Monday, March27, 2017

Marine Weather and Tides
Copper Harbor, 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 7:01AMSunset 7:44PM Monday March 27, 2017 10:37 AM EDT (14:37 UTC) Moonrise 6:31AMMoonset 6:30PM Illumination 0% Phase: New Moon; Moon at 0 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 Copper Harbor, MI
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location: 63.03, -82.89     debug

Area Discussion for - Marquette, MI
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Fxus63 kmqt 271145
area forecast discussion
national weather service marquette mi
745 am edt Mon mar 27 2017

Short term (today and tonight)
issued at 444 am edt Mon mar 27 2017
water vapor imagery and rap analysis show weakening remnants of a
mid-level low moving across northern lower mi/lake huron. Associated
deformation band of -ra that affected central upper mi earlier in
the night is shifting E and weakening. Upstream, a couple of
shortwaves, one over the dakotas and a weaker one over mn, are
generating some sct radar returns to the w, but little in the way of
pcpn per sfc obs.

As upstream shortwaves shift E today, some -ra may streak across the
fcst area. Forcing is weak, but presence of upstream radar returns
along with a number of models indicating some pcpn suggest some low
pops are warranted except over the keweenaw. If there is any pcpn,
it will shift E and SE with time today, exiting the E early this
evening. Temps are currently hovering right around freezing at many
locations, so not out of the question that there could be spotty
icing early this morning where pcpn occurs. Expect high temps in the
mid 30s to lower 40s today. If low clouds hold thru the day
everywhere, temps will not get out of the mid 30s.

Dry weather will follow tonight as sfc high pres ridge builds into
the upper great lakes. Increasingly anticyclonic low-level flow
should help to break up or decrease coverage of low clouds where
they still linger after this aftn. Temps should fall back to the mid
20s to lower 30s. Will be colder if skies clear out in some

Long term (Tuesday through Sunday)
issued at 444 am edt Mon mar 27 2017
tranquil conditions expected Tue and Wed before possible storm
system brings wintry precip back to the region late this week. High
pressure over northern canada gradually expands a ridge toward upper
great lakes. Potential there may be sct-bkn low clouds over cntrl
upper michigan on Tue with the NE winds with the high, but seems
that overall dry airmass with the high will cut down this potential.

Even with mostly sunny skies, NE onshore winds results in highs only
in the mid to upper 30s near lk superior Tue into wed. Farther
inland though mixing to h85 with the sunshine should result in highs
reaching the upper 40s near the wi border and possibly into lower
50s at lnl and imt with the sunshine and little if any snow cover
for those areas.

Uncertainty still present for late week system. ECMWF and gem still
showing southern stream upper trough phasing with northern stream
trough across the great lakes late Thu into fri. Result is sfc low
over the southern plains Thu morning lifting across the western ohio
valley Thu and to the central great lakes vcnty of lk huron by fri
morning. Main surge of precip in this setup would arrive later thu
aftn over the south CWA and spread over all but far western CWA thu
night into Fri morning. Precip would be enhanced on northwest side
of sfc low due to right entrance region of upper jet streak northern
ontario to new england. GFS still mainly south of here with the
system but compared to 24 hr ago there is trend farther north with
upper low/sfc low and associated precip which is now as far north as
central wi to northern lower mi (24 hr ago GFS showed no QPF even
into southern wi or southern lower mi). Another trend emerging from
the farther north ECMWF and gem is a cooler/snowier idea. QPF from
gem and ECMWF and assuming most precip falls as snow would suggest
some areas of CWA could see need for at least an advy late Thu into
fri morning. Won't emphasize that too much yet though given the
model differences in handling this system. Only change to blended
consensus at this point was to increase sky cover Thu into Fri and
lower temps slightly.

Behind the system for the weekend seems area will be affected by
northern branch of split flow regime. Just kept with blended
consensus with various solutions on strength of any systems by that

Aviation (for the 12z tafs through 12z Tuesday morning)
issued at 745 am edt Mon mar 27 2017
abundant low-level moisture over the area this morning should
maintain lifr conditions at kiwd/kcmx/ksaw with CIGS near landing
mins, at least early on. Drier air will be filtering into the area
during the day, but there is uncertainty in how quickly low clouds
will lift and scatter out. At this point, with low-level flow
becoming more anticyclonic into western upper mi as high pres ridges
into the area, kiwd/kcmx are probably more likely to see conditions
improve toVFR this aftn than ksaw. At ksaw, lifr conditions may
only improve to ifr this aftn, then to MVFR this evening. Should see
improvement toVFR tonight, but it is quite possible that ifr or
even lifr conditions could return if low-level drying is more

Marine (for the 4 am lake superior forecast issuance)
issued at 444 am edt Mon mar 27 2017
with no significant weather systems affecting the upper great lakes
this week, no gales are expected on lake superior. In fact, winds
will mostly be under 20kt. Depending on the track/strength of low
pres tracking from the southern plains to the lower great lakes late
this week, thu/fri is on the only period that may have higher winds
than currently fcst.

Mqt watches/warnings/advisories
Upper michigan...


Lake superior...


Lake michigan...


Short term... Rolfson
long term... Jla
aviation... Rolfson
marine... Rolfson

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Wind Forecast for Marquette, MI (10,2,3,4)
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Ground Weather Radar Station Marquette, MI
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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 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 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.