November 2022

[don]

Starting to get in range of the mesoscale models.Unfortunately Thanksgiving evening is looking pretty stormy in SE Texas as the surface low moves inland.Especially for areas along and north of I-10.Still subject to change of course.If it was Spring such a dynamic system would produce a severe weather outbreak in the state.Thank goodness instability will be lacking,so any severe weather should be isolated at best and near the coast where the warm front may move just inland.

[brazoriatx]

Do we know when the rain is suppose to start? I'm trying to smoke a Turkey but if it's going to rain in the morning then there isn't any point

[don]

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0107 AM CST Tue Nov 22 2022

Valid 241200Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
MIDDLE AND UPPER TEXAS COAST VICINITY...

...SUMMARY...
A couple of strong to severe thunderstorms are possible Friday
afternoon and evening across the Middle and Upper Texas Coast
vicinity.

...Middle/Upper TX Coast vicinity...

A positive-tilt large-scale upper trough will extend from the Upper
Midwest to the southern Rockies Thursday morning. An upper low in
the southern branch of the trough is forecast to become increasingly
cut-off from the northern branch of the upper trough. The cut-off
upper low will only slowly develop east toward the southern Plains
through early Friday morning.

There is still quite a bit of uncertainty not only with the
evolution of the upper low, but also with regards to a developing
surface low/trough over the east TX vicinity. The development and
track of the surface low will determine how far inland deeper Gulf
moisture is able to advance, and where a warm front will reside. At
this time, it appears deeper boundary-layer moisture will be
confined to the TX coast vicinity, with a narrow corridor of mid 60s
F surface dewpoints possible. Forecast soundings indicate weak
instability across the middle and upper TX coastal vicinity,
tempered by modest midlevel lapse rates and only weak diurnal
heating due to cloud cover and likely ongoing showers/thunderstorms
through the morning. Isolated thunderstorms will be possible in this
warm advection regime ahead of an east/southeastward-advancing cold
front during the afternoon/evening. Modest vertical shear may
support at least transient organized updrafts, and a couple of
strong to severe thunderstorms may be possible near the middle/upper
TX coast.

..Leitman.. 11/22/2022

[don]

Do we know when the rain is suppose to start? I'm trying to smoke a Turkey but if it's going to rain in the morning then there isn't any point

Still a little early to know for sure,as models are in disagreement on when the rain gets started.Some have heavy rain in SE Texas as early as sunrise Thanksgiving morning.While others don't have the rain becoming widespread until the afternoon/evening.We'll know more later today/tomorrow.

[jasons2k]

Update from Jeff:

Showers and Thunderstorms likely Thursday into Friday.

Surface coastal trough over the NW Gulf is starting to move eastward this morning and this will take the light rain south of I-10 off to the east by midday. Upstream radars still show returns over SW and SC TX, but with slightly drier air starting to enter the region from the northeast, think much of this will dissipate before reaching the ground. Clouds will hold tough however, with maybe some slight clearing off to the northeast where the best bet for dry air to make some play into the area.

Upper level trough entering the NW US will drop SE over the next 24 hours and then begin to deepen and cut-off from the upper level flow over the US. The result will be significant height falls Wednesday into Thursday over E NM and W TX helping to induce surface low pressure over NW TX. Onshore winds will return to coastal TX with warm air advection in place by Wednesday afternoon. Scattered showers will begin to develop in the warm air advection regime Wednesday night over the region.

Thursday:
Surface cold front will slowly move into SE TX with widespread showers and thunderstorms likely. Timing is still in question, but it is likely there will be periods of wet weather throughout the day on Thursday…plan accordingly. Surface front should move off the upper TX coast by early to mid evening on Thursday, but cut-off mid and upper level system will remain to the west and result in strong lift and moisture transport over the surface cool air. The result will be a continued wet pattern into Thursday night and Friday.

Rainfall amounts Thursday into Friday will average .50-1.5 inches over the region with the highest rainfall likely north of I-10. While SPC has outlooked the Matagorda Bay region for a marginal (1 out of 5) risk for severe thunderstorms on Thursday, instability is greatly lacking and while thunderstorms will be possible, think the severe threat is low. If anything maybe some small hail with the cold pool aloft moving over the region.

Friday:
Slow moving upper level system to our west will progress east on Friday, how fast remains in question. Typical closed upper lows tend to move slower than guidance suggests. Some decent agreement that showers will linger into much of Friday with the CMC and GFS continuing to be the slowest and most aggressive with the rainfall. ECWMF has trended in the slower direction over the last 24 hours, but is still faster than much of the guidance. Dry slot may attempt to move into the area Friday afternoon helping to end the rainfall and clearing clouds from the WSW, but I am not confident in this actually occurring and we may stay locked into the cloudy and wet into Friday evening.

