Wednesday, September19, 2018 L-36.com


Marine Weather and Tides
Wilmette, IL

Version 3.4
What's New / NOTES
9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 6:34AMSunset 6:53PM Wednesday September 19, 2018 3:11 PM CDT (20:11 UTC) Moonrise 4:16PMMoonset 1:10AM Illumination 74% Phase: Waxing Gibbous; Moon at 10 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
LMZ741 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 931 Am Cdt Wed Sep 19 2018
Rest of today..Northeast winds 10 to 15 kt. Slight chance of showers and Thunderstorms. Waves 2 to 4 ft.
Tonight..East winds 10 to 15 kt becoming southeast after midnight. Slight chance of showers and Thunderstorms in the evening, then showers and Thunderstorms likely after midnight. Waves 1 to 3 ft.
Thursday..South winds 10 to 20 kt. Chance of showers and Thunderstorms in the morning. Waves 1 to 3 ft.
Thursday night..Southwest winds to 30 kt. Slight chance of showers and Thunderstorms after midnight. Waves 2 to 4 ft building to 3 to 5 ft. A small craft advisory will likely be needed.
LMZ741 Expires:201809192100;;884739 FZUS53 KLOT 191431 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 931 AM CDT Wed Sep 19 2018 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>742-192100-


7 Day Forecast for Marine Location Near Wilmette, IL
   Hourly   EDIT   Help
location: 42.08, -87.73     debug


Area Discussion for - Chicago, IL
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus63 klot 191758
afdlot
area forecast discussion
national weather service chicago romeoville, il
1258 pm cdt Wed sep 19 2018

Update
1134 am cdt
no real big changes to the forecast for today, with precip
chances still remaining this afternoon. Latest regional radar
imagery depicting area of showers and thunderstorms approaching
the CWA through eastern ia and southwest wi. Although still a
larger area, coverage has been lowering with its eastward
movement. As it continues east, it will encounter a drier and more
stable environment in place across northern il. So do think the
diminishing trend will continue. However, moisture instability is
trying to increase across portions of north central il and with
this occurring, do think that locations along and west of i-39
will have a chance to observe this precip this afternoon. Did keep
slight chance pops this afternoon for locations to the east in il
given some lower confidence in this location, but would think a
continued diminishing trend in this location should also occur. At
this time, the threat of any severe weather is low.

Rodriguez

Short term
358 am cdt
today through Friday...

timing of periodic shower and thunderstorm potential, and large
gradient changes in temperatures are main forecast concerns
through the near term, as frontal system across downstate il in
eventually lifts back north as a warm front tonight Thursday.

Early morning surface analysis places the cold front from roughly
kansas city to st louis and evansville indiana. Rap mesoanalysis
indicates the elevated (925-850 mb) frontal zone extends 100-150
miles north of the surface boundary. South-southwesterly low level
jet of 30-35 kts was oriented into eastern nebraska western iowa,
where convergence forced ascent was driving thunderstorm
development in the vicinity of sioux falls and sioux city, with a
few more isolated convective cells extending along the front into
far west central il. Activity back to the west appears to be in
association with a distinct mid-level short wave trough, which
will propagate eastward this morning, spreading elevated
convection across iowa. High-res cam guidance would indicate
showers thunderstorms spreading into northern il by early
afternoon, though with an overall weakening trend depicted.

Farther west, an upper trough over the west coast is progged to
consolidate and deepen surface low pressure over the high plains
later today, which will begin to lift the stalled downstate front
back northward as a warm front.

Renewed thunderstorm development is anticipated this evening
along north of the northward moving warm front, primarily from
northern ia southern mn eastward into southern wi and the il wi
border region. Height falls ahead of the approaching western
trough, strengthening nocturnal low level jet and upper level
divergence beneath the right entrance region to a broad upper jet
lend higher confidence to MCS development across the
aforementioned area tonight. While much of the overnight
convection is depicted just north of the forecast area, cam
guidance does warrant higher pops across far northern il as well,
especially north of the i-88 corridor. Orientation of elevated
baroclinic zone and southwesterly low level jet component suggests
the potential for slow moving, training cells which may lead to
locally heavy rainfall amounts across far northern il overnight
into early Thursday. Wpc has southern edge of their day 1
excessive rainfall outlook across far northern il.

