548
FNUS73 KMQT 211204
FWSMQT

Spot Forecast for Royal Flush...USCG SCC NGL
National Weather Service Marquette MI
804 AM EDT Thu Aug 21 2025

Forecast is based on forecast start time of 0800 EDT on August 22.
If conditions become unrepresentative...contact the National Weather
Service.

.DISCUSSION...

NOTE: Forecast location changed to between Isle Royale and the
Keweenaw Peninsula per phone call with requester.

Friday between Isle Royale and the Keweenaw Peninsula, scattered
rain showers with a few thunderstorms will be over much of the west
half of Lake Superior. Expect winds out of the southwest at 10 to
15 kt with gusts to 20 kt (except in the immediate vicinity of
storms, where winds could be significantly higher). Waves will
build to near 3 ft early and will stay between 2 and 3 feet through
the morning hours.

Chances of thunderstorms fall to around 15 percent in the afternoon
and below 10 percent in the evening, though not much change in the
winds and waves is expected. Saturday, westerly winds will
significantly increase through the day, with chances of gale-force
gusts 20 to 35 percent Saturday afternoon.

.FRIDAY...

Sky/weather.........Partly sunny (45-55 percent). Chance of showers
                    and thunderstorms early in the morning, then
                    slight chance of showers and thunderstorms late
                    in the afternoon.
Chance of pcpn......30 percent.
Chance of thunder...30 percent.
Temperature.........64 at forecast start...Max 69.
Surface winds.......Southwest winds 13 to 14 knots.
Ceiling (kft).......5.4 decreasing to 4.0 late in the morning, then
                    gradually increasing to 11 late in the afternoon.
Visibility (sm).....8.
Wave Height.........Waves 1 to 3 feet.
Wave period.........5 seconds.
Lake Surface Temp...64 Degrees Fahrenheit.
Wave Direction......243.

TIME (EDT)      8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........47  54  64  62  51  55  58  52  46  40
Weather cov.....CHC CHC CHC CHC CHC CHC SCH SCH SCH SCH
Weather type....RW  RW  RW  RW  RW  RW  RW  RW  RW  RW
Tstm cov........CHC CHC CHC CHC CHC CHC SCH SCH SCH SCH
Chc of pcpn (%).30  30  30  30  30  30  20  20  20  20
Chc of thdr (%).30  30  30  30  30  30  20  20  20  20
Temp............64  64  64  65  65  65  65  65  65  65
Ceiling (kft)...6.3 5.8 5.4 4.9 4.6 4.3 4.0 6.3 8.6 11
Visibility (sm).8   9   9   10  9   9   9   9   9   9
Surface wnd dir.SW  SW  SW  SW  SW  SW  SW  SW  SW  SW
Surface wnd spd.14  14  14  14  13  13  13  13  13  13
Surface wnd gst.21  21  21  21  20  20  20  20  20  20
Wave Direction..230 240 240 240 240 240 240 240 240 240
Wave period (s).4   5   5   5   5   5   5   5   5   5
Wave height (ft)3   3   3   3   3   3   3   3   3   3

.FRIDAY NIGHT...

Sky/weather.........Partly cloudy (25-35 percent). Slight chance of
                    showers and thunderstorms early in the evening.
Chance of pcpn......20 percent.
Chance of thunder...17 percent.
Temperature.........Min 62.
Surface winds.......West winds 12 to 15 knots.
Ceiling (kft).......None.
Visibility (sm).....10.
Wave Height.........Waves 1 to 3 feet.
Wave period.........5 seconds.
Lake Surface Temp...64 Degrees Fahrenheit.
Wave Direction......253.

TIME (EDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........35  31  26  28  30  32  30  27  25  25  24  24
Weather cov.....SCH SCH
Weather type....RW  RW
Tstm cov........SCH SCH
Chc of pcpn (%).20  20  10  10  10  10  10  10  10  10  10  10
Chc of thdr (%).20  20  10  10  10  10  10  10  0   0   0   0
Temp............65  66  66  66  65  64  64  64  64  64  64  63
Ceiling (kft)...
Visibility (sm).10  10  10  10  10  10  10  10  10  10  10  10
Surface wnd dir.SW  SW  SW  SW  SW  SW  W   W   W   W   W   W
Surface wnd spd.13  13  13  13  13  13  13  13  13  15  15  15
Surface wnd gst.20  20  20  20  20  20  19  19  19  21  21  21
Wave Direction..250 250 250 240 240 240 240 240 240 250 250 250
Wave period (s).5   5   5   5   5   5   5   5   5   5   5   5
Wave height (ft)3   3   3   3   3   3   3   3   3   3   3   3

$$
Forecaster...GS
Requested by...Gage Parker
Type of request...MARINE
.TAG 2520260.2/MQT
.DELDT 08/21/25
.FormatterVersion 2.0.0
.EMAIL Samuel.H.Clemons@uscg.mil,Gage.M.Parker@uscg.mil