Tuesday, November13, 2018 L-36.com

Marine Weather and Tides
Walhalla, SC

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 7:02AMSunset 5:27PM Tuesday November 13, 2018 9:53 PM EST (02:53 UTC) Moonrise 12:12PMMoonset 10:35PM 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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7 Day Forecast for Marine Location Near Walhalla, SC
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location: 34.77, -83.07     debug

Area Discussion for - Greenville-Spartanburg, SC
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Fxus62 kgsp 140004
area forecast discussion
national weather service greenville-spartanburg sc
704 pm est Tue nov 13 2018

Low pressure moves offshore tonight as cool high pressure sets up
north of our region. Another low pressure will bring widespread rain
Wednesday night into early Thursday. Expect wintry precipitation
where temperatures reach freezing. Cool and dry high pressure moves
over our region for the weekend.

Near term through Wednesday
As of 630 pm: area radars show bands and areas of very light
rain streaming northeast across the fcst area, so a small chance
of precip will be kept in the fcst thru the rest of the evening
hours. Still thinking that a relative lull in precip will take
place overnight, as nwly downglide flow takes over under swly
flow aloft. At the sfc, a modifying arctic air mass can be seen
sprawled across great plains to northern mexico. The leading edge
of the air mass is roughly bumped up against the western slopes
of the appalachians, but will not be able to spill into piedmont
for now, thanks to orientation of the front parallel to the upper
flow. Temps will fall into the 30s, with pockets of near freezing
along the tn line overnight, where there's decent caa. Fortunately,
no measurable precip is expected to overlap the colder temps. East
of the mountains, light rain and sprinkles should taper off this
evening, but a lingering chc will be carried across the extreme
southern tier. Temps east of the mountains will bottom out in the
upper 30s to mid 40s.

Wednesday, the southern stream upper trough will close off into a
progressive low over the ARKLATEX region, drifting across arkansas.

The northern stream will feature a trough crossing the northeast
states. Confluent flow across the mid-atlantic will bring the sfc
high east across the southern great lakes, with cold air spilling
east of the mountains. Meanwhile, an inverted trough will sharpen
over the deep south, producing strong WAA and isentropic lift. This
low-level forcing will start to expand north into the forecast area
and will be coupled with upper divergence from the approaching
southern stream low. Pops ramp up from south to north during the
day. This will bring the onset of diabatically enhanced classic cold
air damming into the carolinas. Skies are not expected to clear
out, and with the precip and cad developing, temps will only warm
slightly and lock in mainly in the mid to upper 40s (upper 30s to
lower 40s mountains). The guidance is in decent agreement on a quick
0.5-1.0" of QPF during the aftn across the southern half of the cwa.

So we will hoist a flood watch that starts at noon Wednesday for all
zones except graham, swain, haywood, madison, and northern jackson,
which did not receive as much rain in the last event. Elsewhere,
with the ground already saturated, additional rain will quickly
lead to run off and rising stream levels.

Short term Wednesday night through Friday
As of 230 pm est Tuesday: a very active (and hazardous) start to the
short term period is looking more likely for Wednesday night through
Thursday morning. First, for the synoptic setup, a deep, closed 500
mb low pressure system over the ms river valley Wednesday night will
gradually migrate to the central appalachians Thursday night as it
slowly phases back into the northern stream. At the surface, an
established cold air damming wedge Wednesday evening will strengthen
further along the eastern slopes of the blue ridge through Wednesday
night. Meanwhile, an occluded, triple point type low will likely
ride up through the region early Thursday morning, before the
trailing surface front moving through the area scours the wedge from
the west through the day on Thursday. The peak period of deep
isentropic lift, strong upper jetlet divergence, and abundant
moisture will occur during the nighttime hours Wednesday night. The
numerical models are now featuring good agreement on freezing wet
bulb surface temperatures spilling southward along the blue ridge
toward the central mountains, while profiles maintain varying
degrees of warm nosing aloft. This setup looks highly favorable for
freezing rain where temps cool to 32 or less, with a decent period
of overnight sleet across the northern blue ridge and adjacent
foothills, mainly north of i-40, where the surface cold layer will
get deep. All of this could well add up to a winter storm and a
watch will be posted for the eastern side of the central and
northern mountains and the adjacent foothills.

