March 2022

[Iceresistance]

15z SREF now has up to 75% STP for the Houston Metro, this is getting very dangerous.

[Cromagnum]

15z SREF now has up to 75% STP for the Houston Metro, this is getting very dangerous.

Geeze. So somebody in Harris County is very likely to get slammed.

[vci_guy2003]

Can someone explain exactly what 75% STP means? I know STP stands for "significant tornado parameter".

[Iceresistance]

15z SREF now has up to 75% STP for the Houston Metro, this is getting very dangerous.

Geeze. So somebody in Harris County is very likely to get slammed.

The HRRR does show Supercellular activity across Southern Texas, San Antonio & Austin, before coming in as a messy Squall line

[Iceresistance]

Can someone explain exactly what 75% STP means? I know STP stands for "significant tornado parameter".

75% means that 3/4 Supercells will produce strong/violent tornadoes in a given location, it also means that the instability is really high.

[txsnowmaker]

15z SREF now has up to 75% STP for the Houston Metro, this is getting very dangerous.

Geeze. So somebody in Harris County is very likely to get slammed.

The HRRR does show Supercellular activity across Southern Texas, San Antonio & Austin, before coming in as a messy Squall line

Much better scenario for Metro Houston.

[Iceresistance]

Geeze. So somebody in Harris County is very likely to get slammed.

The HRRR does show Supercellular activity across Southern Texas, San Antonio & Austin, before coming in as a messy Squall line

Much better scenario for Metro Houston.

Wait, the Squall line lifts North before it reaches Houston, weird. The Model run is still going, but there are storms ahead of the Squall just west of Houston (Closer to Katy), before they get absorbed into the Squall line, it does not reach Houston until 6 AM Tuesday

[Stratton20]

Looks like I am gonna get slammed here

[tireman4]

Let me state this. This has the chance to be a bumpy ride Monday and Tuesday.

[Iceresistance]

Let me state this. This has the chance to be a bumpy ride Monday and Tuesday.

Yes, a really bumpy one, especially Tuesday.

[Cpv17]

Geeze. So somebody in Harris County is very likely to get slammed.

The HRRR does show Supercellular activity across Southern Texas, San Antonio & Austin, before coming in as a messy Squall line

Much better scenario for Metro Houston.

You would think that but I’m hearing with this particular setup even if it turns into a squall line there could be tornadoes. Anyone else hearing that? Sounds unusual.

[Stratton20]

Yeah usually with a squall line it would be more of a straight line wind threat , that definitely has me a little bit nervous

[jabcwb2]

[don]

The HRRR does show Supercellular activity across Southern Texas, San Antonio & Austin, before coming in as a messy Squall line

Much better scenario for Metro Houston.

You would think that but I’m hearing with this particular setup even if it turns into a squall line there could be tornadoes. Anyone else hearing that? Sounds unusual.

Yep this is the kind of setup that due to how high the shear is, there could be tornadoes embedded within the squall line.

[Katdaddy]

This is the time to be weather aware. Much concern for this severe weather event. As alway's the HOU-GAL NWS sum it up well in their afternoon Area Forecast Discussion:

Overall, Southeast Texas should remain weather aware throughout the day on Monday. Make sure you have a safety plan in place and have multiple ways to receive warnings.

[don]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
348 PM CDT Sun Mar 20 2022

.SHORT TERM [Tonight Through Monday Night]...

Surface high pressure continues to move eastward and onshore flow
has returned. The local pressure gradient has tightened due to a
strengthening leeside low over the Four Corners region and
therefore, it`s been a breezy day for Southeast Texas. Gusts
should subside after sunset this evening, but winds will still
remain near 10-15 mph as the aforementioned low approaches the
Southern Plains. Overnight lows will only cool down to the upper
50s to low 60s as low level cloud cover sneaks in overnight and
traps excess heat.

You know it`s spring time in Texas when you can go from sunny and in
the 70s from one day to strong/severe storms the next day. That`s
the case for tomorrow as a warm front is expected to push through
our CWA and a dry line approaching from the west will bring the
potential for severe storms tomorrow afternoon and evening. You can
cherry pick from various CAMs and global models, but they all tell
the same story. With SBCAPE greater than 2000 J/kg, 0-1km SRH at
300+, 0-3km SRH at 450+, low level shear near 40 kts, STP 2.5+, and
supercell parameters 10+, ingredients are in place for supercell
formation. All severe hazards will be possible such as large hail,
isolated tornadoes, damaging winds, frequent lightning, and
flooding. The likelihood for this severe weather increases mid
afternoon and into the late evening for most of southeast Texas as
the dry line approaches our western counties a few hours before
sunset.

