Scientific Forecaster Discussion
fxus64 khgx 081119
Area forecast discussion
National Weather Service Houston/Galveston Texas
519 am CST sun Dec 8 2019
Aviation [12z taf issuance]...
Poor flight conditions exist mainly to the west and southwest of
the terminals, but will impinge at least partially at sgr, hou,
and lbx into mid-morning when conditions will improve to VFR
across the area. More low stratus and/or fog will be possible
tonight, though winds appear more likely to stay up enough for
the main feature to be stratus over fog.
Previous discussion /issued 353 am CST sun Dec 8 2019/...
Short term [through monday]...
Moisture is streaming back into southeast Texas from the Gulf as
obs show that onshore flow has re-established itself with a
surface high pressure center drifting east of the region to the
lower Mississippi Valley.
With surface and low level winds fairly light, and favorable T-TD
spreads setting up, we're seeing widespread fog with numerous
dense patches across the western bulk of the area, and a dense fog
advisory has been issued to match. Less dense fog is developing
across the rest of the area, and will have to be watched carefully
through morning. Some of that dense fog is bleeding over into
Houston proper, as hobby has briefly fallen as low as 1/8 mile
visibility. But, for now those intrusions have been small and
transient, so will try to hold off expanding the advisory into The
Heart of the Houston Metro unless a more significant trend of
dense fog emerges.
Fog can be expected to hold on into the mid-morning, but should
improve fairly rapidly once temperatures rise enough to eliminate
the nighttime surface inversion. From there, we'll be looking for
temperatures to rise into the 70s - higher in the west, lower in
the east. The increased dewpoints will keep temperatures up quite
high overnight, closer to typical high temperatures than low
temperatures for early December. This low floor will get US
started to an even warmer Monday. We may begin to see some showers
crop up east of the Houston Metro on Monday afternoon, but the
best chance for rain will hold off until the front arrives...but
more on that in the long term section.
Long term [monday night through sunday]...
After the warm day on Monday, colder temperatures will return to southeast
Texas after a cold front moves into the area Monday night and off the
coast Tuesday morning. Look for increasing rain chances as the front
moves across the area, but our best rain chances are anticipated
on Tuesday behind the front as the lagging upper level trough moves
eastward across the state. Enough lift and instability could lead
to some isolated thunderstorms, but the majority of activity will
be rain/showers. Temperatures on Tuesday will be falling as the day
progresses with the official highs for the day probably occurring
around midnight inland and around sunrise near the coast. The cold
rains should be coming to an end late from Tuesday night through early
Wednesday morning with near freezing temperatures coming into parts
of our northern counties after the rains move on out. Cool and drier
weather is anticipated for the remainder of the week with the coldest
overnight temperatures coming on Wednesday and Thursday. Look for a
gradual warming trend to set in at the end of the week, and we currently
are showing this trend to continue on into next weekend. 42
Light onshore winds should continue through the day today, but
become more moderate to strong overnight into Monday. It will be
marginal for both winds and waves, but scec conditions may emerge
on the offshore waters at some point on Monday ahead of the
Monday night front. Winds will briefly slacken Monday night as the
front pushes through, with rain showers becoming very likely into
Tuesday. Northerly winds will strengthen behind the front as well
on Tuesday, with a Small Craft Advisory looking increasingly
likely from some point Tuesday through Tuesday night. Some of the
gusts may even push to near gale force at times on Tuesday night.
Preliminary point temps/pops...
College Station (cll) 76 61 81 44 52 / 0 0 10 70 80
Houston (iah) 74 63 81 53 60 / 0 10 10 90 80
Galveston (gls) 71 65 76 59 66 / 0 10 10 80 80
Texas...dense fog advisory until 9 am CST this morning for the following
zones: Austin...coastal Brazoria...coastal
Jackson...coastal Matagorda...Colorado...Fort Bend...inland
Brazoria...inland Galveston...inland Jackson...inland