886
FXUS64 KFWD 101822 AAA
AFDFWD

Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
1222 PM CST Tue Dec 10 2019


.SHORT TERM...

/Through Wednesday Night/

The main concern in the short term forecast period will be
lingering light rain and possible patchy freezing fog on Wednesday
morning. At this time, the potential is very low and will be
relegated to parts of Central Texas. Otherwise, cold conditions
will persist this afternoon and into the nighttime period. Below
normal temperatures are also anticipated on Wednesday though it`ll
be less gloomy with mostly sunny skies.

The upper level trough responsible for this morning`s light rain
with intermittent sleet continues to churn across the Permian
Basin. With this feature a little slower, mid and upper level
ascent will continue to overspread the area. While I expect that
the radar scope will remain quite illuminated this afternoon, dry
air advection at the surface will likely keep rainfall amounts
very light (just a few hundredths of an inch of additional rain
expected). For most locations, only virga is anticipated. The
lingering ascent will delay the erosion of cloud cover and I`ve
slowed the clearing line by a few hours. This should mean the raw
and unpleasant conditions will continue this afternoon with most
areas struggling to get out of the upper 30s and low 40s. The
exception may be across western North Texas where late day
clearing and thus diabatic heating may be enough to allow
temperatures to climb a little higher into the mid 40s.

For tonight, mostly clear skies, calm winds and large
temperature-dew point temperature spreads will allow for ideal
radiational cooling as the main trough axis aloft translates
eastward. The previous forecast remained well below the model
consensus for MinT`s and I see no reason to deviate from that
based on the expected conditions. Most areas will fall down below
freezing with some locations west of I-35 falling into the low
20s. The recent rainfall may promote the development of some
patchy freezing mist/fog...mainly across Central Texas. At this
time, confidence isn`t high enough to include in the worded
forecast, but this will need to be monitored closely.

Wednesday won`t be quite as cool---though still below normal---
and with ample sunshine, the 50s will actually feel much more
pleasant compared to today. Northeast winds will be replaced with
southerly flow as upstream lee-side trough commences.

Bain

&&

.AVIATION...

/18 UTC TAF Cycle/

Concerns---Ceiling trends and low BR potential at Waco.

VFR will continue at Metroplex TAFs through the entire period as
dry air plunges southward. I cannot rule out some occasional virga
resulting in some turbulence below 12,000 feet. Otherwise,
northerly winds will become light and somewhat variable overnight.
For now, I`ll show a light northeast wind in the TAF with flow
becoming more southerly through mid-morning Wednesday. Speeds
should be light enough such that a return to south flow may be
possible prior to the Tuesday evening push.

For Waco...MVFR with occasional -RA and IFR cigs are expected
through this afternoon. As dry air heads south toward the
airfield, cigs will lift and VFR is anticipated around 2100 UTC.
VFR will prevail through the remainder of the TAF cycle. There is
a low potential for some BR toward daybreak and given that
surface temperatures will be below 32 degrees, I cannot completely
rule out the potential for some very minor icing on idle aircraft
at the airfield. The BR potential is low and not included in the
TAF at this point, but trends will be monitored. Otherwise,
northerly winds will become southerly through the end of the valid
TAF cycle.

Bain

&&


.LONG TERM... /Issued 336 AM CST Tue Dec 10 2019/
/Wednesday and Beyond/

Return flow will begin on Wednesday as the axis of a surface
ridge shifts to our east and a rapidly-approaching shortwave
trough strengthens a surface low to our northwest. The shortwave
will swing relatively uneventfully across the Southern Plains, as
it will not be able to tap into any significant amount of Gulf
moisture until it gets east of the Mississippi Valley. A weak
front will accompany the shortwave, but will likely stall before
reaching North Texas. This should allow for a gradual warming
trend during he second half of the work week.

A pair of disturbances will then rotate through the Midwest over
the weekend, giving the front enough of a push to make it through
the region. The current plan is to follow the faster side of
guidance with the front at this time, which brings the boundary
through the area on Saturday. Little to no precipitation is
expected with the initial passage of the front due to the absence
of moisture and lack of any appreciable lift.

The next upper level trough will drop southeast from the Pacific
Northwest to the Four-Corners region on Sunday, then work its way
into the Southern Plains on Monday. Isentropic lift will increase
as the system approaches, which will begin our next decent
chances for our rain late in the day Sunday. The surface boundary
will retreat northward as a warm front Sunday-Sunday night, and
may reach the Central Texas counties before pushing south again.
The Sunday-Monday temperature forecast hence contains a fairly
large spread from north to south. This forecast also includes
isolated thunder, as elevated instability looks sufficient for the
occasional lightning strike. Pops will be mainly along and east of
Interstate 35, with the western third of the region likely
remaining dry.

The front will surge southward on Monday as the upper trough moves
east of the region, ending rain chances from west to east Monday
night. After Monday, a cooler than normal and dry period looks
likely through most of next week.

30

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    47  31  53  34  54 /  80   0   0   0   0
Waco                45  29  55  31  56 / 100   0   5   0   0
Paris               44  28  51  31  51 /  60   0   0   0   0
Denton              46  28  52  32  54 /  40   0   0   0   0
McKinney            46  29  52  32  53 /  70   0   0   0   0
Dallas              47  30  53  34  54 /  90   0   0   0   0
Terrell             44  29  53  32  54 / 100   0   5   0   0
Corsicana           45  30  54  33  54 / 100   5   5   0   0
Temple              44  30  54  32  56 / 100   0   5   0   0
Mineral Wells       46  25  53  31  54 /  50   0   0   0   0

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

24/08

NWS FWD Office Area Forecast Discussion