142 
FXUS64 KFWD 241755
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1255 PM CDT Thu Oct 24 2019


.AVIATION...
/18Z TAFs/

Several aviation impacts and poor flying conditions are expected 
over the next 24-30 hours...

A cold front is currently making its way into the far northwestern
portions of the D10 airspace. Ahead of the front, southeasterly 
winds between 12-20 kts are prevailing. Patchy MVFR ceilings and  
light rain showers should intermittently move through the D10 
terminals until frontal passage occurs early this afternoon.

The front will continue moving southeast over the next several
hours, moving through KAFW by 18Z...KDFW by 19Z...KDAL by 20Z. An
abrupt northerly wind shift will accompany the front as well as a
swift lowering of ceilings to IFR with bases AOB 800 ft. A steady
rain will also begin after frontal passage with prevailing vsby 
between 5-6 SM in the precipitation. Isolated to scattered 
thunderstorms are expected throughout the D10 airspace, most likely
between 19-22Z. These storms should intermittently drop the
terminals to LIFR with ceilings near 400 ft and visibility AOB 2 SM.
The same conditions are expected at the KACT terminal, but delayed
by a few hours...KACT frontal passage is currently expected 
between 23-01Z.

Off and on rain showers with IFR ceilings prevailing are expected
to continue through the evening and overnight hours across the 
D10 airspace and the KACT terminal. The winds will also become 
gusty from the northwest with speeds peaking between 25-30 kts 
starting around 23-02Z. Slight improvement is expected tomorrow 
morning when the ceilings should lift to MVFR around mid morning.

Bonnette

&&

.UPDATE... /Issued 938 AM CDT Thu Oct 24 2019/
A quick update to the forecast was sent out this morning as shower
and thunderstorm activity north of a warm front currently observed
along the I-30 corridor northeast of the Metroplex slowly moves
northeast. Isentropic ascent aided by a 35-40 kt LLJ overtop of 
the boundary is helping to trigger the elevated storms, with a few
cells capable of producing brief sub-severe hail (generally less 
than 0.5"). To our west, Water Vapor imagery indicates a shortwave
trough moving through Big County and entering our western 
forecast zones. This will help to enhance the precipitation along 
and ahead of the cold front this morning. A few thunderstorms are 
likely to develop around and north of Highway 377 and west of I-35
with a few storms capable of producing sub-severe hail, gusty 
winds, and brief heavy rain.

The leading edge of the surface cold front has just pushed through
Montague County and Abilene, however the cold push is still lagging
behind the boundary and is currently analyzed in the Ardmore and 
Wichita Falls areas. We expect the cold air to catch up to the 
leading edge of the boundary within the next few hours and begin 
progressing through the Metroplex and Central Texas in the late 
morning to early afternoon hours. A slightly more organized line 
of storms should develop in this time frame, bringing the threat 
for a few strong to severe storms to the areas south of I-20 this 
afternoon and evening. The main threats are damaging wind gusts 
and marginally severe hail, and the tornado threat is low. The 
thunderstorms will also bring the potential for localized flooding
in any training storms. Additional details regarding this system 
can be found below in the Short Term discussion.

Bonnette

&&

.SHORT TERM... /Issued 313 AM CDT Thu Oct 24 2019/
/Today through Friday Night/

A sharpening trough currently dropping south over Colorado will 
close off today as it sweeps across northeast New Mexico.
Strengthening lift ahead of this system is resulting in scattered
showers and a few storms along a cold front, which stretched from 
Missouri to West Texas as of 3 AM. The front is on the doorstep of
the northwest zones of North Texas and has been inching southward
through the overnight hours. The front should pick up speed later
this morning as the upper low drops farther south, and a lead 
shortwave over Iowa races off to the Great Lakes. This will shift 
the band of showers and storms southward near a Sherman- 
Breckenridge line around 10 AM. 

The best rain chances will continue along the frontal zone as it 
shifts southward through the region today. Convection will be
predominantly in the form of showers this morning, but
thunderstorms will increase in coverage along the front as diurnal
instability increases this afternoon. After assessing a plethora 
of model guidance over the past few hours, it looks as though peak
instability will begin as the front approaches a line from Sherman 
to DFW to Lampasas in the 1 to 4 PM time frame. 

For areas north of I-20, maximum CAPE is likely to remain below 
500 J/KG, which will minimize the potential for strong to severe 
storms. South of I-20, it is possible that up to 1000 J/G will be 
attained. When coupled with bulk shear values around 45 KT, a few 
storms may become capable of producing quarter-size hail and 
damaging wind gusts. The most recent run of the HRRR convection-
allowing model captures this pretty well I think and hints at the
possibility of stronger convection from the DFW area southward. 
That said, with poor mid level lapse rates and the fact that 
storms may very well be undercut by the front, the vast majority 
of convection will remain sub-severe.

