Thursday, January17, 2019

Marine Weather and Tides
Charlotte, NC

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 7:29AMSunset 5:37PM Thursday January 17, 2019 4:00 AM EST (09:00 UTC) Moonrise 2:21PMMoonset 3:39AM Illumination 86% Phase: Waxing Gibbous; Moon at 11 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 Charlotte, NC
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location: 35.21, -80.83     debug

Area Discussion for - Greenville-Spartanburg, SC
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Fxus62 kgsp 170819
area forecast discussion
national weather service greenville-spartanburg sc
319 am est Thu jan 17 2019

A weak cold front will approach today and cross the region tonight,
bringing some light rain to the area and a brief wintry mix to
portions of the mountains. A stronger and wetter system will move
in over the weekend, followed by very cold high pressure early next

Near term through Friday
As of 230 am est Thursday: shortwave ridging over the area tonight
will push east this morning, giving way to a shortwave trough
(currently over the lower mo valley). Meanwhile surface high
pressure over extreme southern ontario will slide east toward the
canada us new england border and will try to briefly ridge down
eastern slopes of the appalachians. Not really a true damming event,
but will force some colder air into the region, holding temperatures
quite a bit cooler than those yesterday. Meanwhile, moisture
associated with the shortwave will begin streaming in later this
morning, with the deeper moisture arriving in the mountains just
after daybreak. Pops will increase quickly along the tn line. The
initial surge of moisture will weaken as it crosses the mountains,
bringing lighter precip to the piedmont, as additional moisture gets
hung up in the mountains as is typical.

Despite the high clouds streaming across the area, lows this morning
in the mountains will be below freezing, with even some mid 20s in
the northern mountains. As moisture increases, temperatures will be
slow to rise, and with lack of ice nuclei (at first) could see onset
of precip as a little light freezing rain drizzle until the column
saturates. Deep near-freezing isothermal layer could lead to some
brief snow or sleet before the warm nose builds in this evening,
with a mixture of sleet or freezing rain (nam has a little bit more
of a warm nose, but seems to be enough agreement that going with a
blend looks good). Non-diurnal temperature trend should actually see
temperatures this evening bottom out around 00z (give or take an
hour or two), with a very slow but steady rise thereafter overnight;
expect that the highest elevations will rise above above freezing
not long after midnight, with all liquid after that. Very little if
any accumulation is expected, though some of the more aggressive
guidance brings a quick couple of inches of snow to the highest
elevations. A trace of freezing rain on elevated surfaces mainly in
avery county is possible, but not expected to be widespread even
there. With that, will mention in hwo and issue an sps to discuss
the light accums, but no need for a winter weather advisory at this

The shortwave axis will traverse the area overnight as the
progressive pattern remains in place, with near-zonal flow (weak
ridging) on Friday. Lingering NW flow moisture should dry up not
long after sunrise Friday, with everyone seeing at least some
sunshine by the afternoon. Highs on Friday should rise a good 5-8
degrees above normal with nearly full Sun and the slow increase in
thicknesses, as well as low-level WAA with surface flow having
flipped back around to SW tonight. Moisture will begin picking up
again from the south and west late in the period ahead of the next
system to affect us in the short term.

Short term Friday night through Sunday night
As of 300 am Thursday: the next system will already be knocking on
the door of the fa Friday night, as a deep trough digs across the
southern plains. Deep-layer isent lift will spread across the
southeast states ahead of a deepening sfc low over ok, while high
pressure retreats to the ne. It will take a little time for the
low-levels to moisten up, but shallow light rain showers are
expected to break out by daybreak in the SW mountains, aided by
mechanical lift in the increasing swly flow. Fortunately, thermal
profiles support the precip type to be all rain even at onset early
Saturday. Low overcast and increasing showers should be on tap thru
the day on Saturday across the entire fa with temps slightly above

The strongest forcing and heaviest rain is still expected to be
Saturday night, as the sfc low crosses the central appalachians and
drags a strong cold front across the fa. Guidance is showing a
little more SBCAPE just ahead of the front, but still only a few
hundred j kg at most across the extreme southern tier of the fa.

Will continue to mention slight chc of thunder, but the severe
threat continues to be very low. Temps will remain well above normal
overnight under the clouds heavy precip. QPF amounts still look to
be in the 1-3" range (locally higher in SW flow upslope areas).

