Area Forecast Discussion

FXUS64 KFWD 180901
Area Forecast Discussion
National Weather Service Fort Worth TX
301 AM CST Sun Nov 18 2018
/Today and Tonight/
A strong cold front continues to race through North Texas early
this morning and was located along a line from near Paris to
Corsicana to Killeen around 2 am. Temperatures quickly fall into
the upper 30s and lower 40s behind the front with gusty northwest
winds. A thin line of showers developed along the front and low
rain chances will continue through this morning mainly along and
just ahead of the front. The front should clear all of our area
shortly after sunrise. Extensive low cloud cover persists well
back to the west and skies will generally be cloudy through the
day with temperatures remaining in the 40s. There could be some
breaks in the cloud cover across our western counties around
midday as strong drying aloft occurs, but a thicker band of cirrus
is expected to overspread the area into the afternoon.
Tonight will be cold particularly across the northwest where the
center of the surface high will be located. Skies should become
mostly clear across the northwest allowing temperatures to fall to
or just below freezing. More extensive cloud cover will persist
from the Metroplex southward into Central Texas. Temperatures in
these areas will remain in the mid 30s to lower 40s. Weak
isentropic ascent will persist across our far southern counties
overnight and we could see some continued light rain in these
areas into the early morning hours on Monday.
/Monday Onward/
Monday will be off to a cool and mostly dry start in wake of
Sunday's cold front with gradual clearing occurring from north to
south. The exception will be across our far southeastern counties
where some isentropic upglide will still be occurring in the 
850-700mb layer above the steeply sloped frontal boundary. This 
should contribute to continued cloudiness and lingering rain 
chances roughly south of a Killeen/Palestine line into the day. 
Meanwhile, the elongated trough axis currently draped from 
Colorado to Wisconsin will continue drifting southward towards the
Southern Plains. This will help deliver a secondary shot of drier
low-level air as a strong surface high builds across the Central 
US in its wake. The arrival of drier air will shunt all remaining 
moisture south of the area, bringing an end to any remaining rain 
chances by Monday afternoon/evening. Following a cool and cloudy 
Sunday, Monday's high temperatures should easily rebound into the 
50s, especially across North Texas where there will be less cloud 
cover. High pressure and shortwave ridging aloft will prevail into
Tuesday with a continued warming trend. Clear skies, dry air, and
abundant sunshine should allow temperatures to return to the 
upper 50s and low 60s area-wide. 
By Wednesday, a split flow regime is expected to materialize to
our west, with the vigorous southern stream shortwave forecast to
track over the area later Wednesday afternoon. Model solutions 
have been quite erratic regarding rain chances with this feature, 
primarily due to inconsistencies with handling moisture recovery. 
The 00z suite of guidance is on the drier side since guidance was 
slower to turn low-level wind fields to the south. As a result, 
the GFS is holding PWs around 0.75" or less through Wednesday 
with the greatest moisture confined to South Texas and the Gulf. 
With strong lift expected to track overhead, this should still 
result in at least some scattered rainfall activity, although 
coverage would be fairly meager. The ECMWF remains a slightly 
wetter solution, and will maintain some PoPs for the entire 
forecast area through Wednesday afternoon when ascent will be 
maximized over the area. There should be very limited instability 
present during this time, so thunder would be scarce and confined
to Central Texas where there will be some slightly steeper lapse 
rates. Otherwise, activity should consist of showers or lighter 
stratiform rain. Hopefully model moisture fields will come into 
better agreement over the next couple of days so that the rain 
coverage expectations can be refined. Folks with holiday travel
interests on Wednesday afternoon or evening will want to keep an
eye on the forecast. 
The aformentioned shortwave is forecast to depart the region 
Wednesday night, taking any rain chances with it. This will mean a
dry Thanksgiving forecast for the time being with some lingering 
clouds throughout the day. Temperatures should be fairly close to 
normal, mostly in the 60s or upper 50s. From this point on, model 
solutions and ensembles diverge substantially. While there is 
general agreement that a potent tough will dig southward along the
Pacific coast before the end of the week, models are all over the
map for how to handle this energy after it moves onshore. The 
latest ECMWF stands in stark contrast to previous runs, digging 
this energy much farther south and into the Southern Plains by 
Friday. This would quickly pull a surge of moisture northward 
through the southern US and result in fairly widespread showers 
and storms heading into the weekend. The GFS remains a few hundred
miles farther north with the strongest energy, thereby limiting 
precip chances for our forecast area. I'll show some low PoPs on 
Friday for now with very low confidence in the forecast beyond 
day 5. It does at least look like another cold frontal passage 
can be expected sometime in the day 6-8 time period, with a 
progressive pattern and broad synoptic scale troughing forecast to
continue through next weekend. 
.AVIATION... /Issued 1115 PM CST Sat Nov 17 2018/
A strong cold front was moving across FTW and AFW as of 05Z. This
front will be through all Metroplex terminals by 06Z and Waco
around 07Z (which is a bit faster than previously thought).
Thus far, the front has come through dry, however, a few showers
should develop as the front encounters a bit better low level
moisture generally along and east of the I-35 corridor. Any 
showers that do develop should be brief and have little impact to 
air operations.
The wind will turn to the northwest with the passage of the cold
front at speeds between 12 and 16 knots along with some higher
gusts. These winds will continue through Sunday morning, but 
slowly decrease in the afternoon/evening as the pressure gradient 
Some MVFR ceilings will move in behind the cold front and remain
in place through about midday Sunday before lifting above 4000 ft.
VFR conditions are expected Sunday afternoon and evening with
broken to overcast mid and upper level clouds.  
Dallas-Ft. Worth    48  36  57  39  60 /   0   5   5   0   0 
Waco                52  38  58  40  63 /   5  10   5   0   0 
Paris               48  34  54  37  58 /   5   5   5   0   0 
Denton              46  32  57  37  60 /   0   5   5   0   0 
McKinney            47  33  55  38  59 /   0   5   5   0   0 
Dallas              49  38  58  39  60 /   0   5   5   0   0 
Terrell             50  36  57  38  61 /   5   5   5   0   0 
Corsicana           52  38  55  39  61 /  10  10   5   0   0 
Temple              52  39  56  40  63 /  10  20  20   5   0 
Mineral Wells       46  33  59  35  60 /   0   5   5   0   0