June 2024

[Stratton20]

Euro is further south by alot , but right now it is the outlier in that department

[Stratton20]

WPC buying into the GFS solution more, big increase in QPF, newest outlook

[MontgomeryCoWx]

Ags win and 2 feet of rain in Weimar. Bring it!

[Pas_Bon]

Ags win and 2 feet of rain in Weimar. Bring it!

Boooo! Everybody knows that LSU deserves to be there more. Lol

I’m kidding, but Geaux Tigers.

[don]

Moderate risk now added for Tuesday.

wpc_excgessive_rainfall_day3.us_sc.png

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
425 AM EDT Sun Jun 16 2024
Day 3
Valid 12Z Tue Jun 18 2024 - 12Z Wed Jun 19 2024

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR THE UPPER
TEXAS COAST AND SOUTHWESTERN LOUISIANA...

...Upper Texas Coast and Southwest Louisiana...

A Moderate Risk upgrade was introduced with this update in
coordination with LCH/Lake Charles, LA and HGX/Houston, TX forecast
offices.

The northern side of a developing tropical low in the western Gulf
is expected to begin impacting the Upper Texas Coast and southwest
Louisiana on Tuesday. The north side of the low will continue the
broader southeasterly flow from the Caribbean across the Gulf and
into the Upper Texas and southwest Louisiana Gulf Coasts. PWATs
with this air mass are very impressive, at times approaching 3
inches. Unlike on Day 2/Monday, by Tuesday the low itself and any
associated upper level energy will provide the forcing for
convection, so there's higher confidence on more widespread heavy
rainfall and resultant high storm total rainfall amounts. Where
confidence remains lacking is where the forcing
tracks...particularly how far north it gets. This will play a
critical role as to where the heaviest rainfall amounts will be.
For now there appears to be fair consensus on heavy rainfall
impacting the Gulf Coast from as far east as Pecan
Island/Vermilion Bay, LA to as far west as Corpus
Christi/Brownsville, TX. There's better agreement highlighting the
section of coast from Cameron, LA to Matagorda, TX. This includes
Lake Charles, LA and Houston, TX.

Since the forcing is highly concentrated, there's likely to be a
sharp gradient on the northern end as to who sees the heaviest
precipitation. It appears likely that areas along a Leesville, LA
west to College Station, TX line and points north will remain with
either no or light, unimpactful rain. Those details too will need
to be hashed out with better guidance agreement in the coming days.
For now, therefore, the Moderate Risk largely stays along and south
of the I-10 corridor.

The heaviest rain will slowly track westward with time, so the back
edge of the rain should move west along the Louisiana coast with
time. Houston looks to get periods of heavy rain throughout Tuesday
and Tuesday night as the storms track westward in waves. The
heaviest rain rates are likely Tuesday night from Houston south
along the coast as the strongest forcing associated with a front
north of the low moves ashore from the Gulf into mainland Texas.
PWATs approaching 3 inches would support highly efficient warm rain
processes given the very high freezing levels associated with this
fully tropical air mass. Any storms that track across this region
will be capable of 3 inch per hour rain rates that would quickly
overwhelm all but the sandiest/most flood resistant soils in a
hurry. Thus, despite prior dry weather and dry soils from Houston
south along the coast, these prodigious rainfall rates would easily
overwhelm those soils, leading to local flash flooding. Urban and
flood prone areas would be particularly susceptible. Interests in
and around Houston should monitor forecast updates closely.

The surrounding Slight Risk was shifted west with guidance trends,
and includes nearly the entire Texas Gulf coast now, including into
Brownsville in deep south Texas. Any rain that far south is likely
to start just prior to the 12Z Wed cutoff and continue into D4/Wed.
There remains significant uncertainty as to how far north the core
of heaviest rain, and latitudinal adjustments are likely with
future updates.

[don]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
408 AM CDT Sun Jun 16 2024

...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE...

.SYNOPSIS...
Issued at 256 AM CDT Sun Jun 16 2024

Heavy rainfall, hazardous marine conditions, and dangerous coastal
surf are expected this week.

A broad area of low pressure is expected to materialize over the
western Gulf of Mexico bringing unsettled weather to the region
from Monday to Thursday. As of 2AM CDT, the National Hurricane
Center is giving the system a 60% chance of development by the
middle of the week. However, the expected impacts are the same
regardless of development.

Below are the primary weather concerns for this week.


1) Heavy Rainfall

There is a good chance of showers and thunderstorms Monday
through Thursday. There will be a daily risk of heavy rainfall
during this time frame. However, the time frame of most concern
is Tuesday evening through Wednesday. A Moderate Risk (Level 3
of 4) of excessive rainfall has been issued across most of the
southern half of our region (including the Houston metro) for
late Tuesday into Wednesday. The rest of our region is under a
Slight Risk (Level 2 of 4). Street flooding as well as rising
creeks, rivers, and bayous are a concern this week.

2) Hazardous Marine Conditions in the Bays and Offshore

Winds and seas will gradually build through Wednesday. Small
Craft Advisory criteria is likely to be met by Monday. Gale
conditions are possible offshore, and potentially in the bays,
by Tuesday and Wednesday. Seas are likely to exceed 10 feet
offshore and could approach 15 feet Tuesday afternoon through
Wednesday afternoon.

3) Coastal Flooding

Water levels at the coast are likely to remain higher than
normal all week. By Tuesday and Wednesday (possibly Thursday),
water levels may become high enough to result in coastal
flooding, especially during high tide. Water levels could exceed
5 feet above MLLW (Mean Lower Low Water) during high tide on
Wednesday.


