April 2024

[DoctorMu]

NWS has an 80% chance of rain here tomorrow - they've been steadily going up.

Just watched KPRC-2 and they only have a 30%. The TV models don't show much until Tuesday - all north of here tomorrow. Interesting...

The low clouds rolled in about 7 pm tonight heading NW to shroud the eclipse path. Things were partly to mostly sunny prior to that and a DP in the upper 40s. Another very nice day.

Then the cloud bank of of doom appeared, which has reached Bastrop now. Mega humid air surging on an ironically Montgomery to Weimar line.

[don]

An Enhanced risk has been issued for areas north of I-10.With very large hail being a concern area wide.Strong Tornadoes are also a possibility in northeast portions of SE Texas... Like i said a couple of weeks ago severe weather season is here.Stay weather aware.

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Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1253 AM CDT Mon Apr 08 2024

Valid 091200Z - 101200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHEAST TX
TO WEST LA...

..SUMMARY...
Severe thunderstorms are expected from Tuesday into early morning
Wednesday across most of Texas towards the Lower Mississippi River
Valley. Several tornadoes, a couple of which should be strong,
significant large hail, and damaging winds are likely.

...Synopsis...
A shortwave trough centered near the AZ/NM/northwest Mexico border
area at 12Z Tuesday will progress steadily eastward into west TX
by early Wednesday. Two separate mid-level speed maxes, one curling
through the base of the trough and another farther east closer to
the northwest Gulf Coastal Plain will gradually translate eastward,
likely phasing by 12Z Wednesday. As this occurs, multiple surface
lows should consolidate into a primary cyclone in the southeast TX
vicinity early Wednesday.

...TX/LA...
Several rounds of deep convection are expected across a large
portion of TX towards the Ark-La-Tex and Lower MS Valley vicinity
during the period. A corridor of enhanced severe potential is
evident across a part of southeast TX into west LA, where the
environment should be most favorable for regenerative supercells and
organized clustering.

An MCS will likely be ongoing at 12Z Tuesday in the Ark-La-Tex to
Ark-La-Miss vicinity with scattered to widespread convection
trailing westward into west TX. An isolated supercell or two may be
ongoing in the south-central TX area as well. Primary convective
coverage during the day will be tied to the persistent
low-level warm theta-e advection regime, with regenerative periods
of convection expected across at least east TX to the Ark-La-Miss.
Surface heating of a richly moist Gulf air mass to the south of the
convective plume, coupled with steep mid-level lapse rates from 8-9
C/km should support a broad swath of moderate to large buoyancy by
afternoon. This will yield an uptick in severe storms in a portion
of southeast TX to west LA. Although convective mode should
predominately consist of clusters, embedded supercells are expected
within a favorable low-level hodograph and deep-layer shear,
supporting all severe hazards.

Farther west, isolated convective redevelopment should occur during
the early evening along the trailing outflow boundary intersection
with the dryline/surface trough in the central TX vicinity.
Low-level shear should be substantially weaker relative to the
Sabine Valley, but the favorable deep shear/thermodynamic
environment should yield a threat for significant severe hail. An
increase in storm coverage is expected Tuesday night across
south-central TX to southwest LA. Overall tornado potential should
be centered on the Sabine Valley, with potential for discrete
warm-sector supercells merging into the residual large-scale outflow
boundary. A couple strong tornadoes will be possible.

Finally, in west TX, early-day large hail potential should subside
for a time, before additional storms refire later into the afternoon
near the mid-level trough. While surface winds should largely be
northerly by this time, adequate buoyancy within the approaching
mid-level cold pocket will yield a renewed threat for large hail.
This should wane after dusk.

[Cromagnum]

Yep. At eclipse time it's just going to get darker. Nobody down here is going to see a thing.

[tireman4]

Eclipse Update

[tireman4]

00
FXUS64 KHGX 081130
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
630 AM CDT Mon Apr 8 2024

...New AVIATION...

.SHORT TERM...
(Today through Tuesday Night)
Issued at 319 AM CDT Mon Apr 8 2024

For those of you who are familiar with meteorology, or have taken a
Skywarn course, we know there are three main ingredients for
thunderstorm development: Moisture, instability, and a
lifting/forcing mechanism. Well, all of those ingredients are in
play today along with an ample amount of shear...hence our severe
weather threat for the next couple of days.

