Don’t lose hope. The NWS is always conservative when it comes to forecasting winter weather in southeast Texas. We’re still 36 hours or so out from the event.
January 2021
-
srainhoutx
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- Location: Maggie Valley, NC
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Morning weather briefing from Jeff:
Winter Storm heading for Texas
Winter Storm Watch is in effect for the following counties: Burleson, Brazos, Washington, Grimes, Madison, Houston, Trinity, and Walker in SE TX
Discussion:
Upper level trough is currently digging SE across the western US into the 4-corners area and will begin to turn ESE across New Mexico and into W TX later today. This trough will induce surface low pressure along the NE coast of Mexico which will move NE toward the mid TX coast and then ENE over the NW Gulf of Mexico by Sunday night. The surface low offshore of the TX coast will supply ample moisture northward and this moisture return is already clearly noted in satellite images over S TX showing a large cloud shield advancing quickly NNE. While the surface low provides the moisture, the upper level trough will help to provide a degree of cold air in the mid and upper levels. A surface cold front will develop over TX and surge SE on Sunday afternoon and evening, but the more important temperature profiles for P-type will be in the portion of the atmosphere from above the surface to around 4000-5000 ft.
Rain will overspread much of the region early Sunday from SW to NE and there may be a brief period of evaporational cooling as the dry surface layer quickly saturates…thereafter there will be little room for much decrease in the surface temperatures until the surface cold front arrives Sunday late afternoon/evening. Surface temperatures will likely be in the low to mid 40’s for much of the day Sunday with rain. By the afternoon, mid and upper level temperatures will begin to cool from NW to SE over the area as the colder air aloft associated with the upper level trough approaches. This will start the transition from rain to a rain/snow mix to all snow across the northern portions of SE TX Sunday afternoon. There is good lift and moisture in the “snow growth zone” over the winter storm watch area by Sunday afternoon/evening and this will likely support banding of the precipitation and increased snowfall rates which will help to cool the lower level warm nose. South of the watch area to I-10 colder temperatures aloft will take longer to advect in and longer for the rain to mix with snow…it remains unclear how far south a complete all snow transition may occur.
Accumulations:
Widespread snow accumulations of 1-3 inches is likely in the Winter Storm Watch counties or that area generally NW of a line from Brenham to Huntsville to Trinity. South of this line to I-10 (especially across portions of Austin, Waller, Montgomery, Polk, and San Jacinto Counites) a dusting up to 1 inch of snow is possible. Given the likely potential for banded heavy precipitation, locally higher amounts are certainly possible and totals upwards of 6 inches are not out of the question in the watch area. In fact several of the meso scale models are showing bands of heavy snow in the watch area Sunday late afternoon and early evening which could result in quick accumulations.
Impacts:
Travel impacts and disruption are increasing likely in the Winter Storm Watch area where snow accumulation is likely. Main impacts will be to bridges and overpasses where falling snow melts on contact with the road surface and then freezes into a layer of ice as surface temperatures fall to and possibly below freezing. South of the watch area, impacts are expected to be minimal with surface temperatures remaining above freezing limiting accumulation and ice formation from melting snowfall.
Confidence:
Overall confidence has increased over the last 24 hours, but small shifts in the track of the surface and upper level lows could result in changes to the forecast, P-type lines and areas and accumulations…so stay tuned over the next 24 hours.
Winter Storm Watch area will likely be upgraded to a warning later today.
Heavy Rainfall:
While much of the focus is on the snow potential, there is the potential for some heavy rainfall near the coast especially around Matagorda Bay and the coastal bend Sunday as the coastal low develops. Rainfall amounts in these areas could average 1-3 inches.