4) Dangerous Surf / Rip Currents

The beaches will not be safe for swimming Monday-Thursday due to
rough surf and dangerous rip currents. It is possible that
hazardous beach conditions could extend beyond Thursday. In
addition, there will be a daily risk of lightning from
thunderstorms. Not a great weather week for beach activities.

Rains are expected to make themselves a much more significant part
of the forecast going forward, but I`ll leave discussion of that to
the long term forecaster...


.LONG TERM...
(Tuesday through Saturday)
Issued at 256 AM CDT Sun Jun 16 2024

On Tuesday into Wednesday, the LL gradient will steepen between a
high pressure system over eastern CONUS and the low pressure
system over the west and southwest Gulf of Mexico. The increased
ESE to SE flow will continue to push deep tropical moisture into
southeast Texas from the Gulf. This enhanced flow will be
noticeable via gusty winds, especially near the coast where winds
could gust over 40 MPH. Surging PWATS (2.50 to 3.00 inches) and
sufficient lift should allow for scattered to widespread showers
and thunderstorms. This set up alone would suffice for locally
heavy rainfall. However, vort maxes embedded in the low/mid level
flow could introduce additional lift and LL convergence. Global
determinist guidance agrees that a cluster of vort maxes will push
towards the Texas coast sometime between Tuesday evening and
Wednesday afternoon. That being said, there is quite a bit of
model variance regarding exactly where these vorticity maxima
track which has huge implications on the location of heaviest
rainfall. There continues to be some consensus that the highest
risk of heavy rainfall and flooding will be across the southern
CWA. The Weather Prediction Center has upgraded the excessive
rainfall risk to Moderate (Level 3 of 4) over much of the southern
half of our CWA while areas farther north are in a Slight Risk
(Level 2 of 4). Showers and thunderstorms are likely to linger
into Thursday and could linger through the end of the week.

Forecast rainfall totals through Thursday have once again been
revised upwards, ranging from 8-11 inches near the coast, to 5-8
inches near the I-10 corridor, and 2-4 inches across our northern
counties. Given the high PWATs and the potential enhancement from
LL disturbances, rainfall totals could exceed 12 inches in some
locations. Near the coast, any heavy rainfall related problems
could be exacerbated by the enhanced tides, especially if heavy
rainfall occurs near high tide.

Please have multiple ways to receive warnings this week. If you
encounter flooded roads while driving, turn around and avoid water
covered roads. Stay weather aware and please regularly check for
forecast updates in case the risk of heavy rainfall increases
further.

[Stratton20]

06z GFS has been really consistent with hammering se texas

[DoctorMu]

I’m expecting a pretty big increase in QPF across the area on the next update from the WPC. I also expect to see a moderate risk for excessive flooding being put out as well. Tonight’s 0z Euro run will be interesting.

Your wish...

[DoctorMu]

This ain't no party. This ain't no disco...

[tireman4]

This week's highlights

[don]

image4.png

[don]

Getting in range of the Mesoscale models now. 12Z HRRR/12Z RGEM

hrrr_ref_frzn_seus_48.jpg

Scr3eenshot 2024-06-16 a[...].png

Screenshott 2024-06-16 a[...].png

Screenshot 2024-r06-16 a[...].png

[Cpv17]

Getting in range of the Mesoscale models now. 12Z HRRR/12Z RGEM


hrrr_ref_frzn_seus_48.jpg
Scr3eenshot 2024-06-16 a[...].png

Screenshott 2024-06-16 a[...].pngScreenshot 2024-r06-16 a[...].png

Pretty big difference between the two.

[don]

Code Red now

two_atl_7d1.png

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Jun 16 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:


1. A large area of disturbed weather is located over Central America,
the Yucatan Peninsula of Mexico, and the adjacent waters of the
northwestern Caribbean Sea. A broad area of low pressure is
forecast to form from this system over the southwestern Gulf of
Mexico on Monday or Tuesday. Environmental conditions appear
conducive for subsequent gradual development of the low, and a
tropical depression or tropical storm could form by midweek while
it moves slowly westward or west-northwestward.

Regardless of development, several days of heavy rainfall are
expected across portions of southern Mexico and Central America, and
these rains are likely to cause life-threatening flooding and flash
flooding. Locally heavy rainfall is also expected to spread over
portions of the northwestern coast of the Gulf of Mexico by the
middle of the week. In addition, gale warnings have been issued
for portions of the Gulf of Mexico, and more information on these
is available in High Seas Forecasts issued by the National Weather
Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...high...70 percent.

[DoctorMu]

RGEM is bringing it.

[Cpv17]

RGEM is bringing it.

This is interesting because the globals are having a very hard time bringing in the rain very far inland, but this would indicate some pretty good rains much further inland than what globals are showing. It sucks too because I feel like the WPC and local forecasts on air are going by the globals. If the rains can push further inland like what the RGEM is showing here then you could easily double what the WPC is forecasting for much of the area.

[Stratton20]

18z HRRR has the low coming in just north of corpus, shows the rain event just beginning for se texas at the end of its run, has some big 20-25 inch totals off shore though, something to watch very closely

[biggerbyte]

If you know what to look for you can see a spin starting to take shape. There is going to be be some nail biting days ahead.

[don]

18Z HRRR looks a lot like the ICON and shows the northern vorticity becoming the COC, and moving towards the middle Texas coast.

Screejjjnshot 2024-06-16 a[...].png

[DoctorMu]

If you know what to look for you can see a spin starting to take shape. There is going to be be some nail biting days ahead.

Could be spin. Looks like shear (differential cloud movement at different heights).

https://www.star.nesdis.noaa.gov/GOES/s ... &length=24

We better "gyre up!"