National Weather Service Raw Text Product

Displaying AFOS PIL: AFDFWD Received: 2019-03-15 19:56 UTC


859 
FXUS64 KFWD 151956
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
256 PM CDT Fri Mar 15 2019


.SHORT TERM...
/Rest of Today and Tonight/

A weak perturbation is currently zipping through the southwest 
flow aloft, and this is facilitating some increase in mid and 
high cloud cover and radar echos across parts of the Hill Country 
and Upper Texas Coast. Point soundings reveal the presence of some
mid-level instability with lapse rates in the 600-500 mb layer 
running around 7-7.5 C/km, and this is corroborated by the area of
ACCAS on visible satellite imagery. Interestingly, there have 
been a few upstream reports of sleet or small hail across parts of
the Hill Country. While surface temperatures are running in the 
mid and upper 50s, the very dry sub-cloud layer is resulting in a
wet bulb temperature trace that could potentially support a 
couple sleet pellets (or small hail given the aformentioned ACCAS 
and more convective look to the clouds to our south). Think the 
potential for any measurable precipitation will remain under 10 
percent or less, but we'll advertise some sprinkles in the worded 
forecast across our far southeast into the mid-evening hours. 

High pressure will continue to nose into the region tonight. As
this occurs, winds will subside as the pressure gradient relaxes
and the boundary layer decouples. Mostly clear skies and dry low-
levels should promote some decent radiational cooling potential
across the northwestern 2/3rds of the area, and I've sided with 
the cooler guidance here as a result. Mid-high cloud cover will 
probably hold fast through much of the evening across Central 
Texas, tempering the cooling potential a bit. 

Carlaw

&&

.LONG TERM...
/This Weekend Through Thursday/

A dry split-flow/confluent mid level configuration will set up
right over the Southern Plains this weekend, as a piece of energy
sets up camp over the Desert Southwest this weekend. At the 
surface, we'll continue to see a large high pressure ridge 
dominate an area from the Upper Midwest and westward across the 
Plains through Monday which will result in partly to mostly sunny
conditions with occasional spurts of mid-high clouds racing 
eastward with associated shortwave energy moving through the 
fast, confluent flow just to the north across Oklahoma. Dry and 
cool temperatures just below seasonal normals can be expected with
no rain chances expected, as highs gradually warm their way into 
the lower-middle 60s. 

The first system taking residence across the Desert Southwest
lifts eastward while shearing/weakening, as it enters the 
confluent flow over the Southern Plains the early half of the 
week. With surface ridging keeping richer surface moisture at bay
well to the south and little in the way of theta-E advection below
850mb, I don't expect anything more than a period of increasing
cloudiness and the potential for some virga, or at most, a few
sprinkles here and there. A cold front or surface trough arrives 
on Wednesday, bringing in mainly mP type of air and little in the
way of low level cold advection. This may actually assist in a 
warm up Wednesday into Thursday as low level flow veers. Combined 
with a residual dry low level airmass across the region, highs 
should start surpassing the 70 degree threshold across much of the
area, especially as mid level ridging across the Southern High 
Plains amplifies in advance of a more impressive, more vigorous 
mid level system and energy surging southward toward the Desert 
Southwest. 

The upstream, vigorous mid level energy across California/Arizona
appears to become cut off and will be slow to move east into the
latter half of next week. An omega block pattern developing to 
the north across the Pacific Northwest will likely hold this 
system longer than what the GFS is trying to advertise currently.
Another culprit is the aforementioned, strongly amplified ridging
downstream across the Plains. In a nutshell and as one would 
expect, there's plenty of model variability on timing and motion 
with ensembles and their spreads over a week out in time. My 
intuition tells me slower is better here all things considered and
with typical model biases being too progressive with such deep 
energy across the southern latitudes. As such, I buy off more on 
the slower Canadian/European solutions versus the more progressive
12z GFS. I suspect my increasing convective chances by Friday 
night may be too ambitious, as a fairly stout elevated mixed layer
will likely form overhead by Thursday and Friday with better 
storm chances holding off until next weekend.

05/

&&


.AVIATION... /Issued 1224 PM CDT Fri Mar 15 2019/
/18z TAFs/

VFR with no major aviation concerns through the valid TAF cycle.
Breezy and occasionally gusty northerly winds will persist this
afternoon, but these will subside quickly this evening as the
boundary layer decouples and high pressure builds in overhead.
Surface winds will veer more out of the NE on Saturday at speeds
generally under 6-8 kts. A passing sprinkle can't be ruled out at
Waco as a weak disturbance pivots across the area, but no 
operational impacts are expected. 

Carlaw

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    37  58  40  63  41 /   0   0   0   0   0 
Waco                35  57  40  61  39 /   5   0   5   0   0 
Paris               34  57  37  62  38 /   0   0   0   0   0 
Denton              31  57  38  63  38 /   0   0   0   0   0 
McKinney            32  57  38  61  39 /   0   0   0   0   0 
Dallas              37  59  42  64  43 /   0   0   0   0   0 
Terrell             34  58  39  63  39 /   0   0   0   0   0 
Corsicana           37  58  40  61  40 /   0   0   0   0   0 
Temple              35  57  40  61  40 /   5   5  10   0   0 
Mineral Wells       32  58  37  61  38 /   0   0   5   0   0 

&&

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

$$

90/05