910
FNUS72 KCHS 220916
FWSCHS

Spot Forecast for Horse Island Wildfire...USFS
National Weather Service Charleston SC
516 AM EDT Wed Jul 22 2026

Forecast is based on forecast start time of 0600 EDT on July 22.
If conditions become unrepresentative...contact the National Weather
Service.

.DISCUSSION...

Mostly dry and hot conditions will persist again today,
although there is a risk for an isolated shower or thunderstorm
during the late morning into early afternoon hours roughly
between 9 AM and noon. The increasing rain chances now look to
come on Friday as the front has slowed down a bit. Afternoon
relative humidity values will be generally around 45 to 50 percent
this afternoon and Thursday afternoon. The biggest concerns will
be the seabreeze once again this afternoon which will likely
reach the burn site around noon. Wind gusts to around 20 mph will
be possible behind the seabreeze mostly out of the south;
however, stronger gusts could be more variable. Transport winds
will be predominantly southwesterly becoming more southerly by the
late afternoon. Winds should quickly relax around sunset as more
stable coniditons settle in overnight with continued dense smoke
issues possible.


.TODAY...

Sky/weather.........Mostly sunny then becoming partly sunny. Smoke
                    early in the morning. Slight chance of showers
                    and thunderstorms in the late morning and early
                    afternoon.
Chance of pcpn......20 percent.
Max temperature.....Around 94.
Min humidity........54 percent.
Wind (20 ft)........Southwest winds 5 to 11 mph with gusts to
                    around 20 mph. Gusty and erratic winds expected
                    near thunderstorms in the late morning and
                    early afternoon.
Mixing Height.......Max 4800 ft AGL.
Transport winds.....Southwest around 6 mph increasing to 18 to 20
                    mph in the late morning and afternoon.
Max ADI.............81.
Inversion End.......0900

TIME (EDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........41  28  50  48  46  59  70  61  52  53  53  50
Weather type....SMK SMK SMK RW  RW  RW  RW  RW
Tstm cov........            SCH SCH SCH SCH SCH
Chc of pcpn (%).10  10  10  20  20  20  20  20  0   0   0   0
Temp............82  80  82  84  88  89  91  92  93  93  92  93
RH..............82  88  85  82  72  70  64  60  56  54  56  54
20 FT wind dir..SW  SW  SW  SW  SW  S   S   S   S   S   S   S
20 FT wind spd..5   5   6   7   7   8   10  10  10  10  11  11
20 FT wind gust.14  14  18  16  16  16  18  20  18  20  20  20
Mix hgt (kft)...0.5 0.5 0.8 3.0 3.6 3.9 4.3 4.5 4.7 4.8 4.3 4.0
Transp wind dir.SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  SW
Transp wind spd.6   6   6   18  18  18  18  18  18  20  20  20
LVORI...........4   5   4   3   3   3   1   1   1   1   1   1
ADI.............6   6   7   69  81  68  53  54  58  79  76  77

.TONIGHT...

Sky/weather.........Mostly cloudy then becoming partly cloudy.
Chance of pcpn......0 percent.
Min temperature.....Around 79.
Max humidity........91 percent.
Wind (20 ft)........South winds 5 to 9 mph in the evening and
                    overnight becoming light. Gusts up to 22 mph.
Max LVORI...........5.
Min ADI.............1.
Inversion Begin.....2000

TIME (EDT)      6 PM   8 PM   10 PM  MIDNGT 2 AM   4 AM
Sky (%).........55     51     30     19     36     29
Weather type....NONE   NONE   NONE   NONE   NONE   NONE
Tstm cov........
Chc of pcpn (%).0      0      0      0      0      0
Temp............91     88     82     82     82     81
RH..............58     66     82     82     82     85
20 ft wind......S 9    S 7    S 6    S 5    S 4    S 4
20 ft wind gust.20     18     18     16     16     16
Mix hgt (ft)....3300   800    500    500    500    500
Transport wind..S 16   S 16   S 8    S 6    S 6    SW 4
LVORI...........3      3      5      5      5      5
ADI.............1      7      3      3      2      2

.THURSDAY...

Sky/weather.........Mostly sunny then becoming partly sunny. Slight
                    chance of showers and thunderstorms late in the
                    afternoon.
Chance of pcpn......20 percent.
Max temperature.....Around 96.
Min humidity........49 percent.
Wind (20 ft)........Light winds becoming south 5 to 6 mph in the
                    afternoon. Gusty and erratic winds expected
                    near thunderstorms late in the afternoon.
Mixing Height.......Max 6600 ft AGL.
Transport winds.....Light winds becoming southwest around 12 mph in
                    the late morning and afternoon.
Max ADI.............91.
Inversion End.......0900

TIME (EDT)      6 AM      9 AM      NOON      3 PM
Sky (%).........48        33        58        43
Weather type....NONE      NONE      NONE      RNSHWR
Tstm cov........                              S CHC
Chc of pcpn (%).0         0         0         20
Temp............81        84        92        95
RH..............85        82        56        49
20 FT wind......SW 3G13   SW 3G11   SW 4G13   S 5G13
Mix hgt (ft)....400       2300      4700      6600
Transport wind..SW 4      SW 12     SW 12     SW 12
LVORI...........5         3         1         1
ADI.............4         38        70        91

$$
Forecaster...Black
Requested by...Michael Leslie
Type of request...WILDFIRE
.TAG 2617817.1/CHS
.DELDT 07/22/26
.FormatterVersion 2.0.0
.EMAIL michael.c.leslie@usda.gov