoints to gradually increase. Temperatures in
the mid to upper 90s and dewpoints in the mid to upper 60s should
return by the weekend. Rain chances should remain low for most
locations through the weekend, but with Gulf moisture flowing
again, a few isolated showers or weak seabreeze thunderstorms
could develop south of a Killeen to Palestine line on both
Saturday and Sunday.
Aviation... /issued 1127 PM CDT sun Jul 21 2019/
VFR through Monday evening with scattered high clouds tonight and
scattered to broken cu and altocu during the day Monday.
Southerly winds tonight will veer to the southwest/west after
sunrise Monday ahead of a cold front. Frontal passage (and a north wind
shift) will likely occur at the metroplex taf sites around 18z
and a couple of hours later in Waco. Wind speeds ahead of the
front will remain between 6 and 12 knots, but will increase
between 12 and 16 knots Monday afternoon/evening along with some
A few showers and storms will be possible along the front, but
coverage should be limited due to a lack of large scale forcing.
Therefore, we will not include the mention of any showers or
storms in this taf package.
Preliminary point temps/pops...
Dallas-ft. Worth 94 72 90 68 90 / 20 5 5 0 0
Waco 99 71 91 67 91 / 30 30 10 5 0
Paris 92 68 85 63 86 / 30 10 0 0 0
Denton 93 69 89 66 88 / 20 0 5 0 0
McKinney 93 71 89 66 88 / 20 0 5 0 0
Dallas 94 73 90 69 90 / 20 5 5 0 0
Terrell 96 72 91 66 90 / 30 10 10 0 0
Corsicana 98 72 87 65 87 / 30 30 10 0 0
Temple 99 71 90 67 89 / 20 30 20 5 0
Mineral Wells 94 69 88 64 88 / 10 0 5 0 0