Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 221142

Area Forecast Discussion
National Weather Service Houston/Galveston TX
642 AM CDT Fri Jun 22 2018

As of 630 this morning, satellite imagery showed a band of cirrus
stretched across the region, just south of CLL and above IAH and
HOU. These high clouds are continuing to shift southward towards
the coast, and have heavily influenced where areas of fog have
developed. Along and south of this boundary, visibilities and
ceilings have lowered from MVFR to LIFR criteria. North of this
feature, CLL, UTS, and CXO are dealing with IFR ceilings.
Conditions should improve through the mid morning hours with
patchy fog burning off with the help of daytime heating. Ceilings
should rise to VFR criteria by late morning.

Onshore flow will prevail today, increasing to 9-16 kts as we
move into the evening hours and the pressure gradient tightens
over the region. Model guidance and forecast soundings are again
hinting at the possibility of MVFR/IFR ceilings tonight, and have
hinted at this in the latest TAF package.



.PREV DISCUSSION... /ISSUED 343 AM CDT Fri Jun 22 2018/

At 300 AM, weak high pressure was over the eastern Gulf with weak
low pressure over the western plains. A few very weak showers
were moving toward the Matagorda Bay region but these are expected
to wane by sunrise. Upper level ridging over southern CA will
extend eastward today and Saturday bringing very warm temperatures
to the region and a bit more subsidence. 850 temps are progged to
be very warm today and this will translate to very warm surface
temperatures. Bringing the 850 temp to sfc would suggest high
temperatures today will warm into the middle 90`s. Surface dew
points will not mix out efficiently so it`s going to feel very
humid today and heat index values will exceed 105 degrees this
afternoon. After 5 consecutive days in the 80`s, todays heat is
going to feel oppressive. Not much changes is expected on Saturday
with the upper ridge still exerting some influence and 850 temps
remaining very warm. Highs on Saturday will again be in the mid
90`s with heat index values topping 105 degrees. Fcst soundings
all show a bit of capping near 850 mb, PW values near 1.70 inches
and convective temperatures in the mid to upper 90`s. Can`t rule
out a few early morning showers each day or a rogue aftn storm but
the probability of occurrence looks too small to mention at this

At this time, don`t think a Heat Advisory will be required today.
Max heat index values are progged to remain between 105 and 107
degrees this afternoon. It`s going to feel hot and sticky today
and heat safety rules apply. If outdoors, find shade, drink plenty
of water and wear loose light fitting clothing.

On Sunday, a weak inverted trough at 500 mb will approach deep
south Texas. Although this feature is well south of the region,
heights fall a little and 850 temps cool. GFS soundings still look
too dry to generate much rain but capping is weaker. Will mention
20 PoPs for Sunday and trend cooler with sfc temps.

Not much change for much of next week. Upper level ridging will
dominate much of the western half of the country but SE TX will
lie on the periphery of this feature. The upper level high will
shift toward the mid Mississippi valley toward the end of the
week but SE TX generally remains on the periphery of the high.
GFS soundings show PW values between 1.70 and 1.90 inches and
weak capping that can be overcome with heating. Will maintain 20
PoPs for the rest of the week. Temperatures look near to slightly
warmer than normal through the end of next week. 43

The city of Houston recorded 5 consecutive days with high
temperatures below 90 degrees. That will end today. The last time
Houston record more than 5 consecutive days below 90 degrees in
June was back in 2004 (Jun 22-Jun 27 (six days)). 43

Light onshore flow should increase in speed by Friday afternoon to
between 10-15 kts. The pressure gradient should begin to tighten as
pressures fall over the Texas Panhandle and a region of surface high
pressure over the northern Gulf of Mexico continues to nudge
westward late Friday. This should allow for SCEC conditions late
Friday and potentially through Sunday in the offshore waters and at
times in the nearshore waters. Over the weekend, seas could rise to
3-5 feet in the Gulf waters, occasionally reaching 6 feet in the
offshore waters. The pressure gradient should relax early next week,
and winds will back out of the southeast between 10-15 kts, with
seas between 2-4 feet.



College Station (CLL)      95  75  95  77  94 /  10  10  10  10  10
Houston (IAH)              94  77  94  78  93 /  10  10  10  10  20
Galveston (GLS)            88  81  89  82  90 /  10  10  10  10  20




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