287 
FXUS64 KFWD 032057
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
257 PM CST Sun Mar 3 2019


.SHORT TERM...
/Tonight and Monday/

The main concern tonight and tomorrow will be the very cold
temperatures and wind chills expected across North and Central
Texas. With the arctic airmass now in place and a surface high 
across the Texas Panhandle, northerly winds will continue through 
this period helping to advect cold and dry air into the region. 
Lows tonight will be in the teens for areas northwest of a Bonham 
to Denton to Cisco line. The rest of the region will remain in the
20s to around 30 degrees. Winds will gradually decrease in speed 
tonight, but still remain between 10-15 mph, with gusts up to 
around 20 mph. The combination of the cold temperatures and breezy
conditions will yield wind chill values in the single digits 
within the northwestern zones of North Texas. Wind chill values in
the teens and 20s are likely elsewhere. 

The forecast does become a bit more tricky between midnight and 
sunrise Monday as a weak shortwave traverses across Oklahoma. Low
level moisture will be lacking, but further analysis of the mid
levels indicate moisture will be increasing as a region of
positive vorticity moves overhead.  Isentropic ascent will also 
be maximized between the 300K-310K layer beginning around midnight
in the northwest, then continue moving east along the Red River through
6AM. Hi-resolution models are in good agreement that a few snow 
showers may develop in the vicinity of the Red River. Given most 
solutions displayed a higher potential north of the Red River, 
have kept the potential for snow showers at or below 15%. No 
accumulations are anticipated from any snow showers given both the
light intensity and the breezy winds blowing around any flakes 
that fall. 

Snow showers will quickly dissipate around sunrise as the forcing
for ascent moves to the east. Unfortunately for those that are 
ready for spring, we will have to contend with yet another bone- 
chilling day with highs struggling to climb above freezing for 
many. Those east of I-35 and south of I-20 are the lucky few that 
will climb above 32 degrees. With 10-15 mph winds Monday 
afternoon, wind chill values will continue in the teens and 20s 
areawide. 

Another hazard we're assessing, although still appears unlikely, 
is the potential for wintry precipitation across Central Texas 
mid-morning through the afternoon Monday. The presence of 
moderate isentropic ascent in an area of RH around 90% would lead 
one to believe there would be a potential for precipitation. The 
caveat is that lapse-rates still appear to be on the low end along
with the lack of low-level moisture. It may be the case that snow
may be falling from the clouds, but without the low level 
moisture, it would sublimate before reaching the ground. For now, 
we will advertise a dry forecast but will continue monitoring for 
stronger ascent and/or steeper lapse rates, both of which could 
alter the current forecast. 

Hernandez

&&

.LONG TERM...
/Monday Night through Sunday/

A chilly Monday will give way to a cold night as temperatures 
once again plummet into the teens and low 20s. There is still some
uncertainty with how much clearing we'll see throughout the 
overnight hours, but at this time it appears only a thin ribbon 
of mid/upper level moisture will skirt over the forecast area 
leading to some intermittent high cloud cover. The general 
thinking is that this shouldn't be sufficient to prevent 
temperatures from falling quickly, with dewpoints largely in the 
single digits and wind speeds continuing to drop to 5-10 mph. 
While I've trended lows downward from previous guidance, I still 
may not have gone cold enough, with a few isolated locations in 
North Texas possibly falling as low as 12-15F. Because of the more
favorable radiational cooling conditions, temperatures could 
actually be a few degrees colder than Monday morning's lows. 
However, the lighter wind speeds will mean that wind chill values 
will stay a few degrees higher than those expected for Monday 
morning. Temperatures should warm into the mid or upper 40s for 
Tuesday afternoon under mostly sunny skies with light winds as 
surface high pressure becomes centered over the forecast area. 

