May 2023

[walsean1]

https://www.wpc.ncep.noaa.gov/qpf/ero.p ... curr&day=3

[Cpv17]

https://www.wpc.ncep.noaa.gov/qpf/ero.p ... curr&day=3

I think that will be upgraded at the next update.

[Cpv17]

The 0z HRRR is spitting out some 3-6” totals across parts of the area on Tuesday.

[869MB]

Though chances are currently low, we may need to keep one eye on tomorrow afternoon for the chance of isolated strong storms. The HRRR 00Z forecast soundings are depicting a lot of a CAPE (Surface, Mixed Layer, & Most Unstable) over the area on Monday afternoon between 11 am and 4 pm before a capping inversion increases during the evening. Though wind shear and SRH (storm-relative helicity) are lacking, strong, slow-moving thunderstorms with heavy rain are possible tomorrow afternoon over portions of the area during this time frame if we can get some type of lifting mechanism to initiate storm development.

[Stratton20]

Through hour 72 the 00z CMC is much slower with the progression of the cut off surface low, the 12z run had the low in north texas early thursday morning at hour 72 while the 00z run at the same time now has the low right over houston, thats an interesting change, doesnt clear the state until early friday now

[don]

Several of the mesoscale models have moved further east with the surface low FWIW. The HRRR is also showing training storms along the i-10 corridor on Tuesday.

[don]

0Z CMC

[Stratton20]

Closer view of 00z CMC total rainfall through 100 hours, I think 2-4 inches widespread seems like a good bet for most folks, definitely think it’s possible that someone sees a foot or more of rain out of this setup though

[Texashawk]

Well, according to the latest 7-day QPF from this morning, that sure deescalated quickly

[walsean1]

This is from Larry Cosgrove this morning

https://t.co/sVekvIWZpr

[Cpv17]

Well, according to the latest 7-day QPF from this morning, that sure deescalated quickly

West of 45 stands a much better chance of seeing some significant rains. It’s still possible east of 45 but more likely west of there. And I also posted a couple days ago this could be more of a south and central Texas event. Also, it seems like the WPC has decided to go with the GFS. The Euro doesn’t align with the WPC, the GFS does.

[MontgomeryCoWx]

Well, according to the latest 7-day QPF from this morning, that sure deescalated quickly

West of 45 stands a much better chance of seeing some significant rains. It’s still possible east of 45 but more likely west of there. And I also posted a couple days ago this could be more of a south and central Texas event. Also, it seems like the WPC has decided to go with the GFS. The Euro doesn’t align with the WPC, the GFS does.

I’d be just fine with 2-3 inches. Hill country needs and can have 6 plus

[Cromagnum]

Well, according to the latest 7-day QPF from this morning, that sure deescalated quickly

West of 45 stands a much better chance of seeing some significant rains. It’s still possible east of 45 but more likely west of there. And I also posted a couple days ago this could be more of a south and central Texas event. Also, it seems like the WPC has decided to go with the GFS. The Euro doesn’t align with the WPC, the GFS does.

I’d be just fine with 2-3 inches. Hill country needs and can have 6 plus

This

[tireman4]

000
FXUS64 KHGX 081152
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
652 AM CDT Mon May 8 2023

...New AVIATION...

.SHORT TERM...
(Today through Tuesday Night)
Issued at 215 AM CDT Mon May 8 2023

Gonna be a wet, possibly very wet, start to the work week - and
after yesterday`s rainfall overperformance, I sided with the wetter
solutions for both today and tomorrow. The parade of short waves
continues through the short term bringing additional showers and
thunderstorms to the region. The disturbance today will be the
weaker of the two, but with PWATs nearing 1.8" the storms that do
develop may produce some isolated heavy rainfall. Timeframe for
today`s rainfall will be in the morning through late afternoon with
a general winding down in coverage through the evening. The reprieve
overnight will not last long as the next shortwave moves through the
region tomorrow morning. Expect an increase in shower and
thunderstorm activity by sunrise coming from the southwest and
expanding across much of the region by the mid to late morning and
persisting through the afternoon. There may be a reduction in
coverage by the late afternoon, but showers and thunderstorms will
be possible through the night. There is a Slight Risk for Excessive
Rainfall on Tuesday leading to minor urban and small stream
flooding. This is due to not only the potential for up to 2 to 4" of
rain with locally higher amounts (mainly along the coast), but also
due to already wet soils from yesterday`s and today`s rainfall. If
today ends up on the drier side, the potential for excessive
rainfall for Tuesday will be lower, but on the flipside if today
ends up being wetter than expected than the flooding potential
increases on Tuesday. Not looking much like a severe weather threat
for either today or Tuesday, but soundings do show long-skinny CAPE
profiles indicating that the storms will be proficient rain-makers.

Expect high temperatures this afternoon to rise into the upper 80s
(maybe a few spots of 90 degrees where the sun peaks out), but high
temperatures on Tuesday will only get into the low to mid 80s due
to the increased precipitation coverage. Overnight lows tonight and
Tuesday night will be in the low to mid 70s.

