Sunrise 6:29 AM   Sunset 8:06 PM Moonrise 8:19 AM   Moonset 11:14 PM

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GMZ335 Galveston Bay- 1115 Am Cdt Sat May 11 2024
.small craft advisory in effect until 7 pm cdt this evening - .
Rest of today - East winds around 20 knots this afternoon. Bay waters slightly choppy, rising to choppy this afternoon. A slight chance of showers early this afternoon. A chance of showers with a slight chance of Thunderstorms late. Tonight - Southeast winds 10 to 15 knots. Bay waters slightly choppy. A slight chance of showers and Thunderstorms in the evening, then a chance of showers and Thunderstorms after midnight. Sunday - Southeast winds around 15 knots, rising to 15 to 20 knots in the afternoon. Bay waters choppy. A chance of showers early in the morning, then a chance of showers and Thunderstorms in the late morning and afternoon. Sunday night - Southeast winds 15 to 20 knots, becoming south around 15 knots late. Bay waters choppy, easing to slightly choppy late. A chance of showers and Thunderstorms until early morning. Monday - South winds 10 to 15 knots. Bay waters slightly choppy. A chance of showers and Thunderstorms in the morning, then showers and Thunderstorms likely in the afternoon. Monday night - Southeast winds 10 to 15 knots, becoming south around 10 knots after midnight. Bay waters slightly choppy, easing to smooth after midnight. A chance of showers and Thunderstorms in the evening. Tuesday - West winds 5 to 10 knots, veering to north in the afternoon. Bay waters smooth. Tuesday night - East winds around 5 knots. Bay waters smooth. Wednesday - East winds 5 to 10 knots. Bay waters smooth. Wednesday night - Southeast winds 10 to 15 knots. Bay waters slightly choppy. A chance of Thunderstorms. A chance of showers.
winds and waves higher in and near Thunderstorms.

GMZ300 Synopsis For High Island To The Matagorda Ship Channel Out 60 Nautical Miles Including Galveston And Matagorda Bays 1115 Am Cdt Sat May 11 2024
Synopsis for high island to the matagorda ship channel out 60 nm including galveston and matagorda bays
moderate to occasionally strong east northeast winds will veer more east throughout the day, with an attendant increase in seas. Small craft will need to proceed with caution through at least late tonight. Some low rain chances may begin to creep into the picture as early as today, but more shower and Thunderstorm activity is anticipated Sunday into Monday. Tuesday looks to feature some fairer weather and a brief amount of offshore flow, but onshore winds return quickly, followed shortly by the next window for showers and storms.

FXUS64 KHGX 111731 AFDHGX

Area Forecast Discussion National Weather Service Houston/Galveston TX 1231 PM CDT Sat May 11 2024

New AVIATION

SYNOPSIS
Issued at 433 AM CDT Sat May 11 2024

The unsettled, frequently rainy pattern that has been a prominent feature recently doesn't appear to really being going anywhere anytime soon. Over the next week, we can expect multiple opportunities for showers and thunderstorms around Southeast Texas. Given all the recent rain and lingering flooding issues on the Trinity and Brazos rivers, we'll certainly need to be on the lookout for the aggravation or return of flooding concerns, and some of the week's stronger storms will carry some potential for severe weather as well. A quick summary of what to look for: - Amongst the broader unsettled pattern, we're looking at two windows with relatively higher potential for locally heavy rain.
The first is Sunday into Monday. The second is later in the week, Wednesday into Thursday. WPC highlights at least a portion of the area with a slight risk of excessive rainfall (threat level 2 of 4) for both Sunday and Monday. There is also a portion of the area highlighted in their Day 5 outlook with a slight risk.
- These same windows will also have to be watched for some thunderstorms becoming strong to severe. On Sunday, SPC's severe weather outlook indicates a marginal risk area across Southeast Texas (threat level 1 of 5), which increases to a slight risk (threat level 2 of 5) on Monday. There is also some concern about the midweek window mentioned above, but there is not enough confidence yet to highlight a specific threat level at this time.