The front will continue southward and should exit the southern-
most zones this evening. This, however, will not bring an end to
precipitation, due to the upper low lagging well west of the cold
front. The low is progged to move fairly slowly eastward along the
Red River tonight and Friday, keeping rain chances going across
most of the region through the week's end. This will make for a
bitter Friday as high temperatures may struggle to reach the 50s 
along with strong north winds and periods of rain. A few storms 
will remain possible, but these will be elevated, isolated, and 
below severe thresholds. 

Widespread storm-total rainfall amounts in the 1 to 2 inch range 
look likely across just about all of the area today through 
Friday. It is uncertain, but the highest totals could occur 
either along the Red River where the slower forward speed of the
front is expected this morning, or the Central Texas counties 
where the better moisture and instability will reside. Isolated 
2-4 inch amounts, however, cannot be ruled out and would occur if 
and where any storms decide to train. 

Precipitation will dwindle from southwest to northeast Friday 
night as the upper low heads for the Arklatex region. The driest
air and coolest conditions will occur west of I35/35W where 
Saturday morning lows in the mid to upper 30s can be expected. The
rest of the forecast area will bottom out in the 40s around 
daybreak Saturday.


30

&&

.LONG TERM... /Issued 313 AM CDT Thu Oct 24 2019/
/This Weekend Through The Middle of Next Week/

The mid level low is expected to be tracking eastward across the 
Red River Valley as we move into Saturday morning. I have 
maintained low rain chances across our far northeast counties as 
this system rapidly lifts northeast toward the Mid Mississippi and
Tennessee Valleys by Saturday evening. A gradual southwest to 
northeast clearing of clouds is expected over all but the far 
eastern counties through the day Saturday. This will provide a 
mostly sunny and cool day for most of us by afternoon with highs 
recovering to between 65 and even near 70 degrees for our far 
western counties. The east will remain cooler with the clouds and 
remain in the lower 60s. Though the day starts off brisk with 
northwest winds 10-15 mph, a surface high pressure sliding into 
the area will help settle wind speeds down for the afternoon from 
the west or west-northwest less than 10 mph. The surface high 
continues to slide east of the area Saturday night and Sunday. 
South winds near 10 mph will return to the area during the day 
with sunny and warmer conditions with highs recovering back into 
the 70s; after a cool start to the day in the lower-mid 40s. This 
weekend will definitely have a Fall feel to it with Sunday being a
little more pleasant for planned outdoor activities. 

Our next system will begin diving south across the Great Basin 
region of UT/AZ/SoCal as we move into early next week. A lead mid 
level impulse exiting this longwave trough across the Central 
Plains Sunday night and Monday will help draw another cold front 
into the area. This cold front will mainly reinforce the cool and 
dry Fall conditions across North and Central Texas on Monday with 
highs in the 60s north to near 70 degrees south of Highway 84. 
After another cool start in the 40s Tuesday morning, surface high 
pressure will once again slide east of the area with a return to 
modest south breezes in advance of the system during the day. 
Unfortunately, not much of a warm is expected as the area 
experiences an increase of clouds with highs remaining mostly in 
the 60s. 

With the typical medium range, deterministic model issues 
handling strong mid level energy off to the west and northwest of 
our area, I went back to the EPS/GEFS ensembles for the forecast 
moving into the middle of next week. An unsettled pattern appears 
probable as this trough lifts east. Even within the ensembles, the
Euro members are advertising a deeper, slower, and wetter 
solution than it's GFS counterparts. The low level airmass looks 
to remain relatively cool and stable at this time with surface 
dewpoints mostly in the 40s. I have only introduced low convective
rain chances at this time considering the uncertainties and 
discrepancies on system evolution, moisture, etc. We'll continue 
to fine tune our thinking of this system as we move through this 
weekend. At this time, it doesn't appear there's any severe 
weather risk with the majority of storms being elevated in nature.
We will need to be concerned with the potential for more locally 
heavy rain and hydrological impacts this system may bring in the 
future. 


05/

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    70  48  51  46  67 / 100 100  60  30   5 
Waco                75  48  53  45  68 /  90 100  40  20   5 
Paris               68  52  55  47  63 /  70  80  70  60  20 
Denton              65  45  49  44  67 / 100 100  60  40  10 
McKinney            69  49  52  46  65 /  90  90  70  40  10 
Dallas              71  49  51  46  68 /  90 100  60  30   5 
Terrell             74  51  54  46  66 /  60  90  60  40  10 
Corsicana           77  51  52  46  65 /  50 100  50  30  10 
Temple              76  46  53  44  68 /  90 100  30  10   5 
Mineral Wells       65  43  47  39  68 / 100  90  40  30   5 

&&

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

$$

06/79