Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 192353

Area Forecast Discussion
National Weather Service Houston/Galveston TX
653 PM CDT Mon Mar 19 2018



Very warm and dry across the region. Dry thunderstorms have
departed to the east of GLS. Lingering cirrus moving over the
region. WNW-NW winds gusting to around 20kts at 23z will be
relaxing a little this evening then bump back up as reinforcing
cold front in N TX arrives after midnight. Gusty NW winds tomorrow
morning gradually relaxing in the afternoon.


.PREV DISCUSSION... /ISSUED 259 PM CDT Mon Mar 19 2018/

Temperatures were very warm this afternoon and Galveston
established a new record high temperature for the day. A
combination of a warm start to the day and a west wind will
generally deliver very warm temps to the region. At 2 PM, a cold
front extended from low pressure over So Missouri to near
Texarkana to near Rockport to Laredo. Radar is showing a few
showers/thunderstorms along the middle Texas coast as lift from
the front coupled with PW values near an inch and daytime heating
trigger precipitation. The experimental HRRR and TT WRF both show
some showers moving up the coast late this afternoon into this
evening so have added isolated shra/tsra to areas mainly east of
US Highway 59 but showers should mainly be along the coast.

Once the front clears the coast, skies will clear area wide. Winds
will decouple inland and the dry air in place will allow for ideal
radiational cooling. Low temps by Tuesday morning will cool into
the mid and upper 40s. The rest of the week looks quiet with
seasonal temperatures. The surface high will settle over SE TX on
Wednesday morning with the coolest temperatures of the week
occurring that morning. The high moves east of the region by
Wednesday evening and onshore winds will return and bring a slow
increase in low level moisture. Winds will increase Thursday night
into Friday as low pressure in the lee of the Rockies deepens.
Upper level ridging over northern Mexico will amplify and expand
over the state and suppress rain chances through Friday night. Low
level moisture will deepen enough that a few showers will be
possible by Saturday under a strengthening capping inversion. The
cap will remain in place through Monday albeit slightly weaker as
the upper level ridge is displaced to the east as a deepening
upper trough moves into the southern Rockies. The middle of next
week is looking wet as the upper level trough moves very slowly
across the southern plains. 43

A surge of cooler/drier air will arrive overnight across the coastal
waters. Offshore flow should increase after midnight and to near
20kt in the Gulf toward 3am or so. Will be issuing a Small Craft
Advisory for the Gulf waters starting then. Winds will slowly
diminish in the late morning and afternoon hours. Onshore winds will
resume Wednesday as high pressure moves off to the east. As lee side
pressures fall, winds will strengthen across a lengthening fetch and
seas will build going into the weekend. Combination of SCEC/SCA
flags may be needed starting as early as Thurs.  47

Elevated fire weather conditions will continue through Tuesday.

In the very short-term we need to keep an eye for any lightning
strikes from the isolated cells developing to the southwest of the
area. Some Hires guidance takes some of these cells across southern
parts of the region later this afternoon. Any sparks could quickly
start a fire. Very dry conditions are in place across the region
with current RH`s between 12-25%. Though winds are gusting at times,
speeds are mostly below widespread Red flag Warning criteria. Winds
should rapidly diminish toward sunset.

Speeds will increase once again by mid Tuesday morning with mixing
behind a reinforcing surge of a drier airmass. Northerly winds will
be stronger than what we saw today and widespread 13g23kt speeds can
be expected. However, with the cooler temps, RH`s look to bottom out
between 25-35%. Still needs to be monitored closely...  47


College Station (CLL)      47  70  45  75  52 /   0   0   0   0   0
Houston (IAH)              49  73  48  76  54 /  10   0   0   0   0
Galveston (GLS)            56  71  55  72  62 /  10   0   0   0   0


     through Tuesday morning for the following zones: Galveston
     Bay...Matagorda Bay.

     Small Craft Advisory from 3 AM to 10 AM CDT Tuesday for the
     following zones: Coastal waters from Freeport to the
     Matagorda Ship Channel out 20 NM...Coastal waters from High
     Island to Freeport out 20 NM...Waters from Freeport to the
     Matagorda Ship Channel from 20 to 60 NM...Waters from High
     Island to Freeport from 20 to 60 NM.



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