Marine Weather and Tides
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 6:58AM||Sunset 6:07PM||Friday February 22, 2019 12:09 PM EST (17:09 UTC)||Moonrise 9:52PM||Moonset 9:09AM||Illumination 89%|
7 Day Forecast for Marine Location Near Roanoke, VAHourly EDIT Help
Area Discussion for - Blacksburg, VA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 krnk 221412|
area forecast discussion
national weather service blacksburg va
912 am est Fri feb 22 2019
A frontal system will remain nearly stationary close to the
virginia north carolina border through Saturday. A series of
lower pressure systems aloft will track along and near the
frontal boundary bring periods of mostly light to moderate
rainfall to the region through Saturday. This will continue the
threat for flooding across the region through the weekend. A
cold front will push through the region Sunday finally bringing
an end to the rain by afternoon. Temperatures are expected to be
near normal values through the weekend.
Near term through tonight
As of 415 am est Friday...
very little change in the upper atmospheric pattern across the
u.S. Is expected through the period. Deep troughing will remain
in the western u.S. With a strong 590+dm ridge aloft just off
the florida east coast. The ridge is keeping a baroclinic
zone nearly stationary frontal boundary draped across the
Meanwhile, a series of upper-level disturbances will track
northeast from the main upper low in the southwest u.S. And
along and through the baroclinic zone. To complicate matters, a
new area of canadian high pressure will move from the great
lakes toward new england allowing yet another wedge of cold air
to develop east of the appalachians, having just seen the last
one (largely responsible for our most recent snow ice storm)
depart Thursday afternoon.
With the baroclinic zone established over near the blacksburg
forecast area today through Friday and increasing isentropic
lift as the cool air wedge develops today through Saturday,
along with numerous upper-level impulses steered by the mean
southwest flow aloft across our region, look for periods of
rain today through Saturday. While most of the rain will be
light, brief periods of heavier rainfall can be expected.
Expected QPF today and tonight will be mostly in the 1 to 1.5
inch range, with the higher totals in the west where upper-level
forcing is better.
Soil conditions across much of the rnk CWA remain very saturated
thanks to repeated recent rainfall events for months on end
along with recent snow ice melt. Rainfall today and tonight will
simply aggravate the situation. Thus, the flood watch, which was
issued for the entire forecast area yesterday afternoon, will remain
in effect until Saturday night west and Sunday morning east.
Finally, there are a couple of other considerations complicated
by the development of yet another cold air wedge tonight and
early Saturday. As the cool wedge intensifies over the area
today and tonight, sufficient dry air may be entrained southward
into the northern fringe of the advancing rain shield for
temperatures to wet-bulb down toward the freezing mark late
tonight early Saturday across the southern shenandoah valley
into the greenbrier and new river valleys. Thus, a brief period
of freezing rain and or freezing drizzle is possible around
daybreak Saturday. With temperatures only expected to reach 32f
and limited to spotty locations at that, ice accumulations are
expected to only amount to a trace at best. Will mention in the
hwo ehwo, but no headlines are warranted at this time.
The other consideration related to the wedge is that the
attendant drier air advecting southwest could reduce
precipitation amounts for a while tonight Saturday morning
across northern parts of the cwa. With the wedge beginning to
erode again later Saturday into Sunday, no changes to the cwa
wide flood watch are warranted given as noted above the very
saturated soil conditions across the entire region.
With the development of a wedge once again, look for cold
temperatures to return today and Saturday. Temperatures will
hold mostly in the 30s higher elevations to 40s lower elevations
Confidence in forecast parameters
temperatures - moderate to high,
precipitation probabilities - moderate to high,
winds - high.
Short term Saturday through Monday night
As of 300 am est Friday...
very active weather into the first part of next week with both a hydro
and wind threat.
The deep upper trof ejecting out of the southwestern us will amplify
the southwesterly flow aloft and moisture transport over the
appalachians and central mid atlantic region through Saturday.
Simulated water vapor imagery shows a well defined moisture plume with
teleconnections back to the pacific ocean, helping to generate
precipitable water valued of 2 to 3 standard deviations above normal.
Acting on this moisture will be prolonged strong isentropic lift as a
warm front pushes the moist air up and over a well entrenched wedge
east of the mountains. This will generate additional widespread
rainfall on top of our saturated ground, and good clustering of
ensemble precip plumes adds confidence in this very wet scenario.
Temperature profiles may also be problematic for some freezing rain
with surface readings near freezing at the typical locations in the
heart of the wedge Saturday morning, but it currently looks like we
will stay just warm enough to avoid any icing. With the ground
already saturated from recent and ongoing precipitation, expect any
ongoing flooding will be amplified and new flooding initiated before
the best forcing slides to our north by Saturday evening.
Any lull in the action will be short lived as low pressure moving into
the great lakes will push showers ahead of a cold front back into
the region form the west later Sunday night, with an outside chance
of some thunder as well but would like to see instability lapse
rates a bit more pronounced to warrant a mention in the forecast.
Low level southwesterly winds will amplify considerably ahead of the|
front Saturday night with strong wind gusts developing across the
mountains of north carolina, up through the grayson highlands and
mountain empire or virginia, and into western greenbrier in west
virginia. With the waterlogged soil some uprooted trees and
associated power outages look possible. The front will cross the
area Sunday morning with the low level wind field still energized.