Winter Storm heading for Texas
Winter Storm Watch is in effect for the following counties: Burleson, Brazos, Washington, Grimes, Madison, Houston, Trinity, and Walker in SE TX
Discussion:
Upper level trough is currently digging SE across the western US into the 4-corners area and will begin to turn ESE across New Mexico and into W TX later today. This trough will induce surface low pressure along the NE coast of Mexico which will move NE toward the mid TX coast and then ENE over the NW Gulf of Mexico by Sunday night. The surface low offshore of the TX coast will supply ample moisture northward and this moisture return is already clearly noted in satellite images over S TX showing a large cloud shield advancing quickly NNE. While the surface low provides the moisture, the upper level trough will help to provide a degree of cold air in the mid and upper levels. A surface cold front will develop over TX and surge SE on Sunday afternoon and evening, but the more important temperature profiles for P-type will be in the portion of the atmosphere from above the surface to around 4000-5000 ft.
Rain will overspread much of the region early Sunday from SW to NE and there may be a brief period of evaporational cooling as the dry surface layer quickly saturates…thereafter there will be little room for much decrease in the surface temperatures until the surface cold front arrives Sunday late afternoon/evening. Surface temperatures will likely be in the low to mid 40’s for much of the day Sunday with rain. By the afternoon, mid and upper level temperatures will begin to cool from NW to SE over the area as the colder air aloft associated with the upper level trough approaches. This will start the transition from rain to a rain/snow mix to all snow across the northern portions of SE TX Sunday afternoon. There is good lift and moisture in the “snow growth zone” over the winter storm watch area by Sunday afternoon/evening and this will likely support banding of the precipitation and increased snowfall rates which will help to cool the lower level warm nose. South of the watch area to I-10 colder temperatures aloft will take longer to advect in and longer for the rain to mix with snow…it remains unclear how far south a complete all snow transition may occur.
Accumulations:
Widespread snow accumulations of 1-3 inches is likely in the Winter Storm Watch counties or that area generally NW of a line from Brenham to Huntsville to Trinity. South of this line to I-10 (especially across portions of Austin, Waller, Montgomery, Polk, and San Jacinto Counites) a dusting up to 1 inch of snow is possible. Given the likely potential for banded heavy precipitation, locally higher amounts are certainly possible and totals upwards of 6 inches are not out of the question in the watch area. In fact several of the meso scale models are showing bands of heavy snow in the watch area Sunday late afternoon and early evening which could result in quick accumulations.
Impacts:
Travel impacts and disruption are increasing likely in the Winter Storm Watch area where snow accumulation is likely. Main impacts will be to bridges and overpasses where falling snow melts on contact with the road surface and then freezes into a layer of ice as surface temperatures fall to and possibly below freezing. South of the watch area, impacts are expected to be minimal with surface temperatures remaining above freezing limiting accumulation and ice formation from melting snowfall.
Confidence:
Overall confidence has increased over the last 24 hours, but small shifts in the track of the surface and upper level lows could result in changes to the forecast, P-type lines and areas and accumulations…so stay tuned over the next 24 hours.
Winter Storm Watch area will likely be upgraded to a warning later today.
Heavy Rainfall:
While much of the focus is on the snow potential, there is the potential for some heavy rainfall near the coast especially around Matagorda Bay and the coastal bend Sunday as the coastal low develops. Rainfall amounts in these areas could average 1-3 inches.
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Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
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Kingwood36
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Well ill be sitting outside enjoying the rain as it comes down cuz I know its actually snowing farther up in the sky but its jist melting as it falls to me 
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tireman4
- Global Moderator
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- Location: Humble, Texas
- Contact:
000
FXUS64 KHGX 091140
AFDHGX
Area Forecast Discussion
National Weather Service Houston/Galveston TX
540 AM CST Sat Jan 9 2021
.SHORT TERM [Through Monday]...
Quiet wx is on tap today before conditions deteriorate later
tonight into Sunday morning. Our next wx system can be seen on wv
imagery dropping sewd toward the Four Corners region. As it
continues to dig southeast and into West Texas tonight, expect a
coastal low to begin developing between Corpus and Matagorda Bay.
With increasing moisture and large scale lift, look for sct precip
to begin developing late tonight...increase in areal coverage and
overspread southeast Tx from west-to-east during the day Sunday.
