Sunday, May20, 2018 L-36.com


Marine Weather and Tides
San Leon, TX

Version 3.4
What's New / NOTES
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.

Sunrise 6:22AMSunset 8:09PM Sunday May 20, 2018 7:53 PM CDT (00:53 UTC) Moonrise 10:37AMMoonset 12:00AM Illumination 36% Phase: Waxing Crescent; Moon at 6 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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GMZ335 Galveston Bay- 333 Pm Cdt Sun May 20 2018
Tonight..Southeast winds 5 to 10 knots increasing to 10 to 15 knots after midnight. Bay waters smooth becoming slightly choppy after midnight. A slight chance of showers. A slight chance of Thunderstorms after midnight.
Monday..East winds around 5 knots becoming southeast in the afternoon. Bay waters smooth. A slight chance of showers and Thunderstorms.
Monday night..South winds 5 to 10 knots. Bay waters smooth.
Tuesday..Southeast winds around 5 knots becoming 5 to 10 knots in the afternoon. Bay waters smooth. A slight chance of showers and Thunderstorms.
Tuesday night..South winds 5 to 10 knots. Bay waters smooth.
Wednesday..Southeast winds 5 to 10 knots. Bay waters smooth. A slight chance of showers and Thunderstorms.
Wednesday night..South winds 5 to 10 knots becoming southwest after midnight. Bay waters smooth.
Thursday..Northwest winds around 5 knots becoming south in the afternoon. Bay waters smooth. A chance of showers and a slight chance of Thunderstorms.
Thursday night..South winds 5 to 10 knots becoming west after midnight. Bay waters smooth. A slight chance of showers and Thunderstorms.
Friday..Northwest winds around 5 knots becoming south in the afternoon. Bay waters smooth. A chance of showers and Thunderstorms.
Friday night..South winds 5 to 10 knots becoming west after midnight. Bay waters smooth. A slight chance of showers and Thunderstorms.
GMZ300 Synopsis For High Island To The Matagorda Ship Channel Out 60 Nautical Miles Including Galveston And Matagorda Bays 333 Pm Cdt Sun May 20 2018
Synopsis for high island to matagorda ship channel out 60 nm.. Light to moderate onshore winds this afternoon and evening will gradually diminish after midnight as high pressure settles into east texas. A large area of showers and Thunderstorms over southeast texas should shift toward the coast and could push out into the nearshore waters tonight. Gusty winds would accompany the storms. Light winds are expected most of the upcoming week.

7 Day Forecast for Marine Location Near San Leon, TX
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location: 29.48, -94.92     debug


Area Discussion for - Houston/Galveston, TX
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Fxus64 khgx 210002
afdhgx
area forecast discussion
national weather service houston galveston tx
702 pm cdt Sun may 20 2018

Aviation
Showers and thunderstorms are building southward this evening while
overall motion of precipitation is toward the east. Cll is
beginning to see clearing while uts, cxo, iah are continuing to be
impacted by thunderstorms. An outflow boundary is currently
racing out ahead of the main line of thunderstorms and pushing
through sgr and hou. Winds will be variable with gusty conditions
beneath stronger storms. Anticipating most of the thunderstorm
development to weaken by 03z, with showers lingering into the
early morning hours. The precipitation should clear from the
northwest to southeast. Some patchy fog will also be possible
between 09-15z across our northern TAF sites.

Should see a small break in the way of precipitation for the
coastal sites tomorrow morning. The possibility of shower
development will return at lbx and gls around sunrise. MVFR
ceilings will begin to rise toVFR in the late morning and into
the early afternoon hours. E-se winds will return by the afternoon
between 5-10kts.

Hathaway

Prev discussion issued 404 pm cdt Sun may 20 2018
discussion...

showers and storms will largely be welcome rainfall for much of
the area today. However, there is enough instability that an
isolated strong to marginally severe storm is still possible, and
these strongest storms could create a very localized minor
flooding problem is it dumps enough rainfall quickly enough over a
vulnerable location. Beyond that, we settle into a rather
summer-like pattern for most of the week.

Near term [through tonight]...

for the first time in a while, the radar is lit up with a number
of showers and thunderstorms near and to the northwest of houston.

Ir satellite shows the coldest cloud tops right around -70c,
though most of the area shows warmer tops. As one might expect
given this, rainfall totals have varied wildly from near nothing,
to a maximum gauge total of 2.36 inches north of iah, though
radar estimates imply a cell has dropped roughly three inches in
extreme southwestern montgomery county as well.

