Sunday, April23, 2017 L-36.com


Marine Weather and Tides
Nevada, IA

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:18AMSunset 8:06PM Sunday April 23, 2017 2:49 PM CDT (19:49 UTC) Moonrise 3:58AMMoonset 3:53PM Illumination 6% Phase: Waning Crescent; Moon at 27 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 Nevada, IA
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location: 42.02, -93.46     debug


Area Discussion for - Des Moines, IA
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Fxus63 kdmx 231728
afddmx
area forecast discussion
national weather service des moines ia
1228 pm cdt Sun apr 23 2017

Short term /today through tonight/
issued at 351 am cdt Sun apr 23 2017
surface ridge currently sliding across central iowa with light and
variable winds across the southern half of the state. Farther
north, winds have increased from the southwest as warm advection
commences. The high will continue its retreat to the southeast
today with a tightening pressure gradient over the state with low
pressure developing in western south dakota. This will increase the
southwest winds through midday with gusty conditions in the
northwest corner of the forecast area by this afternoon. The
increasing winds will help mixing today and should push temperatures
into the 70s across the entire area. The tighter gradient will
persist tonight with surface winds remaining stronger overnight,
especially in the north and west. This, in turn, will keep near
surface mixing ongoing overnight helping temperatures to remain
relatively warm in the northwest forecast area. The lighter winds
in the south and east will allow for better cooling and slightly
lower temperatures overnight. Otherwise, little threat of
precipitation today or tonight with a dry atmosphere in place.

Long term /Monday through Saturday/
issued at 351 am cdt Sun apr 23 2017
Monday into Tuesday...

confidence: high
08z Sun water vapor imagery picking up on a subtle upper low
spinning over northern california. This low/longwave trough will
continue to propagate eastward... With its sfc reflection nearing nw
iowa by 00z tue. There continues to be very little model spread with
the track of this low, leading to high confidence forecast. With
high pressure over the gulf of mexico, gulf moisture access will
be closed off ahead of this system. An attendant cold front will
be extending southward through iowa will serve as a sufficient
focusing mechanism for convection. Bufkit analysis of kfod, ksux,
and kfsd shows a lot of low-level dry air... Keeping any convection
elevated and relegating precip, if any, to mainly virga.

More significantly in terms of a hazard, Monday looks to feature
very strong winds. Sounding analysis shows the mixed layer above
800mb. Slight veering with the wind profile and upper clouds may
inhibit complete mixing of 45kt winds at top the mixed layer. Sfc
winds should be out of the south, meaning high profile vehicles
traveling along east-west roadways (such as highways 20 and 30)
may be vulnerable to jackknifing.

Tuesday into Wednesday...

confidence: medium
confidence has increased greatly in this time period, as models
beginning to show run-to-run consistency with clustering around a
solution. Have favored a general consensus model blend for track
and timing. 08z Sun picking up on a more well-defined upper low
spinning just off the washington coastline... Right on the heels of
the Monday system. This upper low looks to be centered over the
dakotas by 12z wed, with the associated trough digging down
through texas. A band of strong frontogenetical forcing,
especially evident at 950mb, will be a signature of this system.

The frontogenetical forcing will be oriented from SW to NE and cut
right through central iowa Tuesday into Wednesday morning. By 18z
wed, models place a 995mb sfc low just east of iowa... Taking
along the best forcing for precip with it. During the day Tuesday,
pwats of 1-1.25 inches will be advected into iowa. Sounding
analysis does not come close to saturating the profile completely,
so lack of precipitation efficiency will likely keep QPF in the
0.25 to 0.5 inch range during this prolonged and widespread period
of rain.

Thursday and beyond...

confidence: low-medium
much uncertainty has existed in the Thursday through Saturday
timeframe. As has been the case time, after time, after time in
the long range, the ECMWF has been the first to show run-to-run
consistency in a plausible solution, and the GFS has been playing
catch-up. In this particular instance, the ECMWF has kept the dmx
cwa cool, with the aforementioned 995mb sfc low over the great
lakes by 12z thu, and a weak, ill-defined sfc high quickly passing
through the upper midwest. 00z Sun ECMWF 850mb temps drop to 0 to
-5c across iowa Thursday morning. Frost/freeze headlines almost a
likelihood across northern iowa.

Both the 00z Sun ECMWF and GFS show stunning agreement with a
potentially high-impact system Saturday into Sunday. By 00z sun,
both models showing an upper low coming off the rockies near
nebraska. This upper low is beginning to come into range in the
pacific, so the next few runs should greatly improve upon capturing
this low, especially its amplitude/strength. 990mb sfc reflection
coming across the oklahoma panhandle and tapping into gulf moisture
big time. Won't get into minutia at this point, other than to say
that the GFS is pushing pwats of 1.5 to 1.75 inches into iowa.

Obviously a lot of time for things to change between now and then,
but pwats of this magnitude this time of year are effectively off
the charts per SPC sounding climatology at koax and kdvn.

Aviation /for the 18z tafs through 18z Monday afternoon/
issued at 1228 pm cdt Sun apr 23 2017
vfr conditions will prevail through the period. Expect breezy
southwest winds over central and northern iowa today and light in
variable near kotm. The wind will diminish toward sunset and
become light southerly. Local wind shear is possible late tonight.

Breezy to windy southwest winds will develop by mid to late
Monday morning.

Dmx watches/warnings/advisories
None.

Short term... Cogil
long term... Kotenberg
aviation... Donavon


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Ames, Ames Municipal Airport, IA9 mi56 minS 9 G 2110.00 miFair70°F35°F28%1017.6 hPa
Boone Municipal, IA21 mi54 minSW 7 G 1710.00 miFair70°F30°F23%1017.6 hPa
Ankeny, Ankeny Regional Airport, IA24 mi54 minSSW 1010.00 miFair68°F32°F26%1018.6 hPa

Wind History from AMW (wind in knots)
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Last 24hrNE8
G14
N9
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--NE5E8NE6E3CalmCalmCalmSW3SW4CalmCalmCalmCalmCalmCalmCalmW7W6W7W8S7
G16
1 day agoNE12NE11NE17
G22
NE14
G19
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G20
NE10NE9NE9NE7NE8NE7NE5N6NW6NW4NW4N7N7NE5E7E5SE8NE9E7
2 days ago--NW13
G25
W14
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NW17
G26
NW15
G22
NW15NW15NW11NW11NW9NW4W6W7NW5N7N7N6W4N4NE10NE12NE11NE12
G18
NE16
G20

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 Midwest    EDIT
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Wind Forecast for Des Moines, IA (15,3,4,5)
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Ground Weather Radar Station Des Moines, IA
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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.