-- Discussion containing changed information from previous version are highlighted. --
413
FXUS64 KFWD 180829
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
329 AM CDT Wed Sep 18 2024

...New Long Term...

.SHORT TERM... 
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/Issued 110 AM CDT Wed Sep 18 2024/
/Today and Tonight/

North Texas will remain in the grip of an upper level ridge
extending from northern Mexico into the Central Plains. Subsidence
associated with this feature will continue to produce clear skies
and temperatures that are noticeably above normal for the last
half of September. Highs will climb well into the 90s across the
entire area later today, while lows tonight will only manage to
reach the lower 70s. A southerly flow regime will pump renewed
moisture into the region, contributing to heat indices that will
push past the century mark in many locales later today.

Bradshaw
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&&

.LONG TERM... 
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/NEW/
Update:
The current forecast generally remains on track with anomalous
heat persisting through the weekend amid the prevailing mid-level
ridge. Increasing mid-level heights and inflated temperature
anomalies in the 850-700 millibar layer signal particularly strong
heating beginning Thursday. Daytime temperatures have been
adjusted above NBM guidance in favor of recent trends in the MOS
guidance. Friday is currently forecast to be the warmest day of
the week with parts of North Texas topping out around 100F and
widespread triple digit heat indices. Precipitation prospects
unfortunately remain negligible for most areas until at least the
middle of next week. The previous forecast discussion is appended
below for reference.

12

Previous Discussion:
/Thursday Through Early Next Week/

Unseasonably strong ridging will intensify into the weekend above
the Southern Plains as persistent troughing dominates both the
West and the East. Temperatures will steadily climb in tandem with
rising 500mb heights, which will top 5900m by Friday. All
available perfect-prog guidance projects 500mb temperatures above
the Dallas/Fort Worth Metroplex will rise above -1C (into the 30s
in Fahrenheit) on Friday. The NAM has 500mb temperatures above
freezing! This isn`t just near-record for September but would
challenge the all-time record high 500mb temperature for our local
weather balloons (1950 to present), which is -0.5C from July 1951.
Despite intense subsidence and similarly impressive temperature
anomalies at 700 and 850mb, a remarkably humid boundary layer,
combined with the shorter days and lower sun angles of September,
may keep Friday`s high temperatures below daily record highs
(values in the climate section below). MOS guidance has highs near
100F Friday afternoon for many locations, including DFW and Waco.
Heat index values will exceed 100 across much of the region late
in the week and into the upcoming weekend, with the highest values
occurring on Friday.

An upper low will emerge from the Rockies on Saturday. Although
its associated cold front will likely get no closer than the Texas
Panhandle, it will reorient our upper ridge. Combined with an
influx of high clouds, this may shave a few degrees off afternoon
temperatures on Saturday. However, there will still be the
potential for temperatures to threaten the century mark in some
locations. Decaying frontal convection from West Texas may invade
from the west Saturday night into Sunday morning; these showers
are the only rain chances in the 7-day forecast.

Early next week, the ridge will be displaced to our south. While
this will bring an end to the threat of triple digits,
temperatures will remain above normal with highs generally in the
90s Sunday through Tuesday. However, extended guidance knows that
cold fronts cluster around the autumnal equinox (which is on
Sunday). Although there is considerable disparity among
operational solutions and ensemble members, there is some hope for
a cold front during the middle of next week. But don`t break out
the winter coats just yet; the Climate Prediction Center continues
to favor above normal temperatures through the end of the month.

.CLIMATE...

Record Highs for September 20 (Friday)
   DFW       102 in 1953
   Waco      101 in 2021
   Killeen   100 in 2021

(DFW Airport was 100 degrees on September 20, 2021.)

Although all 3 sites recorded later triple-digit days last year,
each location has only reached the century mark this late in the
year (September 20 and later) 5 years this century.

25
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&&

.AVIATION... 
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/Issued 110 AM CDT Wed Sep 18 2024/
/06z TAFs/

VFR conditions will prevail at all TAF sites through 12z Thursday,
as upper level high pressure maintains its grip on the region. Scattered
cumulus clouds will develop areawide after 15z this morning;
otherwise, skies will remain clear. Low level east to southeast
winds prior to dawn will shift to a southerly direction at speeds
of 8-12 knots by midday, as a trough of low pressure develops in
the lee of the Rockies.

Bradshaw
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&&


.PRELIMINARY POINT TEMPS/POPS...
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Dallas-Ft. Worth    94  76  98  77  99 /   0   0   0   0   0
Waco                96  74  99  74  98 /   0   0   0   0   0
Paris               91  71  94  72  96 /   0   0   0   0   0
Denton              96  73  98  74  99 /   0   0   0   0   0
McKinney            95  73  97  75  98 /   0   0   0   0   0
Dallas              96  76  98  77 100 /   0   0   0   0   0
Terrell             94  72  97  73  99 /   0   0   0   0   0
Corsicana           96  74  98  75  98 /   0   0   0   0   0
Temple              97  73  98  72  98 /   0   0   0   0   0
Mineral Wells       97  73  97  72  99 /   0   0   0   0   0
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&&

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

$$