Warm front lifts north of the il wi line during the day Thursday,
though convective outflow may slow the process somewhat. Breezy,
very warm and humid conditions are expected through the day in the
warm sector, with temperatures expected to warm to near record
levels into the lower 90s in many locations. Heat index values of
95-100 are expected during the afternoon hours.

Thunderstorm chances will be fairly low within the warm sector
Thursday, but will ramp up again Thursday night as a cold front
approaches form the west. Strong wind fields and an unusually
warm moist boundary layer for late september will support the
potential for a few strong severe storms Thursday night, though
the severe weather potential will gradually diminish further east
where storms will arrive later in the night. The front will
complete its transit of the forecast area Friday, with storm
potential ending from the northwest during the morning and early
afternoon hours. Cooler temps will arrive with the front, making
for highs in the 70s across the northwest half of the CWA Friday,
and in the low-mid 80s south.

Ratzer

Long term
358 am cdt
Friday night through Tuesday...

surface cold front pushes southeast into the ohio valley Friday
evening, while high pressure builds from the upper mississippi
valley to the western great lakes region overnight in association
with strong height rises in the wake of the departing upper
trough. Breeze north-northeasterly flow pulls much cooler and
drier air into the region, characterized by surface dew point
temps in the 40s. Steep low level lapse rates over lake michigan
will likely support some lake-induced stratocu into northeast il
into Saturday morning, while portions of north central il clear
out and see diminishing winds closer to the surface ridge axis.

This should allow for a chilly night early morning as temps to
fall into the low-mid 40s from the fox valley into north
central northwest il by sunrise Saturday morning. Sunny skies
return Saturday (after some morning lake clouds across northeast
il northwest in), though gradually diminishing northeast surface
flow maintains relatively cool temps across the region. Low level
thermal fields from models support afternoon highs ranging only
from the mid-60s along the lake to the upper 60s generally north
of the i-80 corridor, and low 70s farther to the south.

Surface high pressure across the lakes slowly drifts east
Saturday night and Sunday. Clear skies and lighter winds Saturday
night will again combine to produce cool overnight temps in the
mid-upper 40s in many locations away from the city and immediate
lake michigan shore areas. Some moderation begins Sunday, with
low-mid 70s expected away from the lake shore, where upper 60s are
likely with weaker onshore surface winds.

Guidance is in good agreement in depicting an amplifying upper
pattern late in the weekend. Developing long-wave upper trough
over the western CONUS induces elongated surface low pressure from
the central plains northeast into ontario by Monday, resulting in
return southerly low level flow across the plains and mississippi
valley regions. This in turn, leads to a moderation in
temperatures and the return of shower and thunderstorm chances as
early as Monday. Greatest precip chance appears to be late Monday
night into Tuesday morning, as deepening surface low pressure
passes north of the great lakes and trails a cold front across the
forecast area.

Ratzer

Climate
Record high temps could be jeopardy Thursday, here
are the current records:
chicago 92 (2017)
rockford 92 (1920)

Aviation
For the 18z tafs...

1258 pm... Primary forecast concern is thunderstorm potential
Thursday morning.

The area of showers and thunderstorms across eastern ia and
southwest wi is slowly dissipating and this trend is expected to
continue into this afternoon. How fast it weakens and how far east
the precip spreads is a bit uncertain so added tempo showers at
rfd but this activity is currently not expected to reach the
chicago area terminals.

A stationary front across central il will lift north as a warm
front overnight into Thursday morning. This may allow isolated to
scattered thunderstorms to develop as instability increases aloft.

If any convection develops... The best timing would likely be
centered on sunrise... But may persist into the mid morning hours
and adjusted prob timing by a few hours. After this time period...

the rest of the period appears to be dry as the warm front shifts
north of the area.

