620 
FNUS72 KMLB 191440
FWSMLB

Spot Forecast for Emeralda Marsh Area 4 Cattail Rx...SJRWMD
National Weather Service Melbourne FL
1040 AM EDT Tue Aug 19 2025

Forecast is based on ignition time of 0800 EDT on August 20. 
If conditions become unrepresentative, contact the National Weather
Service.

.DISCUSSION...

Good morning. The NHC forecast keeps Hurricane Erin well east of 
the Florida peninsula as it continues to move northward over the 
next few days. High pressure and some drier air around the 
periphery of Hurricane Erin will keep rain chances lower than 
normal through Wednesday, with a low (30 percent) chance of rain 
and lightning storms on Wednesday. Rain chances increase on 
Thursday as Erin continues to move away from the Florida 
peninsula, with a medium (60 percent) chance of rain and storms in
the afternoon. The pressure gradient will tighten ever so 
slightly over the burn site through Wednesday, producing north to 
northwest winds around 10 mph with gusts to around 15 mph. Winds 
turn westerly on Thursday and become light, with speeds around 5 
mph. No min RH concerns over the next several days. Seasonably 
warm through Thursday, with afternoon highs in the low to mid 90s,
with peak heat indices of 100-105 degrees. Smoke dispersion 
values will be very good through Thursday. 

.WEDNESDAY...

Sky/weather.........Sunny (15-25 percent). Slight chance of showers 
                    early in the morning. Slight chance of 
                    thunderstorms late in the morning, then chance 
                    of showers and thunderstorms late in the 
                    afternoon. 
Chance of pcpn......30 percent. 
Max temperature.....Around 93. 
Min humidity........58 percent. 
Wind (20 ft)........North winds 6 to 7 mph. Gusty and erratic winds 
                    expected near thunderstorms late in the 
                    morning. 
Mixing height.......2600 ft AGL increasing to 5200 ft AGL late in 
                    the morning. 
Transport winds.....North 8 to 14 mph. 
Dispersion index....13 increasing to 30 late in the morning, then 
                    increasing to 46 late in the morning increasing 
                    to 63 late in the morning decreasing to 53 
                    decreasing to 43 late in the afternoon. 
LVORI...............5 decreasing to 1. 

TIME (EDT)      8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 
Sky (%).........5   4   9   14  20  25  31  30  28  27  
Weather cov.....SCH SCH SCH SCH SCH SCH CHC CHC CHC CHC 
Weather type....RW  RW  RW  RW  RW  RW  RW  RW  RW  RW  
Tstm cov........            SCH SCH SCH CHC CHC CHC CHC 
Chc of pcpn (%).20  20  20  20  20  20  30  30  30  30  
Temp............78  81  84  86  88  89  90  90  90  89  
RH..............91  85  77  72  66  64  60  60  58  61  
20 FT wind dir..N   N   N   N   N   N   N   N   N   N   
20 FT wind spd..6   7   7   7   7   6   6   6   6   6   
20 FT wind gust.13  14  15  15  15  16  16  16  16  15  
Mix hgt (kft)...0.8 1.7 2.6 3.5 4.1 4.6 5.2 4.7 4.2 3.7 
Transp wind dir.N   N   N   N   N   N   N   N   N   N   
Transp wind spd.13  14  14  14  13  12  10  9   9   8   
Dispersion idx..13  30  46  60  64  65  65  55  50  43  
LVORI...........5   3   3   2   1   1   1   1   1   1   

.WEDNESDAY NIGHT...

Sky/weather.........Mostly clear (15-25 percent). Chance of showers 
                    and thunderstorms early in the evening. 
Chance of pcpn......30 percent. 
Min temperature.....Around 78. 
Max humidity........91 percent. 
Wind (20 ft)........Northwest winds around 5 mph early in the 
                    evening becoming light. Gusty and erratic winds 
                    expected near thunderstorms early in the 
                    evening. 
Mixing height.......1800 ft AGL decreasing to 500 ft AGL early in 
                    the evening. 
Transport winds.....Northwest 5 to 7 mph shifting to the west 7 to 
                    8 mph in the late evening and overnight. 
Dispersion index....27 decreasing to 3. 
LVORI...............3 increasing to 6. 

