016
FNUS73 KGRR 270839
FWSGRR

Spot Forecast for Split Sock...USFS
National Weather Service Grand Rapids MI
439 AM EDT Sat Apr 27 2024

Forecast is based on ignition time of 1200 EDT on April 27.
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...

Southerly winds will quickly build this morning reaching their
peak around noon with sustained winds reaching 15 to 20 mph
gusting to 30 to 35 mph. Significant moisture advection will
result in dewpoints in the mid to upper 50s today and Sunday. This
results in Min RH values around 65 to 70 percent. Meanwhile, scattered
showers and storms are expected this morning and afternoon with chances
for strong to severe storms this evening and tonight. Scattered
showers and storms will last into Sunday afternoon.

.TODAY...

Sky/weather.........Mostly cloudy (75-85 percent). Chance of
                    showers and thunderstorms late in the day.
Temperature.........65 at ignition...Max 71.
RH..................81 percent at ignition...Min 66 percent.
Wind (20 ft)........Winds south at 18 mph at ignition...otherwise
                    Southwest winds 17 to 21 mph with gusts to
                    around 35 mph. Gusty and erratic winds expected
                    near thunderstorms late in the day.
Mixing height.......1700 ft AGL at ignition...otherwise 2200 ft
                    AGL.
Mixing winds........Southwest 30 to 36 mph decreasing to around 24
                    mph in the evening.
Smoke dispersal.....520 /good/ at ignition. Max...800 /excellent/.
Haines Index........3 or very low potential for large plume
                    dominated fire growth at ignition...max 3.

TIME (EDT)      NOON   2 PM   4 PM   6 PM   8 PM   10 PM
Sky (%).........89     81     73     78     94     100
Weather cov.....                     CHANCE LIKELY LIKELY
Weather type....NONE   NONE   NONE   RNSHWR RNSHWR RNSHWR
Tstm cov........                     CHANCE CHANCE CHANCE
Temp............65     69     70     71     67     63
RH..............81     73     70     66     75     81
20 ft wind......S 18   S 21   SW 21  SW 20  SW 16  SW 15
20 ft wind gust.32     35     35     32     26     22
Mix hgt (ft)....1700   2200   2000   1600   800    700
Mixing wind.....S 31   SW 35  SW 32  SW 30  SW 21  SW 17
Haines index....3      3      3      3      3      3
Smoke disprsl...520    740    670    500    170    130

.TONIGHT...

Sky/weather.........Mostly cloudy (80-90 percent). Rain showers
                    likely in the evening. Chance of thunderstorms.
                    Chance of rain showers overnight.
Temperature.........Min 53.
RH..................Max 96 percent.
Wind (20 ft)........Southwest winds 7 to 16 mph shifting to the
                    west 5 to 6 mph overnight, then becoming light
                    toward daybreak becoming north 6 to 7 mph
                    toward daybreak. Gusty and erratic winds
                    expected near thunderstorms.
Mixing height.......500 ft AGL.
Mixing winds........Southwest 13 to 21 mph shifting to the
                    northwest 8 to 9 mph late at night, then
                    shifting to the north 8 to 10 mph toward
                    daybreak.
Smoke dispersal.....170 (fair) early in the evening decreasing to
                    30 (poor) late in the night.
Haines Index........2 to 3 or very low potential for large plume
                    dominated fire growth.

.SUNDAY...

Sky/weather.........Cloudy (85-95 percent). Rain showers likely
                    until midday, then rain showers in the
                    afternoon. Slight chance of thunderstorms late
                    in the day.
Temperature.........Max 61.
RH..................Min 78 percent.
Wind (20 ft)........Northeast winds 8 to 9 mph shifting to the east
                    9 to 12 mph late in the day. Gusty and erratic
                    winds expected near thunderstorms late in the
                    day.
Mixing height.......1200 ft AGL.
Mixing winds........Northeast 12 to 18 mph shifting to the east 16
                    to 17 mph late in the day.
Smoke dispersal.....80 (poor) early in the morning increasing to
                    190 (fair) in the afternoon.
Haines Index........2 or very low potential for large plume
                    dominated fire growth.

$$
Forecaster...Thielke
Requested by...Brian Stearns
Type of request...PRESCRIBED
.TAG 2412590.0/GRR
.DELDT 04/27/24
.FormatterVersion 2.0.0
.EMAIL brian.stearns@usda.gov