Spot Forecast
Issued by NWS San Juan, PR
Issued by NWS San Juan, PR
169
FNCA72 TJSJ 180859
FWSSJU
Spot Forecast for Bike Trail...PRFD
National Weather Service San Juan PR
459 AM AST Sat Jul 18 2026
Forecast is based on forecast start time of 0800 AST on July 18.
If conditions become unrepresentative...contact the National Weather
Service.
Please contact our office if you have questions or concerns
with this forecast at
PHONE: 787-253-4586.
.DISCUSSION...
Once again, a Fire Danger Statement (RFD) was issued for today.
Elevated fire weather conditions are expected across the southern
coastal plains and hills of Puerto Rico through the weekend. A
combination of an air mass with below normal moisture content,
limited rainfall, above-normal temperatures, and breezy east-
southerly winds will promote additional drying of fuels. Wind
speeds will also be sufficient to support the rapid spread of any
fires that develop.
Persistent rainfall deficits, critically dry fuels, KBDI values
exceeding 700, and ongoing vegetation stress continue across much
of Puerto Rico and the U.S. Virgin Islands. Although isolated
afternoon showers may develop over western Puerto Rico, rainfall
coverage and amounts will be insufficient to provide meaningful
relief to the ongoing dry condition and will usually remain above
the forecast area. Any wildfire could spread rapidly where strong
winds, low humidity, and dry fuels overlap. With no widespread
beneficial rainfall expected through the weekend, little
improvement in fuel conditions or ongoing drought impacts is
anticipated.
.TODAY...
Sky/weather.........Sunny (20-30 percent). Isolated showers in the
afternoon.
Chance of pcpn......20 percent.
Max temperature.....Around 92.
Min humidity........54 percent.
Wind (20 ft)........East winds 5 to 14 mph shifting to the
southeast around 5 mph late in the afternoon.
Gusts up to 28 mph in the late morning and
early afternoon.
Mixing height.......4000 ft AGL.
Transport winds.....East 7 to 16 mph increasing to 9 to 18 mph late
in the morning, then decreasing to around 7 mph
late in the afternoon.
Smoke dispersal.....Poor (1900 knot-ft) early in the morning
increasing to good (40800 knot-ft) in the
afternoon.
Dispersion..........5.
Eye level winds.....East winds up to 10 mph shifting to the
southeast around 4 mph late in the afternoon.
Gusts up to 28 mph in the late morning and
early afternoon.
TIME (AST) 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........5 5 5 5 25 25 25 40 40 40
Weather cov..... ISO ISO ISO ISO ISO ISO
Weather type.... RW RW RW RW RW RW
Tstm cov........
Chc of pcpn (%).0 0 0 0 10 10 10 20 20 20
Temp............85 88 89 91 91 92 92 91 90 88
RH..............61 58 59 56 55 54 54 55 57 62
20 FT wind dir..E E E E E SE SE SE SE SE
20 FT wind spd..6 9 14 16 17 16 14 10 8 6
20 FT wind gust.7 10 23 28 28 26 23 12 9 7
Eye lvl wnd dir.E E E E E SE SE SE SE SE
Eye lvl wnd spd.4 5 8 10 10 10 8 6 5 4
Eye lvl wnd gst. 6 14 17 17 16 14 7
Mix hgt (kft)...1.2 2.2 3.2 3.9 4.0 3.7 3.3 3.2 3.0 2.7
Transp wind dir.E E E E E E SE E E E
Transp wind spd.10 14 16 18 18 17 15 13 9 7
Dispersion......6 6 6 6 6 6 6 6 6 6
Vrate kt-ft/1K..41 41 41 41 41 41 21 21 21 21
Ventrate Cat....FR FR FR FR FR FR PR PR PR PR
.TONIGHT...
Sky/weather.........Partly cloudy (35-45 percent) then becoming
clear (0-10 percent). Isolated showers early in
the evening.
Chance of pcpn......20 percent.
Min temperature.....Around 75.
Max humidity........83 percent.
Wind (20 ft)........East winds 5 to 8 mph becoming light.