TIME (EDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM 
Sky (%).........28  28  29  28  27  26  21  17  12  11  9   8   
Weather cov.....CHC CHC                                         
Weather type....RW  RW                                          
Tstm cov........CHC CHC                                         
Chc of pcpn (%).30  30  10  10  10  10  10  10  0   0   0   0   
Temp............88  87  86  84  83  81  80  79  79  79  79  79  
RH..............63  65  68  72  77  82  85  88  88  88  88  88  
20 FT wind dir..NW  NW  NW  NW  W   W   W   W   W   W   W   W   
20 FT wind spd..5   5   3   3   2   2   2   2   2   2   3   3   
20 FT wind gust.13  10  8   7   6   6   6   6   6   6   7   7   
Mix hgt (kft)...2.8 1.8 0.8 0.8 0.7 0.6 0.6 0.5 0.5 0.5 0.5 0.5 
Transp wind dir.NW  NW  W   W   W   W   W   W   W   W   W   W   
Transp wind spd.7   6   5   6   7   8   8   8   8   8   8   8   
Dispersion idx..27  14  2   3   3   3   3   4   4   4   4   4   
LVORI...........2   2   3   3   4   5   5   6   6   6   6   6   

.THURSDAY...

Sky/weather.........Mostly sunny (25-35 percent). Chance of showers 
                    early in the morning. Slight chance of 
                    thunderstorms late in the morning, then showers 
                    and thunderstorms likely late in the afternoon. 
Chance of pcpn......60 percent. 
Max temperature.....Around 92. 
Min humidity........61 percent. 
Wind (20 ft)........Light winds becoming west 5 to 6 mph in the 
                    late morning and afternoon. Gusty and erratic 
                    winds expected near thunderstorms late in the 
                    morning. 
Mixing height.......1600 ft AGL increasing to 4000 ft AGL late in 
                    the morning, then increasing to 5100 ft AGL 
                    late in the afternoon decreasing to 2200 ft AGL 
                    late in the afternoon. 
Transport winds.....West 7 to 12 mph. 
Dispersion index....5 increasing to 17 late in the morning, then 
                    increasing to 32 late in the morning increasing 
                    to 53 late in the morning increasing to 56 
                    decreasing to 42 late in the afternoon 
                    decreasing to 30. 
LVORI...............6 decreasing to 2. 

TIME (EDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 
Sky (%).........8   8   8   12  17  21  30  40  49  48  47  46  
Weather cov.....        CHC CHC CHC CHC CHC CHC LKY LKY LKY LKY 
Weather type....        RW  RW  RW  RW  RW  RW  RW  RW  RW  RW  
Tstm cov........                    SCH SCH SCH LKY LKY LKY LKY 
Chc of pcpn (%).0   0   30  30  30  30  30  30  60  60  60  60  
Temp............79  78  79  81  84  87  88  89  89  89  88  87  
RH..............88  91  91  85  77  70  66  61  61  61  66  70  
20 FT wind dir..W   W   W   W   W   W   W   W   W   W   W   W   
20 FT wind spd..3   3   3   5   5   6   6   6   6   6   6   6   
20 FT wind gust.7   7   7   8   10  12  13  14  14  14  14  14  
Mix hgt (kft)...0.5 0.6 0.7 1.6 2.5 3.4 4.0 4.6 5.1 4.2 3.2 2.2 
Transp wind dir.W   W   W   W   W   W   W   W   W   W   W   W   
Transp wind spd.7   7   7   8   10  12  12  10  9   10  10  12  
Dispersion idx..4   3   6   17  32  48  55  57  59  52  42  30  
LVORI...........6   6   6   4   3   1   1   1   1   1   1   2   

$$
Forecaster...Watson
Requested by...Brent Keith
Type of request...PRESCRIBED
.TAG 2520210.0/MLB
.DELDT 08/19/25
.FormatterVersion 2.0.0
.EMAIL bkeith@sjrwmd.com