Monday, January 4, 2021

Jan. 4 21

 Area Forecast Discussion

Issued by NWS Houston/Galveston, TX

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KHGX 042334
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
534 PM CST Mon Jan 4 2021

.AVIATION...

A weak trough over Central and East Texas will allow for some
drier air to work into the region overnight. That should keep
northern and central TAF sites generally clear. As you approach
southern TAF sites, moisture levels are deeper and with light
winds, feel another night of fog, possibly dense will develop.
Have been more aggressive with regard to LIFR cigs/vsbys for KSGR
southward after 10z. KHOU is on the cusp and think they will
remain clear but it`s site that bears watching. Skies will clear
on Tuesday areawide after 15z. 43

&&

.PREV DISCUSSION... /ISSUED 329 PM CST Mon Jan 4 2021/

DISCUSSION...

The main focus of the forecast today will continue to be on the
midweek frontal passage, with above average temperatures leading
into the front, and cooler temperatures after the front moves
through. There is some potential for heavy rain in stronger storms
and if any training happens to set up, but that focus looks to be
more to our northeast.

Beyond the front, we are also turning an eye to the weekend, when
we will see rain chances return on the potential development of a
coastal low. Impact to our area will be highly dependent on where
the low forms and its track, and will likely be a key concern of
the forecast later in the week.

SHORT TERM [Tuesday Through Wednesday Night]...

The weather largely remains quiet through the short term. The
development of fog last night and a little bit of afternoon
cumulus right on the coast indicates that we are slowly seeing
moisture return to the area. Expecting pretty similar conditions
again overnight - light, offshore winds for much of the evening
may dry things out enough to keep fog out in the northern half (or
so) of the area, while the coastal plain can likely expect a
repeat of the patchy fog from last night. Evening and overnight
shifts will probably be on dense fog lookout. My early
inclination is that, like last night, conditions will allow for
patches of intermittent dense fog to crop up, but not be quite
conducive enough for widespread, sustained dense fog. But, because
Hashtag Stupid Fog, it`s a possibility that is still on the table.

Tomorrow should likely feel really, really familiar. Go chillier
up north with lows with the thinking that the air will be a touch
drier and radiate slightly better, while keeping lows near the
coast around 50 degrees with a modestly more modified airmass.
This leads to highs that are comparable to - perhaps just a touch
cooler than yesterday. The main feature to note for tomorrow`s
weather will be the return of onshore winds, and a more sustained
moisture return ahead of our front midweek. By late Tuesday night,
there`s a small chance we`ll have enough to support some pre-dawn
streamer showers...but given that progged precipitable water
values are 1.25 inches or lower in the guidance, I am not getting
too crazy with the PoPs yet before turning it over to the long
term...

LONG TERM [Thursday Through Monday]...

Showers/isolated thunderstorms should be starting to move into SE TX
early Weds from the NW via the cold front. Models are keeping with a
rather steady/fast motion with this line as it is forecasted to move
off the coast just before sunset on Weds. We are currently outlooked
for General Thunderstorms for this event. Limited instability (given
the time of day) along with favorable jet dynamics (LFQ and slightly
splitting) and elevated PWs (1.1" to 1.3") should help support wide-
spread development along this line. While the storms are expected to
move quickly east, there is still a marginal risk for excessive rain
fall for portions of the CWA, mainly to our NE and beyond. Otherwise
rainfall totals should average from 1/2 to 1 inch with the event.

With the main upper low associated with this front expected to track
quickly east, any lingering wrap around clouds/post-frontal rain are
likely going to end Weds night. Cooler temperatures along with clear
skies will prevail across SE TX for the rest of the week. Highs will
range from the upper 50s to lower 60s...with lows from the mid/upper
30s north of I-10 and in the lower to mid 40s south.

Looking further ahead into the weekend...models are still hinting at
the possibility of another strong cold front moving across the area,
with perhaps the added "bonus" of its associated upper low tracking
right over the CWFA in its wake. While there have been rumblings of
the possibility of some wintry precipitation with this event, there
is not a lot of consensus at this time. This pattern is not unusual
for this time of year and we still time to see how things shake out.
Stay tuned.

MARINE...

Light and variable - but generally offshore - winds today and
tonight will gradually become more onshore tomorrow, becoming more
moderate tomorrow night. A SCEC may be needed for at least some of
the Gulf waters Tuesday night into Wednesday with pre-frontal
onshore flow, but is more likely to be needed with northerly winds
behind the front. Indeed, a small craft advisory is beginning to
look more likely for at least the offshore Gulf waters on
Wednesday night. Expect winds to diminish and seas to subside late
in the week, but stronger winds and building seas are expected to
return this weekend.

HYDROLOGY...

For most of the area, rivers have crested from last week`s rain
and water levels are coming down. Flood warnings continue on the
San Bernard River at Boling, still in moderate flood, as well as
at Sweeny, in minor flood. Over on the Navasota River, Normangee
is also in minor flood.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      41  69  50  65  40 /   0   0  10  50  10
Houston (IAH)              45  68  52  68  43 /   0   0  10  60  30
Galveston (GLS)            53  65  58  67  49 /   0   0  10  50  40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

No comments:

Post a Comment