January 2020: Unsettled WX Week Ahead

General Weather Discussions and Analysis
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Cpv17
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snowman65 wrote: Mon Jan 06, 2020 9:05 am
Cpv17 wrote: Sun Jan 05, 2020 7:09 pm
snowman65 wrote: Sun Jan 05, 2020 5:48 pm
because it's more than 3 days out. nothing past that is believable anymore...
I agree. Models are horrible. They even have a problem inside of 3 days.
This must be what he is talking about......now....is there anyone out there believing this will actually happen? The way this season has been going?
The Euro isn’t completely onboard yet. Will be interesting to see the 12z run in a couple hours.
Cpv17
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The 12z GFS has backed off on the cold by a good 15 degrees or so. It’s just one run though so it doesn’t really mean much. It still shows a 1050mb high coming down.
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tireman4
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000
FXUS64 KHGX 061737
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1137 AM CST Mon Jan 6 2020

.AVIATION [18Z TAF Issuance]...

Lingering areas of fog this morning have diminished, and VFR
cigs/visibilities look to remain in place through the duration of
the current TAF period at all sites. A weak cold front is expected
to traverse the area this evening, and a wind shift from the
southwest to north/northeast will accompany the passage of the
boundary. This shift should occur at the northern sites around
02-03Z, metro area sites around 04-05Z, and coastal sites by
06-07Z. Cigs will drop to around 5000-8000 ft near the coast along
with the boundary passage this evening, but a further lowering of
any decks to MVFR does not appear to be likely.

Cady

&&

PREV DISCUSSION /Issued 352 AM CST Mon Jan 6 2020/...

SHORT TERM [Through Tuesday]...

The patchy morning fog that has developed will dissipate by 8 to 9am
as the sun begins to work its magic. Water vapor imagery this
morning shows the upper level low that will be swinging across
northern Texas through the day today is currently moving through
the Four Corners region. Southwesterly flow ahead of this system
will bring temperatures back into the low to mid 70s across the
region. The one factor that may inhibit daytime heating compared
to yesterday is that today will see partly cloudy skies across the
central and southern part of the area. This may help keep
temperatures slightly cooler, but we will still be in the 70s. The
cold front associated with the passing disturbance will move
through the area this evening into the overnight hours. The front
looks to pass through the northern counties around 3 to 5z,
Houston area around 5 to 7z, then reaching the coast between 8 and
10z. Will you notice this front? Probably not, unless you are
paying attention to a flag. This front is pretty moisture starved
with PWATS out ahead of the front only around 0.6 to 0.8 inches,
so no showers are expected to accompany its passage over land with
only a slight chance of showers in the far Gulf waters. The winds
will shift from a southerly flow to a northwesterly flow, which
will be the biggest indication of the FROPA.

Drier air moving in behind the front combined with the northeasterly
wind will mean that there really is not fog threat for tonight.
Temperatures will cool into the low to mid 40s tonight with the
cooler temperatures continuing into day on Tuesday. Skies clear out
on Tuesday as a transient high pressure slides in across southeast
Texas. Even with the clear skies temperatures tomorrow afternoon
will max out in the low 60s, so tomorrow will be about 10 degrees
cooler than today. But it will be the coolest day of the week as
southeasterly flow returns midweek.

Fowler

LONG TERM [Tuesday Night Through Monday]...

Clear skies are expected Tuesday night as high pressure over
Central Texas drifts east toward LA. As the high drifts east,
onshore winds will develop on Wednesday and bring a gradual return
of moisture back to the region. Skies will start out sunny
Wednesday morning but clouds should make a return in the afternoon
with cloudy skies expected areawide by evening. Low level
moisture will continue to stream into the area Wednesday night and
fcst soundings show a saturated layer from the surface to around
850 mb with capping noted in the 85-70 mb layer and very dry air
above the inversion. PW values increase to around 1.10 inches so
feel some weak streamer showers will be possible Wednesday night.
A warm front will approach the area on Thursday so skies will
remain cloudy with some spotty light rain/drizzle as the front
pushes north. Low temperatures on Thursday morning will probably
occur around midnight with steady or slowly rising temperatures by
12z Thursday. 850 mb temps warm and high temps on Thursday will
be in the lower/middle 70`s.

On Thursday night, weak warm air advection showers will likely
persist over SE TX. Overnight lows will be unseasonably warm with
low temperatures only cooling into the middle and upper 60`s. A
short wave will move across the Great basin and carve out a long
wave trough over the southern Rockies. The upper trough and
associated surface features will reach West TX by Friday afternoon
and move across the rest of the state Friday night. A sfc low over
the central plains will move NE Thursday night dragging a cold front
into the state. A secondary area of low pressure will develop over N
TX Friday afternoon and this feature will also move NE and drag the
cold front across E-SE TX Friday night. The ECMWF and GFS have come
into better agreement but the GFS is still faster by about 6 hours.
SPC has outlooked SE TX for Friday but not confident in how this
will all play out. CAPE values are between 500-1000 J/Kg and LI
values are between -3 and -5. Lapse rates are around 6.3 degrees,
with helicity values under 100. There is plenty of shear but would
prefer higher CAPE values to support the risk for severe. That said,
there is a weakly splitting jet and SE TX will lie in a weak RRQ.
Will go with likely PoPs for late Friday into Friday night and will
continue to monitor the severe threat as the event nears. 43

MARINE...

