Routine Fire Wx Fcst (With/Without 6-10 Day Outlook)
Issued by NWS San Juan, PR

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FNCA52 TJSJ 180932
FWFSJU

Fire Weather Planning Forecast for Puerto Rico
National Weather Service San Juan PR
532 AM AST Mon Aug 18 2025

.DISCUSSION...

According to the preliminary estimated rainfall from August 15th
through the 17th, accumulations ranged from 1 - 4 inches, with
localized areas reaching 5 - 7 inches. Although some areas such
as the Southern Coastal Plains of Puerto Rico are currently
abnormally dry and under moderate drought, these areas received
around 2-5 inches of precipitation during Hurricane Erin.
Additionally, stations over these areas reported a decrease in
KDBI values in Cabo Rojo (564 to 542), but Guanica went from 632
to 544, which puts them below Fire Weather Criteria. For today,
winds are expected to gradually decrease (16 - 20 mph, gusts up to
24 mph), while relative humidities should stay above thresholds
(68 - 71 %). Additionally, the tropical moisture pooled by
Hurricane Erin is expected to bring showers across the area
throughout the day. Hence, conditions for fire weather criteria
should not be met, and once again, the fire danger risk will be
low for today.


PRZ014-190945-
Southeast Coastal Plains-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Pcldy
Precip Type           Tstms        Tstms        Showers
Chance Precip (%)     80           60           20
Temp (24h trend)      88 (+4)      75 (-2)      90
RH % (24h trend)      71 (+2)      98 (+4)      64
Wind 20ft/early(mph)  S 16 G24     S  9         SE 10
Wind 20ft/late(mph)   S 16 G24     S  9         SE 10
Mixing Hgt(ft-agl/msl)3210                      3860
Transport Wnd (mph)   S 23                      SE 14
Vent Rate (kt-ft)     64200                     46320
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ015-190945-
Southern Hills-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Pcldy
Precip Type           Tstms        Tstms        Showers
Chance Precip (%)     80           60           30
Temp (24h trend)      85 (+6)      72 (-3)      87
RH % (24h trend)      74 (-1)      100 (+3)     68
Wind 20ft/early(mph)  S 17         S 11         SE 12
Wind 20ft/late(mph)   S 17         S 11         SE 12
Mixing Hgt(ft-agl/msl)3340                      4290
Transport Wnd (mph)   S 26                      SE 14
Vent Rate (kt-ft)     76820                     51480
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ016-190945-
North Coastal Plains-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Tstms
Chance Precip (%)     60           30           30
Temp (24h trend)      89 (+3)      75 (-3)      93
RH % (24h trend)      68 (+4)      99 (+7)      59
Wind 20ft/early(mph)  S 19 G22     S 16         SE 12
Wind 20ft/late(mph)   S 19 G22     S 16         SE 12
Mixing Hgt(ft-agl/msl)4080                      4960
Transport Wnd (mph)   S 25                      SE 12
Vent Rate (kt-ft)     89760                     49600
Dispersion            5                         5
DSI                   6            4            5
RH Recovery                        Excellent

Remarks...None.

$$

PRZ017-190945-
Northern Hills-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Tstms
Chance Precip (%)     70           40           60
Temp (24h trend)      87 (+5)      72 (-3)      91
RH % (24h trend)      70 (-3)      100 (+6)     60
Wind 20ft/early(mph)  S 19         S 14         SE 10
Wind 20ft/late(mph)   S 19         S 14         SE 10
Mixing Hgt(ft-agl/msl)3410                      5150
Transport Wnd (mph)   S 24                      SE 10
Vent Rate (kt-ft)     71610                     46350
Dispersion            5                         5
DSI                   6            3            5
RH Recovery                        Excellent

Remarks...None.

