890 
FXUS64 KFWD 200726
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
226 AM CDT Sat Jul 20 2019


.LONG TERM...
/Sunday onward/

Little has changed with the synoptic pattern across North America
during the past 24 hours, with a classic, mid-summer "Ring of 
Fire" pattern remaining in place. Strong zonal flow continues 
across the north-central United States, with an 80 knot jet 
streak centered over eastern Montana and western North Dakota. 
Multiple mesoscale convective complexes are riding through this 
flow from the Dakotas to Lake Erie. To the south of the jet 
stream, a stout subtropical ridge remains anchored across the 
southern two-thirds of the United States, which will bring record 
heat to the East Coast this weekend.

For the rest of the weekend, the ridge will be the dominant
factor, with seasonably hot weather (i.e. hot, but not unusually
so for North Texas in late July) will continue. Highs should 
reach the upper 90s for most locations, with a few spots 
potentially exceeding 100 F. The one piece of good news is that 
humidity shouldn't be too out of control, which will keep heat 
index values below advisory criteria. Saturday and Sunday do
appear to be DFW and Waco's last shot at getting their first
100-degree day for at least the next seven days, because a 
pattern change is coming.

Heading into the work week, a deep mid-tropospheric trough will 
amplify over the eastern two-thirds of the United States, which 
will drive a cold front south across the Great Plains. This cold 
front looks to arrive in our northern counties along the Red River
some time after daybreak on Monday, reach the Dallas/Fort Worth 
Metroplex around noon, and clear our southern counties during the 
evening hours. Rain chances will increase along and immediately 
behind the cold front, with the strongest lift looking to coincide
with the 850 mb cold front (which will lag behind the surface 
cold front by about 50 miles or so). While we will have the 
surface cold front, a lack of strong cyclonic vorticity advection 
aloft should limit larger scale synoptic ascent. Because of this, 
PoPs are not tremendously high, and were mainly kept in the chance
category for now. These PoPs may be bumped up in coming days 
though as the frontal passage gets within the range of the CAMs, 
and we get a better idea of what shower/thunderstorm coverage 
might look like. The bottom line is that many of us will likely 
see rain showers, and probably a few rumbles of thunder as well, 
Monday afternoon and Monday night, but rainfall amounts and 
coverage remain uncertain. With regards to severe weather 
potential, deep layer wind shear will be limited which should 
prevent much in the way of organized thunderstorms, but the 
presence of inverted-V thermal profiles and moderate instability 
along and ahead of the cold front could result in some strong to 
marginally severe thunderstorms capable of producing gusty winds 
and frequent lightning.

Rain chances will likely linger through at least part of the day
Tuesday, especially across Central Texas, where the surface front
will be close enough for some isentropic upglide to keep scattered 
showers and storms going. Rain chances should be generally on the 
decrease however, as drier air slowly moves in. It should be noted
here that this will not be like a cold season cold front where we
see a sharp drop in temperatures and dewpoints with the frontal 
passage. Given the time of year, the front will be somewhat 
diffuse, with the trailing air mass being heavily modified. 
Nevertheless, the persistent northerly winds behind the front 
should eventually get our dewpoints down into the lower 60s and 
possibly even upper 50s by Wednesday. Temperatures on Wednesday 
will also likely struggle to hit 90 for many locations. Given the 
low dewpoints, and temperatures some 5-10 degrees below normal 
that are expected, Wednesday is shaping up to be a very nice day 
by late July standards, so make sure to take advantage of it 
before the summer heat comes roaring back (and it most certainly 
will eventually, since we still have to get through August).

Finally, as we head towards the end of the week, we should see a
warming trend as south flow becomes reestablished, but it looks
like it'll be beyond the end of this forecast before truly intense
summer heat returns.

37

&&


.SHORT TERM... /Issued 1123 PM CDT Fri Jul 19 2019/
/Overnight through Saturday night/

Subsidence under a ridge of high pressure will keep seasonably hot
and rain-free weather in place across North and Central Texas
overnight through Saturday. A weak easterly wave over the Gulf
will drift westward through the day Saturday, bringing scattered 
high clouds to the region. These clouds will have little to no 
influence on temperatures with overnight lows cooling into the 
middle and upper 70s. Highs Saturday will be similar to the past 
several days with middle and upper 90s region wide. The breezy 
southerly winds will continue through Saturday which will keep the
boundary layer well mixed and afternoon heat index values below 
105. 

No major changes are expected Saturday night, but wind speeds may
be a bit lighter ahead of a cold front that will be moving 
through the Central Plains. The lighter wind should result in 
slightly cooler overnight lows (1 or 2 degrees), but it will 
hardly be noticeable.

79

&&

.AVIATION... /Issued 1123 PM CDT Fri Jul 19 2019/
/06Z TAFs/

No changes from the 00Z TAF package with only scattered high
clouds overnight and a breezy south/southeast wind. Stratus  
is still expected to develop across Central Texas overnight, with
temporary MVFR ceilings at Waco for a few hours around sunrise
Saturday. Otherwise, VFR is expected across the entire region 
from mid morning Saturday through the evening. A south wind will
prevail between 12 and 18 knots along with a few higher gusts.

79

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    97  78  98  78  93 /   0   0   0   5  30 
Waco                97  76  98  75  99 /   0   0   0   0  20 
Paris               93  75  93  75  87 /   0   0   5  10  40 
Denton              97  77  98  77  92 /   0   0   0   5  30 
McKinney            96  76  97  77  92 /   0   0   0   5  30 
Dallas              98  79  98  79  94 /   0   0   0   5  30 
Terrell             95  76  98  77  95 /   0   0   5   5  40 
Corsicana           94  75  94  75  93 /   0   0   5   5  30 
Temple              96  74  96  75  98 /   0   0   0   0  20 
Mineral Wells       97  74  97  74  91 /   0   0   0   5  20 

&&

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

$$

37/91