Tuesday, August20, 2019 L-36.com


Marine Weather and Tides
Gurnee, 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 6:02AMSunset 7:47PM Tuesday August 20, 2019 11:34 AM CDT (16:34 UTC) Moonrise 10:28PMMoonset 10:47AM Illumination 75% Phase: Waning Gibbous; Moon at 20 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- 922 Am Cdt Tue Aug 20 2019
Rest of today..Southwest winds 5 to 10 kt, though variable midday in any Thunderstorms. Chance of showers and Thunderstorms. Waves 1 ft or less.
Tonight..Southwest winds 5 to 10 kt becoming west after midnight. Slight chance of showers and Thunderstorms in the evening. Waves 1 ft or less.
Wednesday..West winds 10 to 20 kt becoming north 15 to 20 kt in the afternoon. Slight chance of showers and Thunderstorms through the day. Waves 1 ft or less building to 2 to 4 ft in the afternoon.
Wednesday night..Northeast winds 5 to 10 kt. Mostly cloudy in the evening then becoming partly cloudy. Waves 1 to 3 ft.
LMZ740 Expires:201908202115;;518640 FZUS53 KLOT 201422 NSHLOT NEARSHORE MARINE FORECAST National Weather Service Chicago/Romeoville IL 922 AM CDT Tue Aug 20 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>742-202115-


7 Day Forecast for Marine Location Near Gurnee, IL
   Hourly   EDIT   Help
location: 42.38, -87.94     debug


Area Discussion for - Chicago, IL
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus63 klot 201549
afdlot
area forecast discussion
national weather service chicago romeoville, il
1049 am cdt Tue aug 20 2019

Mesoscale discussion 1038 am cdt
recent aircraft soundings out of mdw indicating a low level
inversion is limiting the ability for any stronger lower level
wind to make it to the surface. But there some rather strong winds
not too far off the deck. With the cloud shield in place, it is
not likely that we will be able to erode that inversion.

The main concerns for the majority of the area will include
lightning, heavy rain, along with strong winds in the 40-50 mph
range, locally stronger in any pulsy stronger cells on the
leading edge of the line. Rochelle recently gusted to 40 mph on
the northern side of the bowing mcs. The complex is maintaining
itself on its northern edge but showing signs of weakening.

The concern area for severe level winds, while still marginal,
will be our far southern counties from la salle - ford - iroquois
and into northwest indiana. Collaboration with SPC suggests a
short extension of the watch into benton-newton-jasper counties is
probable.

Kmd

Short term
316 am cdt
through Wednesday...

main focus through the short term portion of the forecast is on the
potential for strong to severe thunderstorms this morning followed
by additional (but highly conditional and uncertain) storm chances
later this afternoon and on Wednesday.

A soupy airmass is in place across illinois early this morning, with
surface dewpoints analyzed in the low to mid 70s. Light winds and
mainly clear skies (although cloud cover is increasing) will promote
another potential for continued fog development through the rest of
the overnight hours. We'll keep an eye on visibility trends this
morning, but currently don't have plans to hoist a dense fog
advisory with the expectation that mid- and upper-level cloud
cover will just continue to increase although some isolated spots
of sub-1 mile visibilities will be possible.

Surface analysis indicates yesterday's very weak frontal boundary
(partially enhanced a bit by the lake) has stalled out near the i-80
corridor. Dewpoints subtly increase south of this area, with this
boundary arcing southwest towards quincy, illinois before it
continues off to the northwest towards the iowa nebraska state line.

An EML plume has advected atop this boundary, which is characterized
by very steep mid-level lapse rates nearing 9 c km in the 700-500 mb
layer and shows up impressively on the most recent oak raob.

