Forecast Discussion for Dallas/Ft. Worth, Texas

FXUS64 KFWD 061153

Area Forecast Discussion
National Weather Service Fort Worth TX
553 AM CST Mon Feb 6 2023

...New Short Term, Aviation...


No major changes were made to the overnight forecast update, with
exception to integrating observational and guidance trends to the
near-term hourly grids for temp/dewpoint/sky/weather. Forecast
discussion below remains on track. Winds continue to be borderline
Wind Advisory Criteria, and as such, will refrain from issuing a
Wind Advisory at this time.



Previous Discussion:
/Through Tuesday Morning/

The early portions of the new week also mark the beginning of some
unsettled weather across North and Central Texas. The cause of
our mid-week rain chances is a shortwave currently spinning
across California. This shortwave will continue to move toward the
Central Plains over the day on Monday.

The region is currently sandwiched between low pressure in the lee
of the Rockies and high pressure in the Gulf of Mexico. In
response to this, southerly flow at the surface and low-levels
will prevail overnight. A resultant northerly influx of low-level
moisture and stratus, and possibly some advection fog, is
expected to move over portions of the region Monday morning.
Guidance has trended a little later with concern to the cloud
cover moving in, so have trended a little cooler with Monday
morning temperatures as compared to the Sunday evening forecast
update. Expect morning lows in the 40s and 50s.

Cloud cover will erode somewhat over the afternoon hours, but the
region will still be under partly to mostly cloudy skies.
Southerly flow at the surface and low-levels will promote
continued warming, with highs expected to peak in the 60s and
70s. The lower of the afternoon temperatures will be confined to
where the denser cloud cover will persist, mainly along the I-35
corridor and in the northeast counties.

As height falls ahead of the incoming shortwave trough move
closer to the region, the surface pressure gradient will tighten.
This will promote an increase in wind speed and gusts starting
mid-morning. Sustained speeds will peak around 15-25 mph with
gusts to around 35 mph over the mid-afternoon hours on Monday. The
uncertainty with this portion of the forecast remains on whether
or not a Wind Advisory will be needed for portions of the region
Monday afternoon. Criteria is 20-30 mph (average of 25 mph) for 2
hours or more. The NBM reaches this criteria, but most other
current guidances are just behind the benchmark speeds. With the
uncertainty of reaching criteria remaining, have foregone issuing
a Wind Advisory for this forecast update. Will continue to
monitor guidance trends overnight, and will revisit the idea by
the next forecast update time (6 AM).

The aforementioned cyclonic system will set up a dryline out to
our west, and a cold front to our northwest. The front will begin
to encroach the northwestern portions of the region early Tuesday
morning. Lift along the approaching frontal boundary will work in
tandem with the already-present moisture and slight instability
out ahead of the shortwave, and will kick off chances for rain in
the in the northwestern counties overnight into daybreak Tuesday.
Temperatures in the northwest behind the front will be a bit lower
as compared to areas out ahead. Tuesday morning temperatures will
range from the upper 40s in the far northwest to the upper 50s in
our southern Central Texas counties.



.LONG TERM... /Issued 312 AM CST Mon Feb 6 2023/
/Tuesday and Beyond/

Cooler weather and widespread rainfall is expected to start the
long-term period. An upper-level trough progressing eastward
across the Northern Plains will shift a surface cyclone across
Central Canada Monday night into Tuesday morning. A cold front
will extend from the surface low through the Southern Plains
entering our northwestern zones around daybreak Tuesday morning. Many
locations northwest of the DFW Metroplex will likely see their
high temperature early Tuesday morning. An upper-level low will
be off to our west along the AZ/NM border Tuesday morning
gradually shifting eastward toward Texas during the day Tuesday.
Scattered showers may develop along the cold front Tuesday morning
as south-southeasterly flow draws greater quality moisture
northward into North and Central Texas. Scattered showers and
maybe a few thunderstorms will remain possible primarily across
the northern and western portions during the day Tuesday as the
cold front continues progressing southeastward and the region
remains in a modestly favorable area of ascent ahead of the upper-
level low.