Light onshore flow and low seas will continue through the afternoon
hours today, but a weak cold front is expected to push through the
region later this evening into late tonight. While there is only a
very slight chance of showers with this frontal passage, moderate to
strong northeasterly flow is expected in its wake with seas
increasing to around 4 to 6 ft tomorrow morning. SCEC criteria is
expected to begin around 3AM on Tuesday in the Gulf waters, then
increasing to advisory levels a few hours after that. The flow will
decrease and veer through the day tomorrow becoming a light easterly
flow by midnight.

One concern with the moderate to strong offshore flow tomorrow
morning is that low tides will coincide with it creating a marginal
low water advisory. Typically issues arise around -1.0 to -1.5 ft
below MLLW, and operational ETSS has low tide around -0.6 ft while
the experimental ETSS is closer to -0.9 ft. Because of how marginal
the forecast is at the moment, will not be issuing any low tide
highlights with this package. However, it will need to be
re-evaluated later today.

The light onshore flow continues on Wednesday, but will begin to
increase Wednesday night ahead of the next developing upper level
low. The flow remains moderate to strong through through Friday
with seas increasing to 4 to 6 feet, so another round of caution
flags or advisories will be needed in that time frame. Guidance
is getting into better agreement that a cold front will be moving
through the Friday bringing a threat of showers and thunderstorms
through early Saturday morning.

Fowler

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 40 64 37 67 56 / 0 0 0 0 20
Houston (IAH) 46 64 41 67 57 / 0 0 0 0 20
Galveston (GLS) 53 62 53 66 60 / 10 0 0 0 10

&&

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

$$
mcheer23
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Cpv17 wrote: Mon Jan 06, 2020 11:02 am The 12z GFS has backed off on the cold by a good 15 degrees or so. It’s just one run though so it doesn’t really mean much. It still shows a 1050mb high coming down.
Still shows quite a bit of frozen precip too. Especially out toward the hill country.
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MontgomeryCoWx
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Cpv17 wrote: Mon Jan 06, 2020 11:02 am The 12z GFS has backed off on the cold by a good 15 degrees or so. It’s just one run though so it doesn’t really mean much. It still shows a 1050mb high coming down.
High temps are still in the low to mid 30s end of next week. I wouldn't get excited until Saturday, but this is one of those bleeders that overwhelms the pattern.

The key will be the strength and placement of high. I'm less worried about the strength than I am the placement. With that said, the placement should favor a more west based solution given the progression we are seeing.
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Cpv17
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MontgomeryCoWx wrote: Mon Jan 06, 2020 12:59 pm
Cpv17 wrote: Mon Jan 06, 2020 11:02 am The 12z GFS has backed off on the cold by a good 15 degrees or so. It’s just one run though so it doesn’t really mean much. It still shows a 1050mb high coming down.
High temps are still in the low to mid 30s end of next week. I wouldn't get excited until Saturday, but this is one of those bleeders that overwhelms the pattern.

The key will be the strength and placement of high. I'm less worried about the strength than I am the placement. With that said, the placement should favor a more west based solution given the progression we are seeing.
The Euro is a no go.
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MontgomeryCoWx
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Cpv17 wrote: Mon Jan 06, 2020 2:10 pm
MontgomeryCoWx wrote: Mon Jan 06, 2020 12:59 pm
Cpv17 wrote: Mon Jan 06, 2020 11:02 am The 12z GFS has backed off on the cold by a good 15 degrees or so. It’s just one run though so it doesn’t really mean much. It still shows a 1050mb high coming down.
High temps are still in the low to mid 30s end of next week. I wouldn't get excited until Saturday, but this is one of those bleeders that overwhelms the pattern.

The key will be the strength and placement of high. I'm less worried about the strength than I am the placement. With that said, the placement should favor a more west based solution given the progression we are seeing.
The Euro is a no go.
The Operational is a middlin' cold front (nothing unusual). The ensembles on the other hand, side with the GFS.
Team #NeverSummer
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jasons2k
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Had the windows rolled down for the drive home. Not bad for January.
harp
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The GFS has trended less and less cold air each of the last several runs. As a result, the frozen precip is now gone. It was about the only eye candy we have had this year and was fun while it lasted!
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snowman65
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harp wrote: Mon Jan 06, 2020 11:37 pm The GFS has trended less and less cold air each of the last several runs. As a result, the frozen precip is now gone. It was about the only eye candy we have had this year and was fun while it lasted!
That's what it does....lol. It will end up 75.
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