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

Home | Current Version | Previous Version | Text Only | 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
000
FXUS64 KFWD 292356 AAA
AFDFWD

Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
656 PM CDT MON AUG 29 2016

.AVIATION...
Metroplex TAF sites: Expect VFR conditions through 06z Wednesday
outside of thunderstorms. Scattered showers and thunderstorms that
were east of a KGYI to KTRL line at 2330z are expected to weaken
as they approach the Metroplex TAF sites. Have placed VCSH in the
TAFs for the 00-02z period for this. Scattered showers and
thunderstorms are expected to develop across North Texas again
Tuesday afternoon so have placed VCTS in the Metroplex TAF sites
for the 18-00z period. Northeast winds 5 to 10 knots will prevail
outside of showers/thunderstorms.

Waco: Showers and thunderstorms had mostly moved to the west of
Waco as of 2330z. Have placed VCSH in the TAF for the 00-01z
period. Another area of showers and thunderstorms that was east of
a KTYR-KJSO line was moving west at about 20 knots but should
weaken as it approaches Waco. Have placed VCSH for the 02-04z
period for that. Afterward...it should be pretty quiet overnight.
Scattered showers and thunderstorms are expected to develop across
Central Texas again Tuesday afternoon. Thus have placed VCTS in
the Waco TAF starting at 19z Tuesday. East to northeast winds at
less than 10 knots will prevail outside of showers/thunderstorms.

58

&&




.SYNOPSIS...
Rain chances will continue over the next several days across North
and Central TX as easterly flow continues. The highest rain
chances will shift from southern/southeastern areas to western
areas on Tuesday. Wednesday and Thursday should feature increasing
rain chances ahead of an upper trough along the northwest and along
the Red River. Lingering rain chances are expected through the end
of the week with perhaps a reprieve from precipitation for the
upcoming Labor Day Weekend across parts of North and Central TX.

&&

.SHORT TERM (Rest of Today through Wednesday)...

Convection continues to develop this afternoon with continued
moisture advection from the east and additional daytime heating.
In addition, there appears to be some weak mid-level vorticity
advection and this may be responsible for the more concentrated
band of convection that extends from near Hamilton up through the
DFW Metroplex. Similar to yesterday, additional convection will
stroll in from the Piney Woods of East TX towards far
eastern/southeastern zones. This activity is also likely
associated with a minor perturbation in the easterly flow to the
north of the upper low across the TX/LA Gulf Cost. The main
hazards with convection areawide this afternoon and into the early
evening hours will be cloud-to-ground lightning, heavy rain and
gusty winds. Widespread severe weather is not expected, but given
the 25 to near 30 degree dewpoint depressions, there may be a
brief window of time this afternoon for an isolated damaging
downburst or two across the area.

For tonight---Scattered convection will likely continue through
mid-evening, especially for areas along and south of the I-20
corridor. Through the evening hours, however, this activity
should continue to wane in coverage. Most of the short term
guidance seems to agree with this thinking, but there does appear
to be a few more ripples through the easterly flow, even towards
06 UTC Tuesday. HRRR guidance does hint at some lingering
convection down across Central TX, so I will keep a mention of
showers and an isolated storm or two going down near the U.S.
Highway 84 corridor tonight and into tuesday morning. For
tonight, there may be some areas of patchy fog, but similar to
previous nights, the overall areal coverage is not known.

For Tuesday---Slightly lower confidence forecast does exist on
Tuesday with regards to PoPs. Many of the CAMs and medium range
guidance are fairly insistent on developing widespread convection
out across western zones. This is somewhat puzzling given that
most synoptic guidance shift the ridge that is currently located
across the OH River Valley westward towards the Central Plains.
Despite the implied subsidence, with this feature, it`s possible
that convection may still develop given that much of the region
will remain on just the outer fringes of the ridge. For now, I will
go with chance PoPs out across western zones (30-40%) with slight
chance PoPs elsewhere. With the greatest coverage of showers and
storms expected to be out west, I`ve knocked temperatures down by
a few degrees across this area. High temperatures will only climb
into the mid to upper 80s here with low to near mid 90s out to the
east.

For Wednesday---Models remain aggressive with PoPs on Wednesday
ahead of the next upper trough. With a bulk of the forcing for
ascent expected to remain north of the Red River, I`ve undercut
most model guidance with regards to rain chances. The best chances
on Wednesday (outside of some diurnally given convection), appears
to be along and northwest of an Eastland to Denton To Gainesville
line and this seems to be in good agreement with the latest NAM
output. The most recent ECMWF, though still aggressive, has also
trended towards concentrating PoPs out across northwest zones.
Most of this activity should be towards the middle and latter
portions of the day, but as noted above---there may be some
isolated to widely scattered convection that develops earlier with
daytime heating.

&&

.LONG TERM (Thursday through Sunday)...

For Thursday and Friday---More widespread rain chances will
continue as the much anticipated mid-level trough slides to the
south of the Red River. The best ascent should be confined to
areas along the Red River early in the day and with time, the
trough axis should become more diffuse. There does appear to be
some semblance of a weak cold front (slight decrease in theta-e
and increasing heights/pressure) associated with this feature, but
it is very diffuse. That being said, there may be enough weak
convergence to serve as a focus for scattered convection along the
Red River and I`ve increased PoPs a tad here for Thursday.

The boundary appears to lose much of its baroclinicity as it
stalls somewhere across the region on Friday. This boundary does
appear to usher in slightly cooler air and high temperatures
across much of North and Central TX may only climb into the mid 80s
and low 90s. Similar to yesterday, the GFS remains the aggressor
with pushing a large ridge behind the front. This would certainly
spell a drier forecast for most areas (except across western
zones). The ECMWF remains insistent with a weaker ridge and more
widespread rainfall as it slows the progression of the front,
subsequent dry air and subsidence. Regardless it appears that most
of the shower and thunderstorm activity will be aided by daytime
heating, so the coverage of precipitation should decrease a few
hours after sunset. With regards to the overall coverage, I`ll
keep low rain chances across the entire region for Friday, with a
higher coverage out west where there is at least some agreement
with the longer term model solutions.

For Saturday and Sunday---Model solutions continue to diverge,
thus lowering confidence for the Labor Day Weekend. The GFS
actually appears to have trended drier with the ECMWF trending
slightly wetter. For consistency sake, I`ve kept most areas east
of a Bowie to Cleburne to Marquez line dry with only low rain
chances to the west. As mentioned in previous discussions, we will
keep close tabs on this portion of the forecast with the plethora
of expected outdoor activities and festivities.

24-Bain

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    75  92  77  95  76 /  30  30  10  10  10
Waco                73  90  74  93  74 /  50  30  10  10  10
Paris               73  94  74  94  73 /  30  20  10  10  20
Denton              73  92  73  94  73 /  30  30  10  20  20
McKinney            73  92  74  94  74 /  30  30  10  10  20
Dallas              75  93  77  95  77 /  30  30  10  10  10
Terrell             75  93  75  94  74 /  40  20  10  10  10
Corsicana           74  92  76  94  75 /  50  20  10  10  10
Temple              71  90  73  93  73 /  50  30  20  10  10
Mineral Wells       72  89  72  91  72 /  30  40  20  20  10

&&

.FWD Watches/Warnings/Advisories...
None.
&&

$$

58/90



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