Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 272301

Area Forecast Discussion
National Weather Service Houston/Galveston TX
601 PM CDT Mon Mar 27 2017

Looking for 900-2000ft cigs to gradually fill back in across the
region overnight. Cloudiness should erode during the mid/late
morning hours as dry air starts mixing down. SSE winds will
increase to 15-25kt and gusty during the afternoon hours.  47


.PREV DISCUSSION... /ISSUED 403 PM CDT Mon Mar 27 2017/
The shortwave axis associated with the upper level disturbance
has shifted out of the region, with surface low centered north of
Arkansas this afternoon. The trailing boundary behind this system
that was sliding southeastward and into southeast Texas has began
to slow in speed. High pressure behind this feature has helped to
force this system southeastward as the pressure gradient between
the system`s surface low and high pressure out in the west, began
to tighten. Short term guidance such as the HRRR, RAP, and ARW
have been over initializing coverage for this afternoon, but the
overall trend is consistent amongst the various models. Surface
winds behind this boundary are out of the northwest. There is
still a chance showers and thunderstorms could set up in the
southeast section of the CWA. If the precipitation does develop,
it could shift to the northwest as winds become more onshore this
evening. Although the forecast soundings, and short term higher
resolution models are all in agreement regarding this shower and
thunderstorm development, radar analysis has yet to be reflective
of these conditions. Will continue to monitor satellite and radar
for the possibility of development later this evening.

Dry conditions should prevail on Tuesday, as we begin to see a
separation between the temperature and dewpoint in the forecast
soundings. Precipitable water values will be below one inch closer
to the coast in the morning and into the afternoon hours. Late
afternoon Tuesday, the low levels begin to saturate in the northern
region of southeast Texas, out ahead of the next upper level feature
as it pushes into north Texas.

The Storm Prediction Center has all of southeast Texas under a
slight risk Wednesday. Both the ECMWF and GFS bring in multiple
positive vorticity maximums, with the first solenoid reaching the
northern portions of southeast Texas late Wednesday morning. Higher
values of vorticity continue to stream in across southeast Texas,
through Thursday. Forecast soundings still have precipitable waters
remaining fairly high with values between 1.5-1.8 inches. However,
the brunt of the showers and thunderstorms will begin Wednesday
morning in the western counties and exit the far eastern counties
by Thursday morning. A chance of showers and thunderstorms will
linger into late Thursday morning in the eastern most counties of
the CWA, and should mostly push out of the region by 15Z. Guidance
consensus is still indicating a strong to severe threat will be
possible with this system. Favorable jet dynamics will be present,
as the 500 mb winds remain divergent over southeast Texas. This
should allow for decent ventilation for convective initiation.
Forecast soundings also show CAPE values between 1500- 3000 J/kg
on Wednesday afternoon and into the evening, with SRH values also
ranging between 150-300 m^2/s^2.

Temperatures will be slight cooler behind the front Thursday, and
dewpoints will drop from in the 70s down into the 50s. Conditions
will stay fairly dry until late Friday afternoon when dew points
begin to rise once again into the upper 60s.

Continuing to track another upper level low moving into the region
late Saturday. Most of the precipitation associated with this low
should fall on Sunday. Still dealing with some disagreement
between models on the timing of this system, so kept PoPs in the
forecast through Monday.  Hathaway

Light to moderate south to southeast winds tonight will be
strengthening tomorrow and tomorrow night in response to
the developing storm system to our west. Caution/advisory
flags will likely be needed for the winds and also for the
building seas, especially tomorrow night and Wednesday.
Showers and thunderstorm are possible with Wednesday`s
storm system, and they could linger into Wednesday night.
Winds and seas come back down behind this system, then
build once again back to caution/advisory levels starting
around Friday night as the next storm system begins to
organize out west.  42


College Station (CLL)      68  86  69  79  60 /  20  10  60  80  20
Houston (IAH)              68  85  71  82  66 /  10  10  40  80  40
Galveston (GLS)            72  82  73  79  70 /  10  10  10  70  50




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