Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
FXUS64 KFWD 291648 AAA
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
1048 AM CST Tue Nov 29 2016
An area of elevated convection managed to develop earlier this
morning across our southeastern row of counties amidst a region of
strong isentropic upglide and steep 850-700 mb lapse rates. This
area of warm advection continues to press east of our region late
this morning, but and isolated shower or two will remain possible
through about the noon hour across parts of Anderson, Freestone,
and Leon Counties.
To the northwest, yet another cold front is pressing into Montague
County. Breezy northwesterly winds will accompany the frontal
passage and a noticeably cooler night is in store for many of us.
Out ahead of the front, temperatures should continue to rise into
the low to mid 70s and have nudged highs up a few degrees
accordingly. Updated products have been transmitted.
/ISSUED 535 AM CST Tue Nov 29 2016/
VFR conditions will prevail through the TAF period with winds
shifting to the west and eventually northwest as a cold front
moves through the region today. This cold front was positioned
from northern OK southwestward through the TX Panhandle as of
1130z. An intensifying shortwave trough will aid the southern
advance of this front causing winds to turn to the west by midday
and to the northwest by this evening at all area airports.
Westerly wind speeds should be 12-15 kts this afternoon with some
gusts to around 20 kts possible, but these conditions should
remain just below criteria that would cause significant crosswind
concerns on N-S runways. Otherwise, some mid-level VFR cigs from
FL080 to FL130 will be possible due to lingering moisture
associated with the large trough encompassing most of the CONUS.
Northwest winds around 10 kts will continue through the remainder
of the TAF period.
.PREV DISCUSSION... /ISSUED 340 AM CST Tue Nov 29 2016/
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
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.
.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