Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Fort Worth Texas
428 am CDT sun Oct 4 2015

with light winds and low humidity...temperatures have fallen into
the 50s at many locations again this morning. A similar day will
follow with highs ranging from the upper 70s north to the middle 80s
south...but the high clouds will increase in density. As the
upper ridge axis gradually moves to our east...southwest flow will
ensue aloft...allowing a greater volume of Pacific moisture to
stream across the area. The deepening upper low on the West
Coast...responsible for the rare thunderstorms in the San
Francisco Bay area...will dive into Southern California today...
enhancing the tropical plume downstream. In addition to cirrus...
middle clouds will also clutter the skies on Monday...but there
should be enough insolation to add a few degrees to high

As the storm system approaches from will induce
shortwave ridging downstream over the Lone Star state. This should
allow for more sunshine on Tuesday and Wednesday...and additional
surface warming...before diffluent southwest flow sets the stage
for our rain event during the latter part of the week. Highs will
be in the 80s areawide Tuesday and Wednesday...with some locations
in central Texas flirting with 90 degrees. After many days of
northerly surface flow...southerly winds will return on Wednesday.
However...the Gulf will be slow to open...and dew points in the
60s may not return until Thursday.

Guidance is in much better agreement with the evolution of the
approaching upper low...anchoring it near The Trans-Pecos by
Thursday. As moisture and instability steadily increase aloft...
showers and thunderstorms are expected to spread across north and
central Texas from the west on Thursday and Friday. Multiple
rounds of activity will be associated with periodic spokes of
energy. Even with considerable cloudiness...surface-based
instability Thursday afternoon could support strong updrafts. The
extent of updrafts rooted in the boundary layer may hinge on the
timing of a cold front late in the day. Despite the strength of
the system...its distance may result in rather marginal shear
across north and central Texas for severe storms. The paltry 850mb
flow may keep the richest precipitable water values confined to south Texas...but
the unidirectional shear should favor some training echoes...which
could provide some beneficial rains in some areas.

There is still considerable uncertainty about what will become of
the low next weekend. The GFS suite still favors an ejection
through North Texas...though the ensemble consensus is now more
of an open wave. The European model (ecmwf) continues to favor a prolonged cut-off.
In either week looks like a return to unseasonably
warm temperatures and another prolonged rain-free period. In other
words...our rainfall tallies for the first half of October may
hinge on the event later this week.



/issued 1153 PM CDT Sat Oct 3 2015/
VFR will prevail with no concerns. Just some high clouds are
expected. Otherwise north-northeast winds at 5-10kt will continue.


Preliminary point temps/pops...
Dallas-ft. Worth, Texas 81 60 84 64 86 / 0 0 0 5 5
Waco, Texas 84 59 85 61 89 / 0 0 0 5 5
Paris, Texas 79 57 83 62 85 / 0 0 0 5 5
Denton, Texas 80 57 82 59 85 / 0 0 5 5 5
McKinney, Texas 80 57 83 60 85 / 0 0 0 5 5
Dallas, Texas 81 61 83 65 86 / 0 0 0 5 5
Terrell, Texas 81 58 83 63 86 / 0 0 0 5 5
Corsicana, Texas 82 60 84 63 87 / 0 0 0 5 5
Temple, Texas 84 59 84 62 88 / 0 0 0 5 5
Mineral Wells, Texas 82 56 81 58 86 / 0 0 5 5 5


Forward watches/warnings/advisories...




National Weather Service Glossary of Abbreviations