Coastal parts of Jackson, Matagorda & Brazoria may see some
periods of moderate to heavy rainfall at times.
As both the upper trof and coastal low advance ewd later in the
day Sunday, temp profile aloft will cool enough to where northern
parts of the CWA may begin seeing a transition to a rain/snow
mix. Atmos will further cool s/sewd Sunday evening into the
overnight hours and expect precip to transition more to snow
across northern parts and a rain-snow mix possibly as far south to
the I-10 area.
So what has changed since this time last night?
1. Guidance, in general, positions the coastal low a bit further
south and brings the colder air in sooner. Tweaked the fcst to
indicate a mix possible later in the afternoon Sunday across the
north. Some of the latest incoming fcst soundings indicate this
could occur even earlier in the day.
2. Due to #1 and some better frontogenic forcing...several
deterministic, hires and ensemble runs are showing the potential
for higher snow accumulations amounts than what is currently in
the forecast across northern zones. As of now, eyeballing 1-4"
across the Winter Storm Watch area (esp north and northeast
parts). Of note, there are guidance suggestions of even higher &
some lower.
There will likely be a fairly sharp cut-off as to where
accumulations actually occur and I still like the Watch area
currently in place. Chances of any significant accumulations drop
off pretty quickly further one travels south of that. Debated
adding San Jacinto and Polk Counties into it, but since we still
have plenty of time to monitor guidance trends I prefer to wait
and see if we can get some better consistency.
Of course, and as what has been previously been mentioned, even
slight storm track deviations & mesoscale forcing can make a world
of difference in short geographic distances and the fcst will
continue to evolve.
Heading into the late evening Sunday and after midnight, we should
see a bit of dry slotting coming in from the west and available
moisture in the mid levels will wane from west-to-east. Precip
should mostly be done before sunrise Monday followed by a mcldy,
breezy & cold day. 47
&&
.LONG TERM [Monday Night Through Saturday]...
Surface high pressure building over the region will help to keep low
temperatures at/below freezing for a large part of the CWA Mon night
into Tues morning. For locations across the northern third (to half)
of our CWA, there could be up to 6 to 8 hours of freezing/below free-
zing temperatures during this time frame. Temperatures could only be
a little bit warmer for Tues night with lows in the mid to upper 30s
over most inland areas. However, some locations across our far north-
ern counties could still see freezing temperatures briefly overnight.
Otherwise, the forecast for SE TX the rest of the week should remain
fairly dry and quiet despite the goings on aloft. Previous runs that
had indicated the upper trof axis lingering to west of the state are
still hinting along those lines with the latest runs, but there seem
to be more differences regarding the timing of its track east. ECMWF
appears to be more aggressive than GFS at this point...but still not
expecting much beyond increased clouds as overall moisture should be
lacking. So, look for warming temperatures through the week as highs
approach the upper 60s by Thurs/Fri. 41
&&
.AVIATION [12Z TAF Issuance]...
The last of the scattered clouds in the southern half of the CWA
have mostly fizzled out, so most of the area airports are under
clear skies. This will last throughout the morning hours before
upper-level and mid-level clouds gradually work their way into the
area. The clouds will start out as scattered and continue filling in
to form an overcast layer by the afternoon hours. This will not pose
any operational impacts though as VFR conditions will persist
through Sunday morning. Light northerly/northeasterly winds will
gradually transition over to light easterly winds throughout the
day today. Looking ahead for Sunday, ceilings are expected to
steadily decrease as the coastal low approaches the area.
Expecting rain showers to begin moving in from the west early
Sunday morning. The increasing moisture will likely drop ceilings to
MVFR by late Sunday morning. 26
&&
.MARINE...