Mixing height.......0 ft AGL.
Transport winds.....East 5 to 8 mph.
Smoke dispersal.....Fair (21200 knot-ft) early in the evening
decreasing to poor (800 knot-ft) late in the
night.
Dispersion..........4.
Eye level winds.....East winds up to 5 mph decreasing to around 3
mph early in the morning.
TIME (AST) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........40 40 40 5 5 5 5 5 5 5 5 5
Weather cov.....ISO ISO ISO
Weather type....RW RW RW
Tstm cov........
Chc of pcpn (%).20 20 20 0 0 0 0 0 0 0 0 0
Temp............84 82 81 80 79 78 77 76 76 75 75 77
RH..............69 74 77 80 80 82 81 81 83 81 82 76
20 FT wind dir..SE E E E E E E E E E E E
20 FT wind spd..6 6 7 7 7 7 8 9 9 8 6 5
20 FT wind gust.7 7 8 8 8 8 9 10 10 9 7 6
Eye lvl wnd dir.SE E E E E E E E E E E E
Eye lvl wnd spd.4 4 4 4 4 4 5 5 5 5 4 3
Eye lvl wnd gst. 5 5 5 5 6 6 4
Mix hgt (kft)...2.0 1.2 0.6 0.3 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.2
Transp wind dir.E E E E E E E E NE NE NE NE
Transp wind spd.7 7 8 8 7 7 6 6 5 5 5 5
Dispersion......6 6 3 3 3 3 3 3 2 2 2 2
Vrate kt-ft/1K..21 21 1 1 1 1 1 1 1 1 1 1
Ventrate Cat....PR PR PR PR PR PR PR PR PR PR PR PR
.SUNDAY...
Sky/weather.........Sunny (15-25 percent).
Chance of pcpn......10 percent.
Max temperature.....Around 93.
Min humidity........53 percent.
Wind (20 ft)........Light winds becoming east 5 to 14 mph.
Mixing height.......4300 ft AGL.
Transport winds.....East 6 to 15 mph increasing to 10 to 18 mph
late in the morning, then decreasing to around
8 mph late in the afternoon.
Smoke dispersal.....Poor (800 knot-ft) early in the morning
increasing to good (41200 knot-ft) in the
afternoon.
Dispersion..........4.
Eye level winds.....East winds around 3 mph increasing to up to 10
mph.
TIME (AST) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........10 10 10 20 20 20 19 19 19 30 30 30
Weather cov..... ISO ISO ISO
Weather type.... RW RW RW
Tstm cov........
Chc of pcpn (%).0 0 0 0 0 0 0 0 0 10 10 10
Temp............80 83 86 88 90 92 92 93 93 92 91 89
RH..............66 62 57 55 54 53 53 54 54 55 58 62
20 FT wind dir..E E E E E E E SE SE SE E E
20 FT wind spd..5 5 7 9 13 15 16 16 15 12 9 7
20 FT wind gust.6 6 8 10 21 25 26 26 24 21 10 8
Eye lvl wnd dir.E E E E E E E SE SE SE E E
Eye lvl wnd spd.3 3 4 5 8 9 10 10 9 7 5 4
Eye lvl wnd gst.4 4 5 6 13 15 16 16 14 13 6 5
Mix hgt (kft)...0.3 0.6 1.2 2.3 3.5 4.3 4.2 3.7 3.0 2.7 2.4 2.1
Transp wind dir.NE E E E E E E E E E E E
Transp wind spd.6 7 9 13 15 17 18 17 16 14 10 8
Dispersion......2 2 6 6 6 6 6 6 6 6 6 6
Vrate kt-ft/1K..1 1 41 41 41 41 41 41 21 21 21 21
Ventrate Cat....PR PR FR FR FR FR FR FR PR PR PR PR
$$
Forecaster...C. Villanueva-Birriel
Requested by...Jose M. Martinez
Type of request...WILDFIRE
.TAG 2617461.2/SJU
.DELDT 07/18/26
.FormatterVersion 2.0.0
.EMAIL josemartin@dsp.pr.gov