Thursday, April18, 2019

Marine Weather and Tides
Rutherford College, 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 6:48AMSunset 8:03PM Thursday April 18, 2019 2:18 PM EDT (18:18 UTC) Moonrise 6:19PMMoonset 5:38AM Illumination 99% Phase: Waxing Gibbous; Moon at 14 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 Rutherford College, NC
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location: 35.75, -81.54     debug

Area Discussion for - Greenville-Spartanburg, SC
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Fxus62 kgsp 181803
area forecast discussion
national weather service greenville-spartanburg sc
203 pm edt Thu apr 18 2019

An approaching strong cold front from the west will bring the return
of showers and thunderstorms to the area beginning later today,
continuing into Friday. Strong to severe thunderstorms will be
possible on Friday. Cooler temperatures arrive behind the front for
the weekend, with lingering northwest flow moisture across the
mountains on Saturday.

Near term through tonight
As of 200 pm thu: low pressure centered near lake huron is carrying a
cold front through the ohio valley and southwest to texas attm. This
is associated with a highly amplified pattern with a virtually
full-latitude trough over the plains, and a deep ridge just off the
east coast. Moist southerly flow in our area, along with seasonably
warm moist sfc conditions, maintains a shallow CU field across
most of the cwfa. Pops will develop first along the blue ridge
but expand to more of the area as the the synoptic setup continues
to develop tonight into early Friday. Overall, this setup
continues to point to a significant high-shear low-cape qlcs
threat for a swath of the southeast. The shortwave will continue
to dig and sharpen up across the mississippi valley overnight,
with a closed upper low developing near memphis by morning, with
the whole trough shifting east thereafter. The tight gradient
ahead of it will be associated with strong 40-50 kt 850mb winds
persisting through the day, along with a strengthening jet
streak and well-defined region of upper divergence traversing
the area.

Additional details are forthcoming with the full afternoon package.

Short term Friday through Sunday
As of 325 am Thursday: everyone should know the drill by now re:
tomorrow's significant weather and especially the severe convective
potential: a full latitude upper trough developing closed upper low
impacting the southeast, with the trough axis taking on an
increasingly negative tilt as it approaches the coastal states.

Convective band ahead of strongly forced cold front will by pushing
through the CWA at the start of the period, with categorical showers
and at least scattered thunderstorm coverage overtaking the entire
forecast area by late morning. Very strong 50-60 kt low level jet
will be translating across the area by this time, with backed
surface flow anticipated in response to deepening cyclone lifting
west of the appalachians. This will contribute to 0-1 km shear of
around 40 kts. Recent cstar research has shown that this parameter
is an important discriminator between significant severe and null
severe events within low CAPE environments, with 40 kts being a
statistically significant threshold. Meanwhile, the GFS and nam
rapidly destabilize the air mass over along the i-77 corridor (to
around 1000 j kg of sbcape) from late morning into early afternoon.

It's difficult to say if this is guidance simply being too bullish
with low level moisture flux, or if these guidance sources are
actually on to something. However, another finding of recent cstar
research was that the atmosphere often destabilizes rapidly from
little-to-no CAPE to significant levels within the 0-3 hour period
prior to the arrival of forcing during significant low CAPE severe
events. Just something to mull over... SPC has pulled the enhanced
risk westward to just east of i-77, and this seems more than
reasonable based upon the latest guidance.

Otherwise, strong deep meridionally-oriented forcing should
contribute to establishment of a low-topped qlcs capable of
producing locally damaging winds and brief tornadoes within or very
close to the forecast area during by late morning, which will then
likely progress east of the area by mid-afternoon-ish. To the west
of this, another narrow band of showers may develop along the
immediate front and move across the area during mid late afternoon,
but it's not at all clear how much (if any) buoyancy will be left
in the environment by then, and none of the convection-allowing
models are particularly excited about this second round.

As the cold core upper low passes just west of the appalachians
late Friday into Saturday, and associated strong cold front blasts
through the forecast area during the late afternoon and evening,
snow level will begin falling across region, likely reaching the
high peaks and ridge tops of western nc by late Fri evening.

Deformation zone moisture wrapping around the mid-level circulation
could impact the high terrain Fri night into early Saturday, with
some very light accums possible above 4000' by sunrise, especially
across the smokies and balsams (where the cold air will arrive
first). If anything, high elevation snowfall chances increase during
Saturday, at which time forcing associated with short waves rotating
around the upper low and deformation zone moisture will be at a
nadir across the southern appalachians. Still, accums will most
likely be confined to elevations above 4000', with anything more
than a dusting limited to >5500-ish feet (1-4" is the current
forecast for these areas). Precip chances finally begin to taper off
late Saturday into early Sunday across the area. Unseasonably cool
temperatures Sunday morning could yield a concern for patchy frost
in sheltered mountain valleys, and even in portions of the

Long term Sunday night through Thursday
As of 4 am Thursday: temps rebound quickly and dry weather returns
early in the medium range, as deep trough upper low expedite off the
east coast by Monday. In fact, Sunday's maxes will be right around
normal, while maxes are expected to return to the upper 70s lower
80s across much of the area by Monday, and remain there through the
end of the period. It currently appears that the only chance for
precip during the medium range will exist toward the end of the
period, when a developing SE flow may provide enough mechanical lift
and atlantic humidity to allow for isolated convection to develop
across the high terrain Tue and Wed afternoons.

Aviation 18z Thursday through Tuesday
At kclt and elsewhere: the TAF sites are expected to seeVFR
thru the aftn evening. Strengthening southerly flow ahead of
a sharp upper trough will lead to development of MVFR cigs
overnight, dropping to ifr near daybreak at least briefly
at khky kclt. Precip chances initially will develop in this
flow along the blue ridge escarpment, mainly affecting kavl
overnight. Toward dawn, the low-level jet will amplify and precip
should expand more rapidly. Llws is likely to result at kavl, and
possibly kgsp kgmu kand, though confidence is only high enough
to include at kavl. A band of enhanced shra or tsra will enter
the area from the west with the LLJ as well, and development of
a qlcs is expected by mid-morning, which may affect all the taf
sites before it exits mid-afternoon. A short period of torrential
rainfall producing some ifr is likely with that feature; confidence
is low mainly on timing, so a fairly broad prob30 is included to
handle this possibility. Low CIGS could redevelop sometime after
the qlcs moves through, as upper low begins to drift overhead.

Outlook: improving conditions expected late Friday or early
Saturday. Spotty restrictions cannot be ruled out over the mtns
as the upper low passes by on Saturday.

Confidence table...

18-24z 00-06z 06-12z 12-18z
kclt high 100% high 94% high 95% high 95%
kgsp high 100% high 95% high 90% high 94%
kavl high 100% high 86% high 86% high 99%
khky high 100% high 94% med 70% med 71%
kgmu high 100% high 98% high 85% high 88%
kand high 100% high 100% med 72% high 98%
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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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Morganton-Lenoir Airport, NC6 mi38 minSSW 9 G 1410.00 miPartly Cloudy77°F54°F46%1016.9 hPa
Hickory, Hickory Regional Airport, NC9 mi25 minno data10.00 miMostly Cloudy74°F57°F57%1013.6 hPa

Wind History from MRN (wind in knots)
Last 24hrSE5SE6S3CalmSE3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS6SW6SW8S11
1 day agoCalmCalmSW9SW5S5CalmCalmCalmCalmCalmCalmCalmCalmN3CalmCalmCalmCalmCalmCalmCalmN4SE3S5
2 days agoW8

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 Greenville-Spartanburg, SC (14,3,4,5)
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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.