Wednesday, June28, 2017 L-36.com


Marine Weather and Tides
Nevada, IA

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 5:40AMSunset 8:55PM Wednesday June 28, 2017 12:13 AM CDT (05:13 UTC) Moonrise 9:55AMMoonset 11:21PM Illumination 17% 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 280452
afddmx
area forecast discussion
national weather service des moines ia
1152 pm cdt Tue jun 27 2017

Short term tonight through Wednesday
issued at 158 pm cdt Tue jun 27 2017
the primary concern through the period will be convective trends
into Wednesday as an MCS is expected to develop across the high
plains and reach iowa during the early morning hours Wednesday.

There will be a pronounced regime change heading into this with a
return to more seasonal temperature and humidity levels in just a
short amount of time. Dewpoints may rise 20+f in 12-14 hours in
many locations.

Sharply increasing warm theta-e advection will advance through
iowa this evening, but initially be moisture starved with little
sensible weather. However kinematic forcing ahead the current
wy mt short wave will work with persistent plains return flow to
moisten our upstream airmass and feed MCS development. Mucapes
should be 1500-3000 j kg into early tomorrow morning west. This
diminishes by 09z however which supports the west to east gradient
noted in the SPC day 1 outlook and 3hr calibrated severe probs
per the 09z sref. 35-50kts of inflow per 300-305k isent surfaces
will support the MCS in some form into the night however, likely
based on shallow convergence and outflow with some suggestions
that the synoptic warm front will try to surge to northern iowa or
farther north.

It will not take much to get re-generation by tomorrow afternoon
however with most models suggesting uncapped 2000-3000 j kg
mlcapes and 35-45kt of 0-6km shear favorably oriented to the
approaching boundary for discrete cells or at least small
clusters. This will support all modes of severe weather, most
likely over central and southeast sections, and fully expect
current SPC day 2 slight risk to be upgraded once confidence in
location can be better pinned down after overnight outflow shows
its hand. One interesting note is that the convection allowing
model arw cores are less aggressive than one might expect per the
aforementioned shear and instability based on updraft helicity vs
nmm cores, which are often on the higher end anyways. Thus there
is still some uncertainty with the tornado potential versus more
likely damaging wind and hail. If local outflow does not favorably
augment 0-1 SRH the general synoptic regime, broad SW low level
flow, would seem to be less favorable for tornadoes.

Long term Wednesday night through Tuesday
issued at 158 pm cdt Tue jun 27 2017
the potential for additional strong to severe thunderstorms
Wednesday night through Thursday is the focus of the extended
forecast.

Thunderstorm development Wednesday night will be ongoing near a
cold front extended from northeast to southwest iowa. Ahead of
the front, an unstable airmass is expected with forecast models
progging mu CAPE values over 2500 j kg along with a strengthening
and veering low level jet near 30-50 knots. Numerous strong to
severe thunderstorms will develop along this boundary during the
evening and overnight hours aided by the passage of a shortwave in
zonal flow aloft. Damaging winds, large hail, heavy rain and a
few tornadoes within a few hours of initiation will be possible.

The surface front looks to become parallel to the zonal flow
overnight Wednesday into Thursday morning shifting the focus for
showers and thunderstorms and heavy rain to southern iowa.

Surface low deepens on Thursday across kansas in response to a
deepening upper trough over the dakotas with favorable moisture
transport over east west oriented surface boundary. Another round
of strong to severe thunderstorms will develop with shortwave
kicking ahead of a deepening upper trough. Along with heavy rain,
all modes of severe weather will be possible including tornadoes
with thunderstorm development near the front.

Thunderstorms will end west to east across the state Friday with
boundary exiting into the mid-mississippi valley. The upper trough
digs over the midwest Saturday. Northwest winds will increase
with windy conditions expected from strong mixing. A few showers
and thunderstorms will be possible over northern iowa Saturday
afternoon and evening aided by daytime heating and another
shortwave rotating around the base of the upper low.

Next week, the pattern shifts to northwest flow aloft over iowa
with an upper ridge building over the rockies. Could see another
round of showers and thunderstorms on Monday before warmer and
drier weather returns.

Aviation for the 06z tafs through 06z Wednesday night
issued at 1152 pm cdt Tue jun 27 2017
showers and storms still expected to move through much of the
state tonight, with the activity expected across the south pushing
slower across NE than previously expected. Therefore have
adjusted timing. Should see additional activity by late afternoon
so have highlighted with vcts or vcsh depending on greater
confidence and where better chance for thunder expected. Low level
wind shear still possible through sunrise especially across the
western sites, then gusty south to southwesterly winds expected
Wednesday.

Dmx watches warnings advisories None.

Short term... Small
long term... Angle
aviation... Beerends


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Ames, Ames Municipal Airport, IA9 mi21 minSSE 810.00 miMostly Cloudy69°F57°F68%1010.3 hPa
Boone Municipal, IA21 mi19 minSSE 1110.00 miOvercast70°F57°F64%1010.5 hPa
Ankeny Regional Airport, IA24 mi19 minSSE 1010.00 miMostly Cloudy70°F57°F64%1011.8 hPa

Wind History from AMW (wind in knots)
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Last 24hrCalmCalmCalmCalmCalmCalmCalmCalmS7S8S9S12S11S11
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1 day agoCalmCalmNW6N10NW5SW4SW4S8W6W9W5NW6NW6NW7N9
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2 days agoNW5W4W5NW6W5W7NW9NW13NW17
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N13NW11NW8N8N3CalmCalm

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
east_satellite

GOES Local Image of Midwest    EDIT
Geos

Wind Forecast for Des Moines, IA (1,6,7,8)
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Ground Weather Radar Station Des Moines, IA
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weather_mapweather_map weather_map

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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.