Thursday, March30, 2017 L-36.com


Marine Weather and Tides
North Chicago, IL

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 6:33AMSunset 7:17PM Thursday March 30, 2017 3:27 PM CDT (20:27 UTC) Moonrise 8:27AMMoonset 10:29PM Illumination 12% Phase: Waxing Crescent; Moon at 3 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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LMZ740 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 928 Am Cdt Thu Mar 30 2017
.small craft advisory in effect through late Friday night...
Rest of today..East winds 20 to 25 kt becoming northeast. Rain showers and a chance of Thunderstorms. Waves 6 to 9 ft occasionally to 11 ft.
Tonight..Northeast winds 15 to 25 kt becoming north. Rain showers likely. A chance of Thunderstorms in evening. Waves 4 to 7 ft occasionally to 9 ft.
Friday..North winds to 30 kt. Chance of rain through the day. Waves 4 to 7 ft occasionally to 9 ft building to 5 to 8 ft occasionally to 10 ft in the afternoon.
Friday night..North winds to 30 kt diminishing to 10 to 20 kt after midnight. Mostly cloudy in the evening then becoming partly cloudy. Waves 5 to 8 ft occasionally to 10 ft subsiding to 3 to 5 ft occasionally to 7 ft late.
LMZ740 Expires:201703302245;;315773 FZUS53 KLOT 301428 NSHLOT NEARSHORE MARINE FORECAST NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 928 AM CDT THU MAR 30 2017 FOR WATERS WITHIN FIVE NAUTICAL MILES OF SHORE ON LAKE MICHIGAN WAVES ARE PROVIDED AS A RANGE OF SIGNIFICANT WAVE HEIGHTS, WHICH IS THE AVERAGE OF THE HIGHEST 1/3 OF THE WAVES, ALONG WITH THE AVERAGE HEIGHT OF THE HIGHEST 10 PERCENT OF THE WAVES WHICH WILL OCCASIONALLY BE ENCOUNTERED. LMZ740>742-302245-

7 Day Forecast for Marine Location Near North Chicago, IL
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location: 42.35, -87.79     debug


Area Discussion for - Chicago, IL
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Fxus63 klot 301929
afdlot
area forecast discussion
national weather service chicago/romeoville, il
229 pm cdt Thu mar 30 2017

Short term
229 pm cdt
through Friday..

Main concerns are threat for strong to severe
thunderstorms this afternoon through early this evening south of
i-80 and unseasonably chilly and blustery conditions on Friday,
especially near the lake shore.

Continuing to monitor for the threat for strong to severe
thunderstorms south of i-80 later this afternoon, and particularly
south of the kankakee river. The convection that has been lifting
north-northeast across the CWA is associated with a short-wave
disturbance ahead of the closed mid-upper low over missouri. Given
strong moist transport flowing over warm front and pwat values
around or over 1", main threat prior to this activity exiting per
latest radar trends is heavy rainfall and localized
ponding/flooding on some roads. This is especially the case with
saturated grounds due to what already fell overnight. Large areal
flood advisory that was issued remains in effect through 7pm.

Otherwise, can't rule out some small hail to pea or dime size
(especially south of i-80) for stronger cores with cold
temperatures aloft/700 mb temps near or below 0 celsius resulting
in fairly low freezing levels and wet bulb zero heights.

The main risk for strong to severe thunderstorms looks to evolve
over or just south of our southern CWA counties in the mid to late
afternoon, particularly south of the kankakee river. What occurs
will likely be associated with arc of thunderstorms lifting
north-northeast from stl area. Good speed shear will be in place
with strong lower and mid- level flow, but directional shear from
850-500 limited given meridional nature of closed low. As low
pressure just north of stl lifts northeast this afternoon, surface
warm front will continue to progress north and likely reach areas
south of the kankakee river, namely portions of ford, iroquois,
benton, and japser and newton counties.