Moisture channel loops depict a robust shortwave translating into
western minnesota and iowa. Noting an associated increase in the low-
level mass response ahead of this shortwave as a result, with recent
koax VWP data sampling 35 kts of southwesterly 850 mb flow, veering
to 40 kts at 700 mb. This is a bit more robust than currently
depicted by recent rap analyses. Either way, the net result of this
has been the rapid development of robust convective cores across the
western half of iowa as enhanced warm advection has begun to
intercept the aforementioned steep lapse rate plume aloft. An
additional area of elevated convection--which initiated a few hours
ago--is currently drifting into northeastern iowa. This activity
should continue to slowly weaken as it encounters a considerable
pocket of dry air in the 700-500 mb layer, although this will likely
begin the process of saturating this critical layer.

As has been case with recent mcs's, it seems as if hi-res guidance
becomes less and less helpful as we approach the event with recent
guidance not really capturing the current nature of convection.

Thus, we're sort of at the mercy of conceptual models and older cam
guidance here. Based on the current look of radar and satellite and
movement of the gradually congealing storms, it does appear as if a
cohesive MCS will begin to surge towards illinois over the next
several hours. Typically the cold pools associated with these mcss
tend to elongate along the 700 mb flow in the downshear-propagating
portion, which should back a bit to the west-northwest through
daybreak. As a result, have favored a somewhat more northward
solution here and have painted essentially categorical pops across
the entire CWA through the late-morning hours. Latest thinking
(favoring a faster solution) has the leading edge of the forward-
propagation portion of the bow approaching i-39 around 9 am and then
racing towards the i-57 corridor by 11 am to noon and then east of
our CWA by about 2-3 pm.

Effective deep layer shear values do look to decrease with eastward
extent into our CWA this morning, but 25-30 kts oriented almost
orthogonal to the incoming line should be sufficient to keep
updrafts propped up against the gust front resulting in a wind
damage threat likely through most of the cwa. Currently think the
main corridor for the strongest winds is roughly near and south of
a rockford to aurora to valparaiso line. Probably will be a
bookend vortex tracking somewhere through our CWA as well, and
this will likely focus the greatest wind potential. Think that the
embedded qlcs tornado potential is on the lower side with this
event due to the weaker low-level flow (and sub-optimal time of
day) but certainly couldn't rule a spin-up out of the equation.

We'll probably clear out pretty quickly with this system's
passage. This should allow temperatures--at least over parts of
the area--to rebound into the mid and possibly upper 80. There's a
pretty big bust potential on the high temperatures though if this
system decides to slow down. The other question is if we can fire
new convection later this afternoon. Given the quicker arrival, we
may have sufficient time to destabilize and and get away from the
main subsident regime immediately behind the departing mcs. In
addition, there's another shortwave coupled jet near the
international border which may deliver a glancing blow of ascent
to the region during peak heating. Cams remain unenthusiastic with
re-development potential, but we are a bit concerned that we may
indeed be able to re-fire near the remnant outflow boundary which
--based purely on a conceptual model at this point--would stretch
from near a rockford to fowler line. The kinematic and
thermodynamic parameter space would support a severe threat with
large hail and damaging wind gusts. Also worth mentioning that
*should* convection fire on any remnant outflow, the flow
orientation would support training storms with an attendant flash
flood potential. Low confidence in this occurring and will only
show 20-30 percent pops as a result, but something certainly worth
watching.

For tonight, we'll probably see another MCS develop perhaps a bit
farther southwest than the one currently. This may make a run at
our far southwestern counties towards the morning hours. We'll
maintain a stripe of 30% pops south of a dixon to rensselaer line
to account for this potential. Otherwise, a cold front will
probably push through our CWA during the afternoon hours bringing
slightly cooler and drier conditions to the area into the evening
hours.

