NWS Area Forecast Discussion

FXUS64 KFWD 172346

Area Forecast Discussion
National Weather Service Fort Worth TX
546 PM CST Fri Jan 17 2020

/00Z TAFs/

Concerns -- LIFR/VLIFR CIGs/vsby through the evening. Conditions
improving ahead of FROPA, but remaining IFR/MVFR. Gusty northerly
winds behind FROPA.

Terminals across North and Central Texas are generally reporting
IFR, LIFR, or even VLIFR at this time. Dense FG has developed
across much of the region, reducing vsby to less than 1/2SM at
times, along with vertical vsby of less than 300 ft AGL. These
conditions should persist, at least intermittently, for another
few hours. As a warm front (presently near the Red River)
continues to lift north, conditions should improve to IFR.

Late tonight, a cold front will approach from the northwest. Winds
will veer ahead of the cold front, bringing drier air into the
region, resulting in a gradual improvement of CIGs/vsby. The cold
front should arrive in the Metroplex and at KACT around 11-12Z
Saturday morning, with CIGs/vsby improving quickly upon its
passage. While all terminals should be VFR by late morning, strong
and gusty winds of 15-20 KT will overspread the region. Winds
should diminish after sunset Saturday.



.LONG TERM... /Issued 251 PM CST Fri Jan 17 2020/
/Saturday night through Friday/

A building upper ridge across the western U.S. will keep dry
northwest flow aloft across the Southern Plains late in the
weekend through early next week. Dry air will also remain in the
low levels of the atmosphere through the first part of next week
as surface high pressure builds southeast out of the Northern and
Central Plains. After a cold night Saturday night with lows from
the upper 20s to the lower 30s, temperatures will warm closer to
seasonal normals Sunday and Monday with highs in the lower and
middle 50s and lows in the lower and middle 30s.

Tuesday will be a transitional day as an upper ridge axis passes
to the east ahead of a fast moving shortwave. Typically this
pattern would bring a fast return of low level moisture, however,
a weak backdoor cold front will likely keep dry air and below
normal temperatures across the northeast half of the region. Some
low rain chances will return to the western zones late in the day
Tuesday as the shortwave moves across West Texas. Moisture will be
limited so we will keep PoPs low. Better rain chances will arrive
Tuesday night and Wednesday with the passage of the shortwave.
There will likely be enough instability for some isolated thunder
as well.

The extended models continue to develop a deep trough across the
Central Plains Thursday, but the GFS and ECMWF still differ on
the strength. If either solution verifies, it will result in a
good chance of showers and some thunderstorms Thursday/Thursday
night with most of the precipitation ending by Friday. Temperature
profiles suggest that all precipitation will remain liquid, but
depending on how far south the system tracks, there may be a
slight chance for a few flakes of brief sleet wrapping around the
departing system. Since confidence in the track of the upper
system is very low, we will not include any winter precipitation
in the current forecast.



.SHORT TERM... /Issued 1210 PM CST Fri Jan 17 2020/
/This Afternoon through Saturday/

A surface low is currently situated over South Texas with a warm
front extending northeast across Southeast Texas, and a weak
surface trough extending northward along I-35. The Metroplex is
currently split between northwest winds and temperatures in the
40s on the west side of the trough, and southeast winds/lower 50s
temps on the east side. On either side, as is the case across most
of the region, fog and occasional drizzle continues to linger and
may end up hanging around through the afternoon and into the
evening. Fortunately, there is no dense fog as visibilities have
remained a mile or more. There will be a broad range in high
temperatures, with the western-most counties likely topping out in
the 40s, areas east of the I-35 corridor in the 55 to 60 degree
range, and the southern-most counties (who will end up south of
the warm front) near 70.

Showers will be on the increase later this afternoon as a
shortwave disturbance lifts northeast across the region.
Precipitation associated with this feature is already increasing
over South Central/Southwest Texas. Visibilities will likely
improve as the showers move in and mixes out the fog.
Thunderstorms will be possible, but should remain fairly isolated
due to limited instability.

The shortwave will exit to the northeast as a cold front moves in
from the northwest tonight. Convergence along the front should be
sufficient for additional showers overnight, mainly east of I-35
where the better moisture will linger. The front should reach the
I-20 corridor just before daybreak Saturday, then push through
the remainder of the area Saturday morning. Cooler and drier air
behind the front will keep temperatures in the 40s and 50s for



Dallas-Ft. Worth    46  54  33  53  34 /  70   0   0   0   0
Waco                52  57  30  54  31 /  60  20   0   0   0
Paris               47  53  30  51  32 /  80   5   0   0   0
Denton              44  53  31  52  31 /  80   0   0   0   0
McKinney            45  54  32  52  32 /  80   5   0   0   0
Dallas              46  55  34  53  35 /  70   5   0   0   0
Terrell             49  56  32  52  32 /  60  10   0   0   0
Corsicana           52  56  33  53  34 /  60  20   0   0   0
Temple              52  58  33  53  33 /  50  20   0   0   0
Mineral Wells       42  54  30  52  31 /  60   0   0   0   0


Dense Fog Advisory until midnight CST tonight for TXZ092-093-




NWS FWD Office Area Forecast Discussion