601
FNUS73 KGRR 230818
FWSGRR

Spot Forecast for Dune and Swale Rx...MIDNR
National Weather Service Grand Rapids MI
418 AM EDT Thu May 23 2024

Forecast is based on ignition time of 1100 EDT on May 23.
If conditions become unrepresentative, contact the National Weather
Service.

Please contact our office at (616) 949-5150, if you have questions
or concerns with this forecast.

.DISCUSSION...

Winds stay fairly light today and will be mainly westerly around
5 to 10 mph with peak afternoon gusts to 20 mph. Expect plenty of
sunshine today with deep mixing. Surface temperatures rise into
the mid 70s this afternoon while dewpoints fall into the upper 30s
to low 40s. This results in min RH vales ranging from 20 to 30
percent.

Winds become light and variable late this evening, shifting to
the southeast late tonight. Dewpoints increase Friday morning with
showers and storms possible Friday evening.

.REST OF TODAY...

Sky/weather.........Sunny (5-15 percent).
Temperature.........70 at ignition...Max 78.
RH..................55 percent at ignition...Min 28 percent.
Wind (20 ft)........Winds west at 6 mph at ignition...otherwise
                    West winds 5 to 8 mph.
Mixing height.......4300 ft AGL at ignition...otherwise 6900 ft
                    AGL.
Mixing winds........West 9 to 12 mph.
Smoke dispersal.....500 /good/ at ignition. Max...800 /excellent/.
Haines Index........5 or moderate potential for large plume
                    dominated fire growth at ignition...max 6.

TIME (EDT)      11 AM  1 PM   3 PM   5 PM   7 PM   9 PM
Sky (%).........17     11     2      1      1      1
Weather cov.....
Weather type....NONE   NONE   NONE   NONE   NONE   NONE
Tstm cov........
Temp............70     73     76     76     75     69
RH..............55     37     30     28     29     40
20 ft wind......W 6    W 7    W 8    W 7    W 5    NE 2
20 ft wind gust.12     12     13     13     9      3
Mix hgt (ft)....4300   6700   6700   5600   3500   500
Mixing wind.....W 12   W 12   W 12   W 10   W 9    NW 2
Haines index....5      5      6      6      6      5
Smoke disprsl...500    770    780    580    330    10

.TONIGHT...

Sky/weather.........Clear (0-5 percent).
Temperature.........Min 54.
RH..................Max 62 percent.
Wind (20 ft)........Light winds becoming southeast around 5 mph
                    toward daybreak.
Mixing height.......400 ft AGL.
Mixing winds........Northwest 2 to 5 mph shifting to the southeast
                    3 to 6 mph until midnight, then increasing to 6
                    to 9 mph after midnight.
Smoke dispersal.....10 (poor).
Haines Index........5 or moderate potential for large plume
                    dominated fire growth.

.FRIDAY...

Sky/weather.........Mostly sunny (30-40 percent) then becoming
                    mostly cloudy (70-80 percent). Chance of
                    showers in the afternoon.
Temperature.........Max 84.
RH..................Min 40 percent.
Wind (20 ft)........South winds 5 to 12 mph. Gusts up to 21 mph
                    late in the day.
Mixing height.......5700 ft AGL.
Mixing winds........South 10 to 18 mph increasing to 15 to 20 mph
                    late in the day.
Smoke dispersal.....40 (poor) early in the morning increasing to
                    1060 (excellent) in the afternoon.
Haines Index........4 or low potential for large plume dominated
                    fire growth.

$$
Forecaster...Thielke
Requested by...Jeff Vasher
Type of request...PRESCRIBED
.TAG 2414924.0/GRR
.DELDT 05/23/24
.FormatterVersion 2.0.0
.EMAIL vasherj@michigan.gov