Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Fort Worth Texas
300 am CDT Thursday Jul 30 2015
surface analysis early this morning revealed an ill-defined cold
front across Oklahoma and the Texas Panhandle. The leading edge was
denoted by little more than a wind shift. Drier and cooler air was
well behind the initial wind shift and currently located across
the Central Plains.
The front will move slowly into the northeast portion of North
Texas this morning and across most of the region by this
afternoon. The passage of the front will not be obvious but rather
a gradual wind shift to the northeast. Moisture will pool just
behind the front and offset daytime mixing of drier air from
above. This will result in a hot and humid day with afternoon
highs at or just above yesterdays readings. Heat index values will
actually be higher in most locations this afternoon due to the
moisture behind the front. Many locations will see heat index
values between 103 and 106 this afternoon. Since heat index values
will be significantly lower on Friday...we will not issue a heat
advisory. One other factor that will make today seem hotter than
the last several will be relatively light winds.
High res models seem to have a good handle on the cold front and
expected moisture increase. Nearly all model solutions develop
isolated showers/storms across the eastern half of the region
this afternoon/evening. We will keep only slight chances
mentioned since large scale subsidence will still be working
against the smaller scale forcing for ascent.
Large scale subsidence will decrease on Friday as the upper ridge
builds to the west. This will result in increased cloud cover and
slightly better rain chances. The drier and cooler air that is
currently across the Central Plains will finally start to work in
from the north/northeast Friday and this will keep afternoon
temperatures/heat index values lower than today.
A few showers and storms may linger in the west Friday
night/Saturday morning. However...increasing cool/dry air
advection across the region should make for a pleasant
night/morning. Low temperatures Saturday morning will be in the
lower and middle 70s. Highs Saturday will be generally in the
middle 90s...except for a few upper 90s in the extreme south.
The upper ridge axis will slide back to the east early next week
and this will bring increasing temperatures and decreasing rain
chances. Triple digit temperatures will most likely return to
some of North Texas by Tuesday and Wednesday of next week.
/issued 1132 PM CDT Wednesday Jul 29 2015/
no significant changes to previous tafs with VFR conditions
expected at all taf sites through the forecast period. Winds will
remain southeast through Thursday morning before turning
west/southwest in advance of a weak cold front that will begin to
impinge on the region from the northeast Thursday afternoon. With
a relatively diffuse surface pattern in place...there will not be
an abrupt wind shift but rather a slow transition to light
variable winds followed by increasing easterly winds along and
behind the frontal zone. Regardless...wind speeds are expected to
remain at or below 10 kts so cross-wind issues for north/south
runways are not expected.
Guidance has backed off further on convective coverage associated
with the cold front over the next 24 to 48 hours. It is unlikely
that showers or thunderstorms will impact any taf sites on
Thursday with the frontal zone displaced to the east. The best
chances for any convective activity...although still slim...will
be on Friday afternoon just outside of the extended dfw taf.
Preliminary point temps/pops...
Dallas-ft. Worth, Texas 102 79 98 76 95 / 10 10 30 10 5
Waco, Texas 101 76 100 74 97 / 10 10 30 10 10
Paris, Texas 101 72 96 72 95 / 20 20 20 0 5
Denton, Texas 101 73 97 71 95 / 10 20 30 10 10
McKinney, Texas 101 74 97 72 95 / 20 20 30 5 5
Dallas, Texas 102 80 99 77 96 / 10 20 30 10 5
Terrell, Texas 102 75 98 74 96 / 20 20 30 10 5
Corsicana, Texas 101 77 98 74 99 / 10 10 30 10 5
Temple, Texas 102 75 100 75 98 / 10 10 30 20 10
Mineral Wells, Texas 102 74 98 72 96 / 10 10 30 10 20