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Area forecast discussion 
National Weather Service Fort Worth Texas
601 am CST sun Nov 29 2015


For the 12z tafs...IFR cloud ceilings are expected to persist
through the forecast period. Widespread rain shower activity is
expected today...but is expected to diminish or move east of area
taf sites late this afternoon.

The thermodynamic profile of the lower atmosphere remains
characterized by a Stout low-level inversion with the atmosphere
at near saturation from several hundred feet above the ground up
to the 500 mb level. This supports persistent IFR ceilings through
the forecast period as the inversion and at least low-level
saturation are very likely to remain in place over the next 24

Rain showers were moving over the dfw area at the beginning of the
taf period. Rainfall is expected to increase in intensity after
15z when models indicate strong upper level forcing builds over
the region. This forcing is related to the passage of a shortwave
trough upstream. The forcing for ascent is expected to be aligned
with area taf sites from 15 to 21z. After 21z the best lift
appears to weaken and move north and east of area taf sites. Think
that widespread rains will come to an end at that time.

Do not have precipitation in the forecast after 22z...but this
will depend upon the timing of the best lift...and may need to be
amended based on short term radar and satellite trends. Even after
precipitation ends...weak lift may result in some light mist or
drizzle to contend with at times throughout the evening and
overnight hours. Winds are expected to shift around to the west by
sunrise on Monday as a middle-level front moves east over the region.
This front is expected to move east of area taf sites tomorrow
afternoon...with strong subsidence in its wake. May see a return
to VFR conditions late Monday afternoon if the front moves through
before sunset.



Previous discussion... /issued 343 am CST sun Nov 29 2015/
a large upper level low continues to spin over The Rockies keeping
north and central Texas under the influence of southwest flow aloft.
This upper level low will not move much today and will finally start
an eastward progression into the plains on Monday. The rainfall
activity the past 18-24 hours has been more scattered in coverage
and light to moderate in nature. Without persistent rain falling
in many locations yesterday...some of the standing and flood
waters have drained or at least lowered in areas that were
impacted by heavier rains Thursday through Friday night. The
exception is along many rivers and creeks that remain swollen.
Several of our river forecast particular along the
Trinity...Sabine...and Sulphur river basins remain in flood.

Another cold and rainy day is expected across the region today.
Another wave of widespread rainfall is expected to move across the
region and that final wave is already happening over our
northwestern counties. Throughout the day...this final round of
widespread rain will move west to east across the region with
rainfall totals generally 1.25 inches or less. These rainfall
totals...occurring steadily throughout the day...are not expected
to result in additional significant flash flooding...however...
river and creek flooding will continue and levels may rise some
today with additional rains. Based on the observed rainfall
totals the past 48-72 hours and expected rainfall totals today of
less than an inch...have removed the southern row of counties
from the Flash Flood Watch...but left the remainder of the Flash
Flood Watch in tact through 6 PM this evening. Even though it was
previously mentioned that significant flash flooding is not likely
to occur from todays rains...river and creek flooding will
continue and any water that has not already drained will likely
remain with the additional rains today.

This last round of widespread rain will end from west to east this
afternoon and evening with some light rain possibly lingering over
our eastern counties through the night. On Monday...additional
isolated to scattered showers may occur over the region as the 850-
700 mb front finally moves through the region...providing some
additional lift while the main upper level low is moving through the
plains. A good number of the models and hi-res guidance supports
some additional rain activity tomorrow and have increased probability of precipitation
across the region to 20 percent with 30 percent in our eastern and
southeastern counties. Forecast soundings Show Low and middle level
moisture remaining across north and central Texas in advance of
the 850-700 mb front with subsidence and drying quickly setting
in as the elevated front passes.

There continues to be some discrepancy on whether the 850-700 mb
front will stall near our southern counties as a secondary upper
level trough develops over the western Continental U.S. And then swings
through the Southern Plains around the middle of the week. If the
front stalls near our southern counties in central
could be a source for lift under the influence of continued southwest
flow aloft. This may result in additional isolated to scattered
light rain or showers mainly south of an Athens to Lometa line
Monday night through Tuesday night. Will keep 20 probability of precipitation across this
area for now due to low confidence on the location of the front
and low areal coverage of rain. The front gets another push south
on Wednesday as the next upper level trough comes through and the
rain chances end through at least Friday.

Temperatures today will again be cold with afternoon highs in the
40s. Overnight lows tonight will be in the middle 30s to lower 40s.
On Monday...sided with the cooler side of guidance due to
overcast skies expected for most of the day and kept highs only
in the lower 50s. On Tuesday and Wednesday cold air advection
aloft will spread across the region as the upper level trough
moves through the plains. This will keep highs in the lower to middle
50s. Overnight lows will cool into the 30s as the skies clear with
light surface winds. Several locations in our western and
northwestern counties will likely fall to freezing at least one
morning Wednesday through Friday. Temperatures will warm slightly
going into the weekend as brief upper level ridging occurs ahead
of another trough. This trough could bring some more rain but
right now moisture return looks minimal ahead of the system and
there are discrepancies between the models on the strength and
timing of the trough.



Preliminary point temps/pops...
Dallas-ft. Worth, Texas 43 40 50 39 52 / 100 40 20 5 10
Waco, Texas 44 41 51 42 53 / 100 50 20 10 20
Paris, Texas 44 44 51 39 52 / 100 60 30 10 10
Denton, Texas 43 39 51 37 52 / 100 30 20 5 5
McKinney, Texas 44 40 50 38 52 / 100 40 20 5 10
Dallas, Texas 43 41 51 40 52 / 100 40 20 5 10
Terrell, Texas 44 42 51 40 53 / 100 60 20 10 10
Corsicana, Texas 44 43 51 44 53 / 100 60 30 10 10
Temple, Texas 45 42 52 44 54 / 90 50 30 20 20
Mineral Wells, Texas 41 37 50 37 53 / 100 20 20 5 5


Forward watches/warnings/advisories...
Flash Flood Watch through this afternoon for txz091>095-100>107-



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