Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Fort Worth Texas
311 PM CDT sun Oct 4 2015
scattered high cloudiness continued spilling over the upper ridge
and north and central Texas today. More extensive cloudiness and
some light convective activity was occurring well west and southwest
across Mexico... New Mexico and West Texas. This good fetch of
elevated Pacific moisture was occurring well east of an upper low
centered near Los Angeles California currently. At the surface...
dry air was still entrenched across the area in response to
continued ridging and northerly flow within the lower levels of
The detached upper low over the southwest U.S will drift over Las
Vegas Nevada on Monday...before drifting southeast over central
Arizona on Tuesday. A shortwave ridge well out ahead of the upper
low will remain over the top of north and central Texas with
increasing middle and high cloudiness continuing to move northeast
from the equatorial Pacific Monday and Tuesday. Temperatures will
moderate slowly back into the 80s everywhere by Tuesday.
Medium range models remain in good agreement having a slower...
more cut off upper low moving over far West Texas and southern
New Mexico on Wednesday. In addition...increasing Lee cyclogenesis
along the New Mexico Front Range will help veer surface winds east
or southeast...with increasing moisture moving north from the Gulf
of Mexico. With better forcing remaining well west of the area
and a strengthening elevated mixed layer aloft...I have removed
rain chances across the western counties on Wednesday and delayed
chances until after midnight Thursday for our western counties.
Models remain in good continuity outside of the Canadian model on
retrograding the upper low south over The Big Bend and northern
Mexico Thursday and Thursday night. Meanwhile...a surface cold
front will move southward through the panhandles and into Oklahoma
Thursday night into Friday. Thursday night through Saturday
morning appears to be the period with the highest confidence for
showers and thunderstorms...as frontal forcing with the cold front
combines with deformation forcing between the upper low to the
southwest and a shortwave dropping southeast across the middle
Mississippi Valley. Combined with above normal column moisture
with precipitable water/S either side of 1.50 inches...the areas should see some
beneficial rainfall...though not overly heavy unless training were
to occur. Check of instability and flow from the surface to middle
levels does not appear to be impressive...so at this time we do
not expect a severe weather threat. We cannot rule out gusty
winds and more frequent lighting with stronger activity however.
Next weekend is a little more uncertain...as models and mean
ensemble spreads increase dramatically on both the upper low to
the southwest and the cold front on progression. Gut feeling from
previous extended systems cut off and this far south is to go with
the cut off...retrograding solution with the surface front
continuing on into south Texas. Will hold higher rain chances
across south Texas with the front on Saturday...then dry it out
heading into next Sunday and early next week...as the upper low
remains well west of the area with an upper ridge reestablishing
over North Texas.
Temperatures will will warm to between 85-90 degrees Tuesday and
Wednesday with more humidity and more mild overnight lows. The
increasing rain chances and subsequent cold front will help cool
highs back into the 70s and lower 80s across many areas Thursday
through Saturday...warming back up next Sunday and beyond.
/issued 1225 PM CDT sun Oct 4 2015/
similar conditions to the last couple of days exist today across
North Texas today...with a blocking ridge overhead and a light
pressure gradient at the surface. Light easterly surface winds are
showing signs of backing to the northeast again as boundary layer
mixing gradually brings low level northeast winds to the surface.
We will continue to include a second line in the tafs which show a
shift to northeast winds in the 7-9 knots range by 21z. Otherwise VFR
conditions will persist area-wide.
Preliminary point temps/pops...
Dallas-ft. Worth, Texas 61 83 64 86 67 / 0 0 0 0 0
Waco, Texas 60 85 62 89 65 / 0 0 0 0 0
Paris, Texas 58 83 62 85 64 / 0 0 0 5 5
Denton, Texas 58 81 59 85 63 / 0 0 0 0 0
McKinney, Texas 58 83 60 85 64 / 0 0 0 0 0
Dallas, Texas 62 84 65 86 68 / 0 0 0 0 0
Terrell, Texas 59 83 63 86 65 / 0 0 0 0 0
Corsicana, Texas 61 84 63 87 66 / 0 0 0 0 0
Temple, Texas 60 84 63 88 65 / 0 0 0 0 0
Mineral Wells, Texas 57 81 58 86 63 / 0 0 0 0 0