Sunday into Sunday night will definitely be the trickiest part of
the forecast. A very tight temp gradient behind the cold front is
depicted in all the guidance. Once the low-level flow toggles from
sw to nw, CAA should cause temps to drop sharply in the nc
mountains. The 00z guidance has trended a little slower with this
timing, and not surprisingly, this results in most of the moisture
pulling out before thicknesses fall to support snow. There will still
be a period of moist N NW flow that should produce some accums. The
highest peaks could still see several inches of snow, if snow levels
can fall before the main precip band exits early Sunday morning. The
bigger concern will probably be a flash freeze of the roads, as rain
ends Sunday morning, and temps are forecast to fall below freezing
across most of the tn border counties by noon, and even further
south and east by mid-aftn. Winds will also pick up, and could
briefly approach wind advisory criteria during the aftn and evening
hours. I tried to go with model blend hourly temp grids Saturday
night thru Sunday evening, and derived the min and MAX temp from
that. Winds should start to diminish a little overnight, but with
temps expected to fall into the single digits and teens in the high
elevations, wind chills may fall into the -5 to -15 f range by
daybreak Monday. A wind chill advisory will likely be needed for the
northern mountains for late Sunday night thru Monday morning. The
rest of the area should see precip taper off by midday and feel the
chill starting in the late aftn. Lows may be in the upper teens to
mid 20s across the piedmont, with wind chill making it feel even colder.

Long term Monday through Wednesday
As of 315 am Thursday: a fast, progressive upper pattern will
continue thru the extended forecast, with an upper ridge quickly
building back in behind the sharp trough on Tuesday. Fortunately,
this should keep the unseasonably cold temps short-lived and avoid a
full blown cold wave for the region. Monday's temps look to be about
10-15 deg below normal, with Monday night another chilly one, but
fortunately, with less wind. Tuesday's temps rebound slightly to
just 8-10 deg below normal.

The 00z operational models are in much better agreement on the next
low pressure system, but differences in timing remain. The upper
trough is progged to phase into another full-latitude trough as it
digs across the plains late Tuesday. The associated low pressure
system is expected to develop over the central plains and have a
little bit more northerly track than the previous storm. This should
once again place the fa in the warm sector and result in precip
being all rain for the most part. The GFS is still a little faster
than the overall consensus, while the 00z ECMWF lines up well with
the wpc preference. So will have pops start to ramp up Tuesday
night, peaking on Wednesday in the high-end chc to likely range.

With the precip onset overnight, temps may support some wintry mix
in the high terrain early. But confidence in this is still low that
far out. Temps should be back to slightly above normal by Wednesday.

Aviation 08z Thursday through Monday
At kclt and elsewhere:VFR to start the period with areas of cirrus
passing by overhead. Mountain valley low clouds are pretty close to
the kavl and will continue mention of possible MVFR there for a
couple of hours in a tempo. Moisture will increase from the west and
slowly lower through the day, but remainVFR until this afternoon
when a decline to solid MVFR can be expected as -ra moves in. Best
chances of -ra remain at kavl but all sites continue with prob30 and
will reevaluate with morning package. Some disagreement in guidance
as to how low CIGS will go, but went mostly with low MVFR and
mention of ifr in prob30, though expect that kavl (with the better
moisture) will see ifr by the end of the period. For the extra 6
hours at kclt guidance varies fromVFR to ifr so again kept MVFR
prevailing. Winds N of E at TAF time but should shift SE by midday,
veering to SW overnight.

Outlook: unsettled weather will continue Thursday night, with
brief improvements on Friday before yet another system pushes in
for the weekend with associated precipitation and restrictions.

Confidence table...

08-14z 14-20z 20-02z 02-06z
kclt high 100% high 100% high 100% med 77%
kgsp high 100% high 100% high 100% med 75%
kavl high 98% high 100% med 71% high 96%
khky high 100% high 100% med 75% high 83%
kgmu high 100% high 100% high 100% med 66%
kand high 100% high 100% high 98% high 81%
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
WATS1 - Lake Wateree, SC 61 mi30 min Calm G 4.1 34°F
LMFS1 - Lake Murray SC 80 mi40 min Calm G 1 39°F 1023.4 hPa

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Charlotte, Charlotte / Douglas International Airport, NC6 mi68 minENE 710.00 miA Few Clouds37°F30°F79%1025.2 hPa
Gastonia Municipal Airport, NC17 mi66 minNNE 410.00 miFair37°F28°F73%1025 hPa
Monroe, Monroe Airport, NC17 mi67 minE 410.00 miFair36°F28°F76%1026.4 hPa
Rock Hill, Rock Hill - York County Airport, SC20 mi66 minN 010.00 miFair32°F30°F96%1025.2 hPa

Wind History from CLT (wind in knots)
Last 24hrCalmCalmCalmSW3Calm4SW4455SW34S7S5S5S3SE6CalmNE8
1 day agoCalmCalmNW3NW3NW5NW5CalmN3N5NW4W6SW5SW4S3S4S4S5S4CalmSE3SE3CalmCalmCalm
2 days agoN5N4NE5N5N3N3NE3NE4CalmNE6NE6CalmCalmSW3CalmE4NE4SE4SE5CalmCalmCalmCalmCalm

Tide / Current Tables for
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Weather Map and Satellite Images
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GOES Local Image of Mid-Atlantic    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 (4,6,7,8)
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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 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.