Expect some significant wind gusts with the actual frontal passage,
followed by strong gusty winds spreading eastward across the entire
region even into the piedmont through Sunday afternoon, along with a
greater than normal likelihood for uprooted trees and power outages
due to the waterlogged soil. Strong gusty winds will continue west
of the blue ridge as lowering inversion squeezes the flow in the
mountains. Moisture behind the front looks to be fairly limited and
this should inhibit development of upslope showers. Winds gradually
subside as high pressure builds in with quiet weather for Monday.
Long term Tuesday through Thursday
As of 345 pm est Thursday...
transient cool high pressure will move out to sea Tuesday night. A
northern stream cold front will join forces with a southern stream
disturbance late Tuesday night Wednesday morning to bring a chance for
rain back into the area. At this time, the two do not phase until both
systems move off the mid atlantic coast Wednesday evening. Dry high
pressure will follow with no rain expected until the weekend.
Near normal temperatures are expected for next week.
Aviation 14z Friday through Tuesday
As of 645 am est Friday...
poor aviation conditions expected through the TAF valid period.
Most conditions early this morning are MVFR, but are expected to
deteriorate quickly to ifr-lifr by mid to late morning and
remain mostly ifr-lifr through the remainder of the TAF valid
period in light rain and fog, transitioning to light rain,
drizzle, and fog overnight into early Saturday. Ceilings will
mostly fall into the 005-015 range while visibilities generally
hold in the 2-4sm range through 22z, then mostly in the 1 2-2sm
range after 22z. This as the result of a stationary front
draped across the region which will remain in the area through
Saturday while high pressure to our northeast helps to develop
another wedge through the day today into Saturday, and a series
of upper-level disturbances move northeast from deep low
pressure in the south central u.S.
Winds will generally trend toward the east and northeast as weak
low pressure remains to our southeast and high pressure
strengthens to our northeast. Speeds are expected to be mostly
5-6kts or less through the TAF valid period. As southeast flow
develops toward the kblf area, speeds may increase in that
region more toward 10kts with low end gusts.
Confidence in forecast parameters
ceilings - moderate to high,
visibilities - moderate to high,
winds - moderate to high.
Extended aviation discussion...
cold front is expected to sweep east through the terminal
forecast area on Sunday, gradually diminishing ending the threat
for precipitation with subsequent return toVFR conditions east
of the blue ridge by during the afternoon.
However, colder upsloping winds from the west or northwest
following the frontal passage will likely maintain the threat
for sub-vfr weather west of the blue ridge through Sunday
night, but dry air will allowVFR conditions to return to all
areas Monday, which should continue into Tuesday before the next
frontal system arrives in the wed-thu time frame.
Winds are expected to become quite strong and gusty behind the
front Sunday into Monday, especially over the mountains, until
high pressure can sufficiently build into the region later
Monday into Tuesday, thereby allowing winds to gradually relax.
As of 430 am est Friday...
a quasi-stationary frontal boundary will remain over or near the
rnk CWA during the next several days as a series of weather
disturbances lift northeast along the boundary. Each system will
bring a period of widespread mostly light to moderate rain,
possibly briefly heavy at times, especially in the south and
west. Rainfall totals over the next several days are expected
to be in the 1 to 3 inch range in many areas, with locally
higher amounts quite possible. Runoff from rain falling on a
totally saturated ground from a very wet fall and winter season,
combined with recent snow ice melt, will increase the threat of
general areal flooding in low-lying, poor drainage, and normally
flood prone areas as well as along creeks, streams, and even
some of the main rivers with time.
Ensemble river forecasts reflect minor to potentially moderate
flooding of most major waterways and associated tributaries.
Please remain abreast of possible flood and river flood warnings
that me be issued through the weekend.
Rnk watches warnings advisories
Va... Flood watch through late Saturday night for vaz007-009>020.
Flood watch through Sunday morning for vaz022>024-032>035-
Nc... Flood watch through late Saturday night for ncz001-002-018.
Flood watch through Sunday morning for ncz003>006-019-020.
Wv... Flood watch through late Saturday night for wvz042>044-507-508.
near term... Rab
short term... mbs
long term... mbs rcs
hydrology... mbs rab wert
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Roanoke, Roanoke Regional Airport, VA||3 mi||16 min||N 0||10.00 mi||Light Rain||46°F||42°F||86%||1028.8 hPa|
|Virginia Tech Airport, VA||24 mi||35 min||E 5||10.00 mi||Light Drizzle||44°F||44°F||100%||1028.1 hPa|
Wind History from ROA (wind in knots)
|1 day ago||E||Calm||Calm||Calm||SW||S||Calm||SE||Calm||Calm||Calm||Calm||SE||Calm||N||NE||N||N||NE||NW||NW||W||NW||W|
|2 days ago||SE||SE||SE||SE||SE||E||S||S||Calm||SE||E||E||SE||SE||SE||SE||SE||SE||S||SE||Calm|
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Wind Forecast for Blacksburg, VA (12,3,4,5)(on/off)  Help
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