SHORT TERM
(Today through Sunday Night)
Issued at 433 AM CDT Sat May 11 2024

We ended up having to make some changes to the forecast today which lead to increased rain chances, particularly across the southern half of the CWA So let's talk about it! Sfc high pressure dominates the low levels this morning. Northeast flow on the east side of the high has pushed drier dew points (50s and 60s) down into SE TX.
Therefore, conditions should feel relatively pleasant early this morning. As the aforementioned high progresses east, LL flow will veer more easterly. Meanwhile offshore, a building gradient between the high to the north and lower pressure over S TX will result in increasing easterly winds. For those of us on land, this will impact us in two different ways. 1) Expect conditions to become quite breezy at the coast, possibly gusting to around 30 MPH this afternoon at the beaches. 2) A LL convergence zone will become enhanced over our coastal counties, possibly providing enough lift for shower and isolated thunderstorm development by the afternoon.
Large scale forcing won't be too impressive today. However, PWs across our southern / coastal counties may be approaching 2.0 inches as early as this afternoon. These PWs coupled with the LL convergence and weak disturbances embedded in the flow aloft have warranted the addition of PoPs in today's forecast. Today's PoPs range from 15-20% north of I-10, to 20-30% along and south of I-10.
Model guidance varies a lot with today's precip. If the NBM had its way, I wouldn't have added PoPs. Meanwhile, many of the overnight HRRR runs suggest that our current PoPs could be conservative. Temperatures this afternoon are expected to warm into the low/mid 80s.

The strong easterly winds across the Gulf Waters and adjacent coast will ease as we head into this evening, weakening LL convergence over our coastal zones. However, a stalled frontal boundary offshore is expected to lift northward as a warm front overnight, reintroducing LL convergence to the area. Meanwhile, a mid/upper trough over SW CONUS will approach from the west. Large scale lift and mid/upper shear will gradually increase as a result. The trough will also induce a sfc low over Kansas and Oklahoma. Deep, moist, LL S to SE flow ahead of the low will result in a PW surge across SE TX. ECMWF deterministic / ensembles guidance is particularly aggressive with this surge, showing widespread PW values of at least 2.0 inches by Sunday morning. GFS global/ensemble guidance as well as HRRR means are a tad more conservative (though still quite juicy)
with widespread 1.8-2.0 inches. While the lower levels remain warm and moist, the upper levels are likely to cool as the trough approaches. Guidance indicates there will be no shortage of LL/ML instability, setting the stage for deep convection Sunday afternoon and evening. There does appear to be some model variance regarding how far south deep convection will occur on Sunday with the GFS keeping it over our northern counties while the ECMWF shows areas as far south of I-10 partaking in the action. This is why Sunday's PoPs are highest over the northern CWA, ranging from 80-90% in our Brazos Valley / Piney Woods counties, to 70-80% near I-10, and 50-60% near the coast.

The primary concern on Sunday will be heavy rainfall. WPC has kept much of the region under a Slight Risk (Level 2 of 4) for excessive rainfall on Sunday. Our southwest most counties near Matagorda Bay are under a Marginal Risk (Level 1 of 4) of excessive rainfall.
Given the instability and shear parameters, we cannot rule out locally strong to severe thunderstorms. Hail and damaging winds will be the primary concerns. The impact Sunday's rains have on our SE TX rivers will largely depend on where the heaviest showers / thunderstorms occur. There exists some uncertainty regarding the exact location of these storms. But generally speaking, the best chance of heavy rainfall will be north of I-10.

LONG TERM
(Monday through Friday)
Issued at 433 AM CDT Sat May 11 2024

If you're looking for the long term portion of the forecast to give you some fairer weather to look forward to...I haven't got a whole lot to give you. Although if you read the synopsis section up top, you probably already know I don't have much to offer but more chances for showers and storms.

While Sunday's activity does look to generally move off to the east, we've still got ourselves an upper trough over the Great Plains to deal with on Monday. While I certainly won't stop you from hoping that Sunday's rains work over the atmosphere, you also won't find me promoting any of that hope, either. Low level flow looks to stay primarily onshore to continue pumping in warm and humid boundary layer air, and mid-level heights look to fall with the upper trough making its way across the Plains. This should hammer out a thicker CAPE profile for us, with NBM SBCAPE numbers in excess of 3000 J/Kg. and largely create an environment that just reloads for another round of showers and storms, and likely is one that could better support severe weather than Sunday.

Indeed, with such ample moisture and instability, the primary bottleneck on severe potential might actually be that we get convective initiation too early and too numerous, creating a situation where many storms are battling for "clean" air, and only allowing fewer individual cells to fully realize their potential. That's...not an ideal way to do it, especially since we are already dealing with lingering flooding issues that Sunday will aggravate, and will only be further aggravated by numerous storms on Monday. We can likely peg the primary hazard to be large hail earlier in the day thanks to the instability present - though if things do cluster on an incoming front, that may be far enough back to largely spare us of that threat, except for up in our far north/northwest. That threat will likely shift to damaging wind gusts later, as storms grow upscale into some sort of convective complex. I don't want to write of tornado potential entirely, and that will pose a secondary threat...but the anticipated evolution here has me focusing more on the hail and wind hazards.