Showers have already begun to develop just off the coast and in some
inland areas this morning. Expect these showers to continue a
northward movement this morning, evolving into showers and
thunderstorms this afternoon.

Digging a bit deeper into the setup for today...the stalled boundary
has retreated north, and with dew point values this morning in the
upper 60s to low 70s, it is evident that the onshore flow has
produced a pretty moist environment. Expect moisture to continue to
increase through the day as PWAT values reach 1.7-2.0" by this
afternoon.

On a more synoptic scale, as the low pressure system that brought
our stalled boundary retreats north, a second area of low pressure
will develop behind the retreating low, and will deepen as it swings
into the Four Corners region during the day today. As it amplifies,
a strong upper-level jet will strengthen over much of Texas
(assisting with upward motion). Shortwaves within the main flow of
this approaching low will push through SE Texas as the trough
deepens over the Four Corners, leading to an increase in PVA, or
upward motion).

Daytime heating will help contribute to destabilization today, with
CAPE values in the 1500-2500 J/kg range. Highest CAPE values will
generally be North and West of the city of Houston.

In addition to the ample moisture available, the instability, and
the lift provided by incoming shortwaves, forecast soundings
continue to show a decent amount of bulk shear across the Brazos
Valley and Piney Woods (around 60 knots, courtesy of a strengthening
LLJ to the north). Mid-level lapse rates will be on the steeper side
as rates exceed 7°C/km. The bulk shear will help storms to become
better organized and potentially supercellular. Steep mid-level
lapse rates will create the potential for hail within these storms.
Furthermore, Storm Relative Helicity values (SRH) will be elevated
this afternoon, which may lead to rotating updrafts within some of
these storms. Finally, DCAPE values are forecast to exceed 1000
J/kg, indicating an increased potential for damaging winds.

With all of these ingredients and parameters in place, SPC has
placed an area along and north of a Brenham--Huntsville--Livingston
line in a SLIGHT risk (level 2 of 5) of severe weather. In addition
to the Slight Risk, these locations are also in a "hatched" area for
significant severe hail, meaning there is a 10 percent or more
chance of seeing hail with a diameter of 2" or greater.
The rest of the area (with the exception of a small portion of the
coast south of Galveston) will be in a MARGINAL risk (level 1 of 5)
for severe weather today.

The primary hazard for today will be large hail (and as mentioned
last paragraph the potential for very large hail in portions of the
Brazos Valley and Piney Woods). Locally heavy rainfall, damaging
winds, and isolated tornadoes will also be possible in any of the
stronger storms.

With numerous people traveling north to get into the path of
totality Monday, it is going to be especially important to stay up
to date on the forecast, have multiple ways to receive warnings, and
have a plan of action should severe weather impact you while out on
the roadways.

Additional showers and thunderstorms will be possible late tonight
into the overnight hours.

The chance of severe weather will increase Tuesday as the low
pressure system that moved into the Four Corner Monday will move
into Texas on Tuesday. The environment will be even more favorable
for thunderstorm development with scattered to numerous strong to
severe thunderstorms expected A deep layer of rich moisture will be
available as PWAT values are set to reach to around 2.0". An
unstable environment will remain in place with strong shear (around
50-60 kts), CAPE in excess of 1500 J/kg and steep mid-level lapse
rates (8-9°C/km). Once again, this will create an environment
favorable for organized thunderstorms with strong updrafts, some of
which could become supercellular in nature.

SPC has increased the threat to an ENHANCED level (level 3 of 5) on
Tuesday for an area along and north of a line from Columbus to just
north of the Metro. The rest of SE Texas will be in a SLIGHT risk
(level 2 of 5), with the exception of the immediate coast south of
Freeport.

With dynamics even more favorable for all modes of severe weather,
SPC has placed an area from Columbus to Liberty and north in a 30-
44% chance for severe hail and most of the rest of SE Texas in a 15-
29% chance of severe hail. These locations are also in the hatched
area with a 10% or greater chance of significant severe hail (2" or
more in diameter).

There is a small portion of SE Texas around Livingston that has a 30-
44% chance of experiencing severe winds, while much of the rest of
SE Texas lies in a 15-29% chance for severe winds.