The streamer showers and storms that had made up the bulk of the
morning's rainfall has largely merged with a broken line of
thunderstorms following its cold pool's outflow boundary slowly to
the southeast. Mesoanalysis shows 1500 or so j kg of CAPE in the
environment ahead of the line, indicating we still have ample
instability for continued storms. Dcape west of houston is now
over 800 j kg, which implies that our main severe threat is
damaging straight-line winds, though even that is a fairly
marginal threat. In addition, high precipitable water values and
a CAPE profile that this evening will resemble more a heavy rain
look, also means that the strongest cells could generate some
briefly torrential downpours, creating localized flooding issues
in areas of poor drainage and near flashy small streams.

However, bulk shear is pretty weak, and this will inhibit updraft
organization and the ultimate severe and rain threats. The threat
will largely be confined to the most robust updrafts before they
collapse and where cells pass over a site repeatedly.

Additionally, since these storms are largely sustained by
instability alone, we'll see them very slowly wind down into the
nighttime hours once the Sun sets. This will further limit
rainfall potential near the coast, where the forecast doesn't
really have pops above 30 percent. Rainfall here may be fairly low
unless the line can push coastward more effectively in the next
several hours.

Short term [Monday through Tuesday night]...

in many ways, tomorrow looks very similar to today. However,
without the upstream spark of a large convective system, I would
expect rainfall potential to be much more subdued despite similar
midlevel heights and what appears to be another shortwave moving
through. Ditto, really, for Tuesday. We'll definitely have some
things that will help support showers or storms that do develop,
but finding triggers for storms looks to be more difficult. Though
places that have seen plenty of rain today will obviously be
warmer with more isolated convection, temperatures as a whole look
to be pretty stable the next couple of days.

Long term [Wednesday through Sunday]...

we spend the latter half of the week pinned between a building
ridge over western mexico and an upper low over the northern gulf
coast, which keeps us in a situation with potential for isolated
to scattered showers and storms, but lacking in obvious triggers,
keeping convective potential in check. Heights do look to rise,
and so introduce a slow rise in temperatures into the weekend.

Now, the potential wrench in the whole works: it appears the 12z
euro has got a bug in it to bring the upper low lifting out of the
caribbean sea towards louisiana this weekend. This could put an
end to any warming trend, and open us up to higher rain chances,
though i've undercut the guidance as i've leaned a little more to
the gfs, which was a little more like yesterday's forecast.

Now, as for what the euro does next week? I'm not gonna talk about
it. It's beyond the forecast period, I refuse to discuss it. It's
probably going to change before it gets into the forecast period
anyway. And if it doesn't change, then I will discuss it then.

Aviation [18z TAF issuance]...

impressively large area of showers and thunderstorms from del rio
fanning out to near fort worth to houston. Storms have been
getting stronger with the continued destabilization over the area.

Can't rule out strong thunderstorms with winds over 40 knots with
these probably near the cll uts cxo terminals this afternoon.

Expect the deeper cold pool with the large cluster of storms near
tpl-t35 to help steer the development southeastward. Have gone
more pessimistic in area tafs with vcts this afternoon
interspersed with tempo shra tsra through mid evening. Expect the
area of storms to shift southeastward late afternoon evening and
many of the hrrr WRF support this movement development as upper
short wave moves into the area aiding the ventilation. Between
03-08z expect that most precip will wane but a boundary is likely
to be present near the coast around sunrise and anticipate at
least some scattered showers in proximity to the boundary so will
reinstate vcsh near 12z for the coastal sites. After the storms
wane late evening some patchy fog possible in rain cooled areas.

45
marine...

southeast winds 10-15 knots probably getting a little stronger
and gustier tonight as inflow to deep convection shifts close to
the coast with the storms. Storm may spread out into the nearshore
waters this evening before weakening. Boundary remains in the
morning and could be focus for additional showers. Expect lighter
wind regime Monday through Thursday. Will be keeping an eye on the
eastern gulf this week with most models indicating lowering
pressures as upper low meanders about.

45
hydrology...

despite a good amount of rain upstream and some more rains
expected through tonight, widespread hydrology concerns are nil.

Rivers are well below bankfull, and given the recent dry weather,
the rain will largely be beneficial. The potential for isolated
stronger storms and high available atmospheric moisture does mean
some briefly torrential rainfall is possible with the strongest
cells. This could potentially cause very localized minor flooding
issues on flashy small streams.

Preliminary point temps pops
College station (cll) 68 90 70 91 70 60 20 10 20 10
houston (iah) 71 91 72 91 73 90 20 10 20 10
galveston (gls) 78 85 78 85 78 20 20 10 20 0

Hgx watches warnings advisories
Tx... None.