Fowler

&&

.LONG TERM...
(Wednesday through Sunday)
Issued at 215 AM CDT Mon May 8 2023

Tuesday`s shortwave will drift north of our area by Wednesday. In
its wake will be another series of shortwaves, though not as
aggressive as Tuesday`s shortwave. Continued deep onshore flow
will keep PWATs high through week`s end. Therefore, we continue to
think that there will be a daily risk of scattered showers and
thunderstorms through the end of the week. The primary concern
from the thunderstorms will be locally heavy rainfall. There is
some indication that another more aggressive shortwave could
impact the region by the weekend. However, confidence is low that
far out into the forecast period. We continued to bias our daily
long term PoPs higher than the NBM guidance due to the high PWs
and expected shortwave induced PVA. Afternoon temperatures through
the long term are expected to be in the low/mid-80s with
overnight lows in the low/mid-70s. Couldn`t rule out slightly
hotter temperatures on some days if rainfall activity and cloud
cover prove to be less widespread like the NBM suggests.

Self

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 553 AM CDT Mon May 8 2023

MVFR to occasionally IFR conditions will prevail through the rest
of this morning with CIGs hanging out around 1500ft with the
occasional 700ft CIG down along the coast. There will be an
increase in showers and and thunderstorms developing this
afternoon, so VCTS has been added to all terminals south of UTS.
These scattered storms will persist into the evening before
dissipating, but MVFR to IFR conditions return later tonight with
CIGs down to 700ft possible along the coast. Southerly winds of 7
to 10kts will persist through the period. Some isolated showers
and thunderstorms will begin to reappear tomorrow morning with
widespread precipitation expected tomorrow afternoon.

Fowler

&&

.MARINE...
Issued at 215 AM CDT Mon May 8 2023

The onshore flow regime is expected to continue through the
forecast period. Generally moderate southeasterly winds are
expected through the weekend. Winds may occasionally be stronger,
especially at night through the early morning hours. This may
warrant caution flags and even potential advisories. Seas are
expected to be in the 3-6 foot range. Occasionally higher seas
cannot be ruled out. There will also be a daily risk of showers
and thunderstorms through the end of the week. Locally higher
winds and seas will be possible in an near any thunderstorm.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 88 71 83 68 / 50 20 70 40
Houston (IAH) 87 72 83 70 / 50 20 70 40
Galveston (GLS) 82 75 81 74 / 40 20 50 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through this evening for TXZ436>439.

GM...Small Craft Should Exercise Caution until 10 AM CDT this morning
for GMZ330-335-350-355-370-375.

&&

$$

SHORT TERM...Fowler
LONG TERM....Self
AVIATION...Fowler
MARINE...Self

[don]

WPC mentions a higher risk may be needed if confidence increases.

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
333 AM EDT Mon May 08 2023

Day 2
Valid 12Z Tue May 09 2023 - 12Z Wed May 10 2023

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS SOUTHEAST
TEXAS...

TX...
A southerly low level flow combined with a forming mid-level
cyclone should lead to ample moisture, instability, and effective
bulk shear to support organized convection capable of producing
heavy to potentially excessive rainfall. A few pieces of guidance
indicate the potential for local amounts in the 5-10" range but
don't show a great deal of overlap with their heavy rainfall
signal. However, that overlap does exist across southeast TX so
the threat level has been raised to Slight Risk in that region.
There remains dispersion on placement, but given time, the
instability gradient should recede to the Gulf Coast and the best
onshore flow appears targeted into portions of the Middle and
Upper TX coast, which fits the guidance overlap and conceptual
models. Should the signal become stronger, increased risk levels
are possible in succeeding cycles.

[Cpv17]

Well, according to the latest 7-day QPF from this morning, that sure deescalated quickly

West of 45 stands a much better chance of seeing some significant rains. It’s still possible east of 45 but more likely west of there. And I also posted a couple days ago this could be more of a south and central Texas event. Also, it seems like the WPC has decided to go with the GFS. The Euro doesn’t align with the WPC, the GFS does.

I’d be just fine with 2-3 inches. Hill country needs and can have 6 plus

Agreed!

[Stratton20]

Hopefully we can get some agreement on where the heaviest rains will fall, models still are not in good agreement on that, also important to say dont become focused on the WPC QPF outlook, the general expectation across se texas is 1-3 inches widespread, but if training sets up, some areas could easily double or triple those amounts easily, mesocale models do a much better job with heavy rain event’s compared to the global models

[Cpv17]

The DP is 78° here..crazy!!

[redneckweather]

Well, according to the latest 7-day QPF from this morning, that sure deescalated quickly

West of 45 stands a much better chance of seeing some significant rains. It’s still possible east of 45 but more likely west of there. And I also posted a couple days ago this could be more of a south and central Texas event. Also, it seems like the WPC has decided to go with the GFS. The Euro doesn’t align with the WPC, the GFS does.

I’d be just fine with 2-3 inches. Hill country needs and can have 6 plus

Yep, get that Frio River rolling good before my visit in late June.

[don]

There may be some pretty heavy rain this afternoon as a leftover boundary flares up with the heating of the day.The HRRR is showing isolated areas of up to 6 inches today.