Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 191538

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1038 AM CDT Mon Mar 19 2018

A pre-frontal trough has pushed into the coastal waters with west
winds overtaking coastal counties. A narrow band of clouds
persists between the trough and a weak cold front that extends
from low pressure over SW Missouri to Huntsville to Columbus to
Laredo. The weak front will push into the coastal waters this
afternoon and winds will veer to the NW. Vis satellite imagery
shows clouds trying to redevelop behind the front and short term
guidance seems to support a bit more cloud cover this afternoon.
Temperatures are already in the upper 70`s along the coast and it
won`t take much heating for Galveston to reach the lower 80`s this
afternoon. (Record for GLS is 80). Will let the current temp
forecast ride as is but the warm start coupled with offshore winds
generally yields very warm temperatures and may need to bump
coastal temps upward. Rest of the forecast looks on track. 43


.PREV DISCUSSION... /ISSUED 626 AM CDT Mon Mar 19 2018/

AVIATION [12Z TAF Issuance]...

The initial cold front has entered the area - and though a bit
slower than expected - should reach the coast by 13Z or so. CLL
reported light showers after the wind shift and do bring that
potential to all the downstream sites. Short term guidance does
indicate some potential for thunder towards the coast as we warm
up some, but at this time think that it will be quick enough to
restrict everything to showers. If the front does slow any more,
coastal sites may need to have some thunder introduced.

Beyond that, skies clear relatively quickly once showers come to
an end, and we should rise rapidly into VFR conditions with breezy
northwesterly winds. Though the gusts should drop off overnight,
think sustained wind speeds will only decrease modestly.

On an equipment note, UTS has not reported since yesterday
evening, and suspect that the station has lost power. Until
service can be restored, amendments for the site should not be


PREV DISCUSSION /Issued 411 AM CDT Mon Mar 19 2018/...

NEAR TERM [Through Today]...

Water vapor imagery and upper air analysis show a nicely stacked,
negative tilted trough over the Plains at the KS/OK border. To
the south over MS/AL, the strong jet streak that initiated severe
convection over the Brazos Valley and East Texas yesterday
continues to move east. Surface analysis has surface low pressure
stacked with the upper low over the KS/OK border with a Pacific
front occluding around it over OK. This Pacific front stretches
from E OK through DFW and into central Texas. South of the
boundary remains a moist airmass with areas of fog over SE Texas.

Overall think the near term forecast looks on track with this
front pushing into the region later this morning with a chance of
showers and perhaps a thunderstorm or two. Again this will hinge
on cap strength over the region. Forecast will keep some 30 PoPs
for areas north of Houston where cap is weaker and 20 PoPs along
the coast. The front may be running about 3 hours slower than
previously forecast but should push off the coast 15-18Z today.

Previously held fire weather concerns have lessoned given the
amount of rainfall the northern third of the area received
yesterday. This is also the reason for dropping the fire weather
watch. There will still be plenty of dry air for this afternoon
with some gusty winds, but fuels should be moist enough to lower
concerns. The lone exception may be for areas west and southwest
of Houston where there has not been as much rainfall. Regardless
much of the area should have RH less than 25 percent with winds
around 10-15 mph and gusts around 20 mph. Temperatures should
reach the mid 80s for the southern half of the area with good
mixing conditions in the boundary layer. Galveston may break
another record high temperature as a result.

SHORT TERM [Tonight Through Wednesday]...

Dry condition will continue Tuesday/Wednesday as high pressure
moves over the area. Upper level pattern becomes more amplified
with a trough over the east coast and ridging over the Rockies.
Low temperatures should reach the 40s both mornings but Wednesday
morning should be the coldest with high pressure parked over the

LONG TERM [Wednesday Night Through Monday]...

Thursday through Friday upper level ridging will keep conditions
quite with return flow setting up at the surface with high
pressure moving east. This should allow for temperatures to go
back above normal for the weekend with maybe a few showers
possible starting Saturday. Forecast will keep some low end rain
chances going for the weekend but forecast confidence is quite
low. Keeping in mind there are model differences, overall pattern
looks to be more wet and active as a frontal boundary stalls in
Texas. At this point just something to monitor but pattern would
support possible heavy rainfall for Texas.


Another night of sea fog at the Gulf shores, and while producing
variable visibility, spots are seeing dense fog again. This may be
expected to continue until winds veer to become offshore and start
to usher in some drier air. Winds will be reinforced late tonight
into tomorrow, and a SCEC will be likely and an advisory may be
needed in the offshore waters. These offshore winds should take tide
levels below astronomical predictions, but at this point it does not
look to be quite low enough to require a low water advisory. Spots
on the upper part of Galveston Bay may need to be watched closely,

Winds will slowly diminish into the midweek as high pressure drops
into the region, and slowly veer to northeasterly, and then back to
onshore by late Wednesday. For the late week, with the high moving
off and developing low pressure in the lee of the Rockies, winds
should perk back up again.



Opted to drop the fire weather watch without upgrading to a red flag
warning for Monday. This choice was made on the relatively heavy
rainfall seen over much of the watch area on Sunday thanks to severe
thunderstorms. It is important to note that not much has changed in
regards to expectations for the weather - it will still be very dry,
and winds will be marginally breezy. But fortunately, it will take
some time for fine fuels to dry out. So while the dry air and winds
may promote some fire spread, the fuel conditions will likely
preclude explosive growth.

The next time frame to watch will be Tuesday. Winds are still
expected to be stronger then, and for areas south of I-10 well to
the west and southwest of Houston which saw little rain Sunday,
fuels will be drier. But there is still the expectation that
relative humidity will not be critically low. This creates another
situation in which fire weather conditions may be elevated, but not
quite serious enough to support explosive fire conditions. Due to
this, will opt against a fire weather watch at this time. This can
be reconsidered later today if observations indicate sufficiently
drier air than forecast were to work into the area.



College Station (CLL)      80  47  69  45  75 /   0   0   0   0   0
Houston (IAH)              85  49  72  48  76 /   0   0   0   0   0
Galveston (GLS)            82  56  70  55  71 /  10   0   0   0   0




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