Weekend:
Upper low should begin to move east, but how fast is in question. The faster solutions have the system east of TX by Saturday with clearing skies and warming temperatures…the slower guidance keeps clouds in place on Saturday and possibly some light showers. Temperatures will warm into the 60’s and 70’s by Sunday with clearing skies and a return of southerly winds.

West TX/TX Panhandle:
With lots on travel late this week, those traveling to W TX/E NM/TX Panhandle should be aware that the same storm system will bring potentially significant snowfall, especially in the TX panhandle from Wednesday night-Friday night. Snowfall amounts of 6-12 inches will be possible which will result in significant travel disruption.

Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District
9900 Northwest Freeway | Houston, Texas 77092
346-286-4000 (main) | 346-286-4165 (direct) | 281-924-2091 (cell)
jeff.lindner@hcfcd.org | Twitter: @jefflindner1

[jasons2k]

NWS Fort Worth on Twitter:

Unfortunately, the Thanksgiving forecast has took a turn for the worse. An upper system now looks like it will hang around for several days. Expect rain to start Wednesday and continue off/on through Saturday. The highest rain chances are across North and East Texas. #txwx

[Iceresistance]

Are you serious? the 12z GEFS now has a snowfall signal for my area on Black Friday!

[don]

Street flooding could be an issue on Thanksgiving,mesoscale models are now showing a slow moving MCS along the front.

LONG TERM...
(Thursday through next Tuesday)
Issued at 347 PM CST Tue Nov 22 2022

Thanksgiving Day is setting up to be quite the interesting day,
not just for the variety of food and sports on TV, but weatherwise
as well. By Thursday, an upper level trough and embedded upper
low will be moving its way in along with a surface low moving in
from the northwest (developed through lee cyclogenesis). The track
of this surface low plays a key role into our potential for
strong to severe thunderstorms on Thursday afternoon. This appears
to be somewhat similar to our recent events where we`ve had
isolated to scattered strong/severe thunderstorms where we have
the shear, but the instability is confined to coastal areas. 0-6km
bulk shear ranges around 50-60 knots with 6-7°C 700-500mb lapse
rates. MUCAPE in the latest CAMs shows anywhere from 900-1500
J/kg, but there isn`t much consistency on how far north this
corridor of instability extends. Over our southwestern counties
has the greatest consensus at the moment though, which explains
the placement of SPC`s marginal risk. As per usual, storms
developing out ahead of the cold front will be the ones that we
need to watch for evolution into something stronger. The cold
front itself attached with the previously mentioned area of low
pressure will move through Thursday evening through Thursday
night.

Strong to severe storms aren`t the only threat for Thursday, we`ll
have to keep an eye out for localized flooding especially for areas
south of I-10 where soils are more saturated given the recent rounds
of rainfall. PW values surge out ahead of the front to 1.6"-1.9",
which is well over the 90th percentile (~1.52") and near the MAX
percentile (~1.90"), so locally heavy rainfall is in play. With
storm motion parallel to the boundary of the front, there is
opportunity for training convection to develop as is evident on some
of the latest high-res model guidance. Soil moisture remains on the
low side for most areas in the Brazos Valley and the Piney Woods
area (~20%-30%). Compare this to areas south of I-10 where soil
moisture is more in the range of 50%-60%. Model soundings indicate
convective temperatures in the mid to upper 70s, which we do have in
our grids south of I-10 and west of I-45. This is important to note
because there is fairly good consensus on convective development in
the afternoon in this region, which is where we`ll get the added
nudge of convective rainfall rates. That is also important to note
because this is the region where it`ll take a lower rainfall rate to
cause issues...see where this is going? As a result, there is a
slight risk of excessive rainfall for most of Southeast Texas on
Thursday. Urban areas and low-lying areas could see localized
flooding if a band of shower/storms trains over the area for a few
hours. Let`s just say that hopefully your Thanksgiving plans are
indoors, especially in the afternoon/evening hours.

After the front moves through on Thursday night, rain showers stick
around throughout most of the day on Friday. The upper level low
slows down and gradually pushes northeastward before ejecting out of
Texas on Saturday. There`ll be enough moisture for the PVA to keep
rain in the forecast through at least the evening, but there is a
bit of uncertainty on how fast drier air moves in as the upper low
moves overhead. For now, I`ve kept PoPs close to the NBM which keeps
rain in the grids through Friday night. By Friday night, PW values
quickly decrease to less than 0.6", and with that we can finally say
goodbye to rain chances.

[Ptarmigan]

Last Thanksgiving was wet. This Thanksgiving could be wetter.

