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Area forecast discussion 
National Weather Service Fort Worth Texas
1038 am CDT Sat may 30 2015

Update...
the majority of the heavy rain appears to have ended across North
Texas following this morning/S round of convection. However...we
are still awaiting the arrival of another shortwave trough and its
attendant cold front...both of which will move southeast across
the region this afternoon. These features will likely provide
additional moderate rain and isolated areas of heavier rain this
afternoon. For these reasons...we have extended the Flash Flood
Watch for all of North Texas through 8 PM.

The cold front currently extends from southeast Oklahoma
southwestward across the northwest counties of North Texas. A
swath of rain with isolated embedded thunderstorms accompanies the
boundary...and any additional rain that falls across the region
will aggravate the ongoing flooding conditions...especially for
areas between the I-20 corridor and the Red River. Farther
south...overall precipitation has thus far been less than what has
fallen across the northern half of the region.
However...scattered thunderstorms will become more likely this
afternoon across the southern half of the region as conditions
destabilize ahead of the southward moving cold front. For these
reasons...we have decided to extend the Flash Flood Watch until 8
PM for all counties. Activity should come to an end this evening
as the shortwave moves east and the cold front pushes south of the
region.

30

&&

Aviation...
/issued 657 am CDT Sat may 30 2015/
the line of thunderstorms that is moving through the taf sites
now will continue to head eastward during the morning hours. A
couple of hours of light rain and occasional lightning strikes in
the vicinity are likely immediately behind the line of storms. By
middle morning will show just vcsh at all taf sites through early
afternoon. Some additional convection may develop this afternoon
as an upper trough moves through the region...but airmass will be
pretty worked over for robust or organized convection. Still it is
not out of the question that some new isolated storms may form and
affect taf sites this afternoon so we will have to monitor for
that. Drier air will work in tonight so threat of rain ends from
north to south as the evening progresses.

Otherwise VFR will prevail behind the storms with generally
northwest to north winds at 5-15kt.

Tr.92



&&




Previous discussion... /issued 428 am CDT Sat may 30 2015/
a stalled 850mb front stretches west to east between the I-20
corridor and the Red River. A 30-35kt low level jet has helped to initiate
showers and thunderstorms along this boundary after midnight...
aided by the large-scale lift of an approaching trough. The
steering flow is resulting in training...the heavy rain with which
will re-aggravate flooding issues. However...the training will
eventually be disrupted by the advancing mesoscale convective system in western North
Texas...but the threat of heavy rain will continue until a cold
front arrives later this morning. The linear mesoscale convective system will continue
moving east this morning...impacting areas primarily south of the
I-20 corridor. Despite weak deep layer shear...a damaging wind
threat will continue with the line....but the progressive nature
of the cold pool suggests this will wane as the morning
progresses.

Outflow associated with the mesoscale convective system will gradually become
indistinguishable from the northerly winds behind an advancing
cold front. Although the northerly surface winds will sweep
through the County Warning Area today...the 850mb front will lag behind...and
elevated thunderstorms are expected to redevelop across southern
zones this afternoon. And with the middle-level trough axis not
passing our longitude until this evening...shower and thunderstorm
chances will linger throughout North Texas the remainder of the
day. Precipitable water values will remain well above normal...and any of the
cells that develop this afternoon could contain heavy rain.

As the trough passes to our east...deep northerly flow will ensue
tonight. At long last...rain chances will come to an end from
north to south early Sunday. Subtropical ridging will then build
in...allowing the Lone Star state a chance to dry out. The low is
now prognosticated to be east of the Mississippi Valley much of the
week...which will significantly reduce the chance of rain in East
Texas. As a result...will maintain a dry forecast beyond Sunday
morning. After a cloudy may...the first week of June will get off
to a very sunny start. The wet ground will temper the warming
trend...but high temperatures should reach the upper 80s by late
in the week.

Both the GFS and Canadian hint that the ridge could break down by
next weekend...but the European model (ecmwf) intensifies its grip on Texas. The
European model (ecmwf) may be swayed too strongly by climatology...but the
spaghetti splatter of GFS ensemble members means we should also
have a skeptical eye with the GFS/Canadian operational solutions.
June is among the wettest months of the year climatologically...so
we should expect this respite from the rain will not be permanent.

25




&&



Preliminary point temps/pops...
Dallas-ft. Worth, Texas 79 63 82 63 84 / 80 20 5 5 5
Waco, Texas 81 63 82 61 85 / 80 40 20 0 5
Paris, Texas 78 60 78 60 80 / 60 30 5 0 5
Denton, Texas 77 60 80 59 83 / 60 20 5 5 5
McKinney, Texas 77 60 80 58 82 / 80 20 5 5 5
Dallas, Texas 80 64 82 64 85 / 80 20 10 5 5
Terrell, Texas 79 63 81 61 84 / 90 30 10 5 5
Corsicana, Texas 81 64 81 62 84 / 90 30 20 5 5
Temple, Texas 83 65 81 61 84 / 70 40 20 0 5
Mineral Wells, Texas 77 60 81 59 84 / 50 20 5 5 5

&&

Forward watches/warnings/advisories...
Flash Flood Watch until 8 PM CDT this evening for txz091>095-
100>107-115>123-129>135-141>148-156>162-174-175.



&&

$$

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