515
FNUS72 KJAX 171956
FWSJAX
SPOT FORECAST FOR PAYNES PRAIRIE RX...PAYNES PRAIRIE PRESERVER STATE PARK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
356 PM EDT MON AUG 17 2026
FORECAST IS BASED ON IGNITION TIME OF 0900 EDT ON AUGUST 18.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE.
PLEASE CONTACT OUR OFFICE AT (904) 741-4370 IF YOU HAVE QUESTIONS
OR CONCERNS WITH THIS FORECAST.
..EXTREME HEAT WARNING IN EFFECT FOR TUESDAY 11AM TO 8PM
DISCUSSION
TUESDAY, VERY HOT AND HUMID CONDITIONS ARE EXPECTED AS HIGH PRESSURE
RIDGING REMAINS OVER THE EASTERN GULF WATERS WITH WESTERLY WINDS OF
10 TO 15 MPH AND HIGHS REACHING THE MIDDLE 90S. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST AND ALLOW FOR SCATTERED TO NUMEROUS
THUNDERSTORMS TO DEVELOP IN THE AFTERNOON HOURS. AN EARLY START TO
THE GULF SEABREEZE WILL CREATE ISOLATED SHOWERS AND THUNDERSTORMS
OVER THE SITE DURING THE LATE MORNING TO MIDDAY HOURS. PEAK HEAT
INDEX VALUES 110 TO 114 DEGREES. ISOLATED STRONG TO MARGINALLY
SEVERE THUNDERSTORMS ARE POSSIBLE IN THE AFTERNOON HOURS. STORMS
WILL END AFTER SUNSET.
TUESDAY NIGHT, MOSTLY CLOUDY SKIES WILL REMAIN WITH A FEW SHOWERS
POSSIBLE OVERNIGHT. LOWS WILL BE IN THE UPPER 70S WITH WEST TO
SOUTHWEST WINDS 4-8 MPH.
WEDNESDAY, THE COLD FRONT WILL SINK CLOSER TO THE FLORIDA AND
GEORGIA STATE LINE WITH MID TO LATE MORNING ISOLATED SHOWERS AND
THUNDERSTORMS BECOMING NUMEROUS IN THE AFTERNOON. WESTERLY WINDS
8-12 MPH EXPECTED. ANOTHER HOT AND HUMID AFTERNOON IS EXPECTED
WITH PEAK HEAT INDEX VALUES OF AROUND 110 DEGREES.
DISPERSIONS WILL BE IN THE GOOD RANGE DUE TO ELEVATED MIXING
HEIGHTS AND LIGHT SURFACE AND TRANSPORT WINDS. GUSTY AND ERRATIC
WINDS ARE POSSIBLE WITHIN STRONGER THUNDERSTORMS TUESDAY AND
WEDNESDAY.
TUESDAY
TIME (EDT) 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........42 52 54 55 62 68 73 72 69
WEATHER COV..... CHC CHC CHC CHC CHC CHC CHC
WEATHER TYPE.... RW RW RW RW RW RW RW
TSTM COV........ CHC CHC CHC CHC CHC CHC CHC
CHC OF PCPN (%).10 10 30 30 40 50 40 40 30
CHC OF THDR (%).10 10 30 30 40 50 40 40 30
TEMP............85 90 92 93 94 94 94 94 92
RH..............80 70 66 64 62 60 60 60 64
HEAT INDEX (F)..97 106 109 110 112 110 110 110 107
WIND CHILL (F)..97 106 109 110 112 110 110 110 107
20 FT WIND DIR..W W W W W W W W SW
20 FT WIND SPD..8 10 12 10 10 10 12 13 13
20 FT WIND GUST.13 16 17 16 16 16 17 20 20
MIX HGT (KFT)...1.5 2.2 2.9 3.0 3.0 3.1 2.8 2.4 2.1
TRANSP WIND DIR.W W W W W W W W W
TRANSP WIND SPD.12 12 13 12 10 10 12 13 14
DISPERSION IDX..22 33 40 39 36 35 35 36 35
LVORI...........3 3 2 1 1 1 1 1 1
TUESDAY NIGHT
TIME (EDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........74 73 79 83 79 79 73 69 67 72 68 58
WEATHER COV.....CHC SCH SCH SCH
WEATHER TYPE....RW RW RW RW
TSTM COV........CHC SCH SCH
CHC OF PCPN (%).30 20 10 10 20 10 0 0 10 20 0 0
CHC OF THDR (%).30 20 10 10 20 10 0 0 10 10 0 0
TEMP............90 89 87 84 83 82 81 80 80 79 79 78
RH..............68 68 72 80 82 85 88 91 91 91 91 97
HEAT INDEX (F)..105 102 99 94 92 90 88 87 87 79 79 78
WIND CHILL (F)..105 102 99 94 92 90 88 87 87 79 79 78
20 FT WIND DIR..W W W W SW SW SW SW W W W W
20 FT WIND SPD..13 12 10 8 7 6 6 5 5 5 5 5
20 FT WIND GUST.20 17 16 13 10 9 9 7 7 7 7 7
MIX HGT (KFT)...1.7 1.2 0.8 0.7 0.6 0.5 0.5 0.5 0.4 0.4 0.4 0.4
TRANSP WIND DIR.W W W W W W W W W W W W
TRANSP WIND SPD.13 12 10 9 9 8 8 8 8 8 9 9
DISPERSION IDX..28 19 9 8 6 5 5 5 5 6 6 6
LVORI...........3 3 3 4 4 5 5 6 6 6 6 6
WEDNESDAY
TIME (EDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........53 51 51 43 43 43 43 43 76 76 76 76
WEATHER COV..... SCH SCH SCH SCH SCH SCH LKY LKY LKY LKY
WEATHER TYPE.... RW RW RW RW RW RW RW RW RW RW
TSTM COV........ SCH SCH SCH SCH SCH SCH LKY LKY LKY LKY
CHC OF PCPN (%).0 10 20 20 20 20 20 20 60 60 60 60
CHC OF THDR (%).0 10 20 20 20 20 20 20 60 60 60 60
TEMP............78 78 79 83 87 90 92 94 94 95 95 94
RH..............94 97 94 85 77 70 66 60 58 56 55 56
HEAT INDEX (F)..78 78 79 93 101 106 109 110 109 110 109 107
WIND CHILL (F)..78 78 79 93 101 106 109 110 109 110 109 107
20 FT WIND DIR..W W W W W W W W W W W SW
20 FT WIND SPD..5 5 5 6 7 8 8 9 9 9 10 10
20 FT WIND GUST.7 7 7 9 10 13 13 14 14 14 16 16
MIX HGT (KFT)...0.6 0.8 0.9 1.4 2.0 2.5 3.0 3.5 4.0 3.8 3.6 3.4
TRANSP WIND DIR.W W W W W W W W W W W W
TRANSP WIND SPD.8 8 8 9 9 10 10 9 9 10 12 13
DISPERSION IDX..6 5 10 17 24 32 38 39 44 47 50 41
LVORI...........6 7 6 4 3 3 3 1 1 1 1 1
FORECASTER...BRICKER
REQUESTED BY...BRIAN LAW
TYPE OF REQUEST...PRESCRIBED
.TAG 2619864.0/JAX
.DELDT 08/17/26
.FORMATTERVERSION 2.0.0
.EMAIL BRIAN.LAW@FLORIDADEP.GOV
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