498 
FXUS64 KFWD 111726
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1126 AM CST Sat Jan 11 2020


.AVIATION...
/18Z TAFs/

Concerns -- Gradually improving ceilings and diminishing northerly
winds. Winds becoming southerly this evening.

After a brief round of SN this morning, all precipitation has
moved well off to the northeast of the D10 TRACON area. Ceilings
remain MVFR across the region, but skies should gradually scatter
out through the next few hours, with VFR likely by sunset this
evening. Thereafter, VFR will prevail through the end of the TAF
period.

With regards to winds, winds remain gusty and from the northwest,
but should relax through the afternoon as the pressure gradient
lessens. Winds should become southeasterly late this evening as a
surface high shifts to the east. Winds will increase to around 10
KT on Sunday afternoon.

Godwin

&&


.UPDATE... /Issued 610 AM CST Sat Jan 11 2020/

Regional radar imagery shows a band of precipitation extending
from just east of Breckenridge to Bridgeport to Gainesville.
Moderate to heavy snow was reported near Breckenridge and across
Young County earlier. There is still a transition zone from
rain/sleet to all snow likely across Wise County at this time. A
couple of lightning strikes have been observed in the higher
reflectivity areas west of the Metroplex. There will still be some
potential for moderate to heavy snow to occur as far south as I-20
through the mid morning hours before all of the precipitation ends
later this morning. We've updated the forecast to raise total
snowfall to 1 to 3 inches across parts of the advisory area. We'll
continue to monitor this area of precipitation as it moves east.

Dunn

&&

.SHORT TERM... /Issued 408 AM CST Sat Jan 11 2020/
/Today and Tonight/

Water vapor imagery shows the deep trough axis spreading into
North Texas this morning with all of the stronger convection now 
well east of our area. Strong dynamic forcing for ascent will 
continue for around another 4-6 hours across North Texas before 
subsidence on the back side of the trough takes over. Given the
sufficient supply of moisture still in place, strong lift, and 
very cold temperatures associated with the core of the trough, it
appears more likely that we'll see at least some wintry
precipitation through the early morning hours across parts of
North Texas. Regional radar imagery shows a band of light to
moderate precipitation extending from near Abilene north toward
Wichita Falls. This is expected to increase in coverage and
continue eastward through the mid/late morning hours. As it does,
strong low/mid level cold advection will continue to cool the
thermal profile across the region. Right now, the precipitation is
all rain, but surface temperatures are at or below freezing just
north of Abilene and should drop to below freezing across our
northwest counties by sunrise. Light freezing rain should 
initially occur with perhaps some very light ice accumulation on 
elevated roads to the northwest of the Metroplex. Further cooling 
of the thermal profile between 900-800 mb should support a 
transition to snow in some areas between 6-9 am. 

One complicating factor to all of this is that as the trough axis
approaches, lapse rates will steepen through the mid morning hours
to in excess of 7.5 C/km between 700-500 mb. This would yield
about 50-100 J/kg of elevated instability within the dendritic
growth zone and would support the possibility of a few rumbles of
thunder along with brief bursts of heavier snow. Unfortunately,
where exactly this occurs down to the county level is challenging,
but the combination of best moisture, coldest temperatures, and
strongest lift appear to line up from Jacksboro to Denton and
north of there. We'll have a short duration Winter Weather
Advisory in effect through noon for these areas and continue to
monitor. Heaviest snowfall amounts should generally be between
1-2" at most and should generally be confined to grassy surfaces.
All wintry precipitation should end by late morning as the trough
pulls off to the east. 

Skies will clear out this afternoon with temperatures struggling
to make it back to 40 degrees across the north with mid/upper 40s
across the south. Clear skies tonight with diminishing winds
should allow temperatures to fall to near freezing across the
entire area.

Dunn

&&

.LONG TERM... /Issued 408 AM CST Sat Jan 11 2020/
/Sunday Through The End of Next Week/

A warm up will ensue for Sunday into the first half of this 
coming week. The current pattern appears more indicative of early 
Spring in March and early April versus a more amplified and slow-
moving longwave pattern indicative of Winter in mid-January. After
a blustery and cold Saturday, clearing skies and chilly 
conditions will start the day Sunday. The chill will be gone by 
afternoon, as our surface high shifts quickly east of the region 
with low level warm advection ramping up later on Sunday and 
continuing into Monday and Tuesday. Another strong mid level 
impulse will progressively lift out of the Rockies and into the 
Plains on Sunday and should provide enough of a high cloud canopy 
to keep areas across East Texas and along the Red River Valley 
from not warming up beyond the 50s; but areas west of I-35 should 
be able see more insolation and a warm up into the lower- mid 60s.
The environment below 700mb will be very dry and we do not expect
any measurable rainfall, though I wouldn't rule out some virga 
across areas north of I-20 Sunday afternoon. 

