Wednesday, December12, 2018 L-36.com


Marine Weather and Tides
Grand Ledge, MI

Version 3.4
What's New / NOTES
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 7:58AMSunset 5:06PM Wednesday December 12, 2018 12:23 PM EST (17:23 UTC) Moonrise 11:52AMMoonset 10:06PM Illumination 26% Phase: Waxing Crescent; Moon at 5 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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LMZ846 Holland To Grand Haven Mi- 1128 Am Est Wed Dec 12 2018
.small craft advisory in effect until 5 pm est this afternoon...
Rest of today..Southeast winds 15 to 25 knots veering southwest late in the day. Cloudy, drizzle. Waves 2 to 4 feet.
Tonight..West winds 10 to 20 knots becoming south around 10 knots toward daybreak. Mostly cloudy. A slight chance of drizzle in the evening. Waves 2 to 4 feet.
Thursday..Southeast winds 5 to 15 knots. Partly Sunny. Waves around 1 foot.
Thursday night..Southeast winds 10 to 15 knots backing east toward daybreak. A chance of rain and snow in the evening, then rain and snow overnight. Waves 1 foot or less.
LMZ846 Expires:201812122215;;686277 FZUS53 KGRR 121628 NSHGRR Nearshore Marine Forecast National Weather Service Grand Rapids MI 1128 AM EST Wed Dec 12 2018 For waters within five nautical miles of shore on Lake Michigan LMZ846-122215-


7 Day Forecast for Marine Location Near Grand Ledge, MI
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location: 42.75, -84.75     debug


Area Discussion for - Grand Rapids, MI
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Fxus63 kgrr 121650
afdgrr
area forecast discussion
national weather service grand rapids mi
1150 am est Wed dec 12 2018
latest update...

update hydro

Synopsis
Issued at 318 am est Wed dec 12 2018
the primary forecast changes and forecast concerns are as follows:
- while the low pressure system today will track further north
than previously thought, a band of lake effect precipitation is
possible toward the evening commute. Confidence is low on
precipitation type.

- patchy freezing drizzle is possible tonight as well as
refreezing of roadways, but confidence is low and dependent on
several factors.

- a wave of precipitation will impact lower michigan Thursday
night and into Friday with mostly rain expected.

Update
Issued at 1150 am est Wed dec 12 2018
no major changes to the going forecast. Complicated setup today
with lots of factors involved. Initial band of warm air advection
snow has pushed north through the area, with another band moving
toward the area. This second band is out ahead of the front
pushing through wi with the upper low rotating through the region.

Forecast soundings indicate that the predominate p-type will be
snow. Sfc temps are above freezing, but most of the rest of the
sounding is below freezing. Sfc temps may wet bulb down briefly in
the snow showers, but should remain below freezing aloft.

Once the band moves through, there is a decent chance that we will
fluctuate between a saturated and unsaturated dgz. This will allow
any pcpn to fluctuate between light snow showers and drizzle
freezing drizzle. Thankfully, it appears sfc temps will generally
remain above freezing through the evening commute at most locations.

The better chance of freezing drizzle will be across the far north,
and after 00z.

Discussion (today through next Tuesday)
issued at 318 am est Wed dec 12 2018
we have ourselves an interesting forecast for today...

the well-advertise low pressure system is currently developing
along the iowa minnesota border. A short-lived period of deepening
is expected this morning, though such a phase will be short lived
and the low will actually weaken while passing into lower michigan
this afternoon. High- resolution model guidance continues to
trend northward with the track of the low, with the deformation
band and associated light snow now poised to track along and north
of highway 10. Snow amounts of up to an inch are still on track.

A more northerly low track places much of central lower michigan
in an interesting spot... While the best dynamics from the system
will pass north of our area, model guidance continues to suggest
the low will develop a substantial cold core (850 mb temperatures
dropping to -7 to -9 c) which will push through lower michigan
this afternoon and evening. As such, the possibility exists for a
squall of lake- effect precipitation to sweep through lower
michigan along a cold front, at this point favoring between
20z 3pm and 00z 7pm. Should this occur, there would be inherent
uncertainty in precipitation type given surface temperatures south
of i-96 will warm into the mid to upper 30s (hrrr actually has
lower 40s) early this afternoon before dropping below freezing
after dark. The expected precipitation type with any lake- effect
precipitation would then be rain as the snow encounters the
(albeit cooling) low-level warm layer. However, given the
magnitude of the potential lake instability, precipitation
intensity may be enough to overcome the low-level warm layer
leading to a rain snow mix, if not all snow. There is thus concern
for the evening commute should a lake effect squall indeed
develops with snow as the main precipitation type... But that's
not the only concern at hand.

