Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus64 kfwd 131954 

Area forecast discussion
National Weather Service Fort Worth Texas
254 PM CDT sun Oct 13 2019

Long term...
/Monday night - early next weekend/

The early half of the week continues to be advertised as a wet
period, as we move into late Monday night through Wednesday
evening. With the area fully encompassed within the broader warm
sector, moisture at the mid level will continue to increase within
the southern stream of the westerlies as a tropical disturbance
near Baja California and western Mexico gets drawn quickly east-
northeast toward the Southern Plains and lower Mississippi Valley.
Meanwhile, low level south-southwest flow will draw rich moisture
from the western Gulf of Mexico north-northeast into East Texas,
The Ark-la-tex, and points east. Though the atmosphere will be
warm and moist, thermodynamic profiles do not show impressive
instability until Tuesday and in advance of our next strong
surface cold front. With mid level moisture being enhanced from
the tropics of the eastern Pacific across the area and combining
with the ever increasing low level moisture from the Gulf of
Mexico. It appears the axis of the heaviest rains will be
centered on either side of I-20 from East Texas eastward into
Mississippi and Alabama.

The highest rain chances for our counties will exist well east of
I-35 as low level flow through 850mb veers southwesterly. This
veered component of the low level jet will focus the stronger
Theta-east advection from East Texas and The Ark-la-tex east through
northern louisana into Mississippi/Alabama. That said, increased
forcing from a stronger mid level disturbance moving southeast
out of the northern stream progressive flow over the area will
combine with low level convergence along the approaching cold
front and the right entrance region of a 100-120 knots jet
maximum Tuesday to provide fairly widespread showers with
scattered thunderstorms by afternoon -- continuing through mid
evening Tuesday. Though isolated areas of heavier rainfall to
between 2-3 inches "may" fall across our far eastern counties, it
appears amounts of 1-2 inches will be more the rule thanks to the
progressive nature of the cold front and strong west-northwest
flow aloft and the pre set up occurring east of our County Warning Area.

Speaking of our next surface cold front; this feature is now
being forecast with an earlier arrival. The Red River valley
should see a frontal passage sometime by early-mid afternoon
Tuesday, before surging quickly south through the entire County Warning Area
Tuesday night. This earlier arrival appears reasonable with good
support from the stronger northern stream mid level impulse
moving southeast across the area Tuesday night and into the lower
Mississippi Valley/southeast Continental U.S. Wednesday morning. After a
humid day with highs in the 80s Tuesday, gusty north winds 15-25
mph on Wednesday will usher in a cooler and drier airmass into the
County Warning Area. A few showers and isolated, elevated thunderstorms may linger
across central through daybreak Wednesday as ascent aloft briefly
lingers overhead. That said, most locales will see rapid north-
south clearing of the cloud canopy, the increasing insolation of
which will help to the counter low level cold advection and allow
for high temperatures to warm into the low-mid 70s Wednesday

Surface high pressure settles in across the area Wednesday night
and Thursday morning under good radiational conditions. There will
definitely be fall chill to the air when waking up Thursday
morning with lows falling quickly into the 40s, though immediate
urban areas may stay up closer to 50 degrees Thursday morning.
The rapidly transitioning theme to our weather pattern continues
for the end of the week as the surface high shifts quickly east of
the area late Thursday into Friday morning as shortwave ridging
aloft takes hold. The result will be southerly winds returning at
the surface to areas west of I-35 by Thursday afternoon with highs
pushing 80 degrees across areas west of U.S. 281. Elsewhere,
highs in the 70s can be expected on what should be a beautiful
fall day. Despite the onset of southerly winds Thursday night, the
dry airmass and mostly clear skies in place will still allow for
good radiational cooling with lows in the 50s starting our day on
Friday. Mid-high level moisture will be on the increase from the
west Friday afternoon and Friday night, as a new system begins
organizing over The Rockies. A breezy and warmer day will be on
tap with highs warming well into the 80s. A few areas west of U.S.
281 where lower humidity will be in place may even push 90

