March 2022

[Stratton20]

Absolutely beautiful day at Canyon Lake! Monday will be a whole new ballgame

[davidiowx]

You know what’s beautiful right now? The moon!

[don]

From HGX

[don]

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Sat Mar 19 2022

Valid 211200Z - 221200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS CENTERED OVER
PORTIONS OF EASTERN TEXAS AND INTO WESTERN LOUISIANA...

...SUMMARY...
Severe storms appear likely to occur across an area centered over
eastern Texas and into western Louisiana on Monday.

...Synopsis...
A large/strong upper trough is forecast to emerge from the western
U.S. into the Plains Monday, with strong ridging flanking the trough
to both the west and east.

As an upper low at the base of the trough moves out of New Mexico
and into the Texas South Plains/Panhandle region through the
afternoon, a surface low is forecast to move toward western North
Texas through the afternoon. Ahead of an advancing/trailing cold
front, a preceding dryline should mix eastward into central Texas
during the afternoon. Overnight, an elongated low should be
crossing the eastern Kansas/eastern Oklahoma vicinity, with the cold
front crossing East Texas through the latter stages of the period.

...Portions of central Texas eastward to western Louisiana...
Strong southeasterly/southerly low-level flow is forecast across the
southern Plains early Monday, ahead of the advancing upper low.
Strong warm/moist advection associated with the southerlies, atop a
largely-still-stable boundary layer, will support an expansion of
elevated thunderstorms across central Texas and Oklahoma through the
morning hours.

This blossoming of precipitation complicates the forecast for later
in the day, casting uncertainty onto the degree of surface-based
CAPE which may develop -- particularly with northward extent.
However, with persistent southerlies advecting Gulf moisture
northward, gradual south-to-north destabilization of the boundary
layer is expected -- at least across east-central portions of Texas.

By afternoon, potential for surface-based storm development is
evident near advancing dryline across central Texas. Meanwhile
farther east, storms along the southern portion of the
larger/ongoing area of convection should also become surface-based
with time. Strong/increasing flow with height, combined with
substantial veering through the lowest 3km, will provide shear quite
favorable for supercells. As such, along with potential for large
hail with developing central Texas storms, risk for tornadoes should
increase through the afternoon farther east.

Through the evening and into the overnight hours, the favorably
moist/modestly unstable airmass should expand eastward across the
Sabine River into Louisiana. With very strong deep-layer shear
continuing, risk for tornadoes -- a couple which may be strong --
should persist across East Texas and into Louisiana through the end
of the period.

[don]

From HGX this morning

LONG TERM [Monday through Friday Night]...

Active weather pattern to start the workweek with potential for
strong to severe thunderstorms and heavy rainfall. Drier weather
returns by Tuesday.

A deepening/closed upper level and corresponding sfc low pressure
over the Southern Rockies will work east-northeast into
west/central TX and OK on Monday. Southeast TX will be positioned
in a region with robust southerly surface flow, leading to
increasing Gulf moisture across the region. While latest model
runs still differ a bit with the location of the heaviest
precipitation and amount of rainfall; they are in good agreement
in terms of timing/phase. The environment looks favorable for
showers and thunderstorms, some of them becoming strong to severe.
Models and forecast soundings continue to suggest sfc dew points
from the mid 60s to near 70s and low to mid lapse rates around 7
to 8C/Km by Monday afternoon. Moderate CAPE, strong deep layer
shear and strong SSW low level jet (40-60 knots) will help for the
development of strong updrafts/organized supercells across parts
of the region Monday afternoon and evening. SPC has placed parts
of the forecast area in an Enhanced Risk and Slight Risk for
severe weather in their Day 3 Outlook. This seems appropriate as
the environment becomes less stable along with an increasing surge
of Gulf moisture, deep layer shear and south to north LLJ. While
periods of locally heavy rain look possible on Monday, better
dynamics for moderate to heavy rainfall look favorable Monday
evening into early Tuesday. PWATs over 1.5 inches will be likely
and if storms remain fairly slow moving and/or there is training
taking place, rainfall amounts from 2 to 3 inches with isolated
higher amounts will be possible. It is too early to pinpoint the
exact location of the heaviest precipitation; therefore
confidence remains low to moderate. However, given the location
of the upper jet and the orientation of the LLJ, the most likely
location would be north of I-10. WPC highlights this risk in the
Day 3 Outlook with a Slight and Marginal Risk for excessive
rainfall for SETX. Will keep monitoring this system in the next
couple of days as specific details on timing, hazards and rainfall
amounts become more certain.