After dark, dry air will quickly scour moisture out of the
dendritic growth zone but low-level moisture will be slower to
fade leading to concern for patchy freezing drizzle mainly from
00z 7pm to 06z 1am Thursday. The shallow nature to the low-level
moisture layer leads to uncertainty in whether drizzle would be
able to form, but favorable lake-induced instability may also
provide more lift than expected.

So, to summarize, there exists a scenario for a burst of rain or
snow during the evening commute with patchy freezing drizzle
after dark. At this point, confidence is low in the scenario
unfolding (e.G. A lot of moving parts have to come together just
right). However, should confidence increase after the day crew
comes in, a short-fused headline may become necessary.

The other target of opportunity to watch is the storm system at the
end of the week. While forecast model guidance has converged on a
solution that keeps the surface low south of our area, there
continues to be a signal of a weakening area of precipitation
associated with the northerly wave to push through lower michigan
Thursday night and into the first half of Friday. Given a residual
below-freezing low-level airmass, it's feasible precipitation type
may start out frozen, though a quick change-over to rain is
expected. It's also worth noting that low-level airmass may end
up isothermal and + - 1 degree of freezing, possibly leading to
periods of snow mixed within especially across higher terrain
locations.

Looking into the longer-range, forecast model guidance continues to
offer differing solutions on the upper-level wave pattern early next
week (gfs GEFS call lake effect snow; ECMWF and ensembles call for
dry and maybe even some sun), though interestingly all share
remarkable consistency in showing wintry weather returning toward
the end of next week.

Aviation (for the 12z tafs through 12z Thursday morning)
issued at 652 am est Wed dec 12 2018
light snow is expected to begin by late morning or early afternoon
with some patchy ifr into the evening. Southeast winds will gust
to near 20 knots at times into this afternoon.

Marine
Issued at 318 am est Wed dec 12 2018
offshore winds gusting to 30 knots will relax this afternoon leading
to relatively calm conditions through the remainder of the week.

Hydrology
Issued at 1150 am est Wed dec 12 2018
no significant hydro issues are expected over the next week. Water
levels on the rivers around the area are near-normal for this time
of year. Warm temperatures moving in for the next week will lead to
the melting and runoff of any locations that still have a bit of
snow on the ground, but this shouldn't cause too much rise in the
rivers. The whole area will see rain Thursday night into Friday
morning, but total rainfall should be below one-half inch. This will
result in some rises on the streams in the area, but nothing too
dramatic.

Grr watches warnings advisories
Mi... None.

Lm... Small craft advisory until 5 pm est this afternoon for
lmz844>849.

Update... Njj
synopsis... Borchardt
discussion... Borchardt
aviation... Ostuno
hydrology... Amd
marine... Borchardt


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
HLNM4 - 9087031 - Holland, MI 78 mi41 min SE 13 G 19 1007.7 hPa
MKGM4 - Muskegon, MI 90 mi33 min SSE 11 G 14 35°F 1009.5 hPa27°F
SBLM4 - Saginaw Bay Light #1, MI 91 mi143 min SE 14 G 16 28°F 1015.6 hPa (-1.0)

Wind History for Holland, MI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Capital Region International Airport, MI8 mi30 minSSE 156.00 miMostly Cloudy with Haze35°F27°F72%1012.4 hPa
Charlotte, Fitch H Beach Airport, MI13 mi28 minSE 9 G 147.00 miOvercast36°F27°F72%1009.8 hPa
Mason, Mason Jewett Field Airport, MI21 mi28 minSSE 87.00 miMostly Cloudy35°F28°F76%1011.8 hPa
Ionia County Airport, MI21 mi28 minESE 12 G 197.00 miOvercast34°F25°F72%1009.8 hPa

Wind History from LAN (wind in knots)
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Last 24hrW8NW8NW8W9W7NW5NW5CalmW5CalmCalmCalmS3E4E5SE6SE9SE9SE12SE11SE12SE16
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1 day agoSW5W7W10W9SW9SW6SW7S7S8SW13SW10SW14
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2 days agoW9W10W10W10W8W5W6W4W3NW3NW7NW5N6N3W5NW3NW5NW3CalmCalmSE3S3S6SW4

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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GOES Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for Grand Rapids, MI (12,3,4,5)
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Ground Weather Radar Station Detroit, MI
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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.