Lastly, forecast hodographs and SRH values show an increased chance
for tornadoes on Tuesday (SPC has much of the area is in a 5-10%
chance). The area north of I-10 and East of I-45 is in a 10-14%
chance for tornadoes with at least a 10% chance of observing a
strong tornado.

The severe weather threat will be the greatest during the afternoon
hours Tuesday into the overnight hours and Wednesday morning (more
on that in long-term)

A lot of percentages and values thrown out here...but to summarize,
Severe weather is expected today. A higher threat of severe weather
is expected for Tuesday. All hazards will be possible for both days;
though the greatest threat for severe weather is expected Tuesday.
Primary hazards will be large damaging hail, with the potential for
very large hail. Isolated tornadoes will be possible both days, with
a couple of strong tornadoes possible on Tuesday.

Please make sure to have multiple ways to receive alerts this week
as severe weather persists over the next few days. Stay up to date
on the latest forecasts, and have a plan in place for your family,
including pets.

To finish off a long discussion...temperatures for today and Tuesday
will be in the upper 70s to low 80s. Lows for tonight will be in the
upper 60s to around 70. Sky conditions continue to be unfavorable
for viewing the eclipse here in SE Texas; however, there should be a
noticeable darkening of skies, outside of cloud cover, between 1-3p

Adams

&&

.LONG TERM...
(Wednesday through Sunday)
Issued at 319 AM CDT Mon Apr 8 2024

This storm system, and associated showers and thunderstorms should
finally exit the region from west-to-east during the morning and
early afternoon hours Wednesday with the passage of its associated
cold front. Though we could see some wrap around cloud cover
during the afternoon...the general trend will be for breezy and
drier conditions in the wake of the front.

Under mclr to pcldy skies, temperatures will trend back down
toward seasonable norms Wed night into Saturday. With high
pressure moving off to the east and onshore winds resuming, look
for a corresponding increase in overnight lows and cloud cover as
the weekend progresses. 47

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 623 AM CDT Mon Apr 8 2024

Light showers ongoing across the area this morning. Expect
activity to increase in coverage as showers continue to move
inland through the morning. Thunderstorms will be possible this
afternoon across the area. A break in activity is expected later
this evening before rain chances return early Tuesday morning.
Some thunderstorms today could become strong to severe and produce
large damaging hail and damaging wind gusts. CIGs this morning
are a mixture of MVFR/IFR/LIFR. Expect CIGS to primarily be low
end MVFR to IFR through the period. MVFR VSBYs also occurring this
morning with patchy fog. MVFR VSBYs will be possible again during
the early morning hours Tuesday.

&&

.MARINE...
Issued at 319 AM CDT Mon Apr 8 2024

Periods of unsettled weather can be expected through Wednesday as
the next storm system approaches from the west. A few strong to
severe storms can be anticipated...with the overall risk
increasing late tonight & peaking Tuesday night & Wednesday
morning.

A long fetch of moderate onshore winds and elevated seas will set
up across the western Gulf into early Wednesday. As this occurs,
winds and seas will be on an upward climb locally and small craft
advisories have been issued beginning this afternoon and tonight.
The rip current risk along area beaches will become high as well,
so went ahead and put a statement out for that too. Both of which
will need to be extended in time by later shifts...likely well
into midweek.

With the increased onshore flow and seas, water levels will be
increasing, and per PETSS, probably peak around 3.5 MLLW around
high tide cycles Tuesday along the beaches. This should be mostly
below coastal flood concerns, though the typical low spots on the
Bolivar Peninsula, western Galveston Island, Blue Water Highway
and Surfside may see some elevated wave run-up or minor overwash
at the most susceptible locations.

A cold front will move into the waters during the day Wednesday
with moderate to strong WNW-NW winds in its wake. Elevated water
levels will transition back down...and possibly evolve into low
water conditions in the bays late Wed night & Thurs at low tide
times as water is transported back out.

Much improved marine conditions are anticipated Fri as winds/seas
calm down. Onshore flow resumes Friday then gradually increases to
around 15kt over the weekend. 47

&&

.HYDROLOGY...
Issued at 319 AM CDT Mon Apr 8 2024

With multiple rounds of localized heavy rain, both locally and
upstream, expect some rises on some area watersheds...some
possibly into flood stage. Ensemble guidance suggests to keep an
eye on the Trinity and Navasota Rivers in addition to Davidson,
Middle Yegua, Bedias, Menard Creeks. These are closer to, or
downstream, of where the higher rainfall accumulations are
expected. Some locations across southern parts of the area will
also need to be monitored at some point should heavier rains
impact those watersheds.

