Saturday, August17, 2019

Marine Weather and Tides
Isle of Palms, SC

Version 3.4
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
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Sunrise 6:42AMSunset 8:04PM Saturday August 17, 2019 9:48 AM EDT (13:48 UTC) Moonrise 8:24PMMoonset 7:20AM Illumination 96% Phase: Waning Gibbous; Moon at 17 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 171150
area forecast discussion
national weather service charleston sc
750 am edt Sat aug 17 2019

A weak low pressure system will track northeast along the
georgia and south carolina coast today. A stationary front will
linger nearby through Sunday. Atlantic high pressure and an
inland trough will then prevail through much of the week.

Near term through tonight
As of 740 am: kclx clearly indicated a mesolow just off of
hilton head island, tracking north. Convection associated with
the mesolow has strengthen sharply over the past hour, cloud top
temperatures cooling to -72c. Based on satellite and radar
trends, this feature should track over fripp island and moving
onshore near edisto island by 9 am. Pops will increase through
this morning and afternoon, reaching cate values.

As of 410 am: IR satellite indicated a disorganized area of
convection over northern fl, regional radar appeared to show
slight cyclonic circulation. Water vapor products show a band
of tropical moisture extending from the gulf of mexico NE along
and east of the of the ga and carolina coast. SPC mesoscale
analysis indicated SBCAPE over the coastal counties and adjacent
waters between 2500-3000 j kg. Showers and thunderstorms
sourced over the marine zones should continue to track over the
coastal areas early this morning. After sunrise, convection
should readily develop over the coastal counties with a lfc
around 2 kft. Convection should increase inland by early this
afternoon as temps peak in the low 90s with dewpoints in the mid
70s. Near term guidance generally agrees that a weak low
pressure system will track northeast across the coastal plain of
ga and sc, passing during peak heating. The environment this
afternoon will feature moderate instability, pw between 2.3-2.5
inches, and weak shear. As the low approaches from the sw,
coverage of thunderstorms should steadily increase, primarily
over the sc lowcountry. These storms should produce periods of
torrential downpours, in fact, GFS forecast soundings indicate
k-index around 40 at kchs this afternoon. Given the possibility
of cell mergers and or back building, I will add a mention of
heavy rain along the coastal counties of sc today. Href
highlights the chs tri-county with a 40 percent chance of 3 hr
of 3 inch rainfall at any given point within a 40 km radius at
21z. This placement and timing of the href agrees well with the
latest run of the hrrr. I will mention the potential for heavy
rain the hwo for the sc coast for today. Fortunately, it appears
that the period of greatest rainfall potential will overlap
with low tide during the mid to late afternoon.

This evening and tonight, the weak low pressure is forecast to
lift north of the forecast area. As the low departs, drier air
should arrive from the west, shifting the deep convection
gradually east. However, given weak flow across the area, I will
keep schc to chc pops through the overnight hours. Low
temperatures are forecast to range from the low 70s inland to
the mid to upper 70s near the beaches.

Short term Sunday through Tuesday
Moderate confidence this period. A stalled front inland will
eventually dissipate late in the period while weak upper troughing
lingers across the area. We maintained above normal rain chances,
especially Saturday. With pwats around 2.0 inches most of the time
and forcing from some upper level energy and mesoscale boundaries
like the sea breeze, we think rain chances will generally be higher
than normal, mainly during the afternoon evening. Given the deep
moisture and light low-mid level winds there will be at least a
small risk of localized heavy rain flooding but not expecting
anything much more significant than the norm. Also can't completely
rule out isolated severe storms each day but conditions aren't that
favorable for much severe weather. Temperatures should be near to
above normal.

Long term Tuesday night through Friday
Moderate confidence this period. High pressure will linger to the
east with low pressure inland. We generally expect a fairly typical
summertime pattern with mainly afternoon evening scattered showers
and thunderstorms, although the some showers and storms could
persist overnight depending on the placement strength of the upper
level low. An approaching cold front late in the week could lead to
better rain chances but confidence is low in any significant impacts
at this point. Temperatures should remain near or above normal.

Aviation 12z Saturday through Wednesday
Deep moisture will remain across the terminals through the 12z
taf period. A weak low pressure system is forecast to track ne
along the coast through the daylight hours today. Early this
morning, MOS and forecast soundings indicate that restrictive
ceilings will remain across the ksav until mid-morning.

Convection should readily develop today ahead of the approaching
low pressure, with the greatest coverage near kchs. I will
highlight the convection with fm groups and tempos. By this
evening, the low is expected to track NE of the forecast area,
convection should decrease through this evening.

Extended aviation outlook: periodic restrictions from mainly
afternoon evening showers and thunderstorms expected at
kchs ksav through mid week.

The pressure gradient across the marine zones will tighten today
as weak low pressure track NE over the coastal plain of ga and
sc. As a result, SW winds will increase during the daylight
hours, with gusts around 25 kts across the charleston co.

Nearshore waters and the outer ga waters. Wave heights are
forecast to build to 3-5 ft, with 6 ft expected 50 nm and
beyond. A small craft advisory is in effect until 9 pm for
amz350 and amz374. Thunderstorms will remain common across the
marine zones today into late tonight, greatest coverage across
the nearshore sc waters. Wind and wave conditions will improve
slightly tonight as the weak low lifts north of the region.

Sunday through Thursday: atlantic high pressure and an inland
trough will result in mainly south southwest winds through the
period. No significant marine impacts are expected other than some
stronger storms from time to time.

Chs watches warnings advisories
Ga... None.

Sc... None.

Marine... Small craft advisory until 9 pm edt this evening for amz350-

Near term... Ned
short term... Rjb
long term... Rjb
aviation... Ned rjb
marine... Ned rjb

Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Charleston Executive Airport, SC171 mi94 minS 89.00 miPartly Cloudy82°F77°F84%1014.9 hPa

Link to 5 minute data for KJZI

Wind History from JZI (wind in knots)
Last 24hrS7S7
1 day agoSW7SW44S9S10
2 days agoSW7S6S5S9S13S14NE6W10CalmSW5SW5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS4SW3

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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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 Charleston, SC (9,2,3,4)
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Ground Weather Radar Station Wilmington, NC
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