Thursday, April27, 2017 L-36.com


Marine Weather and Tides
Castle Hills, TX

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:53AMSunset 8:09PM Thursday April 27, 2017 1:45 PM CDT (18:45 UTC) Moonrise 7:05AMMoonset 8:42PM Illumination 3% 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 271743 aaa
afdewx
area forecast discussion... Updated
national weather service austin/san antonio tx
1243 pm cdt Thu apr 27 2017

Aviation
/18z tafs/
breezy and gusty conditions are in place under a southerly wind flow
through this evening.VFR flight conditions are expected to remain
across area airports through late this evening. Wind speeds are
expected to decrease a bit late this evening into Saturday morning
while low clouds develop during the same period. CIGS are expected
to lower to MVFR along the i-35 sites around midnight tonight as
humidity increases. Ifr CIGS are expected to develop few hours after
midnight along the i-35 terminals as moisture continues to increase
and push to the north from the gulf of mexico. There is a slight
chance for light drizzle across the coastal plains and parts of the
escarpment as the surface airmass nears saturation levels.VFR
conditions are expected to return to the i-35 sites by early Friday
afternoon.

Kdrt will remainVFR through late tonight with MVFR conditions
expected for several hours around sunrise times.VFR conditions are
expected to return after by 15z Saturday.

Prev discussion /issued 616 am cdt Thu apr 27 2017/
aviation discussion... For 12z TAF period...

only a few clouds seen across the region this morning keeping all
terminals atVFR. Only impacts during the day will be increasing
winds by around noon to around 15 kts with gust potential up to 25
kts. Wind gust potential should drop by around dusk but winds are
expected to stay at around 10 kts through the evening before becoming
light before dawn tomorrow morning.

MVFR CIGS are expected to return around midnight due to a return of
low level moisture at ksat/kssf and a couple hours later at
kaus/kdrt.

Prev discussion... /issued 349 am cdt Thu apr 27 2017/
short term (today through Friday)...

the main weather highlight to close out the week will be the 10-12f
degrees above normal high temperatures expected Friday that will lead
to heat indices in the upper 90s to near 100f during peak afternoon
heating. While record highs appear unlikely to be broken, some will
come close (aus/drt). Dry weather is expected through at least
Friday night.

A shortwave trough is shifting east and away of the region across
the mid-mississippi valley this morning per water vapor satellite.

This system helped usher in much drier air yesterday and has set the
stage for the cooler than normal temperatures ongoing this morning.

Lows will fall into the mid to upper 40s for the hill country with
low to mid 50s elsewhere. With only high passing clouds, the dry
airmass, and warm south winds expected to increase this afternoon,
temperatures will rebound to near normal highs in the mid 80s most
locations with a few low 90s in the rio grande plains.

Overnight into Friday, surface low pressure will strengthen across
north and west texas. Rapid moisture advection will take place with
pwats nearly doubling from noon today to early afternoon Friday.

Dewpoints will reach into the low 60s to near 70 in the coastal
plains by Friday afternoon. Luckily, a strong capping inversion will
be in place across the entire region despite the high temperatures
and moisture resulting in unrealized instability. Believe there will
be some storms over the higher mexican terrain but it should stay
confined west of the rio grande. The combination of the high heat and
humidity will result in heat indices reaching into the upper 90s to
near 100f Friday afternoon. Please stay hydrated and take frequent
breaks if planning prolonged outdoor activities.

Long term (Saturday through Wednesday)...

main hazard focus will be the increasing strong and severe
thunderstorm risk Saturday afternoon through early Sunday morning
generally along and east of a burnet to san antonio to cuero line.

Main concerns will be straight-line damaging winds and large hail as
a cold front moves through the area. Cooler and dry weather is
expected Sunday through the beginning of the week with slight rain
chances returning by mid-week as another front approaches the area.

A strong and deepening shortwave trough is forecast to develop per
many global and regional models and pivot across north-central texas
Saturday afternoon into Sunday morning. A dryline will shift west to
east through the day and act to sharpen the dewpoint gradient south
of a developing cold front in north texas. By Saturday afternoon, a
well established warm sector characterized by >3500 j/kg mlcape, near
40 kt 0-6km shear, ~30c vertical totals, and weak convective
inhibition will provide a favorable environment for strong/severe
storms. At this time, there appears to be two windows for strong and
severe storms with greater confidence placed on the second window.

