Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Fort Worth Texas
334 am CDT Thursday Jul 28 2016
It looks like north and central Texas will have one more day of
scattered showers and thunderstorms to contend with before upper
ridging builds back into the area effectively ending rain chances
and allowing temperatures to warm back to or slightly above 100
degrees into next week.
Water vapor imagery shows the main shortwave trough (discussed
about yesterday over louisiana) has been pulled northeast and is
now embedded within a larger broad trough over the eastern U.S. In
its wake...a weakness in upper heights still persists between the
stronger ridge to the west and ridging centered off the East Coast
of Florida. This weakness aloft will encounter strengthening
northerly flow by midday around the periphery of the western
ridge. This should in turn induce some cyclonic vorticity
advection and weak forcing for ascent by early afternoon across
the eastern half of the County Warning Area into the arklatex. All of this occurs
within a zone of low to mid level confluence centered right across
the middle of our County Warning Area. Very high precipitable water values in
excess of 2 inches will persist in this area through the
afternoon...so scattered showers and thunderstorms appear likely
to occur again today. Current thinking is that the best coverage
will be within this band of converging 850-700mb flow just south
of the metroplex eastward along the I-20 corridor into East Texas.
Pops will generally be 30-40% in this area with lower coverage
farther north and west. Similar to the last few days...the
strongest storms will still be capable of marginally severe
downburst winds. Locally heavy rainfall will also be a concern
with the slow moving thunderstorms. A little more than normal
cloud cover and scattered outflows will keep temperatures slightly
cooler than normal in most locations today...but still warm and
By tonight...we turn our focus farther north as one of several
weak disturbances moves through the Central Plains. A complex of
thunderstorms should be ongoing across parts of Kansas and
Oklahoma. This activity will slide southeast and could clip our
northern/northeast counties very late tonight into Friday morning.
Otherwise...ridging starts to nudge back to the east by late
Friday. Most areas should stay precipitation free...although our
far eastern areas will still be far enough removed from any large
scale subsidence to possibly see a storm or two.
Ridging continues to build back into the area Saturday and Sunday.
The only areas that may see any precipitation would be our far
northeast where remnant thunderstorm activity from complexes to
the north could clip the region. Drier air aloft will also
accompany the ridging further helping to minimize rain chances.
The forecast will remain precip free Sunday into next week with
highs climbing back to near 100 degrees each afternoon.
/issued 1148 PM CDT Wednesday Jul 27 2016/
north central Texas remains caught in a weakness between two areas
of high pressure, and this will ensure continued unsettled weather
through the forecast period. The 28/00z kfwd sounding reveals a
very moist and unstable profile is in place. As a result, it's not
surprising that showers continue to develop even at this late
hour in the vicinity of an old outflow boundary just to the east
of the metroplex sites. At this time, it appears that activity
should remain outside of the taf sites, but cannot entirely rule
out a stray popup shower during the overnight hours.
The forecast for Thursday will continue to be influenced by
subtle features that makes pinning down the most convectively
active regions and time periods difficult. At this point, decided
to continue vcsh at the metroplex sites Thursday morning as it
appears convection will re-develop near the arklatex and
potentially spread westward into the mid-morning hours.
As this activity dissipates, surface heating, in concert with a
weak shortwave aloft, should be sufficient to encourage
additional scattered thunderstorm development during the afternoon
hours. Opted to prevail a short period of thunderstorms in the vicinity from 20-22z in the
metroplex, and a broader window from 17-22z at Waco as it appears
the metroplex will be at the edge of the better combination of
lift and instability.
Any lingering activity should then wane Thursday evening, with VFR
conditions and light south winds prevailing at 10 kts or less.
Preliminary point temps/pops...
Dallas-ft. Worth 96 77 97 78 97 / 30 10 10 10 10
Waco 96 76 98 77 98 / 30 10 10 5 5
Paris 91 72 94 73 95 / 30 20 20 20 20
Denton 95 74 96 74 97 / 20 10 10 10 10
McKinney 95 75 95 75 96 / 30 10 20 10 10
Dallas 95 77 97 79 98 / 30 10 10 10 10
Terrell 92 75 95 76 97 / 30 10 20 10 10
Corsicana 92 76 96 77 97 / 40 10 10 5 10
Temple 96 75 97 76 98 / 30 10 10 5 5
Mineral Wells 97 73 97 74 99 / 30 10 10 10 5