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000 
FXUS64 KFWD 111144
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
544 AM CST Mon Dec 11 2017


.AVIATION...
12 UTC TAF Cycle

Concerns---FROPA timing. Otherwise, VFR will prevail. 

VFR is expected to continue over the next 30 hours at all North 
and Central TX terminals. West winds will increase a few hours 
after sunrise, with peak speeds of around 10-12 knots. A few gusts
to 15 knots are possible, but significant crosswinds on north- 
south oriented runways are NOT expected. FROPA is expected around 
0200 UTC for Metroplex terminals with a couple of hours later at 
Waco. Breezy northerly winds of around 10 to 15 knots appear
probable after FROPA. Outside of some high clouds around FL300, 
significant obstructions to ceilings or visibility are not 
anticipated through the entire TAF cycle. 

24-Bain

&&


.SHORT TERM... /Issued 316 AM CST Mon Dec 11 2017/
/Today and Tonight/

An unseasonably warm day is forecast to begin the week with near-
record highs expected. Winds will remain out of the west today so
downsloping combined with weak warm advection will allow the very
dry airmass in place to heat up quickly. Temperatures may climb a
bit higher than advertised considering some compressional warming
will occur ahead of an approaching cold front that will move into
the area this evening. Although the current forecast calls mostly
for upper 70s, would not be shocked at all if DFW sets a record 
high (80F in 1938 and 1996) although the record may be more 
difficult to achieve at Waco (82F in 1949). These near-record 
temperatures along with very dry air (RHs 10-20%) will once again 
set the stage for elevated fire danger as west winds increase to 
10-15 mph. Any activities that could ignite wildfires are strongly
discouraged as fuels become more and more favorable for their 
ignition/spread.

By late afternoon and early evening, a dry cold front will move
into the area. This front is associated with the fast-moving 
shortwave located over Minnesota as of 3 AM. A reinforcing shot of
cooler air will arrive with the frontal passage and it will also 
prevent any moisture recovery from occurring while holding 
dewpoints in the 20s through tomorrow. Winds behind the front will
be breezy (15-20 mph) overnight and into Tuesday morning.

-Stalley

&&

.LONG TERM... /Issued 316 AM CST Mon Dec 11 2017/
/Tuesday through Sunday/

The main theme in the long term period will be large daily 
temperature swings courtesy of a few cold fronts and the dry 
airmass in place. The dryness combined with above normal warmth on
a few afternoons this week will result in an elevated fire 
weather threat, especially on Wednesday and Saturday. Rain chances
this weekend continue to look rather unimpressive and I've 
maintained a precipitation-free forecast throughout the long term
outlook.

Tuesday and Wednesday---Tuesday will be noticeably cooler and 
blustery (compared to Monday) as a cold front will have crashed 
southward through all of North and Central TX by daybreak. I've 
cautiously kept temperatures towards the cooler end of the 
guidance spectrum as surface-925mb temperature advection in the 
morning hours are progged to be quite impressive. The stiff north
wind of 15 to 20 MPH will likely make it feel even colder. That 
being said, daytime heating courtesy of full insolation will still
allow temperatures to approach seasonal norms. If the latest NAM 
is to verify, however, it's possible that temperatures may fall 
into the low 50s across all of the area. Winds should relax with 
time as surface pressure tendencies become neutral during the late
afternoon and nighttime hours. With the boundary layer likely to 
decouple, Tuesday night into Wednesday morning will be cold, 
especially across rural and sheltered areas. In general overnight 
low temperatures are forecast to fall into the 20s and 30s. 

Conditions quickly moderate on Wednesday as winds respond to the 
next approaching upper trough across the Midwest. The surface 
pressure gradient will become tight and should allow south to 
southwest winds to approach the 10 to 20 MPH range. Stronger wind 
gusts closer to the 25-30 MPH range will also be possible. The 
southwest flow at the surface combined with low level mixing 
should allow afternoon dewpoints to fall quickly into in the
the 20s and 30s and I've undercut blended model guidance 
dewpoints by a few degrees. The southwest flow will also allow 
temperatures to soar about 10 to 15 degrees above normal. These 
factors combined will likely yield an elevated to near-critical 
fire weather threat across much of North and Central TX on 
Wednesday. The limiting factor, however, may be the magnitude of 
the surface winds, so we will keep a close eye on this crucial 
component of the fire weather forecast over the next day or so. 
Regardless, we urge individuals to take care and avoid activities 
that could result in starting grassfires. Wednesday night into 
Thursday night should be a tad milder as the boundary layer may 
stay a bit more well- mixed with the approach and passage of the 
front.

Thursday and Friday---Breezy northerly winds in the wake of the 
aformentioned front will overspread much of the area on Thursday. 
While temperatures may only be a few degrees above seasonal 
normals, a lingering fire weather threat may materialize due to 10
to 15 MPH north winds and the dry conditions associated with 
FROPA. Similar to Tuesday, it'll feel a little cooler than actual 
temperature readings due to the north wind. The breezy conditions 
should subside after sundown. Another ideal radiational cooling 
night will be on tap Thursday night into Friday as clear skies and
light winds are anticipated. 

Conditions on Friday are expected to moderate as flow quickly 
switches to the south and southwest. At this time, I'm a little 
hesitant to warm things up dramatically as surface winds may not 
attain the necessary westerly component to allow temperatures to 
really soar due to downsloping. Regardless, above normal 
temperatures should occur with breezy conditions continuing.

Saturday and Sunday---Saturday has the potential to be an active
day with regards to fire weather based on the latest model 
projections. Blended model guidance actually outputs near advisory
level wind speeds across the area as a strong pressure gradient 
induces 40-50 knot winds just above the surface. Mixing should 
occur readily, but the potential fly-in-the-ointment will be 
possible mid/high level dense cirrus. It does look like that 
temperatures will still warm almost 10 to 15 degrees above normal 
and with south to southwest winds in the 20 to 25 mph range, the 
threat for rapid fire spread will increase on Saturday afternoon.

Unfortunately, it appears that there is a strong model consensus 
on little hopes of any rainfall late Saturday into Sunday. This 
time yesterday, the 00 UTC deterministic GFS and its ensembles 
were the lone outliers and painted QPF across eastern and 
southeastern zones. The latest deterministic GFS has started to 
shift towards the drier model consensus comprised of 
deterministic and ensemble European and Canadian model output. 
I've maintained a dry forecast as a result and at this point in 
time, it's possible that the next meaningful rain chances may not 
appear until the middle of the following week. 

24-Bain

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    79  40  57  37  74 /   0   0   0   0   0 
Waco                78  38  60  28  70 /   0   0   0   0   0 
Paris               75  37  52  33  67 /   0   0   0   0   0 
Denton              77  36  56  29  71 /   0   0   0   0   0 
McKinney            76  37  55  30  71 /   0   0   0   0   0 
Dallas              78  41  57  38  75 /   0   0   0   0   0 
Terrell             77  39  55  32  70 /   0   0   0   0   0 
Corsicana           77  41  58  36  67 /   0   0   0   0   0 
Temple              78  38  60  33  71 /   0   0   0   0   0 
Mineral Wells       79  36  57  27  73 /   0   0   0   0   0 

&&

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

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