Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
FXUS64 KFWD 130336 AAB
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
936 PM CST Thu Jan 12 2017
The shallow arctic front continues to move southward this evening
and extended southeast of a Sulphur Springs to Hillsboro to
Comanche line as of 9 PM. It looks like the cold front will likely
move to near an Athens to Temple to Lampasas line before becoming
stationary toward daybreak. Have lowered temperatures by a few
degrees across most of the forecast area to the north of the
front. An update was done earlier to delay the development of rain
until after midnight and have delayed the timing by a few more
hours with this update. All updates have been sent.
/ISSUED 600 PM CST Thu Jan 12 2017/
A sharp and very shallow arctic front has cleared all of the
Metroplex TAF sites and presently stretches from near a KCPT to
KJWY to KHQZ line. VFR cigs are expected to persist this evening
before cooling atop the frontal inversion results in the
proliferation of MVFR and then IFR cigs tonight. Timing the
development of these lower clouds, however, is proving difficult.
IFR cigs and drizzle and/or light showers will likely be the rule
through the morning on Friday before some marginal improvement
towards low-end MVFR occurs during the afternoon. At Waco, the big
question remains whether or not this front will make it through
the airfield. Given the shallow/dense nature of this front, the
best guess at this time is that the front will bleed into the area
towards Friday morning, bringing about a north wind shift and the
development of MVFR/IFR cigs.
As warm advection increases on Friday, showers should stream
northward across the region. However, coverage at this time
appears too low to warrant a mention of -SHRA/VCSH, but will
consider this in subsequent TAFs.
Finally, the very shallow nature of this front brings up some
concern from LLWS with north winds at the surface around 10 kts,
surmounted by southerly winds potentially increasing to around
30 kts around 2 kft overnight. We`ll monitor trends regarding
LLWS this evening.
.PREV DISCUSSION... /ISSUED 343 PM CST Thu Jan 12 2017/
A cold front was sliding slowly south across North Texas this
afternoon. The front was beginning to lose its punch and will
most likely stall south of the Interstate 20 corridor tonight.
Temperatures will vary greatly across the CWA with the Red River
counties cooling into the middle 30s and the southwest zones
remaining warm with middle 60s.
Scattered showers are expected to develop tonight with increasing
isentropic lift. The best chance of showers will be along and
just north of the front. Some patchy drizzle and fog will also be
possible generally south of the front during the overnight hours.
The cold front will remain nearly stationary on Friday as two
distinctly different airmasses battle for position. The southern
CWA will remain humid and mild Friday while the northern zones
will struggle to warm out of the 30s.
Large scale upward vertical motion will begin to increase
across the Southern Plains Friday through Saturday as a deep
upper low begins to lift across Southern California/Northern Baja.
As a result, mid level lapse rates will increase slightly which
will result in the potential for isolated thunderstorms along
with scattered showers. The highest rain chances in the Friday
through Saturday timeframe will be across the west/northwest
zones where the best large scale lift will reside. It still
appears that all temperatures will remain above freezing Friday
through Saturday so no freezing/frozen precipitation is expected.
The cold front will quickly lift north Saturday night in response
to the approaching low pressure system. This system will reach
Far West Texas on Sunday and lift to the Central Plains by Monday.
Increasing moisture and lift across the entire region will result
in numerous showers and thunderstorms. It still appears that
heavy rainfall will be the primary threat due to deep moisture.
There will also be abundant shear to sustain updrafts, however
limited instability should keep the storm tops rather low. There
will still be some severe potential Sunday through Monday if the
atmosphere can destabilize more than currently forecast.
The departing upper low will allow a surge of dry and subsident
air Tuesday. This will bring a decrease in precipitation chances
Tuesday/Tuesday night with all precipitation ending on Wednesday.
The second half of next week should be precipitation free with
brief ridging aloft and a slow return of low level moisture.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 40 47 42 51 47 / 40 40 40 40 20
Waco 54 58 47 65 53 / 30 40 30 30 20
Paris 44 57 51 60 56 / 40 50 50 40 20
Denton 37 44 40 47 46 / 40 50 50 40 30
McKinney 40 48 42 51 47 / 40 40 50 40 20
Dallas 41 49 43 53 48 / 30 40 40 40 20
Terrell 48 55 47 60 53 / 30 40 40 30 20
Corsicana 57 62 50 66 56 / 30 40 30 20 20
Temple 61 71 48 68 56 / 30 40 30 30 20
Mineral Wells 36 42 38 47 46 / 40 50 50 50 30