You can monitor current and forecast conditions at this weblink:
water.weather.gov/ahps2/forecasts.php?wfo=HGX

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 81 69 78 62 / 80 60 70 80
Houston (IAH) 80 70 79 66 / 80 60 60 90
Galveston (GLS) 77 69 76 67 / 60 40 40 80

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk from 1 PM CDT this afternoon through
Tuesday morning for TXZ436>439.

GM...Small Craft Should Exercise Caution from 1 PM CDT this afternoon
through this evening for GMZ330-350-370.

Small Craft Advisory from 9 PM this evening to 10 AM CDT Tuesday
for GMZ330-350-370.

Small Craft Should Exercise Caution from 1 PM to 5 PM CDT this
afternoon for GMZ335-355-375.

Small Craft Advisory from 5 PM this afternoon to 10 AM CDT
Tuesday for GMZ335-355-375.

&&

$$

SHORT TERM...Adams
LONG TERM....47
AVIATION...Adams
MARINE...47

[DoctorMu]

Eclipse Update

Welp. The sun is out here in CLL. A reverse Lucy?

I see some breaks in the clouds. We could have gotten lucky N of SA?

[tireman4]

Slight Risk Of Severe Storms

[tireman4]

Severe Storm Risk

[tireman4]

Potential Severe Thunderstorm Watch

[srainhoutx]

Potential Severe Thunderstorm Watch

Mesoscale Discussion 0383
NWS Storm Prediction Center Norman OK
1026 AM CDT Mon Apr 08 2024

Areas affected...parts of the mid/upper Texas coastal plain and
adjacent western Louisiana

Concerning...Severe potential...Watch possible

Valid 081526Z - 081800Z

Probability of Watch Issuance...40 percent

SUMMARY...Widely scattered strong thunderstorms may begin to form
across and inland of mid/upper Texas and southwest Louisiana coastal
areas by early afternoon. This may be accompanied by at least some
risk for severe hail, and perhaps a tornado, before storms increase
and intensify with a more notable increase in severe weather
potential later this afternoon, as activity spreads toward
central/northern Texas.

DISCUSSION...An initial influx of low-level moisture, which
accompanied a significant cyclone now weakening over the Upper
Midwest vicinity, lingers along and south of a stalling/weakening
boundary now extending across the lower Mississippi Valley into
southeastern Texas. This includes surface dew points ranging from
the lower 70s across the northwestern Gulf into immediate Texas Gulf
coastal areas, and upper 60s F further inland across the coastal
plain, which will begin to advect northwestward and northward
through the day, downstream of a significant short wave trough
turning eastward across the Southwest.

Beneath the northeastern periphery of a plume of elevated
mixed-layer air advecting across the lower Rio Grande Valley, this
moisture already appears to be contributing to sizable CAPE on the
order of 2000 J/kg. This probably will increase at least a bit
further through the day, as thin spots and breaks in the overcast
allow for some insolation.

At the same time, models indicate strengthening of southwesterly
flow into mid-levels (30-50+ kts in the 700-500 mb layer), beneath a
strong upper jet emanating from the subtropical eastern Pacific, and
by early afternoon the environment will become increasingly
conducive to potential for supercells. Various model output
suggests that at least widely scattered thunderstorms may begin to
form across and inland of coastal areas by around 17-18Z, before
gradually intensifying and increasing further within northwestward
and northward spreading large-scale ascent aided by low-level warm
advection.

While it is possible that it may take a couple of hours for a more
substantive increase in severe weather potential to develop, as
storms acquire better inflow of more unstable near-surface air,
initial storms may pose at least some risk for severe hail. The
risk for a brief tornado may also not be completely negligible,
though clockwise curved low-level hodographs will initially be weak.

..Kerr/Gleason.. 04/08/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LCH...SHV...HGX...CRP...EWX...

[tireman4]

Eclipse Update

[don]

12Z HRRR showing the potent MCS expected late tomorrow night/overnight.

