Tuesday, November20, 2018 L-36.com


Marine Weather and Tides
Rustburg, VA

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 7:00AMSunset 5:04PM Tuesday November 20, 2018 6:10 AM EST (11:10 UTC) Moonrise 3:52PMMoonset 3:58AM Illumination 93% Phase: Waxing Gibbous; Moon at 12 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 Rustburg, VA
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location: 37.18, -79.05     debug


Area Discussion for - Blacksburg, VA
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Fxus61 krnk 201045
afdrnk
area forecast discussion
national weather service blacksburg va
545 am est Tue nov 20 2018

Synopsis
A cold front will move east across the region this morning, giving
way to variable cloudiness with scattered mountain rain and snow
showers. High pressure then settles across the region tonight
lasting through the thanksgiving holiday, with cooler than
normal temperatures and dry conditions.

Near term through tonight
As of 354 am est Tuesday...

surface cold front continues to progress eastward as of this writing
early this morning, which metars indicate the related frontal
windshift is now entering the i-81 corridor area. Overall little
fanfare with its passage on precipitation chances as it moves into
the blue ridge and points east. A considerable amount of cloud cover
exists across the ohio valley and midwest, and post-frontal
northwest flow will lead to a longer period of upslope clouds and
intervals of mountain rain and snow showers from NW greenbrier mtns
southward into the mountains of northwest nc. Great lakes moisture
advection in northwest flow doesn't really shut off until late
afternoon as the mid-level trough seen in water vapor imagery over
central mo moves into the mid-atlantic region. So by late afternoon
into early evening, we should see precipitation begin to dry up from
south to north along the appalachian divide. Forecast soundings
today show rather steep low-level lapse rates but an unsaturated
dendrite snow growth layer should lead to intervals of generally low-
slr wet shsn in the mountains in NW nc and NW WV above 3000'. Shown
snow accumulations of a dusting to a little more than an inch at
these elevations. From the nrv eastward into the foothills and
piedmont, the only real noticeable effect the front will have on
sensible wx is an increase in northwest winds toward midday, which
may gust up to 30 mph at roanoke. Overall a variably cloudy day with
fairly good chances at precip in the far west, with clear skies and
more Sun the further south and east one goes. Highs for the day
already occurred overnight in far southwest va, NW nc mountains,
part of the nrv and southeast WV which were around 50, but daytime
highs in these areas only in the 40s (mid upper 30s above 3000').

Should see highs in the 50s in the piedmont foothills today.

For tonight, high pressure is expected to ridge eastward from the
mid-mississippi valley into the va nc border for the overnight. Dry
advection should help partially disperse some of the western mtn
stratus stratocu. While some clouds will likely linger into the
overnight in southeast wv, most elsewhere will turn clear with winds
slackening. Good radiational cooling should help plummet
temperatures quickly after sunset to lows in the 20s from the blue
ridge and west. Not out of the question the piedmont and foothills
fall below freezing, but i've kept low temperatures in the low 30s
given some question on how quickly northwest winds can trend calm.

Forecast confidence is overall moderate to high, with some question
on how quickly clouds clear in the west and how fast winds die off
to calm tonight in the piedmont.

Short term Wednesday through Friday night
As of 415 am est Tuesday...

dry... Seasonably cool conditions... Leading to good travel
conditions through the period.

A large surface high pressure area will build into the region
from the great lakes Wed into thu, then shift toward the
northern mid-atlantic region by Friday. Aloft, a vigorous upper
trough will lift out of the northeastern u.S. Thanksgiving day and
be replaced by a progressive upper ridge. Dry, yet unseasonably
cool conditions, will dominate the wed-fri thanksgiving holiday
period as northwest flow aloft prevails. Our region will only
receiving a glancing blow of the bitterly cold air that will
sweep across the northeastern u.S. New england in particular
where 850mb temperatures will plummet into the -24c range. For
our region, 850mb temperatures are destined to drop into the -8c
to -10c range, which is not atypically cold at all for late
november. Lows will mostly be in the 20s west to the 30s east
wed dropping into the 20s with a few teens at locations such as
burkes garden and lewisburg Fri morning, which will be the
coldest. Afternoon highs will average about 10 degrees below
normal in the upper 30s to mid 40s.

