National Weather Service Raw Text Product

Displaying AFOS PIL: AFDFWD Received: 2019-02-11 17:53 UTC


376 
FXUS64 KFWD 111753
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1153 AM CST Mon Feb 11 2019


.AVIATION...
/18z TAFs/

Morning fog and stratus have gradually improved over the past few
hours, and this trend will continue into the afternoon as 
southwest surface winds push drier low-level air into the region. 
At the current time, KDAL is the only Metroplex TAF site still 
experiencing IFR cigs, while airports just to the west have now 
scattered out cloud cover through the low levels. VFR cigs around 
8-9 kft will prevail through the remainder of the day as mid-level
moisture continues to stream overhead, with light rain falling 
from this cloud deck as it overspreads North and Central Texas. 
Will continue to handle this activity with VCSH through this 
evening for the time being. There is some concern that more robust
convection may develop later this evening associated with a 
deepening upper trough which could affect the DFW area TAF sites 
around 01-04z. However, the potential for any TS is too low to 
introduce a mention in the TAFs at this point.

Late tonight, a cold front will move through the area, generally
between 07-10z. Winds will veer to the west and eventually 
northwest over the course of a few hours while increasing in 
speed. By early Tuesday morning, winds will become breezy out of 
the northwest with gusts of 20-30 kts. Some post-frontal stratus 
may attempt to develop, but this potential will be limited owing 
to the rather dry pre-frontal airmass. Have only shown SCT025 in 
the TAFs for now, but some MVFR cigs may have to be introduced 
tonight depending on trends. Northwest winds will continue into 
Tuesday with VFR conditions prevailing. 

-Stalley

&&


.SHORT TERM... /Issued 321 AM CST Mon Feb 11 2019/
/Today through Tonight/

Areas of mainly light fog along with patchy drizzle or light rain
continue this morning, as a shortwave disturbance aloft continues
lifting east across the region. So expect a cool and soupy mess 
for the morning commute this morning, with localized, limited 
visibilities below a mile, along with hit n'miss areas of 
drizzle/light rain, and temperatures in the 40s. The spotty dense 
fog -- if the HRRR/ RAP forecasts are to believed will occur along
the Red River Valley and along/east of I-35/35E where relatively 
richer surface dew point temperatures and most pronounced low 
level warm advection is expected to exist. At this time, we do not
believe any dense fog would be widespread enough at this moment 
in time for a Dense Fog Advisory to be issued with this forecast 
package. However, it isn't out of the realm of possibility that as
we monitor things through daybreak, that a small part of the area
tanks and an advisory is issued due to ongoing mixing/lift 
occurring with this morning's shortwave disturbance aloft. 

Any fog and drizzle should abate by midday, as low level warm 
advection and increasing southwest winds allow surface temperatures
to warm into the 60s at most locals this afternoon. A more vigorous
and dynamic shortwave disturbance will lift out of New Mexico and
across the Southern High Plains and across Oklahoma this afternoon
and through this evening. A pre-frontal surface trough arrives by
00z Tuesday into our northwest counties with plentiful lift, 0-6km
WSW bulk shear in excess of 50 knots, and moisture in advance of 
this feature. The combination of lift and strong low level winds 
should result in a few, mainly elevated thunderstorms later today 
mainly along and east of I-35. Though some small hail can't be 
ruled out with the strongest updrafts across far northern and 
eastern counties this afternoon and evening -- both surface-based
instability and lapse rates aloft appear too meager for any 
organized severe weather. Our main concerns are expected to be 
occasional lightning strikes and the aforementioned threat for 
small hail. The pre-frontal surface trough exits into East Texas 
just before midnight, with a lingering, isolated showers continue 
across the far east/southeast counties with any residual forcing. 

A cold front with a mix of mP/cP air behind is expected to arrive
during the overnight hours, as it is assisted by subsidence in
behind the vigorous shortwave moving over the Ozarks and Mid
Mississippi Valley. In its wake, blustery northwest winds 15-20 
mph with gusts 25-30 mph will arrive in time for the Tuesday 
morning commute. Temperatures will fall into the 30s northwest, 
40s southeast with wind chills at sunrise expected to be in the 
upper 20s to mid 30s, so it would not be a bad idea to have a 
heavy coat handy before leaving for the day Tuesday. 

