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Area Forecast Discussion (AFD)

Issued by Houston/Galveston, TX (HGX)

FXUS64 KHGX 222039

Area Forecast Discussion
National Weather Service Houston/Galveston TX
339 PM CDT Mon Apr 22 2019

Skies have been partly to mostly cloudy across Southeast Texas so far
today with occasionally gusty southeast to south winds. The airmass
will continue to moisten up through midweek as this onshore flow persists,
with today's < 1 inch precipitable water values across our western
counties spreading eastward and approaching 1.50 inches area wide by
this time tomorrow. Disturbances moving across the area in the increasing
southwest flow aloft might be able to squeeze out some rain tomorrow,
but confidence on this happening is low as models continue to indicate
decent capping in area soundings. Will continue to carry rain chances
only around 20%. The midweek storm system is still on track to bring
increasing rain chances to the area beginning on Wednesday and likely
peaking Wednesday night through Thursday morning. A slow moving upper
level trough will be edging eastward into the central Texas area as
the day progresses on Wednesday, and then off to the northeast Wednesday
night through Thursday. An associated slow moving cold front along
with favorable lift/instability/upper level dynamics will support possible
strong to severe storm development probably beginning Wednesday afternoon
off to our southwest and possibly spreading into some of our western
county areas late in the day or maybe on into the overnight hours. Hail/winds
continue to look like the primary severe weather threat. Wednesday
through Thursday rainfall totals of 1 to 2 inches look possible, especially
along and north of the Interstate 10 corridor as this system moves
slowly through the area. Expecting the area to clear out by late Thursday
and on into Thursday night. Weak high pressure building in behind this
system on Friday will move off to the east Friday night and Saturday
and will allow for an onshore flow to return to the area. Look for
a dry weekend with cool nights and warm days.  42 

A moderate onshore flow will persist with high pressure east of the 
region and low pressure over the central plains. A secondary area of 
low pressure will develop over the Texas panhandle early Tuesday and
this will maintain the onshore flow. The low will move slowly NE and 
drag a cold front into the state. The cold front will slowly move across
the state on Wednesday and Wednesday night. The front will cross the coast
early Thursday with a weak offshore flow developing. The offshore flow
will strengthen Thursday night as high pressure builds into West Texas.
Onshore winds will return Friday night as the high moves east and low
pressure develops over the western high plains. 43


College Station (CLL)      65  78  64  77  62 /   0  20  20  60  80 
Houston (IAH)              66  77  65  79  66 /   0  20  10  30  80 
Galveston (GLS)            69  75  69  76  69 /   0  10  10  20  80 


GM...SMALL CRAFT SHOULD EXERCISE CAUTION through late tonight for the 
     following zones: Waters from Freeport to Matagorda Ship 
     Channel TX from 20 to 60 NM...Waters from High Island to 
     Freeport TX from 20 to 60 NM.