Tuesday, May23, 2017 L-36.com


Marine Weather and Tides
Isle of Palms, SC

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 6:13AMSunset 8:18PM Tuesday May 23, 2017 1:02 AM EDT (05:02 UTC) Moonrise 3:40AMMoonset 4:45PM Illumination 7% Phase: Waning Crescent; Moon at 27 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 Isle of Palms, SC
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location: 30.97, -77.7     debug


Area Discussion for - Charleston, SC
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Fxus62 kchs 230446
afdchs
area forecast discussion
national weather service charleston sc
1246 am edt Tue may 23 2017

Synopsis
A series of disturbances will track across the southeast through
midweek. A cold front will push offshore Wednesday night into
Thursday. High pressure will then prevail this weekend.

Near term /until 6 am this morning/
A well defined convectively induced mesoscale circulation can be
seen on kclx reflectivity data across northern effingham county,
ga at 23/04z. This feature will continue to move northeast and
help concentrate convection along the lower south carolina coast
for the next few hours. Increased pops to 100% ahead of the
circulation and nudged QPF values up to an inch for many areas.

Minor flooding of mainly low-lying and poor drainage areas will
be possible, but the heaviest rains are poised to fall around
low tide.

Short term /6 am this morning through Thursday/
On Tuesday, a cold front is expected to run across the piedmont
of the carolinas and ga. Short range guidance indicates that a
front wave will develop along the cold front across ga or sc.

The front wave is forecast to track NE along the front during
the daylight hours on Tuesday. Model forecast soundings suggest
that LFC levels will remain below 2 kft with pw values around
1.9 inches. In addition, a wide field of 1500-2000 j/kg cape
will develop along and east of the front/wave. Convection should
easily form near the frontal wave, supporting categorical pops
for showers and thunderstorms. Shear between 0-6 km will likely
range around 40 kts, yielding loosely organized clusters or
bands of thunderstorms. It is possible to see a few damaging
wind events with the stronger storms. Perhaps more likely,
rainfall rates may become quite heavy during the passage of
thunderstorm clusters, see tide section below. High temperatures
should verify within a degree or two of 80 degrees on Tuesday.

Based on the timing of the frontal wave, coverage of deep
convection should shift NE during the evening hours. It appears
that a noteworthy decrease in coverage of showers and
thunderstorms will occur across forecast area Tuesday night,
highlight with pops decreasing to chc. Lows Tuesday night are
forecast to range in the upper 60s to low 70s.

Wednesday, deep sfc low pressure should organize across the ohio
river valley. Short range guidance indicates that a cold front
will approach from the west during the daylight hours. At the
mid level, h5 trough will swing across the deep south during the
afternoon, gfs1deg shows a wide field of h5 q-vector convergence
will spread west to east across the cwa. The environment ahead
of the cold front is forecast to see CAPE values pool to 1500
j/kg with sweat peaking near 400. I would expect that a band of
deep convection will form along and ahead of the cold front.

Given the synoptic scale forcing, instability, and shear, the
severe risk could peak Wed afternoon and evening. High temps
should range very close to values expected for Tuesday. Dry air
will spread east across the region Wednesday night.

Thursday, large low pressure will circulate across the mid west
and great lakes regions as high pressure builds over the gulf
of mexico. The sfc pressure gradient is forecast to range from
2-3 mbs across the forecast area. Wsw winds should remain gusty
across forecast area, especially during the morning.

Long term /Thursday night through Monday/
A ridge building across the east coast combined with surface high
pressure will provide dry weather in the long term along with a
gradual warming trend each day.

Aviation /06z Tuesday through Saturday/
Showers/tstms will persist at kchs through about 08z, although
convection will remain in the vicinity of the terminal until
just about sunrise. At ksav, risk for tstms has ended, but light
showers will linger there through 07z or so.

Main concern for today is tstms and heavy rain impacts at the
terminals. High atmospheric moisture and passing impulses aloft
suggest showers/tstms could impact either terminal at just about
any time this morning before the risk for more concentrated
activity increases this afternoon. Window for greatest impacts
at both terminals looks to be about 22-03z at kchs and 20-02z at
ksav, give or take an hour or so. Potential for ifr conditions
at times as periods of heavier convective elements push through,
but overall suspect MVFR vsbys will be the dominate mode this
afternoon. Will carry prevailing MVFR conditions at both
terminal, but hold off on ifr tempo groups until event draws a
bit closer. Will reevaluate with the 12z TAF cycle.

Extended aviation outlook: an unsettled weather pattern will bring
periods of flight restrictions through Wednesday night.

Marine
Low-level jet strengthening overnight as shortwave energy
approaches the area. Sustained winds will increase to 15-20 kt
with some gusts approaching 25 kt over outer portions. Seas
will build to 3-4 ft within 20 nm and 4-5 ft well offshore.

Tuesday through Wednesday night: weak low pressure will track ne
along a sfc front across during the daylight hours Tuesday. SW winds
across the marine zones will increase through day. Gusts across
amz350 and 374 are forecast to exceed 25 kts by the afternoon. Wave
heights are forecast to build to 3-4 feet within 20 nm and around 5
feet across amz374. Small craft advisories may be needed for
Tuesday. In addition, rounds of thunderstorms are forecast across
the marine zones on Tuesday. Winds may decrease slight Tuesday
night, however, wave heights are forecast to gradually build through
the night.

Wednesday through Wednesday night, SW winds will increase as a cold
front approaches from the west. SCA conditions are expected. Marine
zones should see common gusts to 25 kts within 20 nm and around 30
kts beyond 20 nm. Wave heights are forecast to peak Wednesday night,
with 6 feet possible within 20 nm and up to 9 feet across eastern
amz374. Then, winds/seas should relax significantly by Friday.

Tides/coastal flooding
Evening high tide levels will trend higher each day approach
the new moon perigee this Friday. The mean lower low water
(mllw) levels are forecast to remain below flood stage. However,
it is possible that thunderstorms could pass over urban coast
areas during the evening high tide cycle. Rainfall rates could
exceed 0.75/hr during any thunderstorm. The combination of
elevated mllw water levels and heavy downpours could result in
deep street and sidewalk water.

Climate
As of 10:00 pm, 6.10 inches of rain had fallen at ksav today,
breaking the old daily record with ease. This amount is also the
most rain recorded on any day in may since climate records began
in 1871.

Chs watches/warnings/advisories
Ga... None.

Sc... None.

Marine... None.



Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Charleston Executive Airport, SC171 mi68 minN 04.00 miThunderstorm in Vicinity Rain75°F75°F100%1014.6 hPa

Wind History from JZI (wind in knots)
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Last 24hrS11S9S10S9S10SW7
G18
SW3S6SW4SW3S6S8S7S7S11S10S10S8S6S4CalmCalmCalmW5
1 day agoS6SE5S4S6S3CalmCalmS86
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2 days agoS4CalmCalmCalmCalmCalmCalmCalmS5S9S7SE7S11S9S9S12S11SE7
G13
S9S4SE4SE4SE5SE5

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 Southeast    EDIT
Geos

Wind Forecast for Charleston, SC (1,6,7,8)
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Ground Weather Radar Station Wilmington, NC
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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.