Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KFWD 290940
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
340 AM CST Tue Nov 29 2016

.DISCUSSION...
A large upper level low spinning over the Northern Plains
continues to be the dominant weather feature affecting the CONUS.
One prominent shortwave which was responsible for the convective
weather over North Texas yesterday has lifted quickly northeast
and out of the area. It can be seen on satellite rotating around
the eastern periphery of the upper low and moving over the Upper
Midwest this morning. The Pacific cold front which moved through
the region yesterday did little more than usher in some drier air.
Meanwhile, a second shortwave located over the Four-Corners
region will swing east across the Southern Plains over the next
24 hours or so. Modest moisture and lift should be enough to keep
some mid-level cloudcover overhead this morning, but it is likely
far too dry for any precipitation.

Another cold front will accompany the upper level system and
should work its way south through North and Central Texas today.
Convection associated with both the shortwave and the front is
not expected to develop until the system encounters sufficient
moisture, and at this time it looks like this will be well east of
the region. For our area, cooler and drier air can be expected
behind the front, with low temperatures falling into the 30s and
40s tonight, then into the 30s area-wide tomorrow night. The
Northern Plains upper low will have headed east across the Great
Lakes during this time, leaving Texas beneath a brief period of
zonal flow and tranquil weather. Both Wednesday and Thursday will
see highs in the 50s and 60s following the aforementioned chilly
nights.

On Friday, we will begin to see a pattern change as an upper low
deepens over the Southwestern U.S., then proceeds to deepen even
further while sliding east over Northern Mexico. The positioning
of this system will allow a modified Arctic airmass to spill south
down the eastern face of the Rockies, reaching North Texas Friday
night and the upper Texas Coast Saturday. The frontal zone will
intensify off the Texas Coast as the upper low continues east.
This will generate strong isentropic lift across much of Texas and
Oklahoma over the weekend. Widespread rain will be the result both
Saturday and Sunday with temperatures remaining in the 40s and 50s
night and day. The dreary weather will continue until the upper
low finally swings east into the Lower MS Valley/Northwest Gulf.

It is in this facet that we continue to see model discrepancies
regarding timing. The models do agree on the transition of the low
into an open trough as it shifts east of Texas. The ECMWF takes
the trough axis east of the forecast area Sunday Night, with the
GFS 18 to 24 hours later (the Canadian through 144 hours is
actually in between the two). So this forecast package will show
a compromise, bringing an end to the heaviest precipitation Sunday
Night, but keeping low POPs in place on Monday.

The upper trough will accelerate as it heads northeast towards
the East Coast. Return flow and a warm-up will occur Tuesday and
Wednesday as yet another upper low dives south from the Pacific
Northwest to the Desert Southwest. This may set us up for another
modified Arctic front and a possible cold/wet episode late next
week or the following weekend.

30

&&

.AVIATION...
/ISSUED 1111 PM CST Mon Nov 28 2016/
/06Z TAFs/

South-southwest winds tonight will become more westerly and
increase in speed by 18Z as a surface low moves through the Plains.
For the Metroplex airports, wind speeds will be sustained 11-16
kts with gusts near 20 kts. At KACT, speeds will be closer to
10-12 kts with occasional slightly higher gusts. Wind speeds will
decrease to less than 10 kts between 22-00Z and become more
northwesterly during the evening hours as a front moves through
the region. Periods of mid and high level clouds will result in
periods of BKN skies.

JLDunn


&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    70  42  59  39  63 /   5   5   5   0   0
Waco                74  42  61  34  64 /  10  10   5   0   0
Paris               69  39  57  35  61 /  10  10   5   0   0
Denton              69  38  58  33  63 /   5   5   5   0   0
McKinney            70  39  58  34  62 /   5   5   5   0   0
Dallas              71  43  59  41  64 /   5   5   5   0   0
Terrell             71  41  59  36  63 /  10  10   5   0   0
Corsicana           73  44  60  38  64 /  10  10   5   0   0
Temple              75  43  61  36  64 /  10  10   5   0   0
Mineral Wells       69  38  59  34  64 /   5   5   5   0   0

&&

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

$$

26/30



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.