Sunday, April30, 2017 L-36.com


Marine Weather and Tides
Roosevelt Park, MI

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 6:36AMSunset 8:47PM Sunday April 30, 2017 12:47 PM EDT (16:47 UTC) Moonrise 9:28AMMoonset 12:00AM Illumination 22% 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
    EDIT      (on/off)   Help
LMZ847 Grand Haven To Whitehall Mi- 1158 Am Edt Sun Apr 30 2017
.small craft advisory in effect through Tuesday evening...
Rest of today..East winds 20 to 25 knots. Showers. Waves 1 to 3 feet.
Tonight..East winds 20 to 25 knots veering southeast toward daybreak. Showers and a chance of Thunderstorms. Waves 1 to 3 feet building to 2 to 4 feet toward daybreak.
Monday..South winds to 30 knots. A chance of light showers until midday, then light showers likely in the afternoon. Waves 4 to 6 feet.
Monday night..Southwest winds to 30 knots. Light showers likely in the evening, then a chance of light showers overnight. Waves 6 to 9 feet.
LMZ847 Expires:201704302115;;511280 FZUS53 KGRR 301558 NSHGRR NEARSHORE MARINE FORECAST NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1158 AM EDT SUN APR 30 2017 FOR WATERS WITHIN FIVE NAUTICAL MILES OF SHORE ON LAKE MICHIGAN LMZ847-302115-

7 Day Forecast for Marine Location Near Roosevelt Park, MI
   Hourly   EDIT   Help
location: 43.22, -86.36     debug


Area Discussion for - Grand Rapids, MI
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus63 kgrr 301536
afdgrr
area forecast discussion
national weather service grand rapids mi
1136 am edt Sun apr 30 2017
latest update...

update/marine

Synopsis
Issued at 326 am edt Sun apr 30 2017
expect periods of rain with embedded thunderstorms today and
tonight. Winds will be strong and gusty. This is all thanks to a
strong and deepening occluded low pressure system that will track
from eastern kansas this morning to central wisconsin Monday.

Temperatures will stay chilly near and north of grand rapids
through tonight but i-94 the warm front may bring temperatures
into the mid to upper 60s by this evening. Rainfall amounts of
over 2 inches are expected by Monday morning. There could be some
strong to possibly severe storms and an isolated tornado south of
i-96 this evening as the warm front comes into our southern
sections before the occluded front moves through.

From Monday afternoon through Tuesday expect occasional rain
showers windy and chilly temperatures. Highs will struggle to make
50 degrees on Tuesday.

Update
Issued at 1136 am edt Sun apr 30 2017
another wave of rain was moving into the CWA late this morning.

This was riding another low level jet that persist through much
of the afternoon. This wave will bring the heaviest rain over the
southern and central cwa, mainly south of highway 20, with another
0.75 to 1.0 inches of rain. Localized amounts could be over an
inch. This fits well with our current flood watch.

Severe potential appears almost nil until after 00z with the lack
of solid instability. Mainly elevated instability arrives
overnight, with some surface based arriving toward daybreak Monday
as the warm front begins to drift north.

Short term (today through Tuesday)
issued at 326 am edt Sun apr 30 2017
i will continue the flood advisory as is even through the
rainfall last night was not quiet as high as expected, even so we
had between a half and three quarters of an inch by 2 am over most
of southwest cwa. We expect periods of showers and thunderstorms
into tonight with additional rainfall of 1 to 3 inches.

The other issue is the potential for strong thunderstorms with
isolated tornadoes this evening near and south of interstate 94 as
the occluded front moves through that area. There is decent cape,
a low lcl, more than 40 knots of effect bulk shear in that area
this evening. This will have to be watched closely as we
typically get tornadoes near warm fronts, this is that sort of set
up.

Beyond this we get into the cold air Monday afternoon and the dgz
is near the top of the clouds with strong cyclonic flow, Monday
afternoon through Tuesday afternoon. This means lake enhanced rain
showers from late Monday afternoon through Tuesday. It will be
breezy and cold then too.

Long term (Tuesday night through Saturday)
issued at 326 am edt Sun apr 30 2017
we're mainly looking at dry weather during the long term. High
pressure over lower michigan will likely lead to some frost Tuesday
night, Wednesday night, and Thursday night. Frost/freeze headlines
may be needed, especially for the central and northern cwa. We added
frost to the grids each of those three nights.

A deep upper trough is progd to develop east of the plains during
the period. The sfc low is a southern stream system that will bring
rain to the ohio valley mid to late week. The ECMWF tracks the low
northeast through pennsylvania during which time pcpn retrogrades
westward a bit through southeast lower. Under this scenario, it's
possible that the far southeast CWA may see a shower Friday and
Friday night, but probably not.

Temperatures will be cool through the period, but moderate somewhat
toward the end of the week with highs mainly in the lower 60s.

