Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 191202
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
600 AM CST Mon Feb 19 2018

.AVIATION...
Despite the relatively drier middle to upper layer air there is
still enough lower level moisture to form and maintain an early
day MVFR stratus deck. A 30-40 knot low level jet stream and drier
air working its way in from the mid levels should aid in scattering
decks out to VFR by early afternoon. A tight onshore pressure
gradient from lowering West Plains pressures have strengthened
regional southerlies. The combination of the mix down of today`s low
level jet and these higher background winds will translate to gusty
surface southerlies to between 20 to 25 knots. Ceilings may fall
back to persistent MVFR categories this evening as the lower levels
saturate back up. Maritime fog may return tonight with areas of
locally dense sea fog impacting coast hubs through the rest of the
week. 31

&&

.PREV DISCUSSION... /ISSUED 426 AM CST Mon Feb 19 2018/

DISCUSSION...
Above normal temperatures will prevail across Southeast Texas for the
next several days, and it looks like some records (mainly overnight
low temperatures) might be in danger of being tied or broken under
a persistent and warm onshore flow. Impulses embedded in the deepening
southwest flow aloft are beginning to move out of Mexico and into
Texas, and this pattern will persist for much of this week. We are
still looking at increasing rain chances beginning on Tuesday and
remaining on the high side into Wednesday, Wednesday night and possibly
into Thursday as moisture levels remain high ahead of a slow moving
cold front that will be edging into our area and will be stalling.
Having increasing confidence that portions of our area could get some
locally heavy rainfall with this event, and have gone ahead and begun
to mention it in our grids for parts of our northwest and north counties
Tuesday night and Wednesday which are locations closest to WPC`s
Day 2 and Day 3 Excessive Rainfall Outlook areas. The frontal boundary`s
location and associated convergence might end up determining where
the highest rainfall amounts will occur, and we`ll have to see how
this all unfolds as we head into the midweek period. Will continue
to carry lower rain chances for the end of the week and on into the
weekend as the frontal boundary moves back inland and out of our area.
Another cold front might become our next rain producer during the
Sunday/Monday time period.  42

MARINE...
A tightened onshore pressure gradient created by lowering Rocky
Mountain leeward pressure will produce all local water Caution winds
through the day...strengthening to Advisory criteria winds across
the far offshore waters latter today. Nearshore waters should remain
in the 3 to 5 foot range...offshore heights may build to the
occansional 6 to 7 feet through Wednesday. Drier air moving up from
southwestern Gulf has significantly eroded the recent dense sea fog
and clearer non-foggy conditions should persist through this
afternoon. Hazy Monday evening with returning fog expected sometime
during the overnight Tuesday morning hours. Fog should still impact
the nearshore and local bay waterways through the majority of the
week. An approaching Wednesday cold front is forecast to reach
eastern Texas but...with backing high pressure remaining far off to
the northeast and not providing a decent northern push of the front
and Gulf upper ridging putting up an eastern wall...this front will
not make it off the coast. Thus...onshore winds will prevail through
the remainder of the work week as will higher moisture over cooler
shelf waters that will keep the threat for fog alive. Disturbances
moving up ahead of this front will also keep shower and thunderstorm
chances alive Wednesday and Thursday. 31

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      79  66  76  62  68 /  20  20  60  80  80
Houston (IAH)              80  67  77  65  77 /  20  20  50  60  80
Galveston (GLS)            75  66  75  64  73 /  10  20  30  50  70

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION through late tonight 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...Galveston Bay...Matagorda
     Bay.

     Small Craft Advisory from 6 PM this evening to 6 AM CST Tuesday
     for the following zones: Waters from Freeport to the
     Matagorda Ship Channel from 20 to 60 NM...Waters from High
     Island to Freeport from 20 to 60 NM.

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

&&

$$

Discussion...42
Aviation/Marine...31


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