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Area forecast discussion
National Weather Service Fort Worth Texas
issued by National Weather Service Norman OK
1242 PM CDT Mon Oct 21 2019

Aviation...
/18z tafs/

VFR conditions are expected to continue in this Post frontal
airmass. Surface winds will remain northerly and while no gusts
were included within the forecast, sporadic northerly gusts can be
expected. Overnight and into Tuesday morning, the wind speeds
will reduce to light and variable.

Zwink




&&



Update... /issued 441 am CDT Mon Oct 21 2019/
a line of strong thunderstorms continues to surge quickly
southeast at 45-50 mph and should exit our southeast counties with
the strong cold front on it's by 5 am CDT. With the severe weather
threat, including any qlcs type tornadic potential, I will be
canceling all of Tornado Watch 680 from our County Warning Area. In addition, I
have updated the timing of the cold front and removed any
thunderstorm potential across our eastern central Texas counties
after sunrise.

Clearing was already seen on satellite moving east into the US
281 corridor and should reach I-35 close to, or just after
daybreak this morning. It'll be later in the morning; possibly as
late as midday before our far eastern counties see the clearing,
as the intense mid level cyclone continues to move northeast
further away from our area. Gusty northwest winds 15-20 mph should
gradually diminish by afternoon to around or below 10 mph.

Winds will decouple readily under clear skies at sunset this
evening, as high pressure settles into the region. Though no fog
is in the forecast with the influx of drier low level air behind
the cold front, we will need to analyze the potential for patchy
fog development tonight where heavier rains from this system fell
with strong radiational cooling expected tonight. With surface dew
points falling into the 20s and 30s, any patchy fog would likely
be shallow or ground fog. Lows tonight will fall into the 40s and
lower 50s with light and variable winds.

05/

&&

Discussion... /issued 221 am CDT Mon Oct 21 2019/
a line of strong to severe thunderstorms continues to make its way
across north and central Texas this morning. This line of storms
is occurring ahead of a cold front stretched along a line from
Joplin to Fort Worth to Fort Stockton. A warm, moist, and unstable
air mass is located ahead of this cold front. Large instability
combined with strong wind shear courtesy of a Stout low-level jet
will result in a continued severe weather threat. A Tornado Watch
continues for much of central Texas through 10:00 a.M. See
mesoscale update discussion below, and the latest Storm Prediction Center products
for more information.

Behind the cold front, cooler and drier air will filter into the
region. We should see a few nice days to start the week, with
highs in the 70s and lows in the 40s/50s through Wednesday. Rain
chances should be near zero on these days as well.

Deep troughing will continue over the eastern two-thirds of the
U.S. And Canada through the week however, leading to a continued
active weather pattern. A strong shortwave trough embedded in the
larger scale flow will drop south across the Great Plains by
Thursday. This will help to drive another, stronger cold front
through our neck of the Woods during the day Thursday. Showers and
thunderstorms will be likely ahead of this cold front. We won't
have as much time to recover our moisture and instability this
time though, which should limit our severe potential. Still, any
time we have strong synoptic-scale ascent, steep mid-level lapse
rates, and thunderstorms in north and central Texas, a few strong
thunderstorms are possible.

Beyond the Thursday cold front passage, there is still some
significant disagreement between the GFS and European model (ecmwf). The GFS
quickly moves the shortwave trough out of our area, building in a
strong, Arctic high across the central Continental U.S.. the bulk of the gefs
members also show this solution. The European model (ecmwf) on the other hand cuts
off the shortwave trough into a closed upper-level low. The latter
solution would bring continued rain chances, but with cooler
weather, for the end of the week and into the weekend. For now,
will indicate slight chance to chance pops through Saturday. While
there is disagreement with respect to rain chances, all global
models do agree that we will see below normal temperatures by next
weekend however as longwave troughing persists over much of the
Continental U.S..

37

&&

Preliminary point temps/pops...
Dallas-ft. Worth mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Waco mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Paris mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Denton mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
McKinney mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Dallas mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Terrell mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Corsicana mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Temple mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm
Mineral Wells mmm mmm mmm mmm mmm / 0 mmm mmm mmm mmm

&&

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