Monday, May29, 2017 L-36.com


Marine Weather and Tides
Nevada, IA

Version 3.4
What's New / NOTES
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 5:40AMSunset 8:43PM Monday May 29, 2017 1:57 PM CDT (18:57 UTC) Moonrise 8:52AMMoonset 11:31PM Illumination 18% Phase: Waxing Crescent; Moon at 4 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 291715
afddmx
area forecast discussion
national weather service des moines ia
1213 pm cdt Mon may 29 2017

Updated for 29 18z aviation discussion...

Update
Issued at 624 am cdt Mon may 29 2017
showers have develop over southern iowa on a weak PV anomaly that
has moved in from nebraska ahead of the shortwave trough pv
anomaly mentioned in the short term discussion below. Have updated
pop sky wx grids for the next few hours based on current trends
and hrrr rap guidance.

Short term today through tonight
issued at 314 am cdt Mon may 29 2017
a shortwave trough and associated PV anomaly will drop through iowa
in the broad northwest flow today. With cooler air aloft behind this
trough PV anomaly, diurnally driven clouds and scattered showers
with perhaps a few peals of thunder will develop late this morning
and afternoon. Used hi-res models over global models to bring pops
farther south toward the highway 30 corridor. Winds from the
northwest will also increase this morning and become gusty similar
to yesterday. Forecast soundings across central iowa show deep
mixing once again, though perhaps not as deep as Sunday.

Nevertheless, with dry adiabatic lapse rates from the surface to the
top of the mixed layer, will be able to mix down wind gusts of 25 to
35 knots. It is also worth noting that soundings show an inverted v
profile. This may allow showers to entrain drier air into their
downdrafts yielding higher wind gusts compared to the synoptic gusts
mentioned above. While highs were adjusted a degree or so upward,
they will still be cooler than yesterday and below normal for late
may.

Showers will end shortly after sunset and winds will decrease
as well as the boundary layer decouples with the loss of daytime
heating. Skies will become partly to mostly clear. Lows will be in
the upper 40s to low 50s. The next shortwave trough PV anomaly will
be dropping out of the dakotas toward iowa in the northwest flow
by 12z Tuesday.

Long term Tuesday through Sunday
issued at 314 am cdt Mon may 29 2017
expectations have changed little from this time yesterday. Our
weather will continue to be dominated by high amplitude broad
cyclonic flow at the start of the period before transitioning to
weaker nondescript flow to end the week. At onset, Tuesday looks
to play out much like today with the potential for unorganized
weak peak heating convection north and east. Winds should again be
brisk from the NW possibly gusting to 30 mph in deep mixing
considering low humidities in this dry airmass.

This pattern will finally break into Wednesday as surface high
pressure slides into the mo valley with a cool start to the day.

Warm advection will finally return again later into the night
however as a weak short wave crosses the plains with lowering
heights pushing the baroclinic zone back into iowa. This will
likely trigger elevated convection and a weak MCS which will
conclude with much of iowa being back into the warm sector
Thursday pushing highs and humidity levels closer to what is
typical for this time of year. The ECMWF and GFS are both in good
agreement with a weak warm front near the ia mn border during the
evening possibly triggering surface based convection which will
sustain itself into the night due to persistent inflow and
moisture transport into deep convergence. Precipitable water and
specific humidity values are nothing anomalous for early june, but
even seasonal levels may still produce appreciable amounts,
especially considering the weak flow and shear. Mlcapes may reach
2-3k j kg during peak heating so there still could be a brief
thermodynamically dominated severe weather window through early
evening.

Confidence in details diminishes somewhat into Friday due to
uncertainties of where outflow may re-focus the weak warm front,
but the general scenario will likely repeat with late peak heating
surface convection following by an MCS into the night with best
chances north and east. Both the ECMWF and GFS suggest some form
of a weak short wave in the maturing NW flow Saturday keeping at
least low pops for convection in the forecast. Although the
deterministic GFS suggests some pops are necessary Sunday, have
gone dry for now as the GEFS and especially the ECMWF and its
ensemble are less aggressive with the NW flow that would drive it
with stronger ridging into the dakotas.

Aviation for the 18z tafs through 18z Tuesday afternoon
issued at 1213 pm cdt Mon may 29 2017
mainlyVFR conditions are expected during the valid TAF period.

Mixing of the boundary layer will result in surface wind gusts of 25
to 35 kt this afternoon. Scattered to isolated showers are psbl this
afternoon mainly along and north of us hwy 20, which may contain
enhanced gusty winds and perhaps a brief period of MVFR cigs. Any
lingering showers will dissipate and winds will abate this evening.

Dmx watches warnings advisories None.

Update... Ansorge
short term... Ansorge
long term... Small
aviation... Zogg


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Ames, Ames Municipal Airport, IA9 mi64 minWNW 18 G 2510.00 miMostly Cloudy and Breezy70°F45°F41%1013.3 hPa
Boone Municipal, IA21 mi62 minWNW 22 G 2710.00 miA Few Clouds and Breezy70°F42°F38%1013.9 hPa
Ankeny, Ankeny Regional Airport, IA24 mi62 minWNW 15 G 2510.00 miA Few Clouds72°F44°F38%1014.6 hPa

Wind History from AMW (wind in knots)
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Last 24hrW15
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NW11W8W8W7NW7SW4W7W4W8CalmCalmW5NW8W12
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1 day agoN8N10NE11
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NE10E11E5NE5NE3CalmCalmW5CalmCalmW4W7W8W6W3W6W11NW13NW9NW11W9
2 days agoCalmW4CalmN5N6N5CalmSE6SE5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS3E3E4N12

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
Geos

Wind Forecast for Des Moines, IA (14,3,4,5)
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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.