Model guidance has trended slower with the movement of this front
Tuesday afternoon into Tuesday night, with some medium-range
guidance suggesting it may briefly stall as it becomes displaced
from its parent cyclone and upper-level support. A pre-frontal
surface trough will enhance during the day Tuesday slowly shifting
eastward pulling the cold front in tow across the forecast area.
By late Tuesday night into early Wednesday morning, a surface low
looks to develop along the frontal zone and quickly translate
northeast allowing for the front to clear the area by late
Wednesday morning. The NAM, although a current outlier, is much
more progressive with this system suggesting the front may clear
our eastern zones by 06Z Wednesday.

Regardless, the potential for heavy rainfall will exist primarily
along and east of I-35 Tuesday evening through Wednesday morning.
Synoptic-scale lift will maximize across this region under
diffluent flow aloft as a 30-40 knot 850 mb low-level jet ramps up
east of I-35 late Tuesday evening into Tuesday night.
Precipitable water values exceeding the 90th percentile of
sounding climatology, warm cloud depths nearing 10,000 feet and
long, skinny CAPE profiles (MUCAPE ~ 300-500J/kg) will support
efficient rain rates. In addition, the mean flow will be nearly
parallel to forecasted storm motions and the surface boundary, so
repeated rounds/training storms will be possible. The WPC currently
has an area along and east of I-35/35W and north of Highway 84 in
a Day 2 Slight Risk for excessive rainfall.

The heaviest rainfall will likely exit the eastern zones by early
Wednesday morning, however light to moderate rain will continue
into Wednesday afternoon as the upper-level low finally pushes
into the forecast area and forcing for ascent is enhanced. In
general, 1 to 2 inches of total rainfall is expected along and
east of the I-35 corridor with locally higher amounts that may
lead to instances of flash flooding. Lesser amounts are expected
west of Highway 281. If guidance continues to trend slower with
the progression of the frontal system, more widespread amounts
over 2 inches will become possible. On the other hand, if model
guidance starts to trend towards the more progressive solution
offered by the NAM, rainfall totals will be less than currently

A second, deeper trough looks to quickly dive southward behind
this initial system pushing another cold front into North and
Central Texas on Thursday. With little moisture to work with, this
frontal passage should remain mostly dry. Behind the front,
afternoon highs are only expected to reach the upper 40s to mid
50s Friday and Saturday with a widespread freeze possible Friday
night into Saturday morning.



/12Z TAFs/

IFR cigs have now overspread ACT, and are beginning to creep into
the southern and eastern D10 sites. All TAF sites will be in IFR
by around 13Z.

The low stratus will lift somewhat over late morning, but will
remain MVFR through the early afternoon before lifting back VFR at
all sites late this afternoon. Southerly winds will begin to
increase in speed to around 15 kts with higher gusts late this
morning. Wind speeds and gusts will peak during the mid afternoon

Speeds will lower somewhat during Tuesday evening, but will stay
above or around 10 kts through the end of the 24-30 hour period.
Another round of MVFR/IFR cigs/vis will be possible at all TAF
sites on Tuesday ahead of a cold front. Showers will begin to be
possible in the D10 sites starting late morning, and have put in
VCSH at DFW starting 07/15Z. The precipitation and lower cigs/vis
will only be in the DFW TAF for now, as it is beyond the 24 hour
period for the other TAF sites.



Dallas-Ft. Worth    70  56  60  44  57 /   0  20  70  70  60
Waco                70  59  64  45  57 /   0  10  70  80  60
Paris               67  54  61  47  56 /   0  10  50  80  70
Denton              69  53  57  39  56 /   0  20  80  70  50
McKinney            68  55  60  43  56 /   0  10  70  80  60
Dallas              69  56  62  44  56 /   0  10  70  80  60
Terrell             70  56  63  45  56 /   0  10  60  80  70
Corsicana           72  58  64  47  57 /   0  10  60  80  70
Temple              72  57  65  43  58 /   0  10  80  80  60
Mineral Wells       73  53  58  38  58 /   0  20  80  60  40




NWS FWD Office Area Forecast Discussion