Northerly/northeasterly winds will transition over to easterly
throughout the day today. As we head into late Saturday night/early
Sunday morning, winds will increase as an area of low pressure
develops in southern Texas. Early Sunday morning will be the start
of a prolonged period of SCA conditions with easterly winds of 20
knots. As the low pressure system moves eastward into the western
Gulf of Mexico, winds will shift to southeasterly and speeds will
increase to around 25 knots. The strongest period of winds will be
following the passage of a cold front on Sunday evening/early Monday
morning with northeasterly wind speeds approaching gale force
(Sunday 6pm-Monday 3am). Elevated seas of 8-11 feet lasting from
Sunday afternoon through Monday afternoon will be another hazard
resulting from this low pressure system. Tide levels in this time
period may be high enough to cause beach flooding. The winds will
gradually diminish throughout the day on Monday as the low moves
away from the area with SCA conditions lasting into Monday
afternoon. Offshore northerly winds will continue into the middle of
next week. 26
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 53 38 40 33 44 / 0 30 90 80 10
Houston (IAH) 55 41 44 36 47 / 0 30 90 80 10
Galveston (GLS) 54 48 51 39 47 / 0 30 90 80 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Winter Storm Watch from Sunday afternoon through Monday morning
for the following zones:
Brazos...Burleson...Grimes...Houston...Madison...Trinity...Walker...Washington.
GM...Low Water Advisory until 3 PM CST this afternoon for the
following zones: Galveston Bay.
&&
$$
FXUS64 KHGX 091140
AFDHGX
Area Forecast Discussion
National Weather Service Houston/Galveston TX
540 AM CST Sat Jan 9 2021
.SHORT TERM [Through Monday]...
Quiet wx is on tap today before conditions deteriorate later
tonight into Sunday morning. Our next wx system can be seen on wv
imagery dropping sewd toward the Four Corners region. As it
continues to dig southeast and into West Texas tonight, expect a
coastal low to begin developing between Corpus and Matagorda Bay.
With increasing moisture and large scale lift, look for sct precip
to begin developing late tonight...increase in areal coverage and
overspread southeast Tx from west-to-east during the day Sunday.
Coastal parts of Jackson, Matagorda & Brazoria may see some
periods of moderate to heavy rainfall at times.
As both the upper trof and coastal low advance ewd later in the
day Sunday, temp profile aloft will cool enough to where northern
parts of the CWA may begin seeing a transition to a rain/snow
mix. Atmos will further cool s/sewd Sunday evening into the
overnight hours and expect precip to transition more to snow
across northern parts and a rain-snow mix possibly as far south to
the I-10 area.
So what has changed since this time last night?
1. Guidance, in general, positions the coastal low a bit further
south and brings the colder air in sooner. Tweaked the fcst to
indicate a mix possible later in the afternoon Sunday across the
north. Some of the latest incoming fcst soundings indicate this
could occur even earlier in the day.
2. Due to #1 and some better frontogenic forcing...several
deterministic, hires and ensemble runs are showing the potential
for higher snow accumulations amounts than what is currently in
the forecast across northern zones. As of now, eyeballing 1-4"
across the Winter Storm Watch area (esp north and northeast
parts). Of note, there are guidance suggestions of even higher &
some lower.
There will likely be a fairly sharp cut-off as to where
accumulations actually occur and I still like the Watch area
currently in place. Chances of any significant accumulations drop
off pretty quickly further one travels south of that. Debated
adding San Jacinto and Polk Counties into it, but since we still
have plenty of time to monitor guidance trends I prefer to wait
and see if we can get some better consistency.
Of course, and as what has been previously been mentioned, even
slight storm track deviations & mesoscale forcing can make a world
of difference in short geographic distances and the fcst will
continue to evolve.
Heading into the late evening Sunday and after midnight, we should
see a bit of dry slotting coming in from the west and available
moisture in the mid levels will wane from west-to-east. Precip
should mostly be done before sunrise Monday followed by a mcldy,
breezy & cold day. 47
&&
.LONG TERM [Monday Night Through Saturday]...
