Marine Forecasts

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7 Day Forecast for Marine Location Near Grand Ledge, MI

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Area Discussion for - Grand Rapids, MI

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FXUS63 KGRR 161020 AFDGRR

Area Forecast Discussion National Weather Service Grand Rapids MI 620 AM EDT Thu Jul 16 2020

LATEST UPDATE . Aviation

SYNOPSIS. Issued at 322 AM EDT Thu Jul 16 2020

- Rain into mid morning then partial clearing

- Pleasant Friday with considerable sunshine

- Warm and humid weekend thunderstorms more so Sunday

- Could be warm and wet next week but not hot

DISCUSSION. (Today through next Wednesday) Issued at 322 AM EDT Thu Jul 16 2020

-- Rain into mid morning then partial clearing --

As we expected the southern stream shortwave developed a surface low that has brought rain to most of our southern and central CWA this morning. The system is in the jet entrance region of a departing northern stream shortwave. It has been tracking largely to the east near I-80 and it should continue to do so. What will slow the end of the rain down is there is an upstream shortwave digging into the large scale trough at upper levels over our area. That will help to keep deformation rain going into mid morning over a good part of the area. Once the trailing shortwaves clears the area later this afternoon we should see clearing skies.

Rainfall amounts have mostly been in the .2 to .3 inch range so far near and south of I-96. We could get another .25 inches or so from this event. That sort of rainfall would not result in any flooding issues.

Since there is a considerable amount of clouds associated with this system and it will take to later in the day for the skies to start to clear it now seems we will not develop enough surface based instability for afternoon thunderstorms. This idea is supported by the SPC SREF which has a less than 5 percent chance of thunderstorms this afternoon over any part of our CWA.

--Pleasant Friday with considerable sunshine--

Once this current system moves east we get shortwave ridging at mid and upper levels for Friday. That should mean a sunny day with light winds and warm afternoon temperatures. There is a fairly strong subsidence inversion around 2000 to 3000 ft, so that should help limit how warm it gets and also keep afternoon convection from developing and keep the high temperatures limited to the mid 80s.

-- Warm and humid weekend thunderstorms more so Sunday--

The next upstream Pacific system is just now coming onshore over western Canada and by the states of Washington and Oregon. This system merges into the longwave trough over the Great Lakes and the eastern 1/2 of Canada over the weekend. The polar jet does sage south into Michigan by midday Sunday. Once there a series of weaker Pacific shortwaves keep Michigan more or less in the entrance region of the polar jet into mid week.

What this means for us is a surge of hot air on Saturday. Model thickness, and the 1000 mb, 925 mb and 850 mb temperatures all suggest highs in the mid 90s Saturday. Because of the approaching cold front Saturday we should not have a strong subsidence inversion so Saturday may well be the hottest day of the month if we can keep the clouds away long enough.

-- Could be warm and wet next week but not hot--

The way this system comes in over the weekend it would seem to me the associated convection will not move into our area till late Saturday night or Sunday. Since we stay for the most part in the jet entrance region into Wednesday do not be surprised if our forecast trends wetter early next week. The front will stall near us. Being on the north side of the front will keep our highs in the 80s but being so close to the front I would expect periods of thunderstorm into Wednesday. After that it seem some sort of ridging tries to move back into this area and if that happens the heat comes back and we dry out.

AVIATION. (For the 12Z TAFS through 12Z Friday morning) Issued at 616 AM EDT Thu Jul 16 2020

Low pressure in NW Indiana will slowly move east today and take the extensive cloud shield with it. Radar currently shows light rain at a few of the terminals, but there's been a decrease in echos over the last few hours. We'll see the rain end this morning. the clearing line has made it to Manistee and will coninue to slowly move east. Current IFR/MVFR will continue through the morning before improving to VFR this afternoon from west to east.

MARINE. Issued at 322 AM EDT Thu Jul 16 2020

The surge of warm air on Saturday may be strong enough that we would need a small craft advisory and likely beach hazard statements.

GRR WATCHES/WARNINGS/ADVISORIES. MI . None. LM . None.

SYNOPSIS . WDM DISCUSSION . WDM AVIATION . 04 MARINE . WDM

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Weather Reporting Stations

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Stations	Dist	Age	Wind	Air Temp	Water Temp	Waves	Pressure	DewPt
HLNM4 - 9087031 - Holland, MI	78 mi	70 min			63°F
MKGM4 - Muskegon, MI	90 mi	30 min	E 6 G 8.9	69°F			1014.1 hPa	66°F
SBLM4 - Saginaw Bay Light #1, MI	91 mi	40 min	ENE 17 G 19	69°F			1014.2 hPa (+0.0)

Wind History for Holland, MI

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Capital Region International Airport, MI	8 mi	47 min	ENE 8	5.00 mi	Fog/Mist	68°F	66°F	93%	1013.3 hPa
Mason, Mason Jewett Field Airport, MI	21 mi	45 min	ENE 5	4.00 mi	Light Drizzle	68°F	68°F	100%	1013.5 hPa
Ionia County Airport, MI	21 mi	45 min	NNE 8	10.00 mi	Overcast	66°F	63°F	93%	1013.9 hPa

Link to 5 minute data for KLAN

Wind History from LAN (wind in knots)

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Tide / Current Tables for

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Tide / Current Tables for

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Weather Map

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GEOS 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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East

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Wind Forecast for Grand Rapids, MI (8,2,3,4)

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Ground Weather Radar Station Detroit, MI

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