Friday, September21, 2018 L-36.com


Marine Weather and Tides
Grosse Pointe, MI

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9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 7:17AMSunset 7:31PM Friday September 21, 2018 11:18 AM EDT (15:18 UTC) Moonrise 5:11PMMoonset 2:38AM Illumination 88% Phase: Waxing Gibbous; Moon at 12 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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LCZ460 Lake St Clair- 353 Am Edt Fri Sep 21 2018
.small craft advisory in effect from 8 am edt this morning through this evening...
Today..Southwest winds 15 to 20 knots with gusts to 30 knots increasing to 20 to 25 knots with gusts to 30 knots early in the afternoon...then becoming west 15 to 20 knots late in the afternoon. Partly Sunny. A chance of light showers in the afternoon. Waves 1 to 3 feet.
Tonight..Northwest winds 15 to 20 knots with gusts to 30 knots. Partly cloudy. Waves 1 to 3 feet.
Saturday..North winds 10 to 15 knots becoming light and variable. Partly Sunny. Waves 2 feet or less.
Saturday night..Light and variable winds. Mostly clear. Waves 2 feet or less.
Sunday..Northeast winds 5 to 10 knots. Mostly Sunny early in the morning becoming clear. Waves 2 feet or less.
Monday..Southeast winds 10 to 15 knots. Partly cloudy. A chance of showers and Thunderstorms. Waves 2 feet or less.
Tuesday..West winds 15 to 20 knots. Mostly cloudy with showers likely and a chance of Thunderstorms. Waves 1 to 3 feet.
LCZ460 Expires:201809212015;;971366 FZUS63 KDTX 210753 GLFSC Lake St Clair Forecast National Weather Service Detroit/Pontiac MI 353 AM EDT Fri Sep 21 2018 Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS...A low pressure system at 29.40 inches over far western Lake Superior will deepen to 29.20 inches this morning as it lifts into Ontario. The trailing cold front will sweep southeast across the central Great Lakes this afternoon as this low races into Quebec while deepening to 28.90 inches. A large high pressure system at 30.30 inches will build into the area this weekend. LCZ460-212015-


7 Day Forecast for Marine Location Near Grosse Pointe, MI
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location: 42.38, -82.9     debug


Area Discussion for - Detroit/Pontiac, MI
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Fxus63 kdtx 211427
afddtx
area forecast discussion
national weather service detroit pontiac mi
1027 am edt Fri sep 21 2018

Update
A prefrontal low-mid level moist axis convergence has been
responsible for the region of showers this morning across much of the
northwestern portion of the forecast area. These showers have been
weakening over the last couple hours. This trend will continue
through the rest of the morning. Diurnal heating and the resultant
destabilization will however support convective redevelopment this
afternoon (mainly east of a sandusky to hillsdale line) as this moist
plume convergence axis continues on an eastward path. The main point
of uncertainty at this stage is whether convective initiation fires
over the eastern counties or east of SE mi (in ontario). The eastward
movement of an outflow boundary from the morning showers (noted on
radar and satellite) will be east of the forecast area by afternoon
and may very well prove to be the focus for convective initiation
this afternoon. Can not however ignore the clear skies over the
eastern third of the forecast area late this morning. This will
afford an opportunity for weak destabilization by early afternoon.

This window of destabilization will be brief (1pm to 4 pm) before the
moist axis and instability heads east of the region. Even with weak
instability (0-1km ml CAPE just under 1k j kg) a strongly sheared
environment (50-60 knots deep layer shear) and some degree of sub
cloud layer dry air will make strong damaging wind gusts possible
with any convection that is able to develop early this afternoon.

The period of clear skies in the east this morning may push a few
peak gusts over 40 mph in the warm sector today within the gusty
southwest flow. The longer duration 40+ mph winds are still expected
across the saginaw valley and thumb region in the post frontal
westerly flow. So no adjustments to the wind headlines will be made
this morning.

Prev discussion
Issued at 624 am edt Fri sep 21 2018
aviation...

winds will be a concern today into tonight as a strong low pressure
system lifts through northern michigan this morning, pulling a cold
front through lower mi this afternoon. Southwesterly winds ahead of
the front will gust to 30 to 40 knots (south to north respectively)
as daytime mixing taps into a low level jet that has 40 knots down
below 3kft. Helping the strongest winds to the surface could be a
line of showers, and possibly thunderstorms, along the front. These
low topped cells may bring slightly higher winds to the surface in a
short window from 15-19z this afternoon. Highest winds should be
near mbs and fnt with lower winds across the detroit terminals.

Winds will drop off quickly after dark as the veer to the northwest
behind the front.

For dtw... Llws could be problematic into the morning with 40 knots
down to 2000 ft agl. Forecast priority remains southwest
sustained gusts as column becomes well environment. Potential exists
to exceed the crosswind threshold. Will continue to watch for
convection potential along the front though expectations are
currently for mainly showers. Regardless, higher gusts could occur
along the front.

Dtw threshold probabilities...

* moderate for ceilings 5000 ft today.

* moderate for thunderstorms impacting terminal in the 16z-19z time
frame.

* moderate for crosswind threshold 240-260 degrees 30-35 knots
to be exceeded after 16z.

