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Area forecast discussion...updated 
National Weather Service Fort Worth Texas
1248 PM CDT Tuesday Sep 16 2014

Update...
as noted in the aviation discussion...isolated thunderstorms will
be possible across the forecast area this afternoon. Thus have
updated the forecast to include this. Have also increased this
afternoon/S highs by a few degrees as thinning middle-high clouds are
allowing for a little more heating.

58

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Aviation...
/issued 1245 PM CDT Tuesday Sep 16 2014/
VFR conditions should prevail throughout the entire taf cycle.
Satellite observations and hi-res model guidance suggests that
isolated showers may be possible this afternoon in response to the
slight thinning of middle and upper level cirrus deck and subsequent
daytime heating. As a result...have included a mention of vcsh at
all taf sites. Confidence is too low at this time to include
thunder in any tafs for this afternoon...but may become warranted
should middle and upper level cirrus continue to thin more than
currently expected. Otherwise...scattered cumulus and towering cumulus should
continue with afternoon heating. Towering cumulus...cu...and any showers that
develop should wane with the loss of daytime heating with light
northeasterly and easterly winds veering more to the south and
southwest in response to the deepening Lee trough across Colorado.

15-Bain



&&



Previous update...
update...
the weather across the region today will remain relatively quiet.
The 12z forward radiosonde observation still shows a pretty moist sounding which is the
same as the soundings that we have seen for the last few days.
With no major sources of lift /only a weak short wave embedded in
the upper flow/ and no significant surface boundaries...we are
counting on diurnal heating for isolated to scattered showers to
develop today. Have lowered the rain chances to isolated across
the north and slight chance across the south for the rest of
today. Rainfall amounts will be light...with most sites that
receive rain picking up less than 1/10th of inch. Temperatures
will be dependent on how many breaks we see in the middle and high
level clouds. Most areas should reach the middle 80s to around 90
degrees.

58

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Previous discussion... /issued 347 am CDT Tuesday Sep 16 2014/
the combination of elevated moisture associated with Tropical
Storm Odile and weak short wave energy embedded in northwest flow
aloft will bring a chance of showers to North Texas today. The
best chances for measurable rainfall will be across the southern
zones where moisture and lift will be the most favorable. Lapse
rates will remain nearly moist adiabatic through the day and
thunder appears unlikely for the most part. However...a brief
storm or two is not completely out of the question across the
southern zones. Earlier thinking was that a weak cold front would
move into North Texas today and provide an additional source of
lift for precipitation but current surface analysis shows only very
weak pressure rises behind the approaching front. Therefore...it
is likely that the front will remain north of the Red River today
so we will reduce the chances of measurable precipitation across
the northern half of the region to 20 percent.

The upper pattern will not change much tonight through Thursday with
high pressure across the west and a long wave trough in the east. All
models continue to indicate that a series of shortwaves will move
across The Hill Country and the southern portions of North Texas
Wednesday through Thursday and bring scattered rain and
thunderstorms. It appears that the best chances for appreciable
rainfall will remain across The Hill Country but we will carry
chance probability of precipitation across about the southern half of the forecast area
Wednesday through Thursday.

Rain chances will decrease Thursday night as the short wave energy
moves southeast and upper level high pressure builds across the
state. Large scale subsidence underneath the area of high pressure
should dominate the region Friday through Saturday and keep rain
chances low.

Some changes are on the way late in the weekend through early next
week as an upper level trough moves east across the middle of the
nation. While most of the energy associated with this system will
remain north of the region....the passage of the trough axis will
allow a cold front to move south across the plains and reach North
Texas Saturday night. The GFS...Canadian and European model (ecmwf) solutions are
in decent agreement on the timing of the cold front and the
associated precipitation...although the European model (ecmwf) is a bit faster
with the front. We have decided to raise probability of precipitation slightly for Sunday
due to the overall model agreement. Much drier air will filter in
behind the front Sunday night and this air will remain in place
through at least the middle of next week.

Temperatures through the weekend will be near normal for this time
of year with highs in the 80s to lower 90s and lows in the upper
60s and 70s. Temperatures on Sunday and Monday should be a bit
cooler with lows from the upper 50s to the upper 60s and highs
generally in the 80s.

79




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Preliminary point temps/pops...
Dallas-ft. Worth, Texas 90 72 90 75 91 / 10 20 20 20 20
Waco, Texas 92 71 89 74 88 / 20 20 30 30 40
Paris, Texas 86 67 88 71 89 / 10 20 20 20 20
Denton, Texas 89 69 91 72 90 / 10 20 20 20 20
McKinney, Texas 89 70 89 71 91 / 10 20 20 20 20
Dallas, Texas 91 74 91 75 90 / 10 20 20 20 20
Terrell, Texas 92 70 89 73 90 / 10 20 20 20 20
Corsicana, Texas 90 70 89 74 89 / 20 20 30 30 30
Temple, Texas 91 71 86 73 87 / 20 20 30 30 40
Mineral Wells, Texas 88 71 90 71 89 / 10 20 20 20 30

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Forward watches/warnings/advisories...
none.

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$$

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