Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/13/21
Area Forecast Discussion
National Weather Service Fort Worth TX
630 PM CDT Mon Apr 12 2021
...New Short Term, Aviation...
.SHORT TERM... /NEW/
The cold front was near a line from Bonham to Grapevine to
Goldthwaite at 600 PM and will continue to slide slowly southward
through the evening. It still appears the best chance for storms
will be across the southwest zones where instability, moisture and
lift along the front will be maximized (See detailed discussion
below). Farther north, the cap will most likely hold, but post
frontal storms (non severe) will be possible late this evening and
overnight as a shortwave ejects out of southwest Texas.
No significant changes are needed to the forecast at this time.
/Today and Tuesday Morning/
A conditional risk for strong to severe storms exists late this
afternoon and into the overnight hours. The area most prone to
severe weather...should storms develop...will be across Central
Texas. The main hazards will be large hail and damaging winds.
Satellite imagery early this afternoon paints the picture for why
there`s a conditional risk for severe weather. A dense cirrus
canopy continues to shade the northern half of the forecast area.
While latest AMDAR from Dallas Love Field indicates the cap has
weakened, the shading likely will mean we won`t reach convective
temperatures across North or even Central Texas. Furthermore, low
level convergence this afternoon along a cold front that extends
from near a San Angelo to Mineral Wells to Ardmore, OK, line will
be insufficient to overcome the cap without large scale forcing
for ascent. Hi-res guidance has steadily latched on to this and
it is appearing more and more likely that this afternoon will
remain quiet for most of North and Central Texas. I`ve nudged PoPs
down to below 20 percent through 00 UTC Tuesday (this evening) a I
expect that convective initiation will likely occur west of our
area across the Concho Valley. If storms can develop across
Central Texas in the warm sector, there will be a large hail and
damaging wind risk with CAPE values over 2000 J/kg and deep layer
shear supportive of supercells.
This evening, the front will slowly move southward into Central
Texas with a subtle upper wave approaching from the southwest.
This will induce some modest upglide atop the cooler frontal
surface and we should see an increase in convective activity
across the Big Country between 0200-0400 UTC. Forecast soundings
indicate plenty of deep layer shear for organized convective modes
with and we may have to contend with a marginal severe hail threat
after dark. PoPs increase to near 50% from the Big Country up
through North Texas after midnight Tuesday with 20-30% lingering
PoPs after daybreak across East and Central Texas. The front will
likely clear just about all of the area before stalling somewhere
across the Brazos Valley Tuesday morning. There could be some
patchy fog along the front where low level moisture convergence
takes place. At present time, I`ll omit this from the forecast
given the low confidence, but we`ll monitor the potential.
Widespread cloud cover is expected to grip most of the area on
Tuesday as the frontal boundary stalls to the south. Another
subtle shortwave will approach from the southwest and 850mb flow
is expected to respond initially with the surface features lagging
a bit thereafter. A slight surge in low-level theta-e will
certainly result in widespread cloud cover as well as increasing
rain chances (slight chance to chance). Right now, the risk for
severe elevated convection looks low during the day on Tuesday,
but we`ll need to watch this potential closely. Otherwise, expect
temperatures in the low to mid 70s with mostly cloudy skies.
.LONG TERM... /Issued 305 PM CDT Mon Apr 12 2021/
/Tuesday Night Onward/
An active period of weather will continue through the remainder of
the week, as several upper level disturbances will bring chances
for showers and thunderstorms each day. With cloudy and cool conditions
sticking around for the next few days, it will be quite dreary
across North and Central Texas.
Tuesday evening, a warm front will retreat northward out of Southeast
Texas. As warm advection/isentropic ascent increase ahead of the
boundary, a few strong storms may develop. With elevated instability
and ample deep layer shear in place, a severe storm or two cant
be ruled out south of I-20 and east of I-35. Additionally, steep
lapse rates may pose a hail threat near and along the Red River if
more robust updrafts are able to develop.
A threat for strong to severe storms is not expected the rest of
the week, but there will be chances for showers and thunderstorms
each day. Much cooler temperatures will continue for the next
several days with highs mostly in the 60s to low 70s (5 to 15+
degrees below normal!). Better rain chances will arrive Thursday
night into Friday as another disturbance swings through the area.
Another cold front will push through the area late Friday into
Saturday. Cooler weather is expected on Saturday behind the
front, along with additional chances for showers and thunderstorms.
It`s possible that the second half of the weekend will be largely
rain-free with even a few peeks of sunshine. Warmer weather will
likely make it`s return sometime early next week.
A weak cold front will continue to slide through North Texas early
this evening bringing a north wind shift and a slight increase in
wind speeds. Thunderstorms along the front will remain well to
the southwest of the area where there is abundant moisture and
instability. It does appear that some post-frontal showers and
thunderstorms will develop late this evening and overnight across
North and Central Texas when a shortwave moves across the region.
The best window of time for showers and elevated storms will be
from about 06Z until 10Z at the Metroplex TAF sites with a
slightly earlier onset time in Waco.
VFR ceilings this evening will lower to MVFR levels overnight as
moisture is lifted over the shallow cold front. MVFR ceilings
between 1500 and 2500 ft should linger at all TAF sites through
at least early afternoon Tuesday, lifting above 3000 ft in the
mid to late afternoon.
The wind at AFW and FTW was already north/northwest as of 23Z and
a north wind shift will occur at DFW, GKY and DAL over the next
hour or so. The front will not move through Waco until about 03Z.
Wind speeds through Tuesday afternoon will range from 7 to 11
knots along with a few higher gusts.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 57 75 55 69 54 / 50 20 60 30 40
Waco 59 75 58 70 55 / 40 30 60 30 40
Paris 56 73 53 66 50 / 30 20 60 20 30
Denton 52 71 52 67 48 / 50 20 60 30 40
McKinney 55 73 54 68 50 / 40 20 60 30 40
Dallas 59 75 56 69 55 / 40 20 60 30 40
Terrell 57 75 56 70 51 / 30 20 60 30 40
Corsicana 59 76 58 69 54 / 30 20 60 30 40
Temple 60 75 59 71 54 / 30 30 50 30 40
Mineral Wells 53 71 52 65 50 / 40 30 60 40 40