Carlaw

Long term
213 am cdt
Wednesday night through Monday...

synoptic front expected to continue sliding south across the
region at the start of the period, with CAA and dry advection the
trend. However, some potential for this boundary to hang up around
the southern CWA Wednesday night. If this were to occur,
additional upstream development to the west during this time could
ride along it and provide some chances for showers and
thunderstorms. Main instability axis will be to the south, with
instability lowering across the CWA through the night. So, would
think that the bulk of any development should stay just to the
south, but with locations along south of the kankakee river valley
possibly observing the northern extent of this development. Will
be trending drier and cooler into the end of the work week, as
high pressure builds across the region. With this high in place,
any precip development into this weekend will stay well
west southwest of the area. Below normal temps are expected late
in the work week into the weekend.

Rodriguez

Aviation
For the 12z tafs...

active pattern expected to bring showers thunderstorms
near across the terminals this morning into midday early
afternoon, and potentially again later this afternoon. Continue to
monitor area of showers thunderstorms currently moving into
northwest il, with higher confidence now in place for these storms
to impact the terminals in northern il and northwest in this
morning. Current timing in the tafs still looks good, and haven't
made any changes at this time. Did lower vis, as it's appearing
that some of the stronger development will move overhead. Mostly
dry conditions then expected later this afternoon through much of
the end of the period. Will need to monitor later trends, as some
isolated thunderstorm development could occur this afternoon. Low
confidence on this possibility at this time. Outside of precip
development this morning, mainlyVFR conditions expected for the
remainder of the day. Do think there is some potential for lower
ceilings later tonight into Wednesday morning. Winds will likely
be highly variable, with the expected precip. A wind shift to more
of a southerly direction is anticipated this morning ahead of the
storms, and think this direction will be the more preferred
direction through much of today.

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 8 mi34 min S 1.9 G 3.9 75°F 75°F1 ft
45187 11 mi34 min WNW 1.9 G 1.9 79°F 74°F1 ft
KNSW3 - Kenosha, WI 16 mi34 min N 2.9 G 2.9 73°F 1015.9 hPa (-0.0)
45174 23 mi34 min SW 1.9 G 1.9 75°F1 ft1012.9 hPa (+0.0)
FSTI2 32 mi94 min S 8.9 78°F
OKSI2 36 mi94 min Calm G 1 81°F
45177 38 mi154 min 76°F
CHII2 - Chicago, IL 38 mi44 min SSW 9.9 G 11 79°F 76°F
CNII2 40 mi34 min S 2.9 G 7 78°F 72°F
JAKI2 46 mi94 min W 1 G 2.9 78°F

Wind History for Calumet Harbor, IL
(wind in knots)    EDIT      (on/off)   Help
11
AM
12
PM
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
Last
24hr
NE7
NE8
NE8
NE6
NE6
NE6
G9
NE5
NE5
NE4
N2
N3
N2
--
N2
SW2
S2
S3
S2
S4
S6
S4
SW4
SW5
S5
1 day
ago
N3
G7
S7
G11
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
2 days
ago
S9
G12
S6
G9
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
--

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chicago/Waukegan Regional Airport, IL5 mi1.7 hrsN 07.00 miOvercast75°F71°F88%1013.9 hPa
Kenosha, Kenosha Regional Airport, WI15 mi1.7 hrsNNE 39.00 miA Few Clouds75°F73°F94%1014.6 hPa
Chicago / Wheeling, Pal-Waukee Airport, IL19 mi1.7 hrsN 06.00 miFog/Mist76°F72°F88%1015.2 hPa

Link to 5 minute data for KUGN

Wind History from UGN (wind in knots)
12
PM
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
Last 24hrE5SE4E7--E6E4E6E4CalmE3--------CalmCalmN3--NE4NE3CalmSW5CalmCalm
1 day agoS13
G23
SW12SW9
G19
W10W5543CalmW3----SW4--Calm----CalmCalmCalmCalmNE5--NE5
2 days agoSE9SE11
G18
E7S8S6S3Calm3CalmCalmCalmCalmCalmSW4Calm--CalmS3S9S10--6
G17
S5SE6

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 Midwest    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 (12,3,4,5)
      (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.