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Area forecast discussion...updated
National Weather Service Fort Worth Texas
909 am CST sun Dec 15 2019

a surface warm front continues to move readily northward toward
the immediate Red River area and Ark-la-tex region this morning.
The warm front has already moved north of the Highway 380 corridor
per latest obs, winds shifting south 10-15 mph, and rapidly
improving visibilities.

I have cancel/expired the dense fog advisory for all but the
immediate Red River counties from Cooke to Lamar, south through
Delta and Hopkins counties.

Otherwise, the remainder of the forecast looks on track with a
mostly sunny, breezy, and warm day for areas along and south of
the I-20/30 corridors. Our next cold front was already crashing
south across western Oklahoma and into northwest Texas between
Childress and Wichita Falls. This cold front will arrive into our
northwest counties this afternoon, where winds will shift north at
15-20 mph with higher gusts with Post-frontal stratus arriving
from Oklahoma. Highs across these areas will reach between 60-65
degrees by midday, before temperatures begin falling later this



Aviation... /issued 559 am CST sun Dec 15 2019/
/12z tafs/

Cigs and vsbys have tanked on schedule with the warm front now
moving towards the Red River. IFR/LIFR conditions with occasional
dense fog will result in poor flying conditions for the next
couple of hours at Waco and the next 3-4 hours around the dfw
metroplex. However, fairly rapid improvement is expected by mid
morning. Increasing southwesterly winds along with daytime
heating/mixing should quickly erode the back edge of the fog and
low stratus, and all taf sites should become VFR by midday at the
latest. Afterwards, VFR conditions and south winds will prevail
into the early afternoon.

The next concern is a cold front set to arrive in at metroplex
airports around 22z and at Waco a few hours later. A northwest
wind shift will accompany this dry frontal passage, with VFR
conditions continuing through about midnight. Afterwards,
the frontal inversion should begin saturating, resulting in
widespread MVFR cigs lasting through Monday morning. Some IFR
cannot be ruled out during this time period, but will be less
common. Areas of drizzle and light rain will also develop atop the
frontal surface, although most of this activity is expected to be
east of the taf sites and therefore has not been introduced with
this forecast issuance.



Short term... /issued 255 am CST sun Dec 15 2019/
/through Monday/

A wide variety of weather is in store over the next ~36 hours,
including multiple chances for fog/drizzle, near record high
temperatures in central Texas, and an abrupt cool down to begin
the workweek.

As of 3 am, a warm front was moving northward through the forecast
area, resulting in climbing temps/dewpoints. Some 60f dewpoints
have been spreading into 40-50 degree air, resulting in widespread
low stratus and some fog east of I-35. The potential for fog and
perhaps some drizzle will continue to accompany the front
northward through the morning hours, and some dense fog any be
possible at times. We'll continue to monitor visibility trends in
case a dense fog advisory becomes necessary.

Following the warm front's passage, sky conditions will improve
while temperatures climb quickly through the day with winds
becoming southwesterly. This will occur in advance of a surface
cold front to our north which will receive a southward push this
afternoon. This cold front will likely enter North Texas prior to
peak heating, holding high temperatures in the 60s across our
northernmost zones. However, a sharp gradient in high temperatures
will exist across the boundary, with some prefrontal warming
occurring during mid afternoon in central Texas. In fact, Waco
has a decent chance to match or break its daily record high of 81f
set in 1995. Temperatures will start dropping steadily behind the
front with moderate cold advection as winds become northwesterly
at 10-15 mph. Everyone should be in the 30s or low 40s by Monday

Although dewpoints will have increased with this morning's warm
frontal passage, moisture quality will still be rather meager and
shallow as the cold front arrives. This will limit precipitation
potential across much of the cwa, and generally confine it to our
southeastern 1/3rd as the front pushes through central and East
Texas later this evening. Precip should consist of mostly
stratiform rain with perhaps some showery activity occurring right
along the boundary. Precipitation potential will actually be a
bit higher well after the frontal passage as the main upper
shortwave swings through, resulting in some isentropic upglide
above the deepening frontal inversion. This should allow for light
rain and drizzle to develop mainly across the eastern half of the
forecast area late tonight and into Monday morning. Pops have
been kept on the low side simply because the chance for measurable
rainfall isn't terribly high, although many locations will see at
least a bit of drizzle or light rain through Monday morning.
Areas receiving precipitation are expected to be above freezing,
so freezing drizzle is not of concern at this time.

