Thursday, August24, 2017 L-36.com


Marine Weather and Tides
Castle Hills, TX

Version 3.4
What's New / NOTES
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.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 7:06AMSunset 8:05PM Thursday August 24, 2017 5:36 AM CDT (10:36 UTC) Moonrise 8:55AMMoonset 9:14PM Illumination 5% Phase: Waxing Crescent; Moon at 2 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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7 Day Forecast for Marine Location Near Castle Hills, TX
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location: 29.51, -98.53     debug


Area Discussion for - Austin/San Antonio, TX
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Fxus64 kewx 240951
afdewx
area forecast discussion
national weather service austin san antonio tx
451 am cdt Thu aug 24 2017

Tropical update harvey upgraded to tropical storm
tropical storm warnings have been issued for the southeast portions
of south central texas including atascosa, wilson, karnes, dewitt,
gonzales, and lavaca counties due to increased confidence for
tropical storm force winds reaching those areas. Additionally,
confidence in the potential for a life-threatening rainfall event
continues to increase for parts of south central texas including san
antonio as well as areas further east along and south of the i-10
corridor. As a result, a flash flood watch will be issued beginning
Friday afternoon and lasting through at least Sunday morning. The
watch will likely require an extension, both in area and timing, as
the system continues to evolve.

Please see our "messaging key points" which are revised below.

Messaging key points:
1) tropical storm warnings have been issued for parts of south central
texas, mostly south of i-10 and along and east of i-35 i-37.

2) harvey is expected to intensify into at least a low end category 1
hurricane prior to making landfall late Friday night or early
Saturday morning somewhere along the middle texas gulf coast. Any
further intensification may require an expansion of the tropical
storm warning area over portions of south central texas.

3) a flash flood watch will go into effect Friday afternoon through
at least Sunday morning for areas east of i-35 and along and south of
i-10 including the city of san antonio.

4) the flash flood watch will likely need to be extended in time and
area as the system evolves through the weekend.

5) average rainfall amounts of 8 to 15 inches with isolated totals
up to 20 inches will be possible in the area under a flash flood
watch east of i-35 i-37 and south of i-10. Rainfall amounts of 5 to
10 inches are expected outside of the watch area along and east of
i-35, with totals of less than 5 inches expected west of i-35.

6) there remains uncertainty in the forecast track of harvey after
landfall. Small changes to the track or speed of harvey could result
in large changes to flooding across south central texas.

Short term (today through Friday)
Convective activity has finally dissipated across south central
texas tonight with only very isolated showers anticipated through the
overnight and morning hours. A weak stationary front reinforced by
an outflow boundary left behind by this evening's convection remains
over southern portions of south central texas, stretching from
hallettsville to pleasanton to eagle pass. This frontal zone should
serve as a weak focus for convection early this afternoon, but we
should also see additional development along the higher terrain of
the hill country similar to yesterday. Therefore, scattered showers
and thunderstorms will be expected across most of the region with
coverage a bit more isolated further west towards the rio grande
plains. Increasing moisture aloft will cause more moist-adiabatic
temperature profiles today to decrease the wind threat aside from
brief localized downbursts while increasing the threat of brief
localized heavy downpours of 2-3 inches. Minor advisory-level flooding
will be possible due to relatively slow northerly storm motions, but
the isolated nature of the heavy downpours and relatively high flash
flood guidance values make flash flooding unlikely today. Although we
should have a lull in convective activity overnight into Friday
morning due to loss of daytime heating and subsidence ahead of
harvey, we have maintained 20-30 pops over the region due to the weak
frontal zone over the region.

The mid-to-upper level ridge that will be further weakening and
lifting northwest into the desert southwest today will allow harvey
to track north-northwest into a weakness towards the middle texas
gulf coast for Friday. Hi-res models are suggesting that the weak
subsidence and high clouds ahead of harvey will limit convective
coverage for most of the region into Friday afternoon, but we still
have 30-40 pops over most of the region due to weak frontal forcing.

The outer rainbands of harvey should begin to move into karnes,
dewitt, and lavaca counties by the afternoon hours, so we have 50-60
pops with the mention of locally heavy rainfall in the grids for
those areas. Therefore, we are issuing a flash flood watch beginning
at 1 pm on Friday to account for the possibility of flash flooding in
these counties as early as Friday afternoon, with flooding possible
in counties further north and west as early as Friday evening. The
current watch area includes atascosa, bexar, comal, caldwell, and
fayette counties and all counties south and east of those in the
coastal plains. However, we stress that any northward or westward
track of harvey and where it will eventually slow and stall would
result in a northward and or westward expansion of the watch area.

