Wednesday, May22, 2019

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 6:21AMSunset 8:33PM Wednesday May 22, 2019 9:11 PM EDT (01:11 UTC) Moonrise 11:16PMMoonset 8:33AM Illumination 84% Phase: Waning Gibbous; Moon at 19 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
    EDIT      (on/off)   Help

7 Day Forecast for Marine Location Near Walhalla, SC
   Hourly   EDIT   Help
location: 34.77, -83.07     debug

Area Discussion for - Greenville-Spartanburg, SC
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus62 kgsp 222357
area forecast discussion
national weather service greenville-spartanburg sc
757 pm edt Wed may 22 2019

Broad high pressure will persist over the southeast through
the rest of the week, limiting daily shower and thunderstorm
activity and keeping temperatures well above normal. The ridge
of high pressure will strengthen over the weekend, resulting
in near-record high temperatures each day.

Near term through Thursday
As of 5:15pm edt Wednesday: current temperatures look pretty good,
despite difficulties of highly variable cloud cover, so let those
be. Most areas have seen clearing this afternoon, and temperatures
have finally warmed up to near the forecast highs around 80. Chance
for an isolated thunder storm continues through the afternoon, with
one possibly severe storm over elbert county. This storm has been
moving slowly, but has been fairly constant in strength.

Some changes will occur over the next 24 hours with our upper
ridge anticyclone getting gradually squished down by a passing
short wave. Sfc high pressure will move out of a favorable
location to maintain our weak wedge, so as the high moves off
the mid-atlantic coast we should bring the low level flow around
more southeasterly. This will act to keep a shower chance near
the escarpment probably all night long, with another cloud deck
forming by daybreak Thursday. The aforementioned short wave
will pass overhead in the afternoon and should serve to move
scattered convection out of the mtns and out over the piedmont
of the carolinas. The improving westerly flow with this feature
will eliminate much of the low cloud cover while the downslope
flow east of the mtns brings temperatures well up into the 80s.

Short term Thursday night through Saturday night
As of 215 pm edt Wednesday: the late may, likely week-long, heat
wave will get started in earnest on Friday across the southeast.

Following a shortwave moving over the southeastern ridge axis and
off the east coast on Thursday night, stronger upper ridging will
build back over the region from the west through the day on Friday.

Northwesterly downsloping flow may aid warming of the airmass east
of the mountains during daytime heating Friday, but this could also
lead to some dew point mixing and keep heat index values from
getting too oppressive. Anticipate plenty of mid 90s high
temperatures east of the mountains, but with dewpoints possibly
bottoming out in the upper 50s during peak heating. Warm mid-level
temperatures should keep any ridge top convection quite isolated.

The amplifying ridge will build overhead through Saturday as a
pacific coast trough sharpens up. Temperatures will be comparable to
Friday but perhaps with a bit less dewpoint mixing to yield more 95
to 100 heat index values southeast of i-85. Ridge top convection
should once again be limited to isolated to scattered activity,
mainly along the northern blue ridge mountains.

Long term Sunday through Wednesday
As of 220 pm edt Wednesday: the eastern ridge will flatten a bit on
Sunday as mid-level shortwaves ride east through the ohio valley,
but this appears to have very little impact on the 591+ dm 500 mb
heights likely still covering the forecast area. With strong
insolation and little to no precipitation chances given the largely
capped profiles, maximum temperatures could well reach the upper 90s
in a few spots, especially along and southeast of i-85. Still
anticipate just enough dew point mixing to keep heat index values
out of the advisory range, but a bit more 100+ values may creep into
the picture in the lower piedmont. Any forcing riding over the ridge
should confine any deep convection to mid-atlantic locations north
of the region Sunday afternoon and Sunday night.

As the shortwaves topping the ridge move off the east coast on
Monday, the eastern 500 mb ridge will become resurgent yet again.

Similar mid to upper 90s MAX temps will be observed, along with
mainly mountain, isolated, late day convection. The upper ridge will
persist over the southeast on Tuesday before migrating off the east
coast on Wednesday as the western trough is finally on the move.

Deep layer southwesterly flow will permit slightly better moisture
to return to the southern appalachians by mid week, and scattered
thunderstorms will may develop across the mountains by Wednesday
afternoon. The heat wave will continue through the period, with
maximum temperatures running some 15 degrees above climo.

Aviation 00z Thursday through Monday
At kclt and elsewhere: some isolated showers and thunder this
evening have a limited chance of reaching any individual location,
but will be more numerous west of the kclt aerodrome. Winds have
been easterly to northeasterly and are expected to become southerly
tonight and then southwesterly Thursday morning as cold-air damming
is disrupted with a warm frontal passage. Warm front also brings in
some moisture which will lead to some low ceilings in the morning
down to MVFR and possibly ifr. Models have some disagreement as to
how low CIGS will go overnight. Slight increase in moisture behind
warm front will lead to some chance for afternoon thunderstorms on
Thursday, primarily over the mountains.

Outlook: morning mountain valley fog will be possible through the
weekend. After Thursday afternoon, diurnal convective chances will
be limited due to developing upper level high pressure.

Confidence table...

00-06z 06-12z 12-18z 18-00z
kclt high 100% high 82% high 89% high 100%
kgsp high 91% high 85% high 89% high 100%
kavl high 93% high 86% high 85% high 100%
khky high 88% high 88% high 88% high 100%
kgmu high 88% high 94% high 88% high 100%
kand high 94% high 90% high 88% high 100%
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
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CHDS1 - Strom Thurmond Dam, SC 89 mi92 min N 8.9 G 13 81°F

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Clemson, Clemson-Oconee County Airport, SC12 mi18 minE 58.00 miFair75°F66°F76%1021.5 hPa
Pickens County Airport, SC20 mi17 minENE 410.00 miMostly Cloudy75°F70°F85%1022.3 hPa

Wind History from CEU (wind in knots)
Last 24hrCalmCalmCalmN3N3CalmN3N4N3E6NE7E7E6E8NE7NE9E8E6E6NE6SE55E4E5
1 day agoW7W4W3N3CalmCalmCalmCalmCalmNW3CalmN43E433Calm344W4SW3CalmCalm
2 days ago3CalmCalmCalmCalmCalmCalm3CalmCalmN43SW74556--S35SW45W5W6

Tide / Current Tables for
   EDIT   Weekend mode (on/off)   (on/off)   Help
Tide / Current Tables for
   EDIT      (on/off)   Help
Weather Map and Satellite Images
       (on/off)   HelpWeather Map
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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Greenville-Spartanburg, SC (21,6,7,8)
      (on/off)   Help

Ground Weather Radar Station Greer, SC
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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 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 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.