Overcast skies may persist through a large portion of Monday
before some clearing begins later in the afternoon. The continued
cold advection and cloudy skies will hold temperatures fairly
steady, mostly in the 40s and low 50s during the day. A steady
north breeze up to 20 mph will make for a rather cold start to the
week, with wind chills in the 30s or low 40s even during the
afternoon. All precipitation is expected to exit the area to the
east by mid afternoon at the latest.



Long term... /issued 255 am CST sun Dec 15 2019/
/Monday night through next weekend/

Strong cold air advection will persist Monday night with good
pressure rises expected through early Tuesday, as surface high
pressure builds southward into north/central Texas. Tuesday
morning lows will be below freezing for the majority of the
region, ranging from the upper 20s in the northwest to the lower
and middle 30s across the south. Winds should begin to decrease
late in the day Tuesday as the surface ridge moves into west-
central Texas, but good cold advection for the majority of the day
will keep afternoon highs around 50 degrees.

The ridge axis is progged to pass just to the west then to the
south of the region Tuesday night and Wednesday. The subsequent
backing of the surface flow will cause a shift to light westerly
winds Tuesday night. Decoupling of the low level flow should still
effectively create good radiational cooling conditions, leading
to Wednesday morning low temperatures mainly in the 25 to 30
degree range. Winds will continue to back to a more southwesterly
direction late Wednesday morning, then light southerly Wednesday
afternoon as the ridge heads east to the Gulf Coast. This will
begin the gradual warm-up with Wednesday afternoon temperatures
climbing well into the 50s. Despite the light south winds, the
airmass will remain dry Wednesday night, allowing overnight
temperatures to fall to near freezing area-wide.

Return flow will continue through the end of the week ahead of a
shortwave trough, which will enter the plains on Friday.
Temperatures will be near-normal Thursday then climb to slightly
above-normal readings on Friday following a few days of warm air
advection. A quick round of showers associated with the shortwave
will arrive on Friday, but will be limited to the eastern third
of the region. Moisture looks to once again be far too limited
for precipitation across the majority of the forecast area.

A weak cold front will slide through the area on the heels of the
shortwave, but should merely keep temperatures near-normal Friday
night. An amplified ridge at the upper levels will bring nice
weather and above-normal temperatures this weekend, and likely
into the first part of the following week. It is a bit too early
to accurately predict the Christmas day weather pattern, but at
this time the 10-day progs indicate another upper trough crossing
The Rockies by Christmas eve, which would likely bring low-end
rain chances by the 25th. We will get a better idea on the depth
of the system and how much moisture will be available, along with
many other specifics, later this week.



Preliminary point temps/pops...
Dallas-ft. Worth 74 39 47 32 50 / 5 10 5 0 0
Waco 83 43 51 32 51 / 0 20 5 0 0
Paris 68 39 45 29 47 / 10 20 20 0 0
Denton 70 35 45 29 50 / 5 10 5 0 0
McKinney 72 37 45 30 49 / 10 10 5 0 0
Dallas 75 40 47 32 50 / 5 10 5 0 0
Terrell 78 41 48 30 49 / 5 20 10 0 0
Corsicana 79 43 51 32 49 / 0 20 10 0 0
Temple 83 44 53 32 51 / 0 20 5 0 0
Mineral Wells 70 35 45 28 49 / 0 5 0 0 0


Forward watches/warnings/advisories...
dense fog advisory until 11 am CST this morning for txz092>095-

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