Saturday, April21, 2018

Marine Weather and Tides
Jamaica Beach, TX

Version 3.4
What's New / NOTES
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.
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.

Sunrise 6:44AMSunset 7:50PM Saturday April 21, 2018 4:46 AM CDT (09:46 UTC) Moonrise 10:40AMMoonset 12:00AM Illumination 35% 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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GMZ355 Coastal Waters From Freeport To The Matagorda Ship Channel Out 20 Nm-coastal Waters From High Island To Freeport Out 20 Nm- 339 Am Cdt Sat Apr 21 2018
.small craft should exercise caution...
Today..Southeast winds 15 to 20 knots. Seas 3 to 5 feet. A chance of showers early in the morning, then a slight chance of showers and Thunderstorms in the late morning and afternoon.
Tonight..Southeast winds 15 to 20 knots becoming south 10 to 15 knots after midnight. Seas 3 to 4 feet. A slight chance of showers and Thunderstorms in the evening, then a chance of showers and Thunderstorms after midnight. Showers and Thunderstorms likely late.
Sunday..Northwest winds 15 to 20 knots decreasing to 10 to 15 knots in the afternoon. Seas 2 to 4 feet. A slight chance of showers and Thunderstorms in the morning.
Sunday night..North winds 10 to 15 knots. Seas 2 to 3 feet.
Monday..Northwest winds 10 to 15 knots. Seas 1 to 2 feet.
Monday night..North winds 5 to 10 knots. Seas 1 to 2 feet.
Tuesday..North winds 5 to 10 knots becoming northeast in the afternoon. Seas 1 to 2 feet.
Tuesday night..Southeast winds 5 to 10 knots becoming east after midnight. Seas 1 to 2 feet.
Wednesday..East winds 5 to 10 knots. Seas 1 foot.
Wednesday night..Northeast winds 5 to 10 knots increasing to 10 to 15 knots after midnight. Seas 1 to 2 feet.
GMZ300 Synopsis For High Island To The Matagorda Ship Channel Out 60 Nautical Miles Including Galveston And Matagorda Bays 339 Am Cdt Sat Apr 21 2018
Synopsis for high island to matagorda ship channel out 60 nm.. Moderate to strong southeast winds will prevail today into this evening. A cold front is expected to cross the waters Sunday morning with showers and storms. Moderate to strong offshore winds develop in the wake of this front will diminish to generally moderate winds through Monday.

7 Day Forecast for Marine Location Near Jamaica Beach, TX
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location: 29.2, -94.99     debug

Area Discussion for - Houston/Galveston, TX
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Fxus64 khgx 210944
area forecast discussion
national weather service houston galveston tx
444 am cdt Sat apr 21 2018

Near term [through today and tonight]
Today's forecast really hinges on careful and thorough analysis,
but even with that, we meteorologists are hoping model boundary
layer parameterization schemes handle the situation correctly.

Water vapor imagery this morning shows an elongated upper level
low over the central and southern rockies with a vorticity center
at the base of the low over new mexico. Polar jet shows up nicely
with drying in all three water vapor channels from the great basin
down to the desert SW and across to the southern rockies. There is
also evidence of the subtropical jet coming across the u.S. Mexico
border into texas with some anti-cyclonic curved cirrus over
central texas. Subtropical jet may also be contributing to some of
the drying on water vapor imagery over the southern rockies.

Polar jet curves north over the plains and can see diffluent flow
over much of texas. As the upper low moves east, this diffluence
along with the coupled jet and height falls should allow for
increasing large scale ascent. NAM gfs ECMWF all show strong q
vector convergence in the 500-300mb layer by this afternoon over
much of texas from i-10 north to the red river. South of i-10 the
lift tapers off quite a bit and more likely where the elevated
mixed layer will be stronger.

At the surface, the warm front was located fairly close to the
leading edge of 60f dewpoints. At 09z this basically was along
i-10. Case in point, kiah had a t TD of 61f 54f, khou at 66f 62f.

Warm front should continue to push north as warm air advection
increases with cyclogenesis over NW central texas by 18z today.