As we move into the late evening hours, these clusters of
thunderstorms will begin to transition into a more linear
convective mode. Training storms will develop and the overall
motion of the front will slow down. With PWs climbing over 1.5
inches and above the 90th percentile for this time of year and
upper level divergence increasing due to a splitting jet aloft,
ingredients are in place for heavy rainfall. During the overnight
hours, rainfall totals of 1 to 3 inches are possible along the
coast and 2 to 6 inches are possible elsewhere. Localized higher
amounts are possible should storms continue to move over the same
area overnight. Severe weather is still possible Monday night and
into Tuesday morning as these thunderstorms become more linear.
Low level shear is still favorable for damaging winds, embedded
supercells, and quick forming mesovortices as this line pushes
further east and into LA/AR.

Overall, Southeast Texas should remain weather aware throughout
the day on Monday. Make sure you have a safety plan in place and
have multiple ways to receive warnings.

Lenninger

[Iceresistance]

Can't see the image

[jabcwb2]

Can't see the image

My android phone won't let me see where you all are located. Was trying to upload a pic of that. Anyway, thank you for the continued updates on the upcoming storm!!

[Iceresistance]

21z SREF has 60-75% STP for the Houston Metro, this is getting really scary.

And this is the LARGEST 90% STP contour I've ever seen!

[Ptarmigan]

000
FXUS64 KHGX 210040
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
740 PM CDT Sun Mar 20 2022

.AVIATION [00Z TAF Issuance]...

Other than the strong gusty SE winds these next few hours, not a
lot of changes planned to the going TAF forecast. VFR conditions
should prevail this evening but with winds decreasing tonight, a
lowering of CIGS are expected overnight. Scattered WAA-type SHRA
will be possible around sunrise with MVFR/IFR ceilings likely in
place for most terminals. An approaching cold front should bring
the threat of thunder by late morning/early afternoon with cover-
age/intensity increasing throughout the rest of the afternoon on
into the evening. Gusty conditions are set to return tomorrow as
well with sustained winds around 15kts and gusts from 25 - 30kts
possible. 41

&&

.PREV DISCUSSION... /ISSUED 348 PM CDT Sun Mar 20 2022/

SHORT TERM [Tonight Through Monday Night]...

Surface high pressure continues to move eastward and onshore flow
has returned. The local pressure gradient has tightened due to a
strengthening leeside low over the Four Corners region and
therefore, it`s been a breezy day for Southeast Texas. Gusts
should subside after sunset this evening, but winds will still
remain near 10-15 mph as the aforementioned low approaches the
Southern Plains. Overnight lows will only cool down to the upper
50s to low 60s as low level cloud cover sneaks in overnight and
traps excess heat.

You know it`s spring time in Texas when you can go from sunny and in
the 70s from one day to strong/severe storms the next day. That`s
the case for tomorrow as a warm front is expected to push through
our CWA and a dry line approaching from the west will bring the
potential for severe storms tomorrow afternoon and evening. You can
cherry pick from various CAMs and global models, but they all tell
the same story. With SBCAPE greater than 2000 J/kg, 0-1km SRH at
300+, 0-3km SRH at 450+, low level shear near 40 kts, STP 2.5+, and
supercell parameters 10+, ingredients are in place for supercell
formation. All severe hazards will be possible such as large hail,
isolated tornadoes, damaging winds, frequent lightning, and
flooding. The likelihood for this severe weather increases mid
afternoon and into the late evening for most of southeast Texas as
the dry line approaches our western counties a few hours before
sunset.

As we move into the late evening hours, these clusters of
thunderstorms will begin to transition into a more linear
convective mode. Training storms will develop and the overall
motion of the front will slow down. With PWs climbing over 1.5
inches and above the 90th percentile for this time of year and
upper level divergence increasing due to a splitting jet aloft,
ingredients are in place for heavy rainfall. During the overnight
hours, rainfall totals of 1 to 3 inches are possible along the
coast and 2 to 6 inches are possible elsewhere. Localized higher
amounts are possible should storms continue to move over the same
area overnight. Severe weather is still possible Monday night and
into Tuesday morning as these thunderstorms become more linear.
Low level shear is still favorable for damaging winds, embedded
supercells, and quick forming mesovortices as this line pushes
further east and into LA/AR.

Overall, Southeast Texas should remain weather aware throughout
the day on Monday. Make sure you have a safety plan in place and
have multiple ways to receive warnings.

Lenninger

LONG TERM [Tuesday Through Saturday]...