Prev discussion...

issued at 401 am edt Fri sep 21 2018
discussion...

dynamic mid level wave now noted on waver vapor lifting across
minnesota will accelerate east-northeast over the next 24 hours,
reaching eastern quebec by Saturday morning. This trajectory will
direct the associated deepening surface low into central ontario,
while sweeping the attendant strong cold front across the lower
peninsula today. Solid kinematic response well underway with this
system, prompting an increase and downstream expansion of stronger
winds within the burgeoning height fall center. Moist mild pre-
frontal environment now entrenched locally, governed by increasing
deep layer southwest flow. Onset of daytime heating and ensuing
growth to the boundary layer will yield increasingly gusty pre-
frontal conditions this morning. The midday frontal timing will
leave a modest window for diurnal destabilization - MLCAPE in excess
of 1000 j kg assuming a temperature dewpoint of 82 69. This will
bring a limited opportunity for a broken line of low topped
convection to emerge along the advancing cold frontal slope,
centered 16z-19z early this afternoon. Greater potential exists
southeast of a howell to flint to bad axe line. Any development
raises concern for the possibility of strong wind gusts mixing down,
with 50 kt winds residing at 800mb. The ensuing cold air advection
timed favorably to capitalize on peak diurnal turbulent mixing will
then maintain gusty post-frontal westerly winds throughout the
latter half of the day. Outside of any convection, model guidance
uniformly support wind gusts today in the 35 to 40 mph range,
strongest winds with northward extent. Recent hrrr rap output and
ensemble probabilistic wind guidance lend moderate confidence for
gusts to reach near wind advisory criteria at times across the tri-
cities and thumb corridor. In collaboration with surrounding
offices, went ahead with an advisory for this corridor.

Winds ease through the evening as the gradient relaxes and diurnal
mixing ceases. A period of stronger cold dry air advection commences
during time. The degree of low level drying will dictate the extent
of low stratus that persists overnight. A moderate northerly flow
will persist tonight immediately downstream of building high
pressure. This will limit the potential for greater radiational
cooling, despite dewpoints plummeting into the lower and middle 40s.

Lows Saturday morning generally bottoming out in the 45 to 50 degree
range.

Dry and cooler conditions will hold through the upcoming weekend, as
high pressure gradually transits the region. Coldest conditions
noted Saturday, as 850 mb temperatures hover in the single digits.

This will favor highs of lower and middle 60s... Or roughly 5-10
degrees below normal. Gradual airmass modification as upper heights
slowly climb will bring daytime highs back closer to normal on
Sunday.

Marine...

a strengthening low pressure system will exit lake superior into
ontario this morning. This low will pull a cold front through the
great lakes today which will result in a window of showers and
possibly thunderstorms. In addition, a tight pressure gradient and
strong wind field very low in the column will combine to produce
gale force winds today into tonight across the lake huron basin. The
day will begin with low end southwesterly gales ahead of the front
but as northwest flow ushers in colder air behind the front early
this afternoon, winds will increase to around 40 to 45 knots.

Farther away from the center of the low, lakes st clair and erie
will likely stay below gales today thus the small craft advisories
will continue. The caveat would be any brief higher gust along or
just behind the front. High pressure will build in quickly behind
this system by Saturday, bringing improved marine conditions for the
weekend.

Dtx watches warnings advisories
Mi... Wind advisory until 6 pm edt this evening for miz047>049-053>055.

Beach hazards statement until 8 pm edt this evening for miz049-055.

Lake huron... Gale warning until midnight edt tonight for lhz361>363-421-422-
441>443-462>464.

Lake st clair... Small craft advisory until midnight edt tonight for lcz460.

Michigan waters of lake erie... Small craft advisory until midnight edt tonight for lez444.

Update... ... .Sc
aviation... ..Drk
discussion... Mr
marine... ... .Drk
you can obtain your latest national weather service forecasts online
at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CLSM4 - St. Clair Shores, MI 6 mi18 min SSW 13 G 26 84°F 1009.5 hPa (-1.3)
45147 - Lake St Clair 12 mi18 min SSW 18 G 19 76°F 69°F2 ft1008.8 hPa (-1.0)
AGCM4 26 mi30 min 78°F 70°F1009.5 hPa
THLO1 - Toledo Light No. 2 OH 41 mi28 min SW 21 G 24 81°F
MBRM4 - 9014090 - Mouth of the Black River, MI 48 mi30 min 81°F 1007.8 hPa

Wind History for Fort Gratiot, MI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Coleman A Young Municipal Airport, MI7 mi85 minSSW 11 G 2010.00 miFair81°F66°F62%1009.3 hPa
Selfridge Air National Guard Base, MI17 mi82 minSSW 1310.00 miA Few Clouds82°F69°F67%1009.2 hPa
Troy, Oakland/Troy Airport, MI19 mi83 minSW 12 G 2310.00 miPartly Cloudy81°F66°F62%1010.5 hPa
Detroit/Grosse Ile, Grosse Ile Airport, MI24 mi83 minSSW 10 G 1510.00 miFair81°F68°F68%1010.5 hPa

Wind History from DET (wind in knots)
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Last 24hrSE3SE11SE7SE5E8E8E7E8SE4SE8SE5E3CalmCalmS6S7S8S8S9SW13
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1 day agoSE6E4E4SE3N3NE6E7E5E6E4NE4NE3NE5CalmSE5NE4SE5CalmCalmNE4SE3CalmSE3NE3
2 days agoCalmCalmS4NW8E8E5E6NE6E5NE7NE9E7E5NE8E4NE5NE4NE4N7N5NE4NE5NE53

Tide / Current Tables for
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Weather Map and Satellite Images
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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 Detroit/Pontiac, MI (11,2,3,4)
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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.