Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Fort Worth Texas
1138 PM CDT sun Aug 30 2015
VFR will prevail with just some afternoon cumulus and middle-high
clouds. There is a small threat of convection Monday afternoon but
this risk is too low to mention at this time. Generally light
south winds will continue.
convection has dissipated across all of North Texas and we will go
ahead and remove thunder from the forecast for the rest of the
overnight hours. No other changes are expected at this time.
Previous discussion... /issued 247 PM CDT sun Aug 30 2015/
a broad longwave middle-level trough extended from the Southern
Plains through the Mississippi...Tennessee and Ohio valleys today
with a positive tilted ridge anchored west over The Rockies. A
myriad of shortwave disturbances were embedded within the broad
longwave trough...two of which over southwest Texas and eastern OK
that may have an impact on North Texas sensible weather. A surface
trough extended from Sherman...to d/fw...to near Comanche with
higher surface dew points yielding SBCAPE values between 1000-2000
j/kg to the east of this feature. Temperatures currently ranged
from the middle- upper 80s in central Texas where a middle-high cloud
canopy has lingered most of the day...to the Lower-Middle 90s north
of I-20 where sunshine has been more abundant.
Challenges abound once again today regarding convective initiation
due to the mesoscale nature of lifting mechanisms noted above.
North and central Texas remain sandwiched between the southwest Texas
and eastern Oklahoma shortwave with both progressing slowly south. In
addition...a deformation/frontogenetical region aloft was noted on
water vapor imagery between these two shortwaves north of I-20.
I am expecting isolated thunderstorms to develop by late afternoon
between I-30 and the Red River to the east of the surface trough
where heating has been strong and where a Theta-E axis has set up.
Further south over central Texas...the majority of activity will
remain in the form of light showers. Any pocket of insolation that
does occur this afternoon across central Texas may allow for isolated
Thunderstorms that do develop across the north and northeast
counties could reach strong limits with gusty downburst winds...
frequent lightning and possibly small hail. Rain chances should
continue primarily south of I-20 for the evening as better forcing
with the middle level frontogenesis shifting slowly south of I-20.
After sunset...stronger isolated storms will likely weaken with
loss of heating and diminishing instability.
The area of middle-level deformation/frontogenesis shifts south into
central Texas on Monday with much the County Warning Area under the influence of
subsidence and drier air north of this feature. The shortwave
further northeast will remain east of Paris and put that part of
the County Warning Area within an area of subsidence as well. I have left the
forecast dry Monday and Monday night with this in mind. The
arklatex shortwave will retrograde westward to near the I-35
corridor Tuesday-Thursday and will advertise diurnal convective
chances east of I-35 and south of I-20 where daily seabreeze
boundaries may aide in a focus for low convective chances.
The middle-level trough will shift back to the east of the area
Friday into next weekend...as middle level system deepens and
organizes over the Pacific northwest. In addition...a potential
Omega block pattern sets up over the upper Midwest and Great Lakes
area which should keep North Texas dry and seasonable.
Temperatures throughout the week are expected to remain near
seasonal normals for early September.
Preliminary point temps/pops...
Dallas-ft. Worth, Texas 75 96 76 93 75 / 10 0 0 5 5
Waco, Texas 73 95 73 93 73 / 20 0 5 10 5
Paris, Texas 71 94 70 92 71 / 20 5 5 10 10
Denton, Texas 72 95 73 93 73 / 10 0 0 5 5
McKinney, Texas 72 95 73 92 73 / 20 0 0 5 5
Dallas, Texas 76 95 77 93 76 / 20 0 0 5 5
Terrell, Texas 71 94 72 92 72 / 20 5 5 10 10
Corsicana, Texas 74 95 74 92 74 / 20 5 5 20 10
Temple, Texas 71 97 72 92 71 / 30 5 5 20 10
Mineral Wells, Texas 70 96 71 94 71 / 10 0 0 5 5