With storm total QPF approaching 2 to 4 inches by Thursday, a flood
watch will continue despite the fact that much of the northern tier
may be more icy than rainy by daybreak Thursday. A mid-level dry
slot will wrap in from the southwest during the day on Thursday to
quickly end precipitation from the southwest. Moisture under the
trailing upper trough will cross the southern appalachians Thursday
night to generate some scattered high terrain snow showers, with
light accumulations possible along the higher ridges and near the tn

Anticipate westerly, zonal, drying flow on Friday as high pressure
starts to build back in from the west. Maximum temperatures should
rebound some 10 to 15 degrees by Friday afternoon.

Long term Friday night through Tuesday
As of 245 pm est Tuesday: upper flow will return toward
southwesterly through the weekend as heights fall once again across
the central plains. Temperatures will return to near climo values. A
clipper-type wave will then move from the northern plains across the
southern appalachians on Monday through Tuesday, accompanied by a
reinforcing cold front. However, associated moisture will be
minimal. Will feature little more than isolated to scattered
rain snow showers with the fropa.

Aviation 00z Wednesday through Sunday
At kclt and elsewhere: still dealing with widespread ifr and in
some cases lifr ceilings across most of the fcst area east of the
mtns, with some patches of MVFR andVFR scattered about. Radar
shows swaths of very light rain moving northeast and that will
continue to occasionally restrict visibility to 6sm or 5sm thru
evening operations. A light and variable wind should strengthen
from the north or northwest later this evening. Model guidance
continues to indicate that drier boundary layer air will work
its way in from the northeast overnight and observations show
the ifr cloud deck being eaten away over the NW piedmont. So,
we get some improvement to MVFR late this evening and thenVFR
before the start of operations Wednesday morning. It will be
short-lived. Moisture and light rain return from the south on
Wednesday afternoon with conditions slowly deteriorating to ifr
in the mid late afternoon. Wind will strengthen from the NE as well.

Outlook: unsettled conditions are expected to return late Wednesday
as another cad event begins. Prolonged flight restrictions will
redevelop and last into Thursday. There is a chance of icing at
kavl late Wednesday night and Thursday morning, but that should
improve by midday.VFR conditions are expected to return at the
end of the week.

Confidence table...

00-06z 06-12z 12-18z 18-00z
kclt high 90% high 98% high 87% high 84%
kgsp high 81% med 75% high 92% high 82%
kavl high 84% high 89% high 82% high 87%
khky high 88% high 100% high 100% high 89%
kgmu med 75% med 76% high 92% high 82%
kand high 81% high 87% high 80% high 84%
the percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CHDS1 - Strom Thurmond Dam, SC 89 mi73 min NNE 6 G 7 54°F

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Clemson, Clemson-Oconee County Airport, SC12 mi59 minN 04.00 miFog/Mist51°F51°F100%1020.9 hPa
Pickens County Airport, SC20 mi58 minENE 37.00 miOvercast50°F50°F100%1020.3 hPa

Wind History from CEU (wind in knots)
Last 24hrNE4NE5E4CalmCalmCalmCalmW3W3CalmCalmCalmCalmW64CalmCalmW3W3CalmW3NE4NE5Calm
1 day agoNE3N3CalmNE3NE5N5NE3NE5NE4NE4NE5E6NE7NE9
2 days agoN4NE4CalmNE4NE4N3N4NE4NE6NE5NE5NE8E7NE8E4Calm--E53CalmCalm3CalmE4

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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GOES Local Image of    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 Greenville-Spartanburg, SC (21,6,7,8)
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Ground Weather Radar Station Greer, SC
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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 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.