Surface high pressure building over the region will help to keep low
temperatures at/below freezing for a large part of the CWA Mon night
into Tues morning. For locations across the northern third (to half)
of our CWA, there could be up to 6 to 8 hours of freezing/below free-
zing temperatures during this time frame. Temperatures could only be
a little bit warmer for Tues night with lows in the mid to upper 30s
over most inland areas. However, some locations across our far north-
ern counties could still see freezing temperatures briefly overnight.
Otherwise, the forecast for SE TX the rest of the week should remain
fairly dry and quiet despite the goings on aloft. Previous runs that
had indicated the upper trof axis lingering to west of the state are
still hinting along those lines with the latest runs, but there seem
to be more differences regarding the timing of its track east. ECMWF
appears to be more aggressive than GFS at this point...but still not
expecting much beyond increased clouds as overall moisture should be
lacking. So, look for warming temperatures through the week as highs
approach the upper 60s by Thurs/Fri. 41
&&
.AVIATION [12Z TAF Issuance]...
The last of the scattered clouds in the southern half of the CWA
have mostly fizzled out, so most of the area airports are under
clear skies. This will last throughout the morning hours before
upper-level and mid-level clouds gradually work their way into the
area. The clouds will start out as scattered and continue filling in
to form an overcast layer by the afternoon hours. This will not pose
any operational impacts though as VFR conditions will persist
through Sunday morning. Light northerly/northeasterly winds will
gradually transition over to light easterly winds throughout the
day today. Looking ahead for Sunday, ceilings are expected to
steadily decrease as the coastal low approaches the area.
Expecting rain showers to begin moving in from the west early
Sunday morning. The increasing moisture will likely drop ceilings to
MVFR by late Sunday morning. 26
&&
.MARINE...
Northerly/northeasterly winds will transition over to easterly
throughout the day today. As we head into late Saturday night/early
Sunday morning, winds will increase as an area of low pressure
develops in southern Texas. Early Sunday morning will be the start
of a prolonged period of SCA conditions with easterly winds of 20
knots. As the low pressure system moves eastward into the western
Gulf of Mexico, winds will shift to southeasterly and speeds will
increase to around 25 knots. The strongest period of winds will be
following the passage of a cold front on Sunday evening/early Monday
morning with northeasterly wind speeds approaching gale force
(Sunday 6pm-Monday 3am). Elevated seas of 8-11 feet lasting from
Sunday afternoon through Monday afternoon will be another hazard
resulting from this low pressure system. Tide levels in this time
period may be high enough to cause beach flooding. The winds will
gradually diminish throughout the day on Monday as the low moves
away from the area with SCA conditions lasting into Monday
afternoon. Offshore northerly winds will continue into the middle of
next week. 26
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 53 38 40 33 44 / 0 30 90 80 10
Houston (IAH) 55 41 44 36 47 / 0 30 90 80 10
Galveston (GLS) 54 48 51 39 47 / 0 30 90 80 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Winter Storm Watch from Sunday afternoon through Monday morning
for the following zones:
Brazos...Burleson...Grimes...Houston...Madison...Trinity...Walker...Washington.
GM...Low Water Advisory until 3 PM CST this afternoon for the
following zones: Galveston Bay.
&&
$$
The Trend is your Friend.
NAM goes even further South.
https://www.tropicaltidbits.com/analysi ... 0912&fh=39
NAM goes even further South.
https://www.tropicaltidbits.com/analysi ... 0912&fh=39
I like that run of the NAM
-
Kingwood36
- Posts: 1592
- Joined: Sat Dec 29, 2018 10:29 am
- Location: Freeport
- Contact:
I mean how reliable is the NAM tho?DoctorMu wrote: ↑Sat Jan 09, 2021 9:50 am The Trend is your Friend.
NAM goes even further South.
https://www.tropicaltidbits.com/analysi ... 0912&fh=39
-
MontgomeryCoWx
- Posts: 2356
- Joined: Wed Dec 14, 2011 4:31 pm
- Location: Weimar, TX
- Contact:
Short term, winter weather and severe weather, it does well. I like to blend NAM, HRRR and WRF although NAM is usually the best within 36 hours.Kingwood36 wrote: ↑Sat Jan 09, 2021 10:04 amI mean how reliable is the NAM tho?DoctorMu wrote: ↑Sat Jan 09, 2021 9:50 am The Trend is your Friend.