[Cromagnum]

Down here in Brazoria County, I guess we are on the feisty, but not too feisty, area for now.

[Stratton20]

I suspect a moderate risk will be issued soon, this could be a dangerous severe weather outbreak, definitely getting at least somewhat nervous as we are 2 days out, had a scary experience a few years ago with a night time severe thunderstorm that produced a tornado, being in a elevated risk or 3/5 definitely makes me a bit uncomfortable

[Cpv17]

Down here in Brazoria County, I guess we are on the feisty, but not too feisty, area for now.

Doesn’t look too bad for my area. Just give me at least a half inch and I’ll be satisfied.

[don]

12Z 3K NAM and its soundings near downtown Houston Monday evening.Its now picking up on the first round of severe weather Monday afternoon/evening. Showing possible supercell development along the I-45 corridor with alarming soundings.The first round of severe weather will be followed by a 2nd round of severe storms with a potent MCS overnight and into Tuesday morning.There is also an increasing threat of flash flooding overnight as several models are showing training storms over portions of the area.Still too soon to know exactly where the heaviest rain will setup though.Stay weather aware Monday - Tuesday Morning.

[Cromagnum]

Looking more and more like a terrific work from home day.

[don]

12Z GFS is starting to pick up on the band of training storms also.And is also showing very rough soundings over the area.(sounding near downtown)

[don]

12Z EURO rainfall amounts

[captainbarbossa19]

12Z EURO rainfall amounts

I think rainfall amounts could be even higher in some areas. The Euro only moves the line about 50-75 miles in 6 hours. That's not very fast at all.

[don]

HGX is concerned about the potential for long lived tornadoes and also flash flooding.Saying a FF watch may be needed...

.LONG TERM [Monday Through Friday]...

Strong to severe thunderstorms will be the issue Monday. An upper
level shortwave should move through the area during the morning as
the profile moistens up quickly and shear ramps up. Very high
SRH/CINH 20 or less/decent instability of 900 to as high as 2200
j/kg - LI -5 to -8 though the heating is going to be a challenge
with the abundant cloud cover and periodic showers. Tornadoes look
to be the main hazard Monday and with the shear have some concerns
that these will be fast moving and possibly longer lived tornadoes.
Hail and damaging winds a concern but likely not nearly as high a
concern. Wind advisories also going to be needed as southerly winds
of 15-25 mph with gusts of 30-40mph should dominated much of the
daylight hours. The cold front should be slowly moving toward the
area and arriving in the northwestern counties after midnight-4 am
window. At this point though very impressive diffluence aloft will
move overhead and should focus heavy rainfall across the
southeastern 2/3rds of the area or along and near the I-69 corridor.
After the rains during the day this heavy rain could lead to street
flooding in these more urban areas and wouldn`t rule out rainfall
rates of 3"/hour though the storm motions will still be fairly high.
Mesoscale features will likely drive much of where the heavy
rainfall occurs and not very confident where that will be yet. May
need a flood watch at some point. The front pushes through early
Tuesday morning taking the storms with it and then much drier
weather will overspread the area.

https://forecast.weather.gov/product.ph ... glossary=1

[Stratton20]

Never thought Id hear the words long live tornadoes in a SE Texas weather discussion i might just skip classes on monday, definitely does not sound like a good day to be out

[TexasBreeze]

Looks like a discussion from an area well north and east of here to me. Not very often they worry about tornadoes more than wind and hail around this general area!

[Rip76]

What time are we looking at on Monday?

[Iceresistance]

A really dangerous situation is possible from this, it's also trending West, Austin may get some of this.

SE Texas may get the Moderate risk of severe storms, Houston may get the Enhanced Risk

[Stratton20]

iceresistance i definitely suspect a moderate risk could be issued tomorrow

[don]

We're just getting in range of the HRRR model.It shows the first round of supercell development along the I-35 corridor and moving east.I also expect a Moderate risk will be issued for some portions of SE Texas.