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Area forecast discussion
National Weather Service Fort Worth Texas
221 PM CST Sat Dec 7 2019



Long term...
/Sunday night through Saturday/

Warm/moist air advection will increase Sunday night ahead of an
approaching low pressure system and cold front. As a result,
temperatures Sunday night will be very mild for December with
lows generally in the 50s.

Monday will start off mostly cloudy and warm as surface winds
veer to the southwest ahead of the front. The front will enter the
northwest zones Monday afternoon and sweep through the entire
forecast area Monday evening. Some light rain will accompany the
cold front as the upper trough moves east across the state,
increasing large scale lift. The rain will linger through Tuesday
morning, but end from northwest to southeast through the day with
increasing subsidence behind the departing upper trough. The
latest deterministic models continue to indicate temperature
profiles that support only a cold rain and we see no reason to
deviate from that solution based on pattern recognition. If the
upper pattern was not as progressive and the cold air could settle
in well before the upper support arrived, then the potential for
winter weather would be higher. Lows Monday night will be
generally in the middle and upper 30s, except for the northwest
zones which may touch freezing briefly around sunrise (precip
should be over before this occurs). Tuesday will be very cool with
highs generally in the 40s and lows from the upper 20s to the
lower 30s.

Brief riding aloft will occur Wednesday ahead of another
approaching shortwave. Although cold air advection will begin to
decease and ample sun is expected, it will still be cool
Wednesday with highs in the 50s and lows in the 30s.

Another upper low is progged to drop out of The Four Corners
region Wednesday night/Thursday, tracking across the Lone Star
state Thursday night/Friday. Although the system will bring
increasing lift and some elevated moisture, a lack of low level
moisture should limit precipitation potential.

An upper ridge is progged to build in from the west behind the
late week system, bringing warmer and rain-free weather as we head
into mid December. Highs Saturday will likely be in the lower and
middle 60s.

79

&&

Short term... /issued 1024 am CST Sat Dec 7 2019/
/today and tomorrow/

A common saying in some circles of meteorologists is "big bubble,
no trouble." This is a reference to the weather when a dominating
ridge of surface high pressure is directly overhead...today is
one of those days. A ridge of surface high pressure is moving
through the region, keeping the winds light and temperatures near
climo norms for this time of the year--in the low to mid 60s.
Passing mid to upper level clouds should even make for a
picturesque sunset this evening.

The surface ridge axis will shift east overnight as a leeside low
moves east into central Kansas. This will allow southerly flow
with warm/moist advection to take hold of the region tonight. A
30-40 kt nocturnal low level jet will develop aloft this evening, however a
gradually veering profile should prevent the development of
widespread status. We are expecting some stratus to develop east
of I-35 in the early morning hours and persist through the day
tomorrow.

A few hours after sunrise tomorrow, the elevated winds associated
with the low level jet will begin to mix down to the surface. A Stout
shortwave trough will move through the desert SW in the early
morning hours, creating almost purely perpendicular flow overtop
of the southern rockies tomorrow. This will enhance the deepening
of a leeside low over SW Colorado, tightening the pressure
gradient locally. These factors will combine to create breezy
conditions across north and central Texas tomorrow with sustained
winds around 15-20 mph with gusts up to 30 mph. This will elevate
the fire weather concerns west of I-35 with relative humidity values remaining
in the 30s through the afternoon. Temperatures will be noticeably
warmer tomorrow, on average 10-15 degrees warmer than they will be
today. No sensible weather is expected until the next storm
system moves through early next week.

Bonnette

&&

Aviation... /issued 1024 am CST Sat Dec 7 2019/
/18z tafs/

Concerns: low-end low level wind shear in the early morning hours; possible MVFR
stratus tomorrow morning; gusty south winds tomorrow.

A ridge of high pressure overhead will allow VFR and light winds
to prevail through the day. A few hours of light and variable
winds are expected early this afternoon, eventually settling out
of the south by 20-21z.

Overnight, a nocturnal low level jet will develop across the area with low-
end low level wind shear possible at all terminals between 09-14z. We did not
include it in the tafs at this time since the surface winds will
also gradually increase through the early morning hours as well.
The increased low level jet will allow for the development of MVFR stratus
across East Texas (east of I-35) after ~09z. We do not expect it
to move over any of the d10 terminals or kact attm, however
current guidance indicates a 30% chance of this occurring between
13-17z.

A tightened pressure gradient across the area will allow for gusty
south winds up to ~25 kts to prevail through the day tomorrow.
The gusts should begin around 14-15z with the initial inversion
break and persist through the afternoon.

Bonnette

&&

Preliminary point temps/pops...
Dallas-ft. Worth 47 72 59 72 36 / 0 0 0 10 70
Waco 46 74 58 78 36 / 0 0 0 5 70
Paris 45 67 56 69 36 / 0 0 0 20 60
Denton 46 72 58 70 34 / 0 0 0 10 60
McKinney 46 70 59 70 35 / 0 0 0 10 70
Dallas 48 72 60 73 36 / 0 0 0 10 70
Terrell 46 71 59 74 36 / 0 0 0 10 70
Corsicana 47 71 59 76 38 / 0 0 0 10 70
Temple 46 73 58 78 38 / 0 0 0 5 70
Mineral Wells 45 75 56 69 33 / 0 0 0 10 70

&&

Forward watches/warnings/advisories...
none.
&&

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