$$

PRZ018-190945-
West Coast-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Mclear
Precip Type           Tstms        Tstms        Showers
Chance Precip (%)     80           60           20
Temp (24h trend)      87 (+2)      74 (-2)      92
RH % (24h trend)      76 (+4)      100 (+3)     63
Wind 20ft/early(mph)  S 20 G23     S 17 G19     SE 14 G17
Wind 20ft/late(mph)   S 20 G23     S 17 G19     SE 14 G17
Mixing Hgt(ft-agl/msl)3160                      3880
Transport Wnd (mph)   S 29                      SE 20
Vent Rate (kt-ft)     79000                     65960
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ019-190945-
Eastern Interior-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Pcldy
Precip Type           Tstms        Tstms        Showers
Chance Precip (%)     60           50           30
Temp (24h trend)      88 (+6)      74 (-2)      91
RH % (24h trend)      71 (0)       100 (+4)     62
Wind 20ft/early(mph)  S 18         S 11         SE 11
Wind 20ft/late(mph)   S 18         S 11         SE 11
Mixing Hgt(ft-agl/msl)4000                      4900
Transport Wnd (mph)   S 26                      SE 13
Vent Rate (kt-ft)     92000                     53900
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ022-190945-
Luquillo Mountain Range-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     60           40           30
Temp (24h trend)      84 (+5)      70 (-3)      86
RH % (24h trend)      75 (+1)      100 (0)      69
Wind 20ft/early(mph)  S 16 G18     S  9         SE 10
Wind 20ft/late(mph)   S 16 G18     S  9         SE 10
Mixing Hgt(ft-agl/msl)3660                      4300
Transport Wnd (mph)   S 29                      SE 13
Vent Rate (kt-ft)     91500                     47300
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ023-190945-
Central Mountain Range-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Pcldy
Precip Type           Tstms        Tstms        Tstms
Chance Precip (%)     80           50           50
Temp (24h trend)      83 (+6)      70 (-3)      86
RH % (24h trend)      76 (-1)      100 (+2)     66
Wind 20ft/early(mph)  S 19         S 14         SE 12
Wind 20ft/late(mph)   S 19         S 14         SE 12
Mixing Hgt(ft-agl/msl)3090                      4820
Transport Wnd (mph)   S 28                      SE 13
Vent Rate (kt-ft)     74160                     53020
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ024-190945-
Cayey Mountain Range-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Pcldy
Precip Type           Tstms        Tstms        Showers
Chance Precip (%)     70           50           30
Temp (24h trend)      83 (+5)      71 (-2)      85
RH % (24h trend)      76 (0)       100 (0)      70
Wind 20ft/early(mph)  S 14 G17     S  9         SE  9
Wind 20ft/late(mph)   S 14 G17     S  9         SE  9
Mixing Hgt(ft-agl/msl)3690                      4440
Transport Wnd (mph)   S 26                      SE 14
Vent Rate (kt-ft)     84870                     53280
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ025-190945-
Vieques-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     70           40           30
Temp (24h trend)      89 (+1)      77 (-1)      90
RH % (24h trend)      64 (-1)      96 (+2)      60
Wind 20ft/early(mph)  S 19 G23     S 13 G17     SE 11
Wind 20ft/late(mph)   S 19 G23     S 13 G17     SE 11
Mixing Hgt(ft-agl/msl)2770                      3000
Transport Wnd (mph)   S 28                      SE 15
Vent Rate (kt-ft)     66480                     39000
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ026-190945-
Culebra-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     60           30           20
Temp (24h trend)      89 (+1)      78 (-1)      92
RH % (24h trend)      68 (+1)      97 (+1)      60
Wind 20ft/early(mph)  S 19 G23     S 13 G17     SE 12
Wind 20ft/late(mph)   S 19 G23     S 13 G17     SE 12
Mixing Hgt(ft-agl/msl)2710                      2950
Transport Wnd (mph)   S 29                      SE 15
Vent Rate (kt-ft)     67750                     38350
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ027-190945-
Southwest Coastal Plains and Mona Island-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Mcldy        Pcldy        Mclear
Precip Type           Tstms        Tstms        Showers
Chance Precip (%)     80           60           10
Temp (24h trend)      87 (+1)      76 (-2)      92
RH % (24h trend)      68 (0)       95 (+5)      61
Wind 20ft/early(mph)  S 19 G28     SE 17 G21    SE 14 G23
Wind 20ft/late(mph)   S 19 G28     SE 17 G21    SE 14 G23
Mixing Hgt(ft-agl/msl)2850                      3960
Transport Wnd (mph)   S 25                      SE 18
Vent Rate (kt-ft)     62700                     63360
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

VIZ001-190945-
Saint Thomas and Saint John-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     50           20           20
Temp (24h trend)      88 (+2)      77 (-2)      89
RH % (24h trend)      67 (-3)      97 (+3)      64
Wind 20ft/early(mph)  S 18 G23     SE 13        SE 13 G17
Wind 20ft/late(mph)   S 18 G23     SE 13        SE 13 G17
Mixing Hgt(ft-agl/msl)2830                      2800
Transport Wnd (mph)   SE 29                     SE 15
Vent Rate (kt-ft)     70750                     36400
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

VIZ002-190945-
St Croix-
532 AM AST Mon Aug 18 2025

                      Today        Tonight      Tue

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     50           30           20
Temp (24h trend)      89 (+2)      78 (-1)      90
RH % (24h trend)      67 (0)       95 (0)       63
Wind 20ft/early(mph)  S 17 G22     SE 11        SE 13 G17
Wind 20ft/late(mph)   S 17 G22     SE 11        SE 13 G17
Mixing Hgt(ft-agl/msl)3830                      4000
Transport Wnd (mph)   S 23                      SE 17
Vent Rate (kt-ft)     76600                     60000
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$


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