Dewpoints in the mid 60s should spread over the area with maybe
some upper 60 dewpoints along the coast. Model soundings show
increasing boundary layer moisture but 3-6km lapse rates going
from 8c to closer to 6.5c-7c as the atmospheric column moistens.

The elevated mixed layer does erode with the lift from 18z today
to 00z Sunday so the warm sector should have some destabilization.

The problem will be persistent cloud cover which will limit any
diabatic heating in the boundary layer. Should there be enough
breaks in the clouds, there could be some pockets of better
heating and destabilizing the atmosphere. As it stands, warm air
advection will have to be enough to increase boundary layer
temperatures to create instability. Most models show around 500 to
maybe 1000 j kg of CAPE with the higher amounts over central
texas towards the brazos valley. This is where boundary layer
parameterization schemes in the models need to be at their best.

Should there be more heating or a lot more moisture than currently
forecast, then the threat for severe weather increases. As it
stands, the marginal at best thermodynamic environment will limit
the threat.

Should surface based updrafts form this afternoon overnight, there
is expected to be plenty of 0-6km bulk shear (45-55kt) for
organized storms. Even 0-1km bulk shear of 20-25kts will be enough
for storm rotation and a small tornado threat. SPC does have a 2%
tornado probability along with a 5% damaging wind probability for
the area. With lapse rates decreasing during the day due to
atmospheric moistening, hail will be a minor threat. Basic timing
of any severe weather looks to be after 21z today for today. There
should be a window from 21z today to 03z Sunday (4pm-10pm) for
severe weather over the brazos valley over to east texas. Timing
of the threat shifts south to 03z to 12z (10pm to 7am Sunday)
Sunday for areas south of college station to lufkin. At this time
storm evolution may go from a few individual cells to a line of
storms or a weak broken qlcs depending upon interaction with the
elevated mixed layer.

Lastly the heavy rainfall threat which I really do not think there
is much of a threat. Nonetheless, wpc has the area in a marginal
risk for excessive rainfall exceeding flash flood guidance. Yes
precipitable water values climb to around 1.7-1.8 inches which is
above the 90-95th percentile of climo per naefs guidance. There is
strong moisture transport with 30 knot LLJ during the day. Overall
think there could be on average a good half inch of rain for the
area with isolated 1-3 inch amounts. Latest basin 3 hr FFG shows
most areas needing more than 4 inches of rain in 3 hrs. So other
than your typical flooding of low lying areas or rapid responses
on creeks bayous, flood threat should be low especially with storm
motions of 30 to 40 knots.

Short term [Sunday through Monday]
Cold front pushes through early Sunday and off the coast 12z to
18z allowing for drying conditions. Sunday afternoon through
Monday should be some of the nicest spring conditions you can get
in SE texas. High pressure will build down through the plains
keeping northerly winds in place and some cold advection through

Long term [Monday night through Saturday]
Overall upper level pattern remains quite amplified with a strong
ridge over the pacific NW which means the long wave trough
pattern should persist over the central u.S. Into the great lakes.

A couple of short wave troughs dip south into texas within nw
flow aloft. Forecast will keep some chances of showers and perhaps
elevated thunderstorms for Wednesday with a stronger trough
coming through Thursday night into Friday. GFS and ECMWF have
trended stronger with this second system so something to monitor
with future forecasts.


Moderate to strong winds are expected to continue through today and
into tonight, and even potentially longer in the offshore waters.

Winds will become more out of the southeast today, and with speeds
of 15-20 knots and seas of 3-5 feet, caution is urged for small
craft on the gulf today. Some drizzle or light showers... And the
afternoon even an isolated thunderstorm will be possible as a warm
front drifts through the area. The onshore winds will also help
elevate tide levels, which may cause run up at times of high tide.

A cold front will push across the waters through Sunday morning,
veering winds to northwesterly, and remaining moderate to strong.

Currently expecting these winds to be similar in strength to the pre-
frontal winds, which would be not quite enough for a small craft
advisory, but still necessitate caution until winds begin to
diminish Sunday night. After that, generally offshore winds prevail
until Tuesday or so, at which point we'll have a brief period of
onshore winds before the next front in the middle of next week.