A weak shortwave along the new jersey coast Tuesday evening
will slide east into the atlantic ocean. A few snow flurries may
linger in the western mountains early. High pressure in the
central u.S. Will build eastward Tuesday night. Low temperatures
Tuesday night will range from the lower 20s in the northwest
mountains to the lower 30s in the piedmont. High pressure will
build east across the tennessee valley Wednesday. High
temperatures on Wednesday will warm into the mid 30s in the
northwest to the lower 50s in the piedmont. A very weak trough
passing to our north might bring snow flurries to the far
northwestern parts of the forecast area Wednesday night or early
Thursday. Low temperatures will range from the mid 20s in
northwest greenbrier county in west virginia to the lower 30s in
the piedmont. A large canadian high will build southeast into
the area on thanksgiving day into Friday. High temperatures
Thursday will be 5 to 10 degrees below normal with readings from
the mid 30s in the west to around 50 degrees along the eastern
slopes of the blue ridge mountains. Thursday night will be cold
with readings generally in the lower and mid 20s. Travel
conditions should be good these parts for the Wednesday through
Friday period.

Clouds will be to increase late in the day Friday, but
precipitation with the next upstream system is expected to hold
off until Friday night or more likely Saturday morning.

Confidence levels in forecast values
moderate to high confidence in forecast temperatures (below
normal),
high confidence in low probabilities of precipitation (mostly
dry through the period)
moderate confidence in projected wind speeds and directions.

Long term Saturday through Monday
As of 430 am est Tuesday...

weather conditions are expected to deteriorate significantly over
the weekend, as low pressure organizes in the northeastern gulf of
mexico and lifts northeastward along the coast and a vigorous
southern stream upper trough moves northeast from the southern
plains. However, the synoptic details among the various models
remain highly discrepant yet today with a variety of solutions
involving potential for winter weather, heavy rainfall, and even
strong to severe thunderstorms early next week.

High pressure will slide east into the western atlantic Friday
into Friday night. Then, a strong negatively tilted trough is
progged to rotate through the region Saturday into Sunday. The
ecmwf remains the weakest with the upper trough and the canadian
remains the strongest. The main problems to consider with this
weather system will be the potential for winter precipitation,
mostly likely in the form of freezing rain or sleet early
Saturday as the precipitation moves over the top of the residual
cold dry air mass yet in place from thu-fri. The second concern
will be the potential for heavy rainfall later in the day
Saturday into early Sunday, with already saturated ground and
low FFG values from our extraordinarily wet fall summer.

With strong canadian high pressure to the northeast Saturday, a
significant cold air wedge should be in place as the upper
trough rotates toward the area. Today the models overall and
especially the MOS guidance have trended a bit colder and dry
for antecedent conditions prior to the arrival of precipitation
early Saturday. This could easily set the stage for a notable
period of freezing rain and or sleet, less likely snow.

Depending on how long the shallow cold air mass lingers and the
precipitation falling into the air mass enhance the wedge, will
determine how along the winter precipitation would last. Still,
there is not 100% confidence by any means that the air
mass ground will be cold enough to support winter precipitation
with gridded model data suggesting temperatures may only be in
the mid 30 to near 40 early Saturday. I am leaning toward the
colder numbers provided by ECMWF and GFS mos given the strength
of the cold air mass to our northeast and that being the source
of the high pressure area supporting the wedge. A situation
similar to last Thursday is still not out of the question and
this event will need to be carefully analyzed in the remaining
days forecasts. The good news is that the worst part of this
weather system and the most likely time frame for winter
precipitation problems will be Saturday morning, typically well
before the big Sunday after thanksgiving travel rush. Stay
tuned!
after a cold Saturday and the potential for temperatures to
hover only near or a few degrees above freezing all day,
temperatures will trend toward above normal levels by Sunday
after the wedge breaks and southwest flow evolves behind the
retreating wedge.

Looking ahead to early next week, another very strong negatively
tilted trough embedded within the southern stream is forecast to
eject across our area mon-tue. Unlike the weekend system,
surface temperatures and dewpoints will be more springlike with
this system and the strong shear and marginal instability
advertised by several models suggests that this could bring a
line of showers and thunderstorms with gusty winds, perhaps a
qlcs with its passage. The potential for such will be analyzed
as well during the coming days. Needless to say, an active
weather pattern is expected much of next week.

