Monday, October23, 2017 L-36.com


Marine Weather and Tides
Hemby Bridge, NC

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 7:35AMSunset 6:38PM Monday October 23, 2017 9:30 AM EDT (13:30 UTC) Moonrise 9:58AMMoonset 8:29PM Illumination 12% Phase: Waxing Crescent; Moon at 3 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 Hemby Bridge, NC
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location: 35.11, -80.62     debug


Area Discussion for - Greenville-Spartanburg, SC
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Fxus62 kgsp 231111
afdgsp
area forecast discussion
national weather service greenville-spartanburg sc
711 am edt Mon oct 23 2017

Synopsis
A cold front will move through the area today bringing increased
chances for showers and thunderstorms, some of which could be
severe. Drier and cooler air will sweep into the region on Tuesday
leading to possible frosty conditions Wednesday and Thursday
morning. Dry conditions are expected to persist through the
remainder of the work week before another front moves in next
weekend.

Near term through tonight
As of 700 am edt: minor adjustments were needed to pop fields
for the current shower coverage, including a lower piedmont lull
over the next couple of hours. Otherwise, the forecast remains on
track as water vapor imagery shows the phasing closed low center
lifting northeast over the middle ms river valley this morning, with
the deep moisture plume ahead of the system moving rapidly eastward
across ga. Surface high pressure continues to retreat offshore, with
just a lingering nose of the ridge stubbornly holding on across the
western carolinas. Very little thermal or moisture contrast is
evident now under the surface high, so any shallow, in-situ cold air
damming should erode very quickly today and permit gusty south to
southeast winds to develop. Dewpoints have already recovered to mid
60s values across most of the southern tier, and the improving
southerly component to the flow should permit mid to upper 60s
values across most of the area east of the mountains by midday.

The primary hazard requiring our focus will be the potential for
strong to severe convection this afternoon. The convection-allowing
models feature general agreement on timing, with widespread showers
breaking out this morning in upslope flow then the main line just
ahead of the cold front arriving in our southwest zones 15z to 18z
and then blasting northeast of the area around 00z. The system will
be strongly forced - with upper jet divergence and deep layer dpva
arriving during the warmest period of the day. The low-level jet
could reach 50 to 55 kt by mid to late afternoon and surface wave
development along the frontal zone in or near the southern
appalachians might serve to keep low level flow a bit more backed.

Thus, anticipate enhanced low-level helicity along with 50 to 60 kt
of surface to 6 km bulk shear to be realized just as the main line
arrives. Despite the lack of insolation, mid-level lapse rates will
adjust up modestly under the passing trough axis this afternoon.

Sbcape remains reserved on the GFS and rap, but it might not matter
much given rich low level theta-e values and strong forcing along
with robust wind fields. The most unstable sections should be
generally along and southeast of i-85 this afternoon and then along
the i-77 corridor through the early evening hours, with some 500 to
1000 j kg of best parcel CAPE available during peak activity. The
upgrade to slight risk is warranted in piedmont sections.

The second issue posed by the southerly low level jet will be very
gusty winds over the high terrain, especially over the southern
mountains this morning early this afternoon. A wind advisory will be
posted there for some 40 to 50 mph gradient wind gusts, especially
at the higher elevations.

Finally, the rounds of upslope showers this morning will serve to
moisten the area and then rainfall rates will pick up through the
day in the better convection. Localized 4 to 5 inch rainfall amounts
look quite likely in the southern escarpment areas. Urban areas
could see street flooding as well given the expected high rates.

However, dry antecedent conditions should preclude any widespread
flooding - so no flood watches are expected at this time.

Mid-level dry slotting will wrap in quickly from the southwest
behind the main convective line and front after 21z. The entire
forecast area should be on the back side of the lifting wave by late
evening, with rapidly drying conditions overnight. Cannot rule out
some continued nocturnal showers near the tn border in westerly
upslope flow. Temps will cool back through the 40s in the mountains
and 50s east.

Short term Tuesday through Wednesday night
As of 230 am edt Monday: the short term fcst period initializes on
Tuesday morning amidst the beginnings of a pattern shift across much
of the eastern conus. As for northeast ga and the western
carolinas, the upper trof axis looks to still be just west of the
region at fcst onset, however will quickly transition east through
the period allowing low mid level flow to veer nwly. With that,
cold advection will commence into Tuesday evening allowing
temperatures to return to below normal levels through the remainder
of the period. Guidance favors some residual moisture behind the
front on Tuesday morning thereby warranting sustained pops along the
tn line where nwly upslope flow is favored. These lingering showers
will cease into the middle part of the day on Tuesday, however only
to have another round of moisture advect into the tn valley as
shortwave energy dives sharply southward out of the upper midwest.

