221
FNUS73 KLOT 151828
FWSLOT

Spot Forecast for Porter Beach Rescue...NPS
National Weather Service Chicago IL
128 PM CDT Thu May 15 2025

Forecast is based on forecast start time of 1400 CDT on May 15.
If conditions become unrepresentative, contact the National Weather
Service.

Please contact our office at (815) 834-0666 if you have questions
or concerns with this forecast.

.DISCUSSION...

.REST OF TODAY...It will be a very warm and breezy afternoon. The
threat of severe thunderstorms will increase across the area after
5 pm as a cold front approaches. After a period of storms early
this evening, expect dry and quieter weather overnight.

Sky/weather.........Partly cloudy. Isolated showers and
                    thunderstorms late in the afternoon.
Temperature.........83 at forecast start...Max 86.
Surface winds (kts).South winds 13 to 16 knots with gusts to around
                    25 knots.
Wave height.........1 foot or less.
Wave period.........2 SECONDS.
Mixing height.......2100 ft AGL at forecast start...otherwise 2100
                    ft AGL.
Transport winds.....South 20 to 22 mph.


TIME (CDT)      2PM 3PM 4PM 5PM
Sky (%).........46  43  50  56
Weather cov.....            ISO
Weather type....            RW
Temp............83  84  86  84
SFC wnd dir.....S   S   S   S
SFC wnd spd kts.13  14  16  16
SFC wnd gst.....24  28  29  29
Mix hgt (kft)...2.1 1.8 1.9 1.6
Transp wind dir.170 170 170 180
Transp wind spd.20  20  21  22
Wave period (s).2   2   2   2
Wave height (ft)1   1   1   1

.TONIGHT...

Sky/weather.........Mostly cloudy in the evening, then clearing.
                    Scattered showers and thunderstorms early in
                    the evening, some may be severe.
Temperature.........Min 58.
Surface winds (kts).Southwest winds 13 to 16 knots with gusts to
                    around 26 knots becoming south 7 to 10 knots
                    late in the evening.
Wave height.........1 foot or less.
Wave period.........3 SECONDS.
Mixing height.......400 ft AGL.
Transport winds.....South 20 to 23 mph becoming southwest 9 to 10
                    mph.
Smoke dispersal.....Fair (20700 knot-ft) early in the evening
                    decreasing to poor (3200 knot-ft) late in the
                    night.

TIME (CDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........63  71  65  59  53  40  27  14  12  9   6   6
Weather cov.....SCT SCT SCT SCT
Weather type....RW  RW  RW  RW
Temp............80  76  72  70  68  66  64  63  60  60  59  59
SFC wnd dir.....S   S   S   SW  SW  SW  SW  W   SW  SW  SW  S
SFC wnd spd kts.16  16  16  15  13  10  9   9   8   8   7   8
SFC wnd gst.....29  29  30  29  24  17  15  14  12      9   10
Mix hgt (kft)...1.0 0.9 0.6 0.6 0.7 0.6 0.6 0.5 0.4 0.4 0.4 0.4
Transp wind dir.180 170 200 220 230 240 240 250 240 220 210 200
Transp wind spd.23  21  20  20  17  18  17  15  13  10  9   10
Vrate kt-ft/1K..21  16  11  11  10  9   9   7   5   4   3   4
Wave period (s).2   2   2   2   3   3   3   3   3   3   3   2
Wave height (ft)1   1   1   1   1   1   1   1   1   1   1   0

$$
Forecaster...Birk
Requested by...M. Frase
Type of request...SAR
.TAG 2514084.0/LOT
.DELDT 05/15/25
.FormatterVersion 2.0.0