05/

&&

.LONG TERM... /Issued 321 AM CST Mon Feb 11 2019/
/Tuesday through Next Weekend/

Stout cold advection will be in progress on Tuesday morning behind
Monday afternoon and evening's latest frontal intrusion. This will
lead to some continued blustery conditions into the early-
afternoon hours before the surface pressure gradient begins to
relax and the core of the strongest CAA peels away to our east.
Even with the renewed push of northerly winds, temperatures should
still manage to climb into the 50s and lower 60s across the
region--right about where we should be this time of year. The much
drier airmass in place combined with generally light winds 
Tuesday evening and overnight should allow temperatures to fall 
pretty quickly into the low to mid 30s. Radiational cooling
potential won't be quite ideal, however, as southerly 5-10 mph
winds look to return after midnight and passing wisps of high
cloud cover may sporadically curtail outgoing longwave radiation. 

The pressure gradient will tighten up again on Wednesday as
pressure falls commence in the lee of the Rockies. Southerly winds
around 15 mph should allow temperatures to rise into the mid and
upper 60s pretty much everywhere across North and Central Texas
even under filtered sunshine with passing high cloud cover. 

Lee cyclogenesis will continue Wednesday night and into Thursday
morning, as the core of a robust 150+ jet streak crosses the
Continental Divide and emerges across the Texas and Oklahoma
Panhandles. As the leading edge of this core of higher winds aloft
noses into our region on Thursday, the low-level mass response
will cause southwesterly 925-850 mb winds to ramp up markedly 
through the morning hours. Stratus will surge northeastward across
primarily the eastward portions of the CWA as low-level warm 
advection really gets cranking. Normally with such a 
robust/dynamic storm system developing to our north, we'd be 
concerned about shower and thunderstorm development for Thursday. 
In this case, however, modification to the moisture profiles in 
the low-levels will only have about 12-18 hours to occur before 
veering flow behind the departing system scours us out once again.
In addition, the aformentioned robust southwesterly flow just off
the surface will advect the base of a pretty warm EML plume 
overhead, with 850-800 mb temperatures increasing to around 10-12 
C. As a result, forecast soundings don't even seem supportive of 
streamer showers under the EML/capping inversion for Thursday, and
have removed precipitation chances entirely east of I-35. 

The main noticeable impacts this next system will have on our 
region will be on temperatures, winds, and relative humidities. 
Strongly veering surface winds through the morning and afternoon- 
hours on Thursday should foster a good deal of adiabatic 
compression--especially for locales west of I-35/35W--where 
temperatures should rocket through the 70s and even into the lower
80s. Winds may flirt with Wind Advisory criteria during the 
afternoon hours and, when combined with relative humidities 
falling under 30 percent, an elevated fire weather threat could 
materialize west of I-35 on Thursday afternoon. 

As this disturbance passes by and gets wound up across the Great
Lakes region on Friday, cooler air will rush in to fill the void 
across our region. There's still quite a bit of spread in the
extended guidance regarding just how much colder we get by
the weekend, but blended guidance offers up some reasonable
starting numbers with highs in the upper 40s/lower 50s north and
60s south. 

We'll be keeping our eyes on the Sunday Night-Monday period next 
week as recent trends in global guidance depict a scenario that we
know tends to trip up the coarse-resolution guidance forecasts of
surface temperatures with surging shallow arctic boundaries. That
is, trends seem to be towards a pinched off mid-level 
low/positively tilted trough axis developing from the Central 
Plains into the Four Corners region with generally light northerly
700 mb flow directed down the eastern spine of the Rockies. These
set ups can result in intense lee side cold air damming scenarios
with extremely shallow arctic airmasses that coarse guidance 
doesn't handle well. For now, we've introduced some low PoPs over 
the entire CWA Sunday night into Monday with a cold rain across 
our Red River counties with low temperatures in the mid and upper
30s. This will be something to keep an eye on this week, however.

Carlaw

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    63  40  59  36  67 /  60  20   0   0   0 
Waco                66  42  61  30  66 /  30   0   0   0   0 
Paris               61  40  55  36  63 /  90  30   0   0   0 
Denton              63  38  58  30  66 /  70  20   0   0   0 
McKinney            62  40  57  30  66 /  70  20   0   0   0 
Dallas              63  42  59  38  67 /  50  20   0   0   0 
Terrell             64  40  58  32  65 /  70  20   0   0   0 
Corsicana           64  42  59  39  66 /  50  10   0   0   0 
Temple              66  42  61  32  65 /  30  10   0   0   0 
Mineral Wells       62  36  60  32  69 /  50  10   0   0   0 

&&

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

$$

26/24