Aviation (for the 12z tafs through 12z Monday morning)
issued at 744 am edt Sun apr 30 2017
expect largely ifr conditons until the cold front comes through
after 09z. Until then there will be periods of showers and
thunderstorms. During the evening as the upper level jet comes
over southwest michigan. Which implies between 00z and 06z is
when thunderstorms would be most likely since that is when the
forcing is the greatest. Once the main shortwave comes through i
would expect mostly rain showers till the front actually comes
through.

During the day today there will be a very strong inversion between
12z and 18z around 5000 ft agl. That will help to keep the
ceiling in the ifr range. During the afternoon the inversion will
get closer to the ground, that is, as the warm front at the
surface, gets closer to our SW mi TAF sites. Below the invasion
winds will be from 120 degrees around 35 knots above the inversion
winds will be 210 degrees around 35 knots. Clearly with 2000 ft
of the front (vertically) there will be a significant wind shear.

There may even be a brief break in the clouds (sky GOES clear)
behind the cold front but I did not try to put that sort of detail
in the forecast as this point.

Marine
Issued at 1136 am edt Sun apr 30 2017
extended the small craft advisory through all of Monday night and
Tuesday, before much improvement is expected.

Hydrology
Issued at 122 pm edt Sat apr 29 2017
flood advisories continue for the grand river at ionia and on the
maple river at maple rapids. A flood watch continues for the same
four points. River statements have been issued for numerous
locations that might experience flooding towards the middle of the
coming week. However, forecast certainty for these sites remains
very low at due to high dependence on the character of precipitation
that occurs over the next 48 hours and how well the models handle
the subsequent river crests.

It is quite certain, however, that widespread rainfall affecting all
area river basins will fall between now and Monday morning. The
latest round of river forecasts were based on 48 hour wpc qpf, which
is slightly greater and shifted farther north than WFO qpf. Sref
guidance shows mean values around 2", although there are a couple
outliers with 4+", making the median QPF a little bit below 2".

Interestingly, downscaled calibrated GEFS output shows only a 40-50%
chance of exceeding 2 inches in most spots. However, we favor the
ece, whose ensemble members show strong consensus squarely in the 2-
3" total QPF range, in line with previous thinking. As noted
already, local maxima in precipitation are likely but there is
little predictability with exactly where they will occur. This of
course has potentially significant implications with what river
basins are most affected.

Grr watches/warnings/advisories
Mi... Flood watch through Monday morning for miz043>046-050>052-
056>059-064>066-071-072.

Lm... Small craft advisory until 10 pm edt Tuesday for lmz844>849.

Update... Jk
synopsis... Wdm
short term... Wdm
long term... 04
aviation... Wdm
hydrology... Tjt
marine... Jk


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
MKGM4 - Muskegon, MI 1 mi38 min E 20 G 27 44°F 1011.8 hPa42°F
45161 3 mi48 min E 19 G 23 44°F 45°F2 ft1011.5 hPa (-3.2)
45029 23 mi28 min E 19 G 27 44°F 45°F3 ft1010.6 hPa40°F
HLNM4 - 9087031 - Holland, MI 32 mi48 min E 23 G 31 44°F

Wind History for Holland, MI
(wind in knots)    EDIT      (on/off)   Help
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
24hr
NE8
NE9
G13
NE9
G13
NE12
G18
NE7
G15
E11
E9
G12
NE8
G12
NE8
G14
NE16
G20
NE21
G31
NE20
G28
E21
G30
NE15
G23
E17
G24
E20
G31
E13
G22
E15
G19
E15
G21
NE17
G24
NE21
G28
E21
G29
E24
G30
E23
G31
1 day
ago
SW5
SW3
W3
N3
NW7
N9
N10
N9
N5
N3
N11
N7
N10
G14
N9
NE7
G11
NE7
G11
N6
NE8
G11
NE7
G14
NE8
G14
NE9
G13
NE9
G14
NE11
G17
NE11
G14
2 days
ago
S17
G22
SW17
S18
SW17
G22
SW17
G21
SW17
G21
S14
G17
SW14
G17
SW14
SW13
SW16
SW21
SW17
G21
SW16
SW17
G21
SW13
G17
SW15
SW12
SW9
W7
G10
SW9
SW11
SW8
G11
SW4

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Muskegon, Muskegon County Airport, MI6 mi53 minE 16 G 247.00 miLight Rain44°F41°F89%1012.4 hPa

Wind History from MKG (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 24hrNE8E8E7NE7NE9NE7E7E4E7E10E9E16
G25
E15
G23
E11
G21
E13
G26
E13
G23
E11E13
G20
E11
G21
E15E16
G23
E15
G24
E14
G25
E16
G24
1 day ago6SW11SW7SW4N4NW4NW4N3N6N8N8N10N8N10
G18
NE9
G17
NE8N11N9N8N6NE12N9
G18
NE11NE10
2 days agoSW19
G24
SW18
G27
SW16
G28
SW13
G23
SW11
G18
SW12SW9SW9SW12SW13SW18
G23
SW15SW12SW11SW11SW13SW9W11W8W6W8SW8SW10SW9

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 GreatLakes    EDIT
Geos

Wind Forecast for Grand Rapids, MI (12,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Grand Rapids/Muskegon, MI
   (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.