Expecting the cold front to be somewhere near an Edna to Katy to
Huntsville to Groveton line at 7 am...though this could be too far
west if the mesoscale overrides the current thinking. With the
location of the front and the very impressive upper level diffluence
with strong LL moisture transport into the boundary expecting the
heavy rainfall to be ongoing in a band co-located along the frontal
boundary. Rainfall rates of 3"/hour look likely and storm motion
probably close to 30 knots with the more linear wind profiles. Still
a severe threat with any bowing segments or embedded supercells but
waning. By late morning the severe threat should be rapidly
waning/ended and the storms pushing into far East TX/LA...12z NAM
interestingly was the slowest moving of the frontal progression and
so did keep the POPs a bit higher in the east on account of this
Tuesday morning. Early afternoon the only lingering rain chances
should be some spotty showers near Galveston bay and then showers
and thunderstorms in the coastal waters south and east of Galveston.

Heavy rain and runoff will be causing rises on the area rivers and
persons with interest near the rivers and bayous should be ready for
this rise. It is possible a flood watch may be needed given the slow
movement of the front and if so would probably be over the eastern
half of the area.

Winds in the wake of the front Tuesday should be west and
northwesterly in the 10-20 mph and gusty range through the
afternoon then diminishing. Wrap around moisture looks to support
a lower cloud deck much of the afternoon Tuesday into early
Wednesday over the northern counties.

Warming up Wednesday before a weak cold front arrives
Thursday...this should bring a band of clouds with the boundary and
possibly a sprinkle though unlikely - the airmass intrusion should
just reinforce the dry air. This pleasant weather should continue
through the weekend.

Tide levels will be rising quickly tonight and early Monday. Strong
rip currents and possibly some minor beach flooding will be
possible. If the guidance continues to be as bullish a coastal flood
watch/warning may be needed for afternoon.

45

MARINE...

Southeast winds gradually increasing over the coastal waters as well
as the dewpoints. The gradient is going to really pucker up tonight
and Monday and have escalated the Gale Watch to a Gale Warning for
Monday morning through the afternoon...and a little longer for the
20-60nm waters. Winds of 20-30 knots should be common Monday with
gusts of 35-40 knots. Seas building to 4-8 feet feet nearshore and 8-
11 feet offshore with this increase in winds Monday. Seas will
probably be slow to come down as the cold front pushes out into the
coastal waters Tuesday. Strong to severe thunderstorms will be
possible Monday night and Tuesday until the front passes through.
Even a waterspout will be possible Monday late in the morning
through the afternoon if any more organized showers get going.

Relatively benign weather across the coastal waters for Wednesday
through Sunday.
45

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 56 75 56 67 42 / 50 90 90 30 0
Houston (IAH) 58 74 61 73 47 / 40 80 90 90 0
Galveston (GLS) 64 74 64 74 52 / 30 60 60 80 0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory from 11 AM to 7 PM CDT Monday for the following
zones: Austin...Bolivar Peninsula...Brazoria Islands...
Brazos...Burleson...Chambers...Coastal Brazoria...Coastal
Galveston...Coastal Harris...Coastal Jackson...Coastal
Matagorda...Colorado...Fort Bend...Galveston Island...
Grimes...Houston...Inland Brazoria...Inland Galveston...
Inland Harris...Inland Jackson...Inland Matagorda...
Madison...Matagorda Islands...Montgomery...Northern
Liberty...Polk...San Jacinto...Southern Liberty...Trinity...
Walker...Waller...Washington...Wharton.

High Rip Current Risk from Monday morning through late Monday
night for the following zones: Bolivar Peninsula...Brazoria
Islands...Galveston Island...Matagorda Islands.

GM...Small Craft Advisory from 7 AM to 11 AM CDT Monday for the
following zones: Galveston Bay...Matagorda Bay.

Gale Warning from 11 AM to 8 PM CDT Monday for the following
zones: Coastal waters from Freeport to Matagorda Ship
Channel TX out 20 NM...Coastal waters from High Island to
Freeport TX out 20 NM...Galveston Bay...Matagorda Bay.

Small Craft Advisory from 3 AM to 11 AM CDT Monday for the
following zones: Coastal waters from Freeport to Matagorda
Ship Channel TX out 20 NM...Coastal waters from High Island
to Freeport TX out 20 NM.

Small Craft Advisory until 11 AM CDT Monday for the following
zones: Waters from Freeport to Matagorda Ship Channel TX
from 20 to 60 NM...Waters from High Island to Freeport TX
from 20 to 60 NM.

Gale Warning from 11 AM to 11 PM CDT Monday for the following
zones: Waters from Freeport to Matagorda Ship Channel TX
from 20 to 60 NM...Waters from High Island to Freeport TX
from 20 to 60 NM.

&&

$$

Discussion...99
Aviation/Marine...99

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