Monday, August19, 2019 L-36.com


Marine Weather and Tides
Lake Forest, IL

Version 3.4
NOTICE
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 6:01AMSunset 7:48PM Monday August 19, 2019 12:08 PM CDT (17:08 UTC) Moonrise 10:03PMMoonset 9:48AM Illumination 83% Phase: Waning Gibbous; Moon at 19 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
LMZ740 Winthrop Harbor To Wilmette Harbor- Wilmette Harbor To Northerly Island- Northerly Island To Calumet Harbor- 955 Am Cdt Mon Aug 19 2019
Rest of today..Northeast winds 5 to 10 kt becoming east 10 to 15 kt in the early afternoon. Mostly Sunny. Waves 1 to 2 ft.
Tonight..East winds 5 to 10 kt. Partly cloudy. Waves 1 ft or less.
Tuesday..Southeast winds 10 to 15 kt. Chance of showers and Thunderstorms. Waves 1 ft or less.
Tuesday night..Southwest winds 5 to 10 kt becoming west after midnight. Chance of showers and Thunderstorms through the night. Waves 1 ft or less.
LMZ740 Expires:201908192115;;470154 FZUS53 KLOT 191455 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 955 AM CDT Mon Aug 19 2019 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>742-192115-


7 Day Forecast for Marine Location Near Lake Forest, IL
   Hourly   EDIT   Help
location: 42.24, -87.86     debug


Area Discussion for - Chicago, IL
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus63 klot 191641 aaa
afdlot
area forecast discussion... Updated
national weather service chicago romeoville, il
1141 am cdt Mon aug 19 2019

Update
1135 am cdt
one minor change with this afternoon's forecast was to inch the
chance for isolated showers and storms northward up to i-88 i-290.

Anything that far north, including into chicago, should be spotty
though. Also inched up high temperatures into the upper 80s across
the south.

As noted in previous afd, moist conditions in the low-levels exist
across the cwa, with low 70s dew points and quick cumulus
development. The frontal boundary is draped from just north of
chicago through the dixon area and ever so slowly sagging
southward, with a lake breeze also oozing inland. These are
sources of some boundary layer convergent flow albeit not very
strong. A short wave noticed on satellite channels is located over
the quad cities and drifting eastward, and looks to be
responsible for some agitated cumulus already. While rap soundings
still indicate quite a bit of dryness above 700 mb, observed 12z
dvn and ilx soundings were not as dry possibly owing to this
subtle wave approaching. Also rap and NAM soundings now both show
slightly overcoming the cap with mid 80s temperatures. There will
likely be some dry air entrainment in the mid-levels with any
cells that do sprout. Because of that and deep layer wind shear
only around 20-25 kt, feel that the potential for well organized
storms remain low.

In the southern CWA have increased temperatures into the upper
80s, which combined with the dew points does result in some spotty
mid 90s heat indices forecast.

Mtf

Short term
239 am cdt
through Tuesday...

the main story of the short term portion of the forecast is that
mainly dry conditions will likely be punctuated by occasional
shower and storm chances. We also continue to monitor a potential
for a forward propogating MCS to drop out of iowa on Tuesday with
an attendant threat for severe weather somewhere across illinois
(whether or not impacts are felt well into northeast illinois
remains to be seen).

A weak cold front is ever-so-slowly sagging southward early this
morning into southern iowa and just now pushing into far
southwestern wisconsin. Ahead of this feature, the airmass remains
noticeably moist, with dewpoints running in the mid and upper 60s
across all of northeast illinois and northwest indiana. Dewpoint
depressions are essentially near nil in most locales at this time.

Given the combination of mainly clear skies (south of i-80),
favorable downward-directed near-surface moisture fluxes with a
notable hydrolapse on area soundings, expect that some visibility
reductions will occur through the mid-morning. Crossover
temperatures will probably be met mainly near and south of i-80
where stunted olr due to incoming mid-level stratus will be
limited. Can't rule out some patches of dense fog into sunrise
where skies can remain clear.

We're also watching a subtle mid-level wave (most prominent around
700 mb) pushing out of southeast iowa early this morning. A
pocket of associated modest warm advection is forecast to drift
out of west-central iowa after 4 am, and rap forecast soundings
immediately south of ford county show the 800-700 mb layer within
a whisper of saturation as a result. Lapse rates are certainly not
steep over a deep layer above this subtle ascent, but thin layers
of lapse rates of 7-8 c km do have me wondering if we'll be able
to pop a few elevated showers and maybe a storm from near and
south of a pontiac to valparaiso line. Lower probability of
occurrence, but have added some 20% pops here through daybreak to
account for this potential.

With the moist airmass in place down low, we'll destabilize quickly
this afternoon with heating. That said, notable drying and warming
in the 500-700 mb layer (a manifestation of subsidence overhead)
look to cap us off (mostly) to surface-based convection. That said,
enhanced surface convergence near a weak surface low and ahead of
the aforementioned cold front may help a few parcels complete the
journey to their lfcs during peak heating. Think the potential for
electrification is on the low side today with the warm air aloft and
poor lapse rates, so we'll indicate 20-30% precip chances but cap
thunder wording just to isolated. The most over-achieving of cells
might be able to produce some gusty winds to 50 mph given the well-
mixed boundary layer today. There might be another shot at some very
patchy fog tonight Tuesday morning, but will leave this mention out
of the gridded forecast for now given very low confidence.

Very late Monday night we'll be turning our attention off to our
northwest as a robust shortwave--readily apparent this morning on
all moisture-channel bands crossing into idaho--dips into the area.

