National Weather Service Raw Text Product

Displaying AFOS PIL: AFDFWD Received: 2018-11-09 11:20 UTC


409 
FXUS64 KFWD 091120 AAA
AFDFWD

Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
520 AM CST Fri Nov 9 2018

.AVIATION...
/12Z TAFs/

MVFR cigs continue across the region behind the cold front that
has now moved through the region. Breezy north winds of 13-18 kts
with gusts around 25 kts will continue today, but will diminish 
this evening to less than 10 kts as a surface high expands into 
the region. The MVFR cigs are expected to scatter out by late 
morning at all the TAF sites with VFR expected through the 
remainder of the period. On Saturday, the winds will gradually 
turn to the southeast by the afternoon and evening hours.

JLDunn

&&


.SHORT TERM... /Issued 329 AM CST Fri Nov 9 2018/
/Today and Tonight/

Our most recent cold front intrusion is now moving across Central
Texas with rain and isolated thunderstorms continuing across our 
southern most counties. Dry air is invading from the north where
dewpoints along the Red River are already in the 30s. As the cold
front and dry air continue to slide south, the rain will end early
this morning, and dry conditions are expected for the remainder of
the day. The low level clouds will eventually clear from north to
south across most of the region but may hang around in parts of
Central Texas for much of the day. High cloud cover will stream
across at times, but we will still see the sun today. The battle
between sun and cold air advection is expected to keep 
temperatures this afternoon in the lower to mid 50s. Breezy winds
will continue.

Overnight, a little bit of isentropic lift moving west to east 
across the central part of the state may result in some light rain
across our far southern counties. The lower levels will likely be
too dry for much precipitation to reach the ground, but have 
included a 20 PoP for light rain.

The main headline overnight is the expected freezing temperatures,
our first of the season. As the surface high slides from the
Central Plains into the lower Mississippi Valley, our winds will
decrease to generally at or below 10 mph. Dewpoints will continue
to fall with the arrival of drier air, and the coarser models
suggest dewpoints in the teens will occur tonight along the Red
River. With mostly clear skies, overnight lows are expected to 
fall into the upper 20s and 30s across much of the region. Parts 
of our southern counties may only fall to around 40 degrees due to
partly-mostly cloudy skies as a result of the isentropic lift 
previously mentioned. Tonight's forecast lowers overnight lows a 
little more over the previous forecast, and have expanded the 
Freeze Watch as a result. Most areas along and north of I-20 may 
fall to at least 32 degrees, but for the expansion of the Watch, I
focused on areas that were more likely to fall to 31 degrees or 
below. The expansion does include the DFW Metroplex, but this is 
mostly for the outer lying areas that may fall to 30-31 degrees. 
In addition to the freezing temperatures, frost may form in some 
of the Watch area, but temperature-dewpoint spreads may be too 
large for frost if dewpoints are in the lower 20s and/or teens. If
the models continue to trend colder, the next shifts may need to 
expand the Watch/Warning a little farther south. Temperatures will
warm above freezing Saturday morning.

If DFW Airport reaches 32 degrees Saturday morning, this freeze 
will not be in the Top 10 for earliest freezes, but it is well 
ahead of the normal first freeze which is November 22nd.

JLDunn

&&

.LONG TERM... /Issued 329 AM CST Fri Nov 9 2018/
/Saturday through the End of Next Week/

North and Central Texas will be on the southern edge of a large 
surface anticyclone at the beginning of the period. Light
northeast winds will veer to the east and then the southeast
during the day Saturday as the surface ridge slides east, with 
wind speeds remaining around 10 MPH for most of the day. Weak 
return flow will allow temperatures to modify, though increasing 
clouds should keep high temperatures around the 50 degree mark. 
Return flow will increase Saturday night and Sunday as a shortwave
trough strengthens over the western CONUS and a lee-side trough
develops.

The upper level pattern will then amplify as the shortwave drops 
south through the Great Basin Sunday, significantly deepening an 
upper trough across the central Plains by Monday. During this
process, another modified arctic airmass will surge south along
the eastern slopes of the Rockies. This front will enter the
northwest counties Sunday night and should clear the southeastern
counties by Monday morning. 

Scattered showers and a few isolated storms will be possible
starting Sunday as warm and moist air advection strengthens ahead
of the digging shortwave and the cold front. Rain chances will
increase Sunday night as large scale ascent increases, with showers
and isolated storms becoming focused in the vicinity of the 
frontal boundary. Isentropic lift will develop late Sunday night
and Monday as the cold airmass quickly overtakes the region and
the upper trough axis remains to the west. The resulting 
overrunning pattern should produce scattered mainly light showers
in the post-frontal airmass, leading to a windy, wet and very 
cold Monday. The National Blend temperatures appear too warm based
on the latest MOS numbers and similar past events, so the high 
temperature grids lean towards the cool side of guidance (and may 
still be too warm). 

Thermal profiles indicate a possibility of a brief period of
rain-snow mix across the northwest counties before precipitation
ends Monday afternoon, but at this time, probabilities appear too
low to include any snow in the grids. The forecast will call for 
a cold windy rain for all areas with highs in the 40s, but if 
future guidance starts to indicate a colder airmass, a rain-snow 
mix (with no accumulation) might be needed across the northwest.

Precipitation will end from west to east Monday night as the 
trough axis swings east across the area. Clearing skies and 
decreasing winds means another cold night with the freezing line 
likely reaching south of the I-20 corridor by daybreak Tuesday. The
upper level pattern will deamplify as the trough moves off to the
east, and it looks like a quiet period may actually occur for the
middle and latter part of next week, with pleasant days and cold 
nights expected from Wednesday through next weekend.

30

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    54  32  50  42  55 /   0   0   5   0  20 
Waco                56  36  50  43  56 /  10  10  20   0  40 
Paris               54  28  49  39  49 /   0   0   5  10  20 
Denton              55  31  49  41  56 /   0   0   5   0  10 
McKinney            55  30  49  41  53 /   0   0   5   5  20 
Dallas              57  33  50  43  54 /   0   0   5   5  20 
Terrell             55  31  50  42  54 /   5   5   5  10  20 
Corsicana           53  35  50  42  52 /  10   5  10  10  40 
Temple              54  38  48  44  56 /  10  20  20   0  40 
Mineral Wells       55  31  51  39  57 /   0   0   5   0  10 

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Freeze Watch from late tonight through Saturday morning for 
TXZ091>095-100>107-116>121-123.

&&

$$

82/30