Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Houston/Galveston Texas
355 PM CDT Monday Jul 28 2014
a stationary boundary draped across central Texas...scattered
thunderstorms firing along it over sjt and fwd's forecast areas.
It's difficult to discern whether there is an existing pre-frontal
trough just downstream of the stationary boundary analyzed somewhere
between Waco and the dfw metroplex. Nwp ensemble backs the 594
Dam Ridge off and centers over The Big Bend/desert SW by late
Tuesday. With a predominant northwest middle-upper flow pattern along the
western leg of the developing eastern Canada/eastern Continental U.S.
Trough...the synoptic boundary should slowly sag into the far
northern reaches of our County Warning Area through tomorrow afternoon. There is
a chance that downstream convective outflow boundaries (along the
southern edge of cold pools propagating from NE Texas storms) will
provide the required focus/lift needed in generating early to middle
day convection. The scene will become a bit muddled from tomorrow
on through Thursday as daily convective behavior will strictly be
driven in the smaller mesoscale/Micro scale(s). More overcast and
frequent periods of rain will aid in regulating late week daily
temperature extrema into the upper 80s to around 90f.
By Thursday...relatively drier middle-week profiles will saturate up
to past 2 inch precipitable waters and whatever is left of the very diffuse
synoptic boundary will waver somewhere over the southern half of
the forecast area. Rain/storm chances will increase Thursday and
Friday and be dependent upon the southern and western extent of a
series of shortwave disturbances passing across the arklatex region.
As of now...the higher positive vorticity advection and more favorable upper levels (slightly
better diffulence)...peg Thursday/Friday as the highest precipitation probability days.
Rain chances remain high going into the weekend...especially in
the vicinity of a near-coastal weak surface (inverted) trough.
Again...periods of rain will be driven by the smaller scale so
timing will needed to be adjusted on a moving scale. The large
scale/background appears favorable for a more wet middle to late week
..from the near-saturated unstable forecast soundings to the better
upper diffulence. 31
the surface high pressure ridge across the northern Gulf of Mexico
will keep onshore winds in place for most of the work week. The
models were pushing a front into the Upper Texas coastal plains by
around Friday. There is some uncertainty on how far south the front
will push. For now went with the consensus of pushing a weak boundary
off the coast on Saturday. Any offshore winds are expected to quickly
swing back around to out of the southeast by Saturday night. 40
Preliminary point temps/pops...
College Station (cll) 76 96 75 96 74 / 30 30 20 20 20
Houston (iah) 77 95 75 95 75 / 30 30 20 20 20
Galveston (gls) 81 91 80 90 81 / 20 30 20 20 20