Confidence levels in forecast values
-moderate confidence in forecast temperatures (below normal
beginning of the period to above normal by the end),
-high confidence in moderate to high probabilities of
precipitation (pops 50-100% Saturday),
-low confidence in precipitation type Friday night Saturday
morning (i.E., rain vs. Sleet, freezing rain, or snow)
-moderate confidence in wind speeds and directions.

Aviation 12z Tuesday through Saturday
As of 544 am est Tuesday...

generallyVFR conditions across the piedmont and into roanoke
through the entire 12z TAF valid period, but looking at a
period of sub-VFR ceilings at bluefield, blacksburg and
lewisburg. Lowest ceilings likely at bluefield (mainly ifr, lifr
at times) through the day, but will begin to trend more MVFR by
evening with a lift toVFR late in the 12z TAF period. MVFR
ceilings for blacksburg and lewisburg, and these will lift
sooner, likely by mid-morning at blacksburg and by afternoon at
lewisburg.

Will see periods of scattered upslope showers at bluefield and
lewisburg post cold frontal. Rain may mix with snow showers at
bluefield but unlikely to produce visibility restrictions worse
thanVFR. Precip ends around 18z.

Passage of a cold front early in the 12z TAF valid period will
shift winds to the northwest, with 15-25 kt gusts by afternoon
at most of the tafs except lynchburg. Sustained winds generally
8-15 kts, but will trend lower into the evening as high pressure
builds in.

Forecast confidence is high.

Extended discussion...

vfr then continues through Wednesday, though weak upslope
increase in clouds may introduce some MVFR ceilings at bluefield
and in the mountains of eastern WV for thanksgiving.

Strong wedge of high pressure sets up at the end of the week and
southeast to east flow may allow for some lower CIGS to set up
along and east of the appalachians, increasing threat of precip
sat and sub-vfr conditions.

Rnk watches warnings advisories
Va... None.

Nc... None.

Wv... None.

Synopsis... Al
near term... Al
short term... Rab
long term... Kk rab
aviation... Al


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Lynchburg, Lynchburg Regional Airport, VA14 mi16 minVar 410.00 miMostly Cloudy50°F44°F80%1013.2 hPa

Wind History from LYH (wind in knots)
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Last 24hrS4CalmCalmS45S8SW6SW10S9SW5S4CalmCalmCalmS3CalmS3CalmCalmS4S5CalmCalm4
1 day agoNE3N33CalmS3S5S6SE5S5SE5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm
2 days agoCalmCalmN6NE84Calm3SE4CalmS4CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm

Tide / Current Tables for Falling Creek entrance, James River, Virginia
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Falling Creek entrance
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Tue -- 01:22 AM EST     3.13 feet High Tide
Tue -- 03:51 AM EST     Moonset
Tue -- 06:54 AM EST     Sunrise
Tue -- 08:05 AM EST     0.04 feet Low Tide
Tue -- 01:40 PM EST     3.43 feet High Tide
Tue -- 03:44 PM EST     Moonrise
Tue -- 04:55 PM EST     Sunset
Tue -- 08:52 PM EST     0.09 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.83.13.12.61.91.20.60.200.20.922.93.33.43.12.51.81.10.60.20.10.41.3

Tide / Current Tables for Petersburg, Appomattox River, James River, Virginia
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Petersburg
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Tue -- 01:18 AM EST     2.84 feet High Tide
Tue -- 03:51 AM EST     Moonset
Tue -- 06:53 AM EST     Sunrise
Tue -- 08:13 AM EST     0.03 feet Low Tide
Tue -- 01:36 PM EST     3.11 feet High Tide
Tue -- 03:44 PM EST     Moonrise
Tue -- 04:56 PM EST     Sunset
Tue -- 09:00 PM EST     0.08 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.52.82.82.41.81.10.60.200.20.81.82.633.12.82.21.610.50.20.10.31.1

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Wind Forecast for Blacksburg, VA (6,6,7,8)
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Ground Weather Radar Station Blacksburg, VA
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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.