NAM goes even further South.
https://www.tropicaltidbits.com/analysi ... 0912&fh=39
Don’t look at it during Hurricane season.
Team #NeverSummer
-
ArizonaAZMeador
- Posts: 36
- Joined: Fri Jan 08, 2021 4:56 pm
bLAKe is a pro met. blake was very positive in his post yesterday about cold and snow. then we had more negativity.
-
MontgomeryCoWx
- Posts: 2356
- Joined: Wed Dec 14, 2011 4:31 pm
- Location: Weimar, TX
- Contact:
That NAM run would be epic if it came to fruition. It’s going to be a long day watching how this evolves into tomorrow and tomorrow evening
-
tireman4
- Global Moderator
- Posts: 4481
- Joined: Wed Feb 03, 2010 9:24 pm
- Location: Humble, Texas
- Contact:
Yeah, during Hurricane season...forgetta bout it. LOL. Remember, the NAM takes into account sleet/snow...MontgomeryCoWx wrote: ↑Sat Jan 09, 2021 10:08 amShort term, winter weather and severe weather, it does well. I like to blend NAM, HRRR and WRF although NAM is usually the best within 36 hours.Kingwood36 wrote: ↑Sat Jan 09, 2021 10:04 amI mean how reliable is the NAM tho?DoctorMu wrote: ↑Sat Jan 09, 2021 9:50 am The Trend is your Friend.
NAM goes even further South.
https://www.tropicaltidbits.com/analysi ... 0912&fh=39
Don’t look at it during Hurricane season.
It does. My understanding is that there won't be much sleet with this system. Rain possibly turning into snow.tireman4 wrote: ↑Sat Jan 09, 2021 10:46 amYeah, during Hurricane season...forgetta bout it. LOL. Remember, the NAM takes into account sleet/snow...MontgomeryCoWx wrote: ↑Sat Jan 09, 2021 10:08 amShort term, winter weather and severe weather, it does well. I like to blend NAM, HRRR and WRF although NAM is usually the best within 36 hours.
Don’t look at it during Hurricane season.
My goodness send it in with that NAM run (unless it gets better than that 
But....as is my motto for wishing for winter pleasantries in all parts of Texas I’ve lived, I’ll wait to see to believe. Tis a finicky state we live in for this kind of fun.
But....as is my motto for wishing for winter pleasantries in all parts of Texas I’ve lived, I’ll wait to see to believe. Tis a finicky state we live in for this kind of fun.
The RAP model has a sleet/rain mix down to the I-10 corridor by tomorrow evening , and then shows a transition to all snow overnight down to I-10 as the trowel(wrap around precip) exits the area.I think there is a good possibility especially with the heavier precip rates we will receive (which will help to cool down the air column) that as early as the afternoon there will probably be many reports of rain mixing with sleet as far south as the 59 corridor.
This setup reminds me alot of the 1929 central Texas snow storm.
https://www.weather.gov/fwd/1929snow
This setup reminds me alot of the 1929 central Texas snow storm.
https://www.weather.gov/fwd/1929snow
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Well, for me it's eehh.....lol.DoctorMu wrote: ↑Sat Jan 09, 2021 11:20 am WRF. OMG
https://www.tropicaltidbits.com/analysi ... 0912&fh=39
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Kingwood36
- Posts: 1592
- Joined: Sat Dec 29, 2018 10:29 am
- Location: Freeport
- Contact:
Its making progress....snowman65 wrote: ↑Sat Jan 09, 2021 11:29 amWell, for me it's eehh.....lol.DoctorMu wrote: ↑Sat Jan 09, 2021 11:20 am WRF. OMG
https://www.tropicaltidbits.com/analysi ... 0912&fh=39