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afdfwd

Area forecast discussion
National Weather Service Fort Worth Texas
817 PM CDT sun Mar 26 2017

Aviation...
the metroplex taf sites have been in The Gap so far with storms
sliding just to the northwest and north while other cells between
kcpt and kbbd have been remaining to the south. Will have to keep
an eye on the storms to the south but they will likely remain
south of the metroplex taf sites. MVFR ceilings will try to
spread north into the metroplex overnight tonight...after the
convection to the south moves east. Have indicated bkn012
starting at 06z and down to IFR (bkn008) from 09z-13z. A cold
front should move through around 13z with ceiling then improving
to MVFR and then to VFR by 16z.

Waco...will keep an eye on the storms to the west and will likely
have to add thunderstorms in the vicinity in for the 02-04z period. Otherwise, expect
IFR ceilings to spread north in the site around 04z and IFR
ceilings by 08z. A cold front will move through around 17z
with steadying improving ceilings thereafter.





58

&&

Mesoscale update...
numerous strong/severe supercellular storms are in progress as of
6pm west of I-35. Hail has been the main concern with these
storms thus far due to their high bases (5-6 kft) and the
favorable hail environment discussed in the previous mesoscale
update. These storms developed along the leading edge of the
dryline along a higher Theta-E axis where slightly more favorable
low-level moisture resides. As these storms continue to shift
eastward toward I-35, they will encounter a more favorable
environment with MLCAPE values exceeding 1500 j/kg and more
moderate low-level moisture with surface dewpoints in the low 60s.
Now that peak heating has passed, boundary layer mixing is
lessening and boundary layer moisture should increase. Storms
should be capable of becoming surface- based rather than elevated
as this occurs. This will imply an increased tornado threat
compared to the initial thunderstorms given that LCLs will
decrease, although the main concern continues to be large hail.

As additional storms develop, as suggested by latest high-res
guidance, they may grow upscale into a complex with embedded
supercellular structures as they shift east of I-35. A Tornado
Watch and Severe Thunderstorm Watch cover north and parts of
central Texas through 11pm. Continue to follow graphics, watches,
and warnings for the latest information.

-Stalley

&&

Previous discussion... /issued 324 PM CDT sun Mar 26 2017/

See locally issued mesoscale update afdfwd and regional Storm Prediction Center
sels mesoscale discussion discussions for short term updates through this evening.

For tonight after midnight most of the convection that occurs this
evening should be waning across our far eastern areas. A cold
front will eventually catch up to the dryline and push through the
remainder of the County Warning Area through mid Monday morning. Drier air will
filter into the region through the day tomorrow with highs in the
mid/upper 70s and lower 80s. While the front will initially clear
the cwa, it is likely to quickly return northward as a warm front,
especially across West Texas late Monday night. This will mean a
gradual increase in moisture again across the southern half of the
County Warning Area as southeasterly winds return.

By Tuesday, another powerful upper low will be moving out of New
Mexico and approaching Texas. Rich Gulf moisture will have spread
northward and should be in place across most of Texas. A dryline
will set up across West Texas with a warm front extending from the
surface low in the Panhandle southeast to along the Red River.
This will set up another favorable scenario for severe weather
Tuesday afternoon and evening. Initially, the more significant
threat will be to the west of our area, but will spread eastward
into the late evening hours. Our best chances for showers and
thunderstorms will arrive late Tuesday night into Wednesday
morning and will continue to be accompanied by a severe weather
threat.

In addition to a severe weather threat, deep southerly flow will
be in place Tuesday night into Wednesday morning accompanied by precipitable water
values near record territory. This suggests that one or more
convective lines or clusters could train over localized areas
resulting in a flash flood threat. The entire system does appear
to be progressive enough to preclude a more serious hydrologic
threat at this time. Precipitation should end quickly from west to
east during the day Wednesday.

The upper pattern remains progressive through the weekend with yet
another system approaching by Saturday. At this time it is a
little early to tell if a significant severe threat will accompany
this system, but rain/storm chances appear to be increasing at
least for Saturday.

Dunn




&&



Preliminary point temps/pops...
Dallas-ft. Worth 60 79 59 81 66 / 70 0 0 20 70
Waco 63 81 64 82 66 / 50 10 5 20 70
Paris 61 76 54 77 63 / 60 10 0 20 50
Denton 56 77 56 78 65 / 70 0 0 20 70
McKinney 59 77 57 79 65 / 70 0 0 20 70
Dallas 61 80 60 81 67 / 70 0 0 20 70
Terrell 62 79 58 81 66 / 50 10 0 20 60
Corsicana 65 81 62 82 67 / 40 20 0 20 50
Temple 64 83 64 83 66 / 30 10 5 30 70
Mineral Wells 52 80 55 78 61 / 20 0 0 40 80

&&

Forward watches/warnings/advisories...
none.
&&

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