Preliminary point temps pops
College station (cll) 75 55 74 52 77 50 70 0 0 0
houston (iah) 76 61 76 55 79 40 70 10 0 0
galveston (gls) 74 66 76 62 76 30 70 10 0 0

Hgx watches warnings advisories
Tx... None.

Gm... Small craft should exercise caution through this afternoon for
the following zones: coastal waters from freeport to the
matagorda ship channel out 20 nm... Coastal waters from high
island to freeport out 20 nm... Waters from freeport to the
matagorda ship channel from 20 to 60 nm... Waters from high
island to freeport from 20 to 60 nm.

Near term... Overpeck
short term... Overpeck
long term... Overpeck
aviation... Luchs
marine... Luchs
fire weather... Luchs

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
GRRT2 9 mi47 min ESE 13 G 18 67°F 67°F1015.7 hPa (-2.4)
LUIT2 11 mi47 min ESE 18 G 21 68°F 1015.5 hPa (-2.5)
GTOT2 13 mi47 min ESE 9.9 G 17 67°F 72°F1015.9 hPa (-2.3)
GNJT2 - 8771341 - Galveston Bay (North Jetty), TX 18 mi53 min ESE 20 G 23 68°F1015.9 hPa
EPTT2 - 8771013 - Eagle Point, TX 20 mi47 min SE 18 G 19 67°F 67°F1016 hPa (-2.4)
FCGT2 - 8772447 - USCG Freeport, TX 24 mi47 min E 15 G 19 69°F 70°F1015.6 hPa (-2.7)
KXIH 25 mi32 min ESE 21 68°F 63°F
42035 - GALVESTON 22NM East of Galveston, TX 31 mi117 min ESE 19 G 21 68°F 70°F4 ft1016.1 hPa (-2.7)62°F
RLOT2 - 8770971 - Rollover Pass, TX 33 mi47 min SE 15 G 19 69°F 64°F1016.5 hPa (-2.4)
MGPT2 - 8770613 - Morgans Point, TX 33 mi47 min E 8.9 G 12 65°F 69°F1016.2 hPa (-2.2)
NCHT2 - 8770777 - Manchester, TX 39 mi47 min E 2.9 G 7 67°F 70°F1015.4 hPa (-2.3)
HIST2 42 mi47 min ESE 8.9 G 12 66°F 68°F1016.8 hPa (-2.5)
SGNT2 45 mi47 min E 13 G 17 70°F 70°F1014.6 hPa (-2.2)

Wind History for Galveston Pleasure Pier, TX
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1 day
2 days

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Galveston, Scholes Field, TX8 mi55 minESE 1410.00 miOvercast67°F63°F87%1016.3 hPa

Wind History from GLS (wind in knots)
Last 24hrNE16
1 day agoN16
2 days agoS13

Tide / Current Tables for Jamaica Beach, West Bay, Galveston Bay, Texas
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Jamaica Beach
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Sat -- 12:49 AM CDT     Moonset
Sat -- 06:00 AM CDT     -0.06 feet Low Tide
Sat -- 06:47 AM CDT     Sunrise
Sat -- 11:40 AM CDT     Moonrise
Sat -- 02:01 PM CDT     1.17 feet High Tide
Sat -- 07:50 PM CDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Tide / Current Tables for Bolivar Roads, Texas Current
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Bolivar Roads
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Sat -- 12:48 AM CDT     Moonset
Sat -- 01:59 AM CDT     -1.93 knots Max Ebb
Sat -- 06:30 AM CDT     0.00 knots Slack
Sat -- 06:46 AM CDT     Sunrise
Sat -- 10:09 AM CDT     2.14 knots Max Flood
Sat -- 11:39 AM CDT     Moonrise
Sat -- 04:48 PM CDT     -0.00 knots Slack
Sat -- 07:49 PM CDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Weather Map and Satellite Images
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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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Wind Forecast for Houston/Galveston, TX (5,6,7,8)
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Ground Weather Radar Station Houston/Galveston, TX
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Gulf Stream Current

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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 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 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.