Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
FXUS64 KHGX 272122
Area Forecast Discussion
National Weather Service Houston/Galveston TX
422 PM CDT Sat Aug 27 2016
Convection is continuing to fire up over the NW edge of the Gulf of
Mexico, associated with an upper level low moving in from the east.
This disturbance is moving at about 10 knots, and has been producing
some strong bands of thunderstorms and scattered showers. This
system should bring in another surge of moisture during 00Z to
06Z Sunday across the southeastern half of our CWA, therefore, a
Flash Flood Watch has been issued until 08Z this evening. Moist
inflow dewpoints at the surface are in the lower 70s, and this
saturation continues up to 850mb where dewpoints are around 15
degrees. Precipitable water is ranging between 2.00 and 2.25
inches over this region as well. Inflow wind speeds are between 10
to 15 knots, continuing to pump this moisture into the area.
During this time period, isolated showers and thunderstorms can be
expected to bring heavy rain across these eastern counties.
Anywhere from 1 to 2 inches of rainfall accumulation can be
expected with locally higher values in the eastern coastal
With the atmosphere being so saturated and skies remaining mostly
cloudy, we can expect our highs for this evening to be in the upper
80s. Tomorrows high temperatures should remain roughly the same as
todays, as a second surge of moisture associated with this system
brings in another round of heavy rainfall, mostly likely between 12
to 18Z on Sunday.
Chances for rain will trend down as we move deeper into the work
week. An area of high pressure will shift back into play this
upcoming Thursday. POPs will begin to approach normal climatology
again next Tuesday, with slightly lower chances of isolated
As expected winds have increased over the nearshore waters and
are near 15 knots and these should gradually diminish after midnight.
Axis of deep tropical moisture just east of the coastal waters but
it will be shifting westward tonight and expect to see scattered to
numerous showers and thunderstorms especially in the east. Moist
axis will remain over the Gulf waters Sunday/Monday and will keep
the scattered coverage going. Most of the guidance keeps 99L in the
Eastern Gulf but new 12z ECMWF gets it almost as far west as 89W
before drifting it very slowly back NE/N - this is probably the far
west side of the envelope of possibilities and have trended winds
more toward the GFS though with the development potential have
nudged seas up slightly from the wave guidance Wed-Fri.
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 74 87 74 89 74 / 20 50 30 50 30
Houston (IAH) 74 87 74 88 75 / 40 60 40 60 30
Galveston (GLS) 78 86 79 86 80 / 70 70 60 60 50
TX...Flash Flood Watch until 3 AM CDT Sunday FOR THE FOLLOWING ZONES: