Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
FXUS64 KFWD 231206 AAA
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
706 AM CDT MON MAY 23 2016
The MCS that has impacted the Red River counties is steadily
weakening, making minimal progress to the south. However, outflow
has already shifted surface winds to the north. The southern
periphery of the complex may graze the Metroplex, but any
lightning would be short-lived. The north flow will also be
temporary. The activity should dissipate by midday, but the
outflow boundaries it lays down may be the focus for additional
thunderstorm development this afternoon. With minimal coverage and
low confidence in placement and timing, have refrained from
introducing any afternoon convection in the TAFs.
A similar MCS may be in the offing late tonight into Tuesday
morning. At this time, have focused on the more likely stratus
intrusion. With deeper moisture in place, the arrival of MVFR
ceilings tonight will be much earlier than previous days.
.PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 23 2016/
Complex of thunderstorms continues to move through southern
Oklahoma and into our Red River counties this morning with a well
defined bow echo likely to produce some severe wind gusts over the
next few hours. Atmosphere out ahead of this line of storms from
I-20 north is moderately unstable with mixed-layer CAPE near
1500j/kg with a healthy low level jet feeding into the system.
Local acoustic profiler indicates southeast winds at 20kt at 500ft
which increase to 40kt at 1800ft per the latest FWS VAD wind
profile. This fairly strong southerly flow and instability should
keep the complex moving into North Texas through early morning
affecting areas primarily north of Interstate 20. The threat for
severe weather (mainly damaging wind) appears that it will be
confined to a few of our Red River counties as instability
diminishes farther to the east and low level winds weaken. We will
have to monitor for additional development farther west which
could eventually dive south into a better environment. So through
the late morning hours...we will have the highest PoPs along our
northern tier of counties...diminishing to 20% from Interstate 20
and areas south.
There are a couple of concerns through the next 6-12 hours or so
with respect to the ongoing convection. Low level warm advection
is quite strong...and several new thunderstorms have developed
well behind the main complex within the mature cold pool. These
storms so far are staying primarily in Oklahoma but we will have
to see if additional development gets close to North Texas. Any of
these storms would likely pose a hail threat. Of slightly higher
concern is the slowing southward progression of the current line
of storms. As we head later into the morning...the low level flow
is expected to veer...becoming oriented more parallel with the
current line or its outflow boundary. As we heat up...there could
be renewed development in the same general area as the current
convection...which could result in a localized flash flood threat.
Rainfall rates with some of these storms have been as high as
3"/hr. If convection persists or trains in any given area for very
long...flash flooding would be an increasing concern. This could
also be problematic later tonight if additional thunderstorms move
over areas that are getting heavy rainfall now. At this time...no
flash flood watch will be issued given uncertainties in the
evolution of this morning`s activity...however...this potential
will be monitored closely.
The current forecast will indicate a gradual weakening of this
complex through late morning...with more stable air in its wake
into the early afternoon. We will have 20% chances of new
thunderstorm development this afternoon across North and Central
Texas. Similar to yesterday...the dryline will likely be the focus
for afternoon/evening thunderstorms across West Texas with the
best chance for storm organization across the Panhandle into
southwestern Oklahoma. These locations will again be closer to any
appreciable forcing aloft. By early evening...the atmosphere
across North Texas should have recovered and become moderately
unstable again. Thunderstorms will once again have the potential
to make a run at North Texas so we will have the highest PoPs
across the northwest half of the CWA.
On Tuesday...flow aloft will become more southwesterly which
should help strengthen the capping inversion across the region.
The dryline will make a push a little farther east by late
afternoon...so will keep some 20% PoPs across our far western
counties...otherwise most areas should remain dry.
Capping will be strongest on Wednesday with little in the way of
convection expected across North Texas. Temperatures will also
warm in response and should be in the upper 80s and lower 90s
across most of the area.
By late Wednesday night...a strong shortwave trough will be moving
into the 4-corners region with ascent spreading east into Texas.
Some elevated moisture will spread across North Texas late
Wednesday night in a region of steep lapse rates. This may result
in some spotty elevated thunderstorms so will include a 20% chance
during that time. Otherwise...thunderstorms are expected to really
increase in coverage during the day Thursday with additional
chances into Friday as the shortwave moves east across the
southern Plains. Severe weather will be possible on both days.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 87 72 88 73 90 / 40 30 10 10 5
Waco 86 71 89 74 90 / 20 10 10 10 5
Paris 85 69 84 70 86 / 60 20 20 10 5
Denton 86 68 87 71 90 / 40 40 10 10 5
McKinney 85 70 86 73 87 / 50 30 20 10 5
Dallas 88 72 89 74 90 / 40 20 20 10 5
Terrell 87 70 87 72 88 / 30 20 20 10 5
Corsicana 87 72 89 73 89 / 20 10 10 10 5
Temple 85 70 87 72 89 / 20 10 10 10 5
Mineral Wells 86 69 87 71 91 / 20 30 20 20 5