[DoctorMu]

Both the 0Z GFS and CMC have come in more aggressive with the Thanksgiving storm system.Both show a potent textbook "bowling ball" low.Producing widespread storms across the state Thanksgiving and Black Friday.Both models have also greatly increases qpf amounts.

I was afraid of that. Go away! Come back in the summer!

Not if you need it to break the drought.

We're not in a drought locally now.

[DoctorMu]

What I would have given to have some rain like this at least once during the hell summer.

Amen.

[Cpv17]

I was afraid of that. Go away! Come back in the summer!

Not if you need it to break the drought.

We're not in a drought locally now.

I’m nowhere really near the point where I’m going to turn down rain. And I bet there’s still some areas around that are at least in D0 or D1.

[don]

From HGX this morning.

Our next rain-maker is a shortwave trough currently entering the
Northern Rockies that will dive towards the Southern Rockies and
exit over the Panhandle of Oklahoma late tonight, generating a
strong leeside surface low over the Southern Plains. As this mid
level shortwave trough enters TX, it`s expected to become a cutoff
low that will continue to linger through the short-term forecast and
into the weekend. The resultant surface trough and cold front will
be over West Texas on Thursday morning and will push through our
area late Thursday evening. Continuous PVA from this cutoff low and
favorable upper level divergence from a 300mb jet streak aloft will
bring widespread showers to Southeast Texas on Thursday. These
showers will start across our northern counties during the early
morning hours on Thursday and quickly spread towards the coast. By
sunrise, there will be a 40-70% coverage in showers for Southeast
Texas with highest values north of I-10. At the same time, a warm
front just off the TX/LA coast will bring widespread showers along
the coast Thursday morning that will spread further inland
throughout the day as well. Some hi-res guidance is also hinting at
this warm front generating a weak coastal low that will push inland
and towards the I-10 corridor. Overall, convergence from these
mesoscale features will occur over the I-10 corridor on Thursday.
This warm front and potential coastal low will be the focus of a
veering low-level wind profile that could generate some stronger
showers and storms and a marginal risk for severe storms. It`ll be a
typical setup where low-level bulk shear will be ample at 40-60+
kts, but SBCAPE and MLCAPE will be lacking. Widespread showers and
cloud cover should keep sfc temperatures and CAPE values relatively
low, but the shear alone could generate an isolated strong to severe
storm across Southeast Texas. In addition to the possibility for
severe storms, there is the possibility for localized flooding on
Thursday. PWs quickly climb to 1.6+ inches and storm motion vectors
parallel to the frontal boundary, indicating a strong possibility
for training storms. Therefore, WPC has placed areas east of
Burleson and Jackson Counties in a Slight Risk for excessive
rainfall. This forecast sounds a little messy, because it is given
all these features to track. It`s important to stay weather aware
this Thanksgiving Holiday, so make sure to take extra precautions if
traveling and to have multiple ways to receive warnings.

Walts

[don]

12Z models have come in less progressive and more south with the storm system.Friday now looks to be a washout also due to the slower movement.Here are some QPF amounts from some of the 12z models.

[Cpv17]

12Z models have come in less progressive and more south with the storm system.Friday now looks to be a washout also due to the slower movement.Here are some QPF amounts from some of the 12z models.

The -NAO is working its magic.

[869MB]

12Z models have come in less progressive and more south with the storm system.Friday now looks to be a washout also due to the slower movement.Here are some QPF amounts from some of the 12z models.

The -NAO is working its magic.

So is the SOI…the lowest I’ve seen all year.

[869MB]

I put this in the December Thread:

In addition to utilizing your local NWS pinpoint forecasts and weather apps, I would strongly recommend also utilizing the National Blend of Models 1D Viewer when determining your local temperature, wind, and precipitation forecasts. Just click on the menu option in the upper right corner to select the point on the map that’s the closest to your location. The link below gives you a good example of what the data looks like…

https://hwp-viz.gsd.esrl.noaa.gov/wave ... ndly=false

[Iceresistance]

12Z models have come in less progressive and more south with the storm system.Friday now looks to be a washout also due to the slower movement.Here are some QPF amounts from some of the 12z models.

The -NAO is working its magic.

So is the SOI…the lowest I’ve seen all year.

The lowest daily SOI was at -30 a couple of weeks ago

[don]

12Z EURO still shows some high rainfall totals like its 6Z run this morning. The WPC has also increased rainfall amounts over the area...

[jasons2k]

I was afraid of that. Go away! Come back in the summer!

Not if you need it to break the drought.

We're not in a drought locally now.

Ummm…yes we are. Check the drought monitor - hot off the presses, a day early. Brazos Valley and especially points west still need rain.

https://droughtmonitor.unl.edu/CurrentM ... or.aspx?TX