Few sct CU are possible this afternoon but there remains quite a
bit of low stratus over southern portions of the lake and this may
move inland after sunset. Confidence is fairly low so only
included few mention for lower clouds at this time. Some patchy
fog is also possible toward sunrise Thursday morning in the usual
locations.

East northeast winds will continue this afternoon and are expected
to slowly shift east southeasterly this evening and more to the
south southeast by sunrise. However... Any precip Thursday morning
is likely going to produce outflows and erratic winds so changes
to the wind forecast Thursday morning are possible. Eventually...

winds will shift more south southwest with the gradient tightening
and the low levels mixing by mid late afternoon. Thus gusts into
the mid 20kt range look reasonable toward the end of the 30 hr
ord mdw tafs. Cms

Lot watches warnings advisories
Il... None.

In... None.

Lm... None.

Visit us at http: weather.Gov chicago (all lowercase)
follow us on facebook... Twitter... And youtube at:


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
45174 5 mi32 min NNE 12 G 16 67°F 71°F3 ft65°F
FSTI2 8 mi132 min ENE 5.1 68°F
CHII2 - Chicago, IL 14 mi42 min N 14 G 15 67°F 64°F
CNII2 17 mi27 min N 8.9 G 13 69°F 62°F
45186 20 mi32 min NNE 7.8 67°F 71°F2 ft
WHRI2 - Waukegan Harbor, IL 20 mi32 min NE 12 G 14 66°F
JAKI2 22 mi132 min NNE 12 G 17 69°F
CMTI2 - 9087044 - Calumet, IL 26 mi42 min N 11 G 13 69°F 1016.8 hPa65°F
45187 29 mi32 min 66°F 70°F2 ft
KNSW3 - Kenosha, WI 35 mi72 min ENE 11 G 14 65°F 1018.3 hPa (-0.0)
BHRI3 - Burns Harbor, IN 43 mi32 min NNE 7 G 7 65°F 1017.3 hPa
45170 46 mi32 min NNE 12 G 16 66°F 71°F3 ft65°F

Wind History for Calumet Harbor, IL
(wind in knots)    EDIT      (on/off)   Help
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
1
PM
2
PM
Last
24hr
N10
G15
N8
E7
E7
N5
G8
N10
G13
NE6
G9
NE6
G9
N3
G8
N5
N6
G10
N8
G11
N6
G10
N8
G12
NE6
G10
NE7
G11
NE7
G10
NE6
G9
NE6
NE4
N7
N9
G14
N9
G14
N11
G15
1 day
ago
NE6
NE5
NE5
E4
E3
E3
S2
--
SW1
SW1
SW2
SW3
W5
G10
W2
N6
N7
G12
N6
N8
G13
N10
G16
SW2
NW3
G8
NE7
N8
G12
N10
G15
2 days
ago
NE8
G11
NE7
G11
NE9
G12
NE12
NE10
G13
E6
G9
E4
E5
E5
SE4
SE6
G10
S3
SE2
S3
S2
SW2
S1
SW3
S3
SW3
G6
S1
G4
NE4
N6
G11
NE5

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago / Wheeling, Pal-Waukee Airport, IL9 mi80 minNNE 910.00 miA Few Clouds71°F60°F68%1017.7 hPa
Chicago, Chicago-O'Hare International Airport, IL11 mi81 minNE 1010.00 miMostly Cloudy73°F62°F69%1017 hPa
Chicago, Chicago Midway Airport, IL20 mi79 minNE 1010.00 miMostly Cloudy76°F62°F62%1016.2 hPa

Wind History from PWK (wind in knots)
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
1
PM
2
PM
3
PM
Last 24hrS7S7N3E8E6N4N3CalmCalmN5N4CalmNE5NE5NE4E3E3E7NE6E6NE7NE9NE9NE9
1 day ago5E4SE4CalmCalmCalmCalmCalmCalmCalmCalmN3NE9NE7N6NE6N9NW4NW4W6N13
G20
N7N8NW7
2 days agoE7E9E7E4E3SE3SE3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmN533CalmW6

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)   HelpWeather Map
wmap_A
GOES 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
Wind Forecast for Chicago, IL (16,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Chicago, IL
   (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.