Long term (Friday night through Wednesday)
Although the forecast track for harvey remains relatively uncertain,
the one area where we have high confidence in the forecast is that
harvey will slow down once it makes landfall late Friday night or
early Saturday morning. As has been discussed previously, the main
reasoning for this is that the steering currents will collapse as
south and south central texas remain in a "col" region between a
blocking subtropical high over the four corners region and another
ridge over the eastern gulf without a trough capable of ingesting
harvey into the westerlies. Thus, the current NHC track has harvey
making landfall near corpus christi before stalling in the vicinity
of bee county just south of our CWA on Sunday into Monday and sliding
back south towards corpus christi on Monday into Tuesday. This
generally reflects the ensemble consensus which has some tracks that
recurve harvey to both the west and east, but generally has the bulk
of them stalling it over south and south central texas. Therefore,
several days of heavy rainfall will be possible, particularly over
our southern and southeastern counties where the flash flood watch is
in place and 8-15 inches of rainfall with isolated totals up to 20
inches are expected. Although this watch currently expires on Sunday
morning at 7 am, it will most likely have to be extended in time with
the area refined once we have stronger confidence in where harvey
will stall and where the biggest problem spots are at based on the
rainfall that falls through the first half of the weekend.

Global models are still predicting that a trough will dig south from
ontario into the ohio river valley on Monday into Tuesday. This
should eventually bring about the extratropical transition of harvey
and recurvature of the system into the westerlies on Tuesday into
Wednesday ending rain chances over the region. However, this trough
is a bit delayed and further east than previous model runs, resulting
in some models taking harvey west towards the rio grande into the
middle of next week. We will stick with the model consensus for now
and remain optimistic that harvey will become ingested into the
westerlies by the middle of next week.

Preliminary point temps pops
Austin camp mabry 95 75 94 74 85 40 30 30 50 80
austin bergstrom intl airport 95 75 94 74 84 40 30 30 50 80
new braunfels muni airport 95 74 93 73 85 40 30 30 60 80
burnet muni airport 89 71 89 69 83 50 30 30 30 60
del rio intl airport 98 75 96 74 93 30 20 30 40 30
georgetown muni airport 91 72 91 71 83 40 30 30 40 70
hondo muni airport 96 73 95 72 89 30 20 30 40 60
san marcos muni airport 96 74 94 73 84 40 30 30 60 80
la grange - fayette regional 96 75 93 74 85 40 30 50 80 90
san antonio intl airport 94 75 92 74 86 40 20 30 50 70
stinson muni airport 94 75 92 74 85 30 20 30 60 70

Ewx watches warnings advisories
Tropical storm watch for the following counties: de witt...

fayette... Gonzales... Karnes... Lavaca... Wilson.

Mesoscale aviation... Lh
synoptic grids... Hampshire
dss... Tb3


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Antonio, San Antonio International Airport, TX4 mi45 minN 410.00 miMostly Cloudy78°F70°F76%1010.9 hPa
Kelly Air Force Base, TX9 mi98 minN 010.00 miOvercast76°F71°F84%1011.3 hPa
San Antonio, Stinson Municipal Airport, TX13 mi43 minN 310.00 miMostly Cloudy80°F72°F76%1010.4 hPa
Randolph Air Force Base, TX13 mi1.7 hrsNW 310.00 miOvercast75°F75°F99%1011.9 hPa
San Antonio Boerne Stage Field, TX17 mi61 minN 010.00 miPartly Cloudy72°F68°F88%1014.2 hPa
Castroville Municipal Airport, TX21 mi61 minN 010.00 miFair76°F68°F76%1013.5 hPa

Wind History from SAT (wind in knots)
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Last 24hrCalmCalmCalmSW54NW3SE53E9E9E93NW13N11N10N8N7E15
G19
E10E6SE4CalmE3N4
1 day agoS5W4SW5SW7W7SW666SE7SE93E6E6CalmSE7SE16
G23
SE9
G18
SE9S10SE5S4S6S4W4
2 days agoCalmCalmCalmSW6S8S8S4SE7SE7CalmS5SE9SE5SE8SE12SE10SE11SE16SE13S13SE10S5S5S5

Tide / Current Tables for
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Tide / Current Tables for
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Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of SouthCentralPlains    EDIT
Geos

Wind Forecast for Austin/San Antonio, TX (6,6,7,8)
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Ground Weather Radar Station Austin/San Antonio, TX
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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.