Tuesday, at least, does give us a brief break from this seemingly unending train of storm events. A weak front (weak, weak, all these fronts are weak) will usher Monday's storms off to the east, and give us (most of) a day with offshore winds and a modest decrease in humidity. I'm not too confident we'll actually see temperatures drop at all...and may even be warmer than the days before and after if enough sun can break in. In fact, this is explicitly in the forecast, where Tuesday is arguably one of the warmest days of the week across the area with a mostly sunny sky.
I didn't even have to step in and force it on this one. It's so obvious that this outcome popped right out of the deterministic NBM output. Often I find myself have to make some sort of tweaking to the NBM's numbers to better highlight this scenario, but not this time...I largely just let its temperatures ride this time around.

Don't get too used to Tuesday, though. In fact, you'll want to savor it. Onshore winds return quickly, by Tuesday night most likely. This will put us back into an environment ready to support showers and thunderstorms again, we'll just be waiting for the next instigator to move in. That will likely be in the form a shortwave trough, and that should move in at some point on Wednesday. I've got PoPs coming up as early as Wednesday afternoon, but for now, it appears that Wednesday night into Thursday is the prime time to look for. Wednesday during the day may yet be a little too early - though Tuesday's post-frontal airmass isn't very effective at scouring out moisture, it may knock precipitable water down just enough that Wednesday will be more iffy, while both the NAEFS and Euro ensembles prog precipitable water to be back up around or above the 90th percentile late Wednesday night into Thursday. At this point, we're at too far a range and models have too much spread to be too confident in specifics, but the increase in moisture certainly points to another locally heavy rain threat emerging, though it looks like it would be the less significant one of the week? That's starting to get a bit speculative, though. Similarly speculative would be a severe threat. I see some of the ingredients there - the Euro ensembles Extreme Forecast Index does show a signal for an enhanced CAPE and shear environment, so we'll have to watch and see how things play out in the days to come.

AVIATION
(18Z TAF Issuance)
Issued at 1223 PM CDT Sat May 11 2024

VFR conditions will prevail through the afternoon, but MVFR to IFR conditions will develop this evening and continue through Sunday morning at least. CIGs will drop to around 1500 to 2500ft between sunset and midnight from south to north. CLL and UTS will also have the chance to see CIGs around 700-800ft by sunrise Sunday along with some patchy fog. Breezy easterly winds today will diminish tonight, then become breezy southeasterly winds through the day on Sunday.

There will be scattered showers with the potential of isolated thunderstorms this afternoon through Sunday morning - but determining exactly where they will develop is not known. Areas along the coast will have the best chance this afternoon, moving up through SGR/HOU this evening, up towards IAH around midnight, and then potentially to UTS/CLL late tonight. But again, confidence is not high on the location of these storms, so have done with mainly PROB30 TS groups at this time. There will be a lull during tomorrow morning, but will see some redevelopment of showers and storms tomorrow afternoon/evening. Highest coverage of these storm will stay north of CXO, but may see some isolated showers and storms down to the I-10 corridor.

Fowler

MARINE
Issued at 433 AM CDT Sat May 11 2024

Moderate northeasterly winds will modestly increase and veer more easterly through the day today, with an attendant increase in seas. This will lead to conditions in which small craft will need to exercise caution through at least the evening. Conditions are expected to degrade enough, that any additional increase in winds or seas over what is expected will necessitate a small craft advisory. Some low rain chances may begin to creep into the picture as early as today, particularly around the coast.

More shower and thunderstorm activity is anticipated Sunday into Monday. Tuesday looks to feature some fairer weather and a brief amount of offshore flow, but onshore winds return quickly, followed shortly by the next window for showers and storms and poorer marine conditions.

PRELIMINARY POINT TEMPS/POPS
College Station (CLL) 68 80 71 86 / 30 70 40 50 Houston (IAH) 69 82 73 88 / 30 70 40 70 Galveston (GLS) 74 81 76 83 / 40 40 20 50

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

GM...Small Craft Advisory until 7 PM CDT this evening for GMZ330-335- 350-355-375.

Small Craft Should Exercise Caution from 7 PM this evening to midnight CDT tonight for GMZ330-335-350-355-375.

Small Craft Should Exercise Caution until midnight CDT tonight for GMZ370.

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