Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
FXUS64 KFWD 180338 AAB
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
938 PM CST Fri Feb 17 2017
The inherited forecast remains in good shape with only a few
minor changes necessary.
Afternoon clouds have continued to clear eastward as dry air
wraps around the back side of a mid/upper level low. Cloud cover
will fill back in; however, the strengthening low level wind
field should induce isentropic ascent along the 295/300K theta
surfaces. The increasing low level moisture/weak ascent will also
likely result in some patchy drizzle, especially for areas along
and northeast of a Jacksboro to Denton to Athens to Rockdale line.
Overnight low temps across the area look to be on track, but I
did nudge them up by a degree or two across far northwestern zones
where a ribbon of low level moisture continues to lift towards
the west and northwest.
The rest of the forecast remains unchanged and updated products
have been transmitted.
/ISSUED 618 PM CST Fri Feb 17 2017/
An upper level low over south central Oklahoma just before 00z
Saturday, will continue to move east northeast. A southerly low
level jet will develop this evening, bringing MVFR stratus
northward along and east of the I-35 corridor (including Waco and
the Metroplex TAF sites). Have brought these ceilings into the
TAF sites 05-07z and kept them into through 16-17z. South winds 10
to 15 knots will prevail through 23z Saturday with winds expected
to back around to the southeast afterward.
.PREV DISCUSSION... /ISSUED 408 PM CST Fri Feb 17 2017/
Afternoon satellite imagery shows extensive cloud cover mainly
across east Texas into Louisiana associated with a shortwave
trough moving through the Southern Plains. There are a few high
based cumulus clouds noted over the last hour across North Texas.
These are associated with some very shallow moisture in the
presence of forcing for ascent. It appears the moisture will be
too sparse for any high based convection to develop through the
remainder of the afternoon...although some virga is likely to be
Tonight will feature some low/mid level drying as the main
shortwave moves to the east of the area...which should lead to
mostly clear skies across the southwestern part of the CWA.
Our eastern and northern counties will likely remain cloudy later
tonight into early Saturday as southerly winds pull in some Gulf
moisture on the east side of a developing surface low. This low is
expected to be near Wichita Falls early Saturday morning. Outside
of some patchy drizzle in our northeast counties late tonight and
early Saturday...skies should remain precipitation free during
this time. The southerly flow will keep temperatures warm tonight
with lows only falling into the mid 50s. Areas to the southeast
where cloud cover is minimal will fall into the mid 40s.
A much stronger upper disturbance will be digging into northwest
Mexico late tomorrow. This will be the system that will bring rain
and thunderstorm chances to North Texas Sunday into Monday. Prior
to this system arriving...brief shortwave ridging will pass
overhead during the day tomorrow. This should result in partly
cloudy skies with temperatures warming into the mid/upper 70s
across most of the region tomorrow. Temperatures may linger in the
60s across the northeast counties where more extensive cloud cover
As we head into Sunday...stronger forcing for ascent will
overspread much of the Southern Plains ahead of the strong upper
low. Deep southerly flow will become established by midday and
allow a little more expansive warm sector to become developed.
This warm sector is likely to spread north through the afternoon
hours. A dryline is expected to move east through midday and will
likely be near our western counties by early afternoon. With the
approach of the upper trough...expect a rather stout capping
inversion to lift and scattered showers and thunderstorms to
develop by afternoon. Latest guidance suggests that the atmosphere
will become moderately unstable with mixed layer CAPE around
1200 j/kg along with 50 kt of deep layer shear. The shear profile
is nearly unidirectional although some localized backing of the
low level flow will be possible during the mid afternoon hours
near the effective warm front. Steep lapse rates and modest low
level flow will primarily support a hail and damaging wind threat
although an isolated tornado can`t be ruled out. The severe
threat will persist into the evening hours before loss of heating
erodes surface based instability.
Later Sunday night...the convective area should become more
organized into a linear structure and will likely transition into
more of a heavy rainfall threat with deep moist southerly flow
feeding into the system. The overall line should remain
progressive to the east...although training echoes within the line
could produce some localized heavy rainfall amounts. At this
time...we think the heaviest rainfall will occur east of I-35 late
Sunday night into early Monday. Precipitation should end from west
to east early on Monday.
The remainder of the forecast will be dry as ridging builds in
behind the main system. Another fast moving system will swing
through the Plains late week...although moisture appears to be too
limited for precipitation at this time.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 55 76 57 76 61 / 5 5 5 50 80
Waco 55 81 58 76 59 / 5 0 10 50 80
Paris 52 68 53 76 60 / 10 10 0 10 80
Denton 53 72 54 74 58 / 5 5 0 50 80
McKinney 54 71 54 76 60 / 5 10 0 30 80
Dallas 56 76 58 76 61 / 5 5 5 40 80
Terrell 54 74 57 78 61 / 10 5 5 30 80
Corsicana 56 77 59 79 61 / 10 5 5 40 80
Temple 54 81 59 75 59 / 5 0 10 50 80
Mineral Wells 51 77 53 74 56 / 0 0 5 50 50