Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
FXUS64 KHGX 211527
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1027 AM CDT Sun Aug 21 2016
Corridor of higher moisture at 700 mb was over the western and
northern counties of the forecast area corelated well with the RAP
PW analysis of 2.1 to 2.4 inches. This moisture axis was over a
frontal boundary that was located at 7 am from near KLFK to just
east of KCLL. An MCV between Columbus and San Antonio will slowly
drift northward as well. HRRR and the RAP13 agreed with a rainfall
potential of 1 to 2 inches over the northern counties. However,
both models differed on the rainfall potential over the south.
With an outflow moving eastward through metro Houston, think that
some locations over the coastal areas may experience isolated
amounts of 1 to 2 inches as well.
Tweaked the rain chances for the rest of the day. Also lowered
the temperatures slightly due to the cloud cover and rainfall
.PREV DISCUSSION... /ISSUED 721 AM CDT Sun Aug 21 2016/
For the 12Z TAFs, the main aviation concerns center around
SHRA/TSRA near the terminals today and patchy fog development
early Monday morning.
Morning surface analysis showed a cold front draped from near KSHV
to KUVA, with regional radars showing SHRA/TSRA ongoing along this
frontal boundary. Also noted was a small surface low centered in
between K3T5 and KVCT, with a north-south outflow boundary
oriented along a KCFD-KELA line. These small scale features were
also serving as focusing mechanisms for TSRA/SHRA activity.
Scattered to numerous SHRA/TSRA are expected to continue across
Southeast Texas through early evening with upper level divergence
and tropical moisture in place across the region, but terminal
impacts and their timing will likely be driven by the evolution
of smaller scale features today and frequent amendments are
likely. SHRA/TSRA will be capable of producing IFR and MVFR
ceilings and visibilities, as well as gusty and erratic winds.
Expect a lull in activity this evening with loss of heating and
the departure of upper level support, with streamer showers
possible near Galveston early Monday morning. Have gone ahead and
included a VCSH mention in for the extended Houston-IAH TAF late
Monday morning, with diurnally driven showers and thunderstorms
Otherwise, recent rainfall and light winds overnight may produce
patchy fog near outside of the Houston terminals/Galveston early
Monday morning. Light south to east winds are expected through the
TAF period with VFR conditions outside of SHRA/TSRA.
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 84 73 89 75 93 / 80 40 40 20 20
Houston (IAH) 87 74 91 76 92 / 70 20 50 10 40
Galveston (GLS) 89 82 89 82 89 / 50 20 40 20 20
TX...Flash Flood Watch until 7 PM CDT this evening FOR THE FOLLOWING