The associated low-level mass response will result in increasing
warm advection on the nose of a burgeoning low-level jet, but
exactly where this occurs remains a bit in question but will have a
great deal of bearing on where a potential MCS initiates and
subsequently tracks. This evening's ECMWF came in a bit farther
southwest, the GFS remains a southern outlier, and the NAM and cmc
are both slightly farther north. The attendant warm advection will
intercept a very steep mid-level lapse rate plume, resulting in
likely robust convective development. Best guess at this point is
ci occurring across north-central to north-west iowa with
activity tracking southeast from there. This would take the brunt
of wind-related impacts from this system mostly south and west of
our cwa, but any northeastward shift in the LLJ would change
this. A potential for wind damage certainly exists, most notably
south and west of a roughly rockford to gibson line. The current
day 2 SPC outlook conveys a reasonable demarcation of the location
of the greatest severe threat based on this evening's multi-model
consensus. We'll obviously keep close tabs on this portion of the
forecast as a reservoir of very high instability will be
available for convective processing into Tuesday afternoon. Most
likely time for any impacts from this system look to be from
daybreak Tuesday into early Tuesday afternoon.

Carlaw

Long term
248 am cdt
Tuesday night through Sunday...

depending on the mesoscale evolution that takes place on Tuesday
afternoon with any MCS activity, we may have to monitor for a
potential for additional convective development into Tuesday
night and Wednesday morning. Some guidance indicates an
approaching jet streak and attendant ageostrophic mass response in
the low-levels (tied to the thermally indirect transverse portion
of the ageostrophic jet circulation) with another LLJ possibly
driving renewed convection near and atop and remnant outflow
boundary (ies). Should something like this take place, a threat
for training convection could develop given the anticipated mid
and upper-level flow orientation. Pops will be capped at 30-40%
through Wednesday due to low confidence nature of this portion of
the forecast.

At this time, Thursday and into the weekend is looking rather
pleasant and dry with refreshing temperatures and low humidity as
dewpoints drop back into the 50s. Some low shower and storm
chances will spread back east across the region towards the very
end of this forecast (Sunday and into Monday) as high pressure
builds off to our east.

Carlaw

Aviation
For the 12z tafs...

quiet and dry conditions expected this morning, withVFR ceilings
in place. Continue to monitor shower thunderstorm development
later this afternoon, and latest trends would suggest that this
development could be slightly further to the north near the
terminals. Have started to trend towards a few hour window this
afternoon, with scattered storms around the terminals but will
need to monitor later trends for possible more prevailing
conditions.VFR ceilings and dry conditions expected tonight, but
with thunderstorm chances increasing across the region by early
Tuesday morning. At this time, the track of this next complex of
storms looks to be south of the terminals. However, will continue
to monitor later trends. Varying winds expected through the
period, though remaining on the lighter side.

Rodriguez

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
45186 9 mi29 min N 3.9 G 5.8 73°F 74°F1 ft
45174 13 mi29 min NNE 5.8 G 7.8 75°F1 ft1015.3 hPa
45187 18 mi29 min NE 5.8 G 7.8 77°F 73°F1 ft
FSTI2 21 mi129 min ENE 5.1 75°F
KNSW3 - Kenosha, WI 24 mi69 min NNE 7 G 7 70°F 1016.9 hPa (+0.3)
OKSI2 26 mi129 min E 4.1 G 6 76°F
45177 27 mi129 min 76°F
CHII2 - Chicago, IL 27 mi39 min NE 9.9 G 11 74°F 72°F
CNII2 30 mi39 min NE 7 G 8.9 78°F 68°F
JAKI2 35 mi129 min ENE 7 G 8.9 76°F
CMTI2 - 9087044 - Calumet, IL 39 mi51 min NNE 7 G 9.9 77°F 1016.2 hPa72°F

Wind History for Calumet Harbor, IL
(wind in knots)    EDIT      (on/off)   Help
1
PM
2
PM
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
Last
24hr
SE13
G19
SW6
G17
SW2
G9
SW5
G8
SW5
G13
SW4
G11
SW6
G10
SW3
G6
SW4
G7
SW3
S3
S1
SW1
S1
SW2
SW2
SW2
G5
SW2
SW1
SW1
NE4
NE4
NE7
NE8
1 day
ago
NE6
E9
S7
SE4
G7
SW8
G11
SW7
G10
S4
G8
S6
G10
SW4
S4
S4
SW2
S4
SE3
S3
S1
SE2
S7
G10
S9
S8
W4
G10
--
N3
G7
S7
G11
2 days
ago
S11
G15
SW11
G18
S10
G14
S12
G15
S10
G13
S9
G13
S8
G11
SW4
G7
SW4
G9
SW3
G7
SW4
SW2
G5
SW3
SW3
SW4
SW3
SW4
SW2
SW3
S2
W1
S5
S9
G12
S6
G9

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago / Wheeling, Pal-Waukee Airport, IL9 mi77 minNE 710.00 miOvercast78°F66°F67%1017 hPa
Chicago/Waukegan Regional Airport, IL12 mi74 minENE 410.00 miOvercast73°F64°F76%1016.2 hPa
Chicago, Chicago-O'Hare International Airport, IL18 mi78 minNE 410.00 miMostly Cloudy81°F66°F61%1015.9 hPa

Link to 5 minute data for KPWK

Wind History from PWK (wind in knots)
1
PM
2
PM
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
Last 24hrS11
G19
W12
G18
W9SW8
G17
W7
G20
W8W9W5W5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmNW3E4NE6NE7N6
1 day agoE6SE5SE6S6S5S7S6SW3S4SE3S5S4CalmCalmCalmE3SE7SE6S7W9NW8SE8SE10S10
2 days agoS12S11
G17
S12SW9SW11
G18
N11
G20
W3SW4W4SW3W4CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmSE5S12

Tide / Current Tables for
   EDIT   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 (13,3,4,5)
      (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.