Friday evening should be breezy and mild for outdoor events;
before moisture advection begins increasing across areas east of
I-35 for low convective chances late Friday night into Saturday.
At this time, Saturday appears to be the next very warm day with
breezy south winds. Once again, highs will surge well into the 80s
most areas with an isolated reading around 90 degrees possible
where the humidity is lower across the western County Warning Area. Our next big
shot of rain and thunderstorms arrive late next weekend into
early next week, but as is typical with deep energy 7 days and
beyond in time, medium range deterministic models are struggling
with the speed and depth of the mid level energy and are thus
fairly unreliable. That said, both the gefs/eps ensembles show a
deep latitudinal trough across the central Continental U.S. And east of The
Rockies for the early part of the following week. What this
signals is likely some unsettled and cool Fall weather for this
part of the country. We should get better upper-air sampling of
the system late next weekend as we move through this week.



Short term... /issued 1236 PM CDT sun Oct 13 2019/
/through Monday afternoon/

Synopsis: after a beautiful weekend, cloud cover and rain chances
will increase on Monday and continue into Tuesday. A few
thunderstorms will be possible in central Texas on Monday, but the
severe weather and heavy rain threats appear low through Monday

An absolutely picture perfect day today across much of north and
central Texas. Temperatures are in the upper 60s to lower 70s
across the County Warning Area, with abundant sunshine along and
west of I-35. Cloud cover has been a little more stubborn to move
out east of I-35, but visible satellite loops do show some breaks
in the cloud cover, so there should at least be a mix of cloud and
sun. Highs today should top out in the low 70s in our southeastern
counties, mid 70s along the I-35 corridor, and upper 70s to near
80 out west where sunshine has been the most abundant. Rain
chances are coming, so please get outside today!

Big changes in the weather will begin tonight. A surface warm
front will lift north across the region late, resulting in a surge
of low-level moisture. Aloft, a steady stream of Pacific moisture
will increase as a weak tropical low moves into Mexico near the
Baja Peninsula. The result of all this will be increasing cloud
cover late tonight, along with enhanced warm air advection. Lows
tonight should be in the 60s for the vast majority of the forecast
area, except in the far northeast around Paris where cloud cover
won't arrive until late, resulting in a bit more radiational
cooling. Rain chances should remain near zero, maybe except for a
few sprinkles in the far southern counties.

Rain chances will increase across central Texas during the day
Monday, with the highest chances expected to be south of a Killeen
to Athens line. High-resolution models are forecasting MUCAPE
rising into the 750-1,000 j/kg range, which should be enough to
support a few embedded thunderstorms, but the severe potential
should be very low. Rain chances will further increase and spread
into North Texas heading into Monday night (see long-term
discussion below).



Aviation... /issued 1236 PM CDT sun Oct 13 2019/
/18z tafs/

Concerns -- increasing cloud cover tonight. MVFR cigs likely at

VFR and south flow prevail this afternoon as high pressure remains
in control. Late tonight...a warm front will lift north ahead of
an upper-level shortwave trough. This will lead to increasing
cloud cover from southwest to northeast across the forecast area. Cigs are
likely to fall to MVFR at kact by mid-morning Monday. Cigs should
remain at or above 3 kft above ground level for metroplex taf sites as low-level moisture
will arrive a little later...but cigs down to around 4 kft above ground level
still appear likely. Trends will need to be monitored.

Extended outlook: look for increasing chances for rain showers/thunderstorms and rain late
Monday night and into Tuesday with impacts possible at all



Preliminary point temps/pops...
Dallas-ft. Worth 62 78 69 86 55 / 0 10 70 60 30
Waco 62 76 70 88 57 / 5 20 40 60 40
Paris 53 76 63 79 52 / 0 10 60 70 30
Denton 59 79 68 86 52 / 0 10 60 60 20
McKinney 58 77 68 85 54 / 0 10 70 60 30
Dallas 63 79 70 86 56 / 0 10 70 70 30
Terrell 59 77 68 85 55 / 0 20 70 70 40
Corsicana 60 77 68 84 56 / 0 20 50 70 50
Temple 64 78 70 89 58 / 10 20 30 50 40
Mineral Wells 60 80 67 87 51 / 0 5 50 50 20


Forward watches/warnings/advisories...

National Weather Service Glossary of Abbreviations