Temperatures in the 60s and dew points approaching or just above
60 topped by relatively steep lapse rates could yield 500-1000
j/kg of SBCAPE near and south of warm front based off obs and
latest rap forecast. In presence of supportive bulk shear,
embedded low topped supercell structures and small scale line are
favored. With earlier mentioned parameters in favor of hail,
threat for marginally severe hail could extend northward to near
i-80 with elevated MUCAPE north of surface warm front. Where warm
sector reaches, anticipating backed (southeast/east-southeast)
surface winds to result in decent veering in lowest 1km, which
could be enough low-level shear/srh for an isolated tornado risk.

In addition, downdrafts from strongest warm sector storms would
pose a risk for damaging winds. Overall thinking hasn't changed
much since previous update and will continue to pay close
attention to observational trends. The threat for any severe
weather should end during the early evening hours.

Approximately 1000 mb surface low will then track east-northeast
south of i-80 tonight into Friday morning, with system
deformation rain/showers diminishing and then shifting east on
Friday morning (with lowering pops in grids). Tight pressure
gradient between the exiting low pressure and high pressure around
1020 mb over the northern great lakes will result in strong and
gusty north to north-northeast winds, with gusts of 25-30 mph near
lake michigan. Expansive stratus will keep skies locked in
overcast, so temperatures will struggle to climb into the mid 40s
away from the lake. Strong northerly boundary layer flow down the
length of the still cold waters of lake michigan will keep
high temperatures even colder near the lake, in the upper 30s to
around 40. March will go out like a lion temperature wise with a
decided brisk/wintry feel, so be sure to dress accordingly.

Castro

Long term
229 pm cdt
Friday night through Thursday...

the upper level split flow pattern will continue through the weekend
and most of next week with some model signals toward a pattern shift
late next week/next weekend toward a more amplified pattern. Such
evolution would bring larger scale mean ridging established over
western north american and mean troughing in the east.

In the meanwhile, main forecast concerns continue to be on
periodic rain with scattered thunderstorms, first later Sunday
into early Monday, with a more potent system with the potential
for more soaking rains Wednesday into Thursday.

As the surface and upper low continue to exit to our east Friday
evening, surface ridging will continue to build into the area
from the west. This combined with rising heights aloft will help
yield a relatively pleasant early spring day for the area
Saturday, albeit chilly for areas near lake michigan with a
prevailing synoptic north flow. With north winds moving across the
40-44 degree surface water, expect MAX temps to hold in the 40s
with highs into the low- mid 50s as you further inland.

The next in the parade of upper level troughs will approach the area
Sunday. Despite a weakening trend as the trough ejects out of the
mountains and into the plains, expect clouds to thicken following
by rain overspreading the area west to east Sunday afternoon.

Better low level forcing remains well south with unphased upper
low moving into the mid mississippi valley inhibiting better
moisture flow this far north. Still a period or two of light rain
likely with upper system and associated surface inverted trough
then exiting to the east across indiana Monday.

With rising heights Tuesday expect a milder day but MAX temps will
again be held back near the lake with the prevailing NE flow.

Significant model differences in the next in the series of upper
lows... This one moving across the central plains Tuesday and
Wednesday. Forecast reflects blended solution with general agreement
toward a fairly dynamic system and potential for another round of
soaking rain and scattered embedded thunderstorms Wednesday into
Thursday.

Ed f

Aviation
For the 18z tafs...

potential for thunderstorms near/south of the terminals
(especially mdw/gyy) and ifr/lifr CIGS are the primary aviation
concerns this afternoon. Gusty north-northeast winds near 25 kts
are expected Friday.

Surface low pressure was just north of stl this midday, with a
warm front extending across central il north of spi to near ind.

The low will continue to track along this northward lifting warm
front through this evening, passing south of the terminals. Areas
of rain/embedded thunderstorms were developing northward into
northern il, and this is expected to persist this afternoon.

Strong to severe thunderstorms will likely develop into/south of
a pnt-ikk to vpz line through late afternoon as well, before
moving off to the east/southeast of the area by early this
evening. Low confidence in thunder coverage at rfd/ord, though do
expect some storms north of the warm front.

Ifr CIGS are expected to gradually lower to lifr tonight as light
rain persists into cool low-level air mass north of low track.

Rain should gradually diminish/end from the west Friday morning.

Surface winds from the ene will gradually shift nne overnight,
becoming gusty by early Friday. Gusts around 25 kts are expected,
possibly a few kts higher during Friday afternoon.

