Monday, August21, 2017 L-36.com


Marine Weather and Tides
Aten, NE

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 6:43AMSunset 8:21PM Monday August 21, 2017 12:57 PM CDT (17:57 UTC) Moonrise 5:29AMMoonset 7:30PM Illumination 0% Phase: New Moon; Moon at 29 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
    EDIT      (on/off)   Help
7 Day Forecast for Marine Location Near Aten, NE
   Hourly   EDIT   Help
location: 42.87, -97.49     debug


Area Discussion for - Sioux Falls, SD
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus63 kfsd 211750
afdfsd
area forecast discussion
national weather service sioux falls sd
1250 pm cdt Mon aug 21 2017

Short term (today and tonight)
issued at 436 am cdt Mon aug 21 2017
eclipse day is upon us, and the main concerns are with the
conditions around eclipse time, as well as the severe weather
potential as an intensifying boundary slides across the area this
afternoon and early evening.

Persistent band of convection across northwest iowa early this
morning on back side of large MCS across ia, feeding on low-level
jet of 35-40 kts and healthy elevated CAPE on order of 1500-2000
j kg. As low-level jet continues to veer and warmer bubble of mid-
level air shifts eastward, should see the convection wind down
across northwest ia fairly early in the morning. Meanwhile, forcing
with main northern stream wave inducing more of an upslope flow into
western sd, and increasing lift forcing resulting in smaller
convective cluster across northwest into north central sd. This
forcing will progress gradually toward k9v9 khon areas early this
morning, but southward spread early on should be limited by the
warmer air aloft to the south.

Ok, the bad news looks to continue for eclipse viewing across the
immediate area. As the outflow pool continues to develop early this
morning, will likely see an expansion of lower clouds westward, the
clouds from northern cluster of storms push into the far northern
areas, and higher clouds start to stream northeast from the high
plains. Won't be widespread overcast in all likelihood, and there
will be some spotty areas with enough breaks in clouds, but overall
looking like a mostly cloudy setup in the 11am - 2pm window, with
perhaps the best potential for lesser opaque clouds toward ksux and
location of outflow strengthen synoptic boundary. In addition to
the clouds, there will be the threat for some convection starting to
enhance along the convergence boundary pushing eastward toward
bkx mhe onl line during the eclipse peak. Cams are also suggesting
that additional warm advective elevated precip could evolve toward
midday along i-20 and north, but much spottier. The impacts on temp
fields will likely be tempered by the degree of cloudiness and the
higher moisture content of the airmass. Have at most worked in a
drop of a couple of degrees.

With forcing from the northern stream wave pushing into eastern sd
in the early to mid afternoon, the surface boundary looks to respond
by sharpening and becoming somewhat more convergent, and works to
pull the outflow synoptic warm frontal boundary northward toward the
lower missouri river valley. Despite warm temps aloft and the
outflow pool yielding an effective cap into midday, the falling
temps aloft and lift forcing should allow convection to begin to
become a bit more boisterous along the boundary as it moves between
the james and i-29 corridors during the early afternoon, although
there is some uncertainty as to what impact the eclipse insolation
drop might have, at least on intensity. The boundary, and subsequent
outflow, is likely to define the greater focus and threat for
severity through the afternoon and early evening as it moves
southeast. Prefrontal instability could reach 2000-2500 j kg,
somewhat capped, but a nicely thick profile thanks to 8-8.5 c km mid-
level lapse rates. Shear through the deep layer appears much more
distributed, with the turning of winds through the 35-40 knots of
westerly mid-level wind. Easily enough shear for organized storms,
including supercells. All modes of severe are possible, including
some hail to around 2 inches. Would expect upscale growth through
the afternoon and early evening as storms progress toward northeast
ne and northwest ia, bowing segments with enhanced wind potential.

Wild card in terms of tornadic potential with storms later in the
afternoon or early evening will be existence interaction with any
boundaries from this overnight convection. Will even have to be
concerned with flooding across northwest ia, given some areas of
very heavy rainfall from the current overnight.

The threat of convection will continue greatest across northwest ia
and parts of southwest mn, but progression of wave will put a fairly
quick end to most by late evening. Cooler high pressure will settle
in behind the convective line, with temps falling well into the 50s
by daybreak for most, with some near 60 readings lingering in areas
closer to ksux kslb.

Long term (Tuesday through Sunday)
issued at 436 am cdt Mon aug 21 2017
by Tuesday, high pressure will settle into the region with northwest
flow aloft. This will result in a few days of generally dry
conditions and temperatures a few degrees below their climatological
normals. The GFS is a little more aggressive with a few low end
precip chances mid week along the theta-e boundary and thus some
slight chance mention was included in this forecast.

By Friday, southerly low level winds will be on the increase as the
upper level flow becomes flattened by an incoming shortwave. This
will bring a better chance of precipitation and convection to the
region from Friday evening into Saturday.

Aviation (for the 18z tafs through 18z Tuesday afternoon)
issued at 1245 pm cdt Mon aug 21 2017
band of showers and thunderstorms will continue to track east
through the region through this evening. Low clouds and reduced
visibility will be a concern in thunderstorm activity. Some severe
weather will also be possible, with hail and wind squalls
possible, mainly along and south of i-90. Ceilings will lift as
skies clear behind the exiting showers and storms this evening
into early morning hours.

Fsd watches warnings advisories
Sd... None.

Mn... None.

Ia... None.

Ne... None.

Short term... Chapman
long term... Jh kalin
aviation...



Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Yankton, Chan Gurney Municipal Airport, SD7 mi62 minSSE 1110.00 miOvercast79°F69°F72%1013 hPa

Wind History from YKN (wind in knots)
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
Last 24hr3E5SE6NE4NE6NE10E6E6--NE7NE8NE9NE5NE7NE7E6SE12E10E6SE8SE9SE11
G17
SE7SE11
1 day agoE8E10SE11SE13SE14
G20
SE13SE10--E5--E11E10E6SE5SE6SE7CalmCalmNW5NW4CalmS3SE5Calm
2 days agoS7--SW7W11W9NW8NW8NW12NW8NW9N8--CalmW4SW7W4--CalmNE3SE3CalmSE6----

Tide / Current Tables for
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help
Tide / Current Tables for
   EDIT      (on/off)   Help
Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Midwest    EDIT
Geos

Wind Forecast for Sioux Falls, SD (13,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Sioux falls, SD
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.