Wednesday will be a transitional day as the low-level high 
pressure circulation shifts eastward and a southerly flow regime 
returns. Moisture will be slow to increase, however, as dewpoints 
were thoroughly scoured by this weekend's cold front. Surface 
dewpoints will remain in the 20s through Wednesday while 
temperatures rise into the 50s via ample sunshine and renewed 
warm advection. A tongue of rich theta-e Gulf air will finally 
make its way back into the forecast area on Thursday. This will be
due to persistent, intensifying southerly flow associated with a 
lead upper-level shortwave. The deepest moisture is progged to 
remain east of I-35, which should contribute to widespread cloud 
cover, particularly through the morning and early afternoon 
hours. Areas west of I-35 on the other hand, may experience mostly
clear skies for the majority of the day. This setup could result 
in a 15+ degree temperature spread from west to east on Thursday, 
with our eastern zones experiencing cloudy and cool conditions 
with possibly some light rain or drizzle as well. 

Continued low-level warm/moist advection will prevail into Friday,
possibly resulting in a few showers across our eastern zones
throughout the day. As the previously-discussed upper shortwave 
peels away to the northeast, an associated weak cold front may 
nudge its way into North Texas by Friday afternoon, possibly as 
far south as I-20. It appears this boundary would be unable to 
generate convection due to a stout capping inversion centered at 
800mb, strengthened by strong prevailing southwesterly flow. Have
continued to withhold a mention of thunder from the forecast 
during this time, as any precipitation would likely consist of 
lighter rain showers rooted beneath the capping inversion. Ahead 
of the front, temperatures may be capable of climbing into the 
mid or upper 70s Friday afternoon, a drastic turnaround from the 
arctic airmass that began our week.

A more potent upper-level system is on track to affect the region
late Friday through Saturday. As low-level wind fields respond to
the approaching upper trough, the stalled weak front from Friday
will quickly surge back northward through the Southern Plains,
engulfing most of the forecast area in a rich warm sector with
mid 60s dewpoints and temperatures mostly in the 70s. These
conditions should contribute to moderate surface-based instability  
within the warm sector as the main forcing with this system 
arrives. While this scenario remains several days into the 
forecast, the overall pattern does support a chance for some 
strong or severe storms, likely along the system's associated 
Pacific front on Saturday. This is also supported by extended CIPS
Analog solutions, which highlight a risk for possible stronger 
storms generally across the ArkLaTex region during this time 
frame. It would be premature to delve further into details with 
this system given the differences among guidance in the large- 
scale environment, but we encourage folks to keep an eye on the 
forecast heading towards next weekend. At this point, it looks 
like much drier and slightly cooler air will filter into the 
region behind the system's trailing cold front next Sunday. 

-Stalley

&&


.AVIATION... /Issued 1152 AM CST Sun Mar 3 2019/
/18Z TAFs/

Improving flying conditions are expected through today as the 
depth of the cold and dry air increases. Ceilings are now in the 
MVFR category across the Dallas/Fort Worth Metroplex TAF sites 
with VFR conditions expected later this afternoon. For Waco, IFR 
will linger through around 19Z before that drier air increases 
ceilings to MVFR for the afternoon. By this evening, Waco will 
join the rest of the TAF sites with VFR conditions. 

Northerly winds have been increasing in speed as the surface
pressure gradient tightens. Wind speeds will continue to
strengthen and will likely be the strongest mid-afternoon.
Sustained winds will be 20-25 kts with some gusts up to around 35
kts. By tonight, northerly winds will continue but will likely 
remain between 15-18 kts.


Hernandez

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    21  31  21  47  27 /   5   5   0   0   0 
Waco                25  36  21  46  26 /   5   5   0   0   0 
Paris               20  33  19  45  23 /  10  10   0   0   0 
Denton              20  30  20  45  24 /   5   5   0   0   0 
McKinney            21  31  20  45  24 /   5   5   0   0   0 
Dallas              23  32  23  47  28 /   5   5   0   0   0 
Terrell             23  35  22  46  24 /   5   5   0   0   0 
Corsicana           25  35  21  46  27 /   5   5   0   0   0 
Temple              25  35  22  46  27 /   5   5   0   0   0 
Mineral Wells       20  31  19  45  24 /   5   5   0   0   0 

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

08/26