Ratzer

Marine
156 pm cdt
surface low pressure tracking across central illinois this
afternoon will move east into ohio overnight, with east-northeast
winds becoming north-northeast by Friday morning. Forecast
soundings support winds generally in the 25-30 kt range, though
there may be a brief period of marginal gale force gusts just
before sunrise on the northern portion of the western (wi) shore.

The gradient will begin to weaken Friday afternoon as the low
continues to pull away and redevelop off the atlantic coast, and
weak high pressure spreads southeast across the upper midwest and
western lakes into Saturday. The surface high pressure ridge will
drift east across lake michigan by Sunday morning, allowing winds
to veer to the southeast during the day. A trough of surface low
pressure will approach from the west Monday morning, with low
centers passing north of lake superior and farther south across
the lower mississippi/tennessee river valleys. Medium range model
guidance depicts a stronger low may impact the midwest Wednesday,
passing near or just south of lake michigan. This may result in a
period of stronger easterlies Wednesday which would shift to the
north-northwest Wednesday night into Thursday.

Ratzer

Lot watches/warnings/advisories
Il... None.

In... None.

Lm... Small craft advisory... Winthrop harbor to burns harbor until
4 am Saturday.

Small craft advisory... Burns harbor to michigan city in until 3 pm Thursday.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WHRI2 - Waukegan Harbor, IL 1 mi48 min NNE 18 G 21 39°F
KNSW3 - Kenosha, WI 17 mi28 min NE 9.9 G 12 39°F 1006.8 hPa (-1.7)
FSTI2 27 mi88 min N 36 40°F
CHII2 - Chicago, IL 32 mi38 min NNE 16 G 17 41°F 41°F
OKSI2 32 mi88 min NNE 11 41°F
CNII2 35 mi13 min NNE 14 40°F
JAKI2 41 mi88 min NE 11 41°F
CMTI2 - 9087044 - Calumet, IL 45 mi40 min N 12 G 18 40°F 1001.7 hPa40°F
MLWW3 - Milwaukee, WI 48 mi38 min NNE 8 G 9.9 37°F

Wind History for Calumet Harbor, IL
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Last
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N12
G16
NE15
G19
NE12
G16
NE6
G9
NE12
NE11
G14
NE11
G14
NE11
G15
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NE10
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G13
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G24
NE15
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NE12
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G20
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G12
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NE13
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N6
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1 day
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N11
G15
N11
N9
G13
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G12
N9
N6
G10
N5
G9
N10
N7
G10
N7
NE8
NE7
NE7
N5
G9
N6
NE6
N6
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N12
G15
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N12
G17
N11
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G18
2 days
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N4
G7
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G10
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G10
N6
G9
N7
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G9
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NW8
G11
NW11
G15
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G14
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G16
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G20
N12
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G18
NW12
G15
NW13
G17
NW12
G16
NW14
G17
NW12
G18
N13
G16
N13
G17
NW11
G16

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago/Waukegan Regional Airport, IL6 mi33 minNE 82.50 miLight Rain Fog/Mist40°F39°F100%1006.4 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL18 mi36 minNE 144.00 miLight Rain Fog/Mist41°F41°F100%1004.5 hPa
Kenosha, Kenosha Regional Airport, WI18 mi35 minENE 91.50 miRain Fog/Mist40°F37°F93%1007.2 hPa

Wind History from UGN (wind in knots)
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Last 24hrNE7NE13NE10
G20
N10NE11
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N11
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G23
E17
G25
E17
G24
E15
G22
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E14E13E14
G21
--NE10E9E8E13NE15
G21
NE7NE8
1 day agoNE12NE8NE6NE6NE5NE7NE5NE6N5N4CalmCalmNE3NE5N4CalmNE4NE6NE7NE8NE8NE9NE6NE8
2 days agoNE7NE5NE7NE8NE4NE5NE5N5N45N7N7N6N5N6N6N6N12N9
G17
NE11NE11NE12NE10NE10

Tide / Current Tables for
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Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Midwest    EDIT
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Wind Forecast for Chicago, IL (16,3,4,5)
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Ground Weather Radar Station Chicago, IL
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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.