Screenshot 2024-04-08 at 11-45-41 Models HRRR - Pivotal Weather.png (583.47 KiB) Viewed 341 times

Screenshot 2024-04-08 at 11-41-36 Models HRRR - Pivotal Weather.png (608.62 KiB) Viewed 341 times

[Cpv17]

12Z HRRR showing the potent MCS expected late tomorrow night/overnight.


Screenshot 2024-04-08 at 11-45-41 Models HRRR - Pivotal Weather.png

Screenshot 2024-04-08 at 11-41-36 Models HRRR - Pivotal Weather.png

That’s what I’m talking about!

[Cromagnum]

Thats some serious stuff in Fort Bend and Brazoria counties if that HRRR holds.

[jasons2k]

Thick clouds here now. Had some breaks earlier. Looks like folks on the northern arc of the eclipse (Kerrville, etc.) are getting lucky.

[jasons2k]

The eclipse shadow is starting to appear over Texas on the visible satellite images.

[don]

Enhance risk expanded south. ALL modes of severe weather are in play.

TX_swody2.png (368.26 KiB) Viewed 292 times

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1238 PM CDT Mon Apr 08 2024

Valid 091200Z - 101200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
TEXAS EASTWARD TO CENTRAL LOUISIANA...

...SUMMARY...
Severe thunderstorms are expected from Tuesday through Wednesday
morning across most of Texas towards the Lower Mississippi River
Valley. Several tornadoes, a couple of which should be strong,
significant large hail, and damaging winds are likely.

...Synopsis...
An upper low is forecast to reside over northwestern Mexico and
adjacent portions of Arizona/New Mexico at the start of the period,
flanked by ridging over both the western and eastern states. The
low is forecast to advance steadily eastward, moving across West
Texas through the second half of the period. Several lead
disturbances within southwesterly/cyclonic flow ahead of this system
will spread across the south-central U.S. through the period.

At the surface, an outflow-reinforced warm front should reside from
central Texas east-northeastward to the Louisiana/Arkansas border
vicinity at the start of the period, while a rather ill-defined
trough/front shifts eastward across western Texas through the day,
and then becomes a bit better defined while moving across central
and eventually eastern Texas through the overnight hours.

...Texas eastward to the lower Mississippi Valley...
A warm-advection regime will persist across Texas through the
period, shifting gradually eastward with time, ahead of the
advancing upper system -- supporting broad ascent across the region.
With northward advection of rich low-level Gulf moisture, beneath a
plume of steep mid-level lapse rates, the aforementioned ascent will
combine with abundant CAPE to support multiple rounds/widespread
deep convection across the region.

Given the widespread, strong-to-severe convection which likely to be
ongoing from west-central Texas eastward to northern Louisiana at
the start of the period, highlighting areas of greater severe
potential through the day and into the evening/overnight remains
quite difficult/uncertain at this time.

One possible corridor of enhanced severe potential is evident across
portions of southeast TX and into west LA, near roughly west-to-east
outflow-reinforced surface boundary associated with ongoing, locally
severe storms. Near and south of this boundary, favorably
strong/veering deep-layer flow with height -- residing over the
broader region -- will combine with a zone of potential
heating/afternoon destabilization to support one area of
concentrated severe risk. Large hail and damaging winds will be
possible, along with a few tornadoes -- and some risk for a strong
tornado or two -- where a few supercells are expected, especially on
the southern fringe of what should be more clustered convection.

Farther west, isolated convective redevelopment is expected during
the afternoon and evening along the trailing outflow boundary
intersection with the dryline/cold front across the central TX
vicinity, and southward toward the Rio Grande. Weaker low-level
shear is expected across this area, but the favorably strong flow
aloft combined with mixed-layer CAPE in excess of 2000 J/kg should
yield a threat for significant severe hail. Storms will spread
eastward with time, with a broad area of all-hazards severe risk
spreading across the eastern half of Texas and into Louisiana
through the evening and overnight.

[jasons2k]

Of course this “line” takes off the moment is passes me…

[Stratton20]

Their go all my plans down the drain, never thought i could hate rain and cloud cover, now I do, i would be fine with not seeing a drop of rain again

[jasons2k]

Bummer. Solid line forms to my north literally as it passes over me, just early enough in the day to jack-up the eclipse without the beneficial rain…and oh look…breaks in the clouds to the south. The sun will probably come out just when the eclipse is over.