Gm... None.

Discussion... 31
aviation marine... 08


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
EPTT2 - 8771013 - Eagle Point, TX 0 mi54 min S 9.9 G 13 82°F 85°F1015.4 hPa (+0.6)
GRRT2 12 mi54 min SE 6 G 8.9 81°F 84°F1015.1 hPa (+0.4)
GNJT2 - 8771341 - Galveston Bay (North Jetty), TX 13 mi54 min SSE 7 G 8.9 80°F 81°F1015.1 hPa (+0.4)
MGPT2 - 8770613 - Morgans Point, TX 14 mi54 min SE 6 G 9.9 82°F 83°F1015.4 hPa (+0.6)
GTOT2 14 mi54 min SSE 2.9 G 7 82°F 83°F1015.2 hPa (+0.4)
RLOT2 - 8770971 - Rollover Pass, TX 22 mi54 min S 7 G 8.9 81°F 84°F1015.8 hPa (+0.6)
NCHT2 - 8770777 - Manchester, TX 25 mi54 min NW 8.9 G 12 76°F 82°F1015.5 hPa (+1.7)
HIST2 29 mi54 min SSE 5.1 G 7 82°F 85°F1016 hPa (+0.6)
KXIH 30 mi39 min SE 9.9 81°F 75°F
LUIT2 30 mi54 min SE 6 G 8 81°F 82°F1014.9 hPa (+0.0)
42043 - GA-252 TABS B 34 mi114 min 7.8 G 9.7 80°F 80°F1014.8 hPa (+0.0)
FCGT2 - 8772447 - USCG Freeport, TX 42 mi54 min ESE 8 G 8.9 81°F 80°F1015.2 hPa (+0.0)
SRST2 - Sabine Pass, TX 49 mi54 min S 8 G 9.9 81°F 1016.1 hPa (-0.0)

Wind History for Eagle Point, TX
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Galveston, Scholes Field, TX15 mi62 minSE 710.00 miMostly Cloudy82°F75°F82%1015.6 hPa
Houston / Ellington, TX16 mi2.1 hrsSE 1010.00 miMostly Cloudy84°F71°F66%1015.6 hPa
Houston, Pearland Regional Airport, TX17 mi61 minSSE 510.00 miOvercast82°F73°F77%1015.6 hPa
Houston, Houston Hobby Airport, TX22 mi61 minSSE 610.00 miThunderstorm82°F73°F77%1015.6 hPa

Wind History from GLS (wind in knots)
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Last 24hrSE11SE11SE11SE13SE13SE11SE12SE9SE8SE8SE8SE8SE10SE11SE11SE18
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1 day agoS9S9S8SE9SE10S10S11S12S12S12S12S13S15S14S15S15S13S12S14SE12SE12SE12SE13SE11
2 days agoS13SW12SW11SW14SW10SW8SW10SW7S8S8S9SW6SW10S11S13S14SW15S15S13S15S15S14S14S13

Tide / Current Tables for Eagle Point, Galveston Bay, Texas
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Eagle Point
Click for Map
Sun -- 12:36 AM CDT     Moonset
Sun -- 05:15 AM CDT     -0.09 feet Low Tide
Sun -- 06:24 AM CDT     Sunrise
Sun -- 11:37 AM CDT     Moonrise
Sun -- 04:50 PM CDT     1.35 feet High Tide
Sun -- 08:08 PM CDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.60.40.20.1-0-0.1-0.100.20.40.60.80.91.11.21.31.31.41.31.31.21.21.10.9

Tide / Current Tables for Bolivar Roads, Texas Current
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Bolivar Roads
Click for Map
Sun -- 12:35 AM CDT     Moonset
Sun -- 01:58 AM CDT     -2.02 knots Max Ebb
Sun -- 06:24 AM CDT     Sunrise
Sun -- 06:32 AM CDT     0.00 knots Slack
Sun -- 10:12 AM CDT     2.09 knots Max Flood
Sun -- 11:36 AM CDT     Moonrise
Sun -- 04:50 PM CDT     -0.00 knots Slack
Sun -- 08:07 PM CDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1.8-2-2-1.9-1.7-1.2-0.50.41.31.92.121.81.41.10.70.3-0.1-0.4-0.6-0.6-0.7-0.8-1

Weather Map and Satellite Images
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wmap_A
GOES Local Image of SouthCentralPlains    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Houston/Galveston, TX (20,4,5,8)
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Ground Weather Radar Station Houston/Galveston, TX
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Gulf Stream Current


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Disclaimer:
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.