Said moisture will once again bank against the western slopes of the
southern appalachians, lifting orographically. Guidance seems to be
trending downward with regards to QPF response Wednesday morning,
thus pops have been lowered to include only minimal slight chances
along the tn line. By that point thermal profiles will have cooled
enough to support possible wintry precip in the form of snow showers
at the highest elevations, if moisture is sufficient, with no
accumulation expected. Finally, given the aforementioned below
normal temperatures, chances for patchy widespread frost in the
sheltered mtn valleys are high with some patchy frost also possible
for outlying locales across the fthills on Wednesday morning.

Chances for a more widespread frost will be highest on Thursday
morning as temperatures bottom out and winds calm, with the first
widespread freeze possible in the mtns.

Long term Thursday through Sunday
As of 245 am edt Monday: the medium range fcst period initializes
on Thursday morning as the persistent h5 trof finally shifts east
over the western atlantic allowing for a region of upper confluence
to settle across the southern appalachians atop building surface
high pressure. The pattern remains rather progressive as said
surface high shifts northeast into Friday and another deep upper
trof digs out west as a series of h5 shortwaves deepen in both the
northern southern streams. The pattern moves further east into
Saturday as the two shortwaves phase into a full latitude trof with
a potent surface cold front beneath marching through the ms river
valley, while moist sely flow persists across northeast ga and the
western carolinas. Some model discontinuity is present with regards
to the timing of the frontal intrusion into the fcst area at this
range, however it looks to make a run at the region either Saturday
afternoon evening or Sunday, bringing along with it increased
chances for showers and perhaps thunderstorms. As for the fcst,
pops will remain below mentionable levels through Friday before
increasing slowly into through Saturday morning from the west with
widespread chance levels highlighted. These pops will remain spread
about the region through Sunday as well given timing uncertainty
with the fropa. Temperatures through the period will start off well
below normal levels then gradually warm back to near normal through
Saturday, before cooling once again behind the front.

Aviation 11z Monday through Friday
At kclt and elsewhere: shower coverage has been quite high this
morning and soupy boundary layer conditions are leading to ifr tempo
lifr ceiling conditions at many sites. Atlantic and gulf moisture
will continue to deepen ahead of the rapidly lifting wave and
associated frontal zone to the west. Thunder chances will pick up
from the southwest late this morning through the afternoon hours.

Gradient winds will increase and become gusty from the southeast
through the day, and llws conditions cannot be ruled out from kgsp
to kclt to khky this afternoon as the southerly low level jet
rapidly increases to 50 to 60 kt. Will generally time thunder from
17z to 21z over the upstate tafs and kavl, and run TS chances later
through 23z from khky to kclt. Any recovery to MVFR at times through
the day should be quite short-lived, but rapid clearing and drying
is expected with the FROPA through the evening hours.

Outlook: drier and cooler conditions will build back into the area
behind a cold front Tuesday through Thursday. Moisture will slowly
return ahead of another cold front toward next weekend.

Confidence table...

11-17z 17-23z 23-05z 05-06z
kclt med 72% high 100% med 68% high 100%
kgsp high 89% med 75% high 100% high 100%
kavl high 100% high 80% high 100% high 100%
khky med 61% med 75% med 65% high 100%
kgmu high 94% med 75% high 100% high 100%
kand high 94% low 46% high 100% 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
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WATS1 - Lake Wateree, SC 54 mi61 min SE 6 G 11 70°F
LMFS1 - Lake Murray SC 77 mi71 min ESE 7 G 12 71°F 1016.6 hPa

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Monroe, Monroe Airport, NC6 mi38 minN 09.00 miOvercast67°F66°F100%1018.5 hPa
Charlotte, Charlotte / Douglas International Airport, NC18 mi39 minSE 157.00 miLight Rain68°F68°F100%1017.1 hPa
Concord Regional Airport, NC20 mi1.7 hrsSE 52.00 miRain Fog/Mist66°F64°F94%1019.6 hPa

Wind History from EQY (wind in knots)
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Last 24hr3E444Calm54CalmCalmCalmE4CalmCalmCalm333443434Calm
1 day agoNE33CalmCalm3NE5CalmN3NE3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmNE4CalmNE4NE4
2 days agoN45NE7CalmN4N4CalmCalmN3CalmCalmCalmCalmCalmCalmCalmCalmNE3NE4CalmCalmCalmCalmNE4

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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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Mid-Atlantic    EDIT
Geos

Wind Forecast for Greenville-Spartanburg, SC (9,2,3,4)
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Ground Weather Radar Station Columbia, SC
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Disclaimer:
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.