Another mid level disturbance lifts east across the Plains once 
again on Monday, but further north with more insolation expected. 
The combination of the insolation and low level warm advection and 
breezy southerly winds should help everyone warm well into the 
60s; with even a few readings in the lower 70s possible across 
Central Texas and our western CWA. Tuesday will even be warmer and
continued breezy, as low level flow veers and we experience the 
passage of a surface trough and winds veering west-southwest from 
the surface-925mb. This will be our warmest day of the week as 
compressional warming coming off the higher terrain of the Big 
Country and South Plains helps add to the diurnal warm up by 
afternoon. Highs should soar well up into the 70s and honestly, it
wouldn't surprise me to see a few lower 80s across western 
Central Texas considering the mild start to the day in the 50s and
plentiful sunshine. I am going warmer than national blended 
guidance, but not quite brave enough to go there just yet. There 
will be a stripe of richer moisture with PWAT near 1 inch, along 
with subtle surface-based instability and steep lapse rates. Low 
convective chances will occur across our East Texas counties, 
particularly those along and south of I-20 as periodic and fast-
moving mid level impulses track east-northeast across Central and 
East/Southeast Texas. 

Wednesday will be our last Spring-like day with well-above normal
temperatures, before we're brought back to reality by an arctic 
front arriving late in the day north of I-20, then more Wednesday
evening in Central Texas and Thursday morning. Veered west-southwest
low level flow in advance of the approaching arctic cold front
will be enough to minimize surface convergence, but enough to warm
temperatures to between 65-70 degrees across areas north of I-20;
then affect Central Texas more by Wednesday evening. I did temper
highs a bit near the Red River into the upper 60s, but the 
remainder of the CWA, especially Central Texas will see another 
balmy day well into the 70s. Like Tuesday, I wouldn't be surprised
if a few areas in Central Texas high 80 degrees as we experience
shortwave ridging in advance of yet another longwave mid level
trough digging southward across the Great Basin. Meanwhile, our
area will be affected more by the Sub-tropical portion of the
broader scale westerlies with more progressive mid level energy
riding northeast across the state. Areas from I-35 will see a
brief surge of rich surface dew point temperatures in the mid 50s
to mid 60s which will yield just enough SB/MLCAPE near 1000 J/KG
or less to coincide with steep lapse rates aloft of 7-7.5 Deg C/km
and WSW deep bulk shear near 50 knots for at least the potential 
for a few strong to marginally severe storms late morning into the
afternoon hours on Wednesday east of I-35/35E, but particularly
the I-45 corridor in eastern Central Texas. 

Our "cold reality" unfortunately returns Wednesday night and 
through the end of the week, as blustery north-northeast winds 
10-20 mph usher in our reminder that it's still mid-January and
Winter in North-Central Texas. I have lingered low rain chances 
in our eastern counties Wednesday night, but do increase rain
chances later Thursday and continuing into Friday. This will be in
response to the main Western CONUS system opening up and moving
readily east across the Central Plains and into the Mississippi
and Ohio Valleys the end of next week. I can't even rule out some 
occasional, elevated rumbles of late Thursday night and Friday, as
steep lapse rates continue above a modified and elevated mixed 
layer aloft. At this time, the arctic airmass will remain modified
enough at the end of the week that temperatures will remain above
freezing during the time of any rain or elevated convection. So 
we're not expecting any winter mix or impacts, but just a cloudy 
and occasionally cool and wet pattern. Lows each morning 
Thursday/Friday will be in the mid-upper 30s Red River Valley to 
between 45 and 50 degrees across eastern Central Texas where cloud
cover is expected to be more stubborn and not erode at night. 

We'll see a reinforcement of the cool airmass the weekend after
this one and will maintain high temperatures below national
blended guidance for the late week/following weekend. The good
part for the following weekend is we anticipate it to be dry with
partly to mostly sunny conditions. 

05/

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    42  33  57  41  68 /  70   0   0   0   5 
Waco                46  32  59  42  69 /   0   0   0   0  10 
Paris               37  30  51  37  64 /  70   0   0   0  10 
Denton              41  30  56  38  67 / 100   0   0   0   5 
McKinney            40  30  54  38  66 / 100   0   0   0   5 
Dallas              43  33  57  42  67 /  50   0   0   0   5 
Terrell             41  30  56  40  68 /  50   0   0   0  10 
Corsicana           43  34  57  42  70 /  10   0   0   0  10 
Temple              48  33  59  43  69 /   0   0   0   0  10 
Mineral Wells       44  32  62  40  69 /  80   0   0   0   5 

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST today for TXZ091>094-
100>104-115>117-129.

&&

$$

37/26