The first window will be mid to late afternoon across the warm
sector but limited synoptic forcing and just enough capping could
preclude storm development during this timeframe. However, if a storm
does develop during this window, it will go severe quickly given
very steep h7-h5 lapse rates near 8c/km - favoring hail and
downburst winds. Greater confidence in deep, moist convection will be
after 7pm Saturday as the dryline merges with the southward
progressing front and storms form along this boundary. With deeper
upward forcing and height falls Saturday evening, feel this is the
most likely time of strong/sever storms to develop into a line along
the front. Favorable thermodynamics will remain in place to support
the hail and wind risk. Low-level 0-1km and 0-3km shear will be low
and does not align well with the most unstable area. Therefore, the
potential for tornadoes associated with this activity appears very
low at this time. However, the tornado threat appears to increase
into Sunday morning as the line shifts into east texas and the
coastal plains will have to be closely watched for this evolving
risk late Saturday night/early Sunday morning. While pockets of
heavy rain will be likely, the progressive nature of the front will
sweep the entire system through quickly Sunday morning. Overall
rainfall totals will be 0.5 to 1.5 with some localized 2 inch spots
east of i-35 possible if the earlier afternoon round develops.

All storm activity will push east by Sunday morning as a cool and
dry airmass shifts in. Temperatures will be well below normal Sunday
afternoon - only reaching the low 70s north to low 80s south. Fire
weather concerns may increase for western locations where wind and
low humidity combine for elevated fire weather concerns.

Monday and Tuesday will be tranquil with below normal temperatures to
start with a warming trend expected into mid-week. Both ec/gfs agree
on another cool front shifting into the region near mid-week with
low-end rain chances.

Preliminary point temps/pops
Austin camp mabry 69 93 75 88 58 / 10 10 20 40 70
austin bergstrom intl airport 69 92 76 87 58 / 10 10 20 40 80
new braunfels muni airport 69 93 75 88 58 / 10 10 20 30 70
burnet muni airport 67 91 72 84 52 / 10 10 20 40 60
del rio intl airport 68 97 71 93 55 / 0 - 10 10 10
georgetown muni airport 68 91 74 86 56 / 10 10 20 40 70
hondo muni airport 68 95 73 91 57 / - - 10 20 40
san marcos muni airport 69 92 76 88 58 / 10 10 20 30 80
la grange - fayette regional 69 93 77 86 60 / 10 10 10 40 80
san antonio intl airport 70 93 75 90 59 / 10 10 20 20 70
stinson muni airport 70 95 75 89 60 / 10 10 10 20 60

Ewx watches/warnings/advisories
None.

Mesoscale/aviation... 17
synoptic/grids... Runyen
public service/data collection... 33


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Antonio, San Antonio International Airport, TX4 mi55 minSSE 610.00 miMostly Cloudy75°F48°F40%1007.8 hPa
Kelly Air Force Base, TX9 mi48 minS 1010.00 miFair77°F46°F33%1007.9 hPa
San Antonio, Stinson Municipal Airport, TX13 mi53 minSSE 9 G 1610.00 miLight Rain78°F46°F33%1007.8 hPa
Randolph Air Force Base, TX13 mi48 minS 1010.00 miA Few Clouds76°F45°F34%1008.2 hPa
San Antonio Boerne Stage Field, TX17 mi51 minS 14 G 1810.00 miFair72°F42°F36%1009.1 hPa
Castroville Municipal Airport, TX21 mi71 minS 510.00 miFair77°F43°F30%1009.8 hPa

Wind History from SAT (wind in knots)
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Last 24hrW20
G26
NW17
G28
W21
G30
NW18
G25
NW21
G27
NW21
G27
NW12
G23
N9
G20
N15
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NE7N8NE4N8N5SW3E3NE5E5E4E6E74SE10
G15
SE8
1 day agoS11S10SE7S8S13
G17
S11
G17
S11SE15
G21
E14SE15SE12SE12SE13SE14S11SE12SE10S11SW4CalmSW5SW9NW12NW16
G22
2 days agoSE9S11--S9S14S14
G17
S9S9S9S14S14
G18
S11S12S10S9S7S6S8S12S8S10S8S9S11

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
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of SouthCentralPlains    EDIT
Geos

Wind Forecast for Austin/San Antonio, TX (14,3,4,5)
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Ground Weather Radar Station Austin/San Antonio, TX
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weather_mapweather_map weather_map

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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.