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

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031
FNCA52 TJSJ 240923
FWFSJU

Fire Weather Planning Forecast for Puerto Rico
National Weather Service San Juan PR
523 AM AST Sun Aug 24 2025

.DISCUSSION...

Today, east southeasterly winds should increase, between 12 to 17
mph with higher gusts. Breezy wind conditions will prevail for the
next few days, particularly over the southern coastal plains. Stations
across these areas are indicating a slight increase in KDBI
values with Cabo Rojo already exceeding once again Fire Weather
Criteria (557) but with Guanica still below fire weather
thresholds (499). St. Croix continues with elevated KBDI values of
705. Although 24h relative humidity trend shows values almost at
mid 50s today across the southern coastal plains and 64% over St.
Croix, southeasterly winds should keep relative humidity above
threshold values. Given these conditions and the expected weather
forecast, the fire weather risk will remain low for today.
However, the combination of breezy winds and much drier conditions
may increase the fire weather risk in the coming days.


PRZ014-250930-
Southeast Coastal Plains-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Mclear       Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     0            10           10
Temp (24h trend)      94 (+6)      74 (-2)      92
RH % (24h trend)      56 (-8)      95 (0)       56
Wind 20ft/early(mph)  E 16 G24     E 11         E 16 G23
Wind 20ft/late(mph)   E 16 G24     E 11         E 16 G23
Mixing Hgt(ft-agl/msl)4590                      5380
Transport Wnd (mph)   E 17                      E 22
Vent Rate (kt-ft)     68850                     102220
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ015-250930-
Southern Hills-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Pcldy        Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     30           10           10
Temp (24h trend)      90 (+5)      70 (-3)      88
RH % (24h trend)      60 (-12)     99 (+3)      59
Wind 20ft/early(mph)  E 13         E 14         E 16
Wind 20ft/late(mph)   E 13         E 14         E 16
Mixing Hgt(ft-agl/msl)5110                      5950
Transport Wnd (mph)   E 16                      E 22
Vent Rate (kt-ft)     71540                     113050
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ016-250930-
North Coastal Plains-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     10           10           10
Temp (24h trend)      92 (+4)      74 (-2)      90
RH % (24h trend)      64 (-10)     99 (+1)      65
Wind 20ft/early(mph)  E 19 G22     E 18         E 21 G24
Wind 20ft/late(mph)   E 19 G22     E 18         E 21 G24
Mixing Hgt(ft-agl/msl)4640                      5380
Transport Wnd (mph)   E 16                      E 23
Vent Rate (kt-ft)     64960                     107600
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ017-250930-
Northern Hills-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     20           10           10
Temp (24h trend)      90 (+3)      71 (-2)      88
RH % (24h trend)      63 (-9)      100 (0)      64
Wind 20ft/early(mph)  NE 17        E 17         E 20
Wind 20ft/late(mph)   NE 17        E 17         E 20
Mixing Hgt(ft-agl/msl)5460                      5830
Transport Wnd (mph)   E 15                      E 21
Vent Rate (kt-ft)     70980                     104940
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ018-250930-
West Coast-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     60           30           30
Temp (24h trend)      93 (+6)      71 (-3)      92
RH % (24h trend)      62 (-11)     100 (+1)     60
Wind 20ft/early(mph)  E 13         E 14         E 18
Wind 20ft/late(mph)   E 13         E 14         E 18
Mixing Hgt(ft-agl/msl)4210                      5400
Transport Wnd (mph)   E  8                      E 14
Vent Rate (kt-ft)     29470                     64800
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ019-250930-
Eastern Interior-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Showers      Showers      Showers
Chance Precip (%)     20           20           10
Temp (24h trend)      91 (+5)      72 (-3)      88
RH % (24h trend)      62 (-11)     100 (+2)     66
Wind 20ft/early(mph)  E 13         E 14         E 16
Wind 20ft/late(mph)   E 13         E 14         E 16
Mixing Hgt(ft-agl/msl)5540                      5750
Transport Wnd (mph)   E 16                      E 22
Vent Rate (kt-ft)     77560                     109250
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ022-250930-
Luquillo Mountain Range-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Showers      Showers      Showers
Chance Precip (%)     30           20           20
Temp (24h trend)      86 (+5)      69 (-4)      84
RH % (24h trend)      70 (-11)     100 (0)      72
Wind 20ft/early(mph)  E 12         E 12         E 14
Wind 20ft/late(mph)   E 12         E 12         E 14
Mixing Hgt(ft-agl/msl)4240                      4940
Transport Wnd (mph)   E 15                      E 23
Vent Rate (kt-ft)     55120                     98800
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ023-250930-
Central Mountain Range-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     60           10           20
Temp (24h trend)      89 (+7)      68 (-3)      87
RH % (24h trend)      63 (-12)     100 (+1)     64
Wind 20ft/early(mph)  E 11         E 13         E 17
Wind 20ft/late(mph)   E 11         E 13         E 17
Mixing Hgt(ft-agl/msl)6670                      6900
Transport Wnd (mph)   E 10                      E 18
Vent Rate (kt-ft)     60030                     110400
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ024-250930-
Cayey Mountain Range-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Mclear       Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     10           10           10
Temp (24h trend)      87 (+4)      70 (-2)      84
RH % (24h trend)      64 (-12)     100 (0)      69
Wind 20ft/early(mph)  E 11         E 12         E 14
Wind 20ft/late(mph)   E 11         E 12         E 14
Mixing Hgt(ft-agl/msl)4630                      5230
Transport Wnd (mph)   E 17                      E 24
Vent Rate (kt-ft)     69450                     109830
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ025-250930-
Vieques-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     20           10           10
Temp (24h trend)      90 (+4)      77 (-1)      89
RH % (24h trend)      61 (-9)      93 (-3)      61
Wind 20ft/early(mph)  E 18 G22     E 19 G23     E 19 G23
Wind 20ft/late(mph)   E 18 G22     E 19 G23     E 19 G23
Mixing Hgt(ft-agl/msl)3070                      4070
Transport Wnd (mph)   E 17                      E 24
Vent Rate (kt-ft)     46050                     85470
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

PRZ026-250930-
Culebra-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     20           10           10
Temp (24h trend)      91 (+5)      78 (-1)      91
RH % (24h trend)      62 (-13)     93 (-4)      61
Wind 20ft/early(mph)  E 18 G22     E 19 G23     E 19 G23
Wind 20ft/late(mph)   E 18 G22     E 19 G23     E 19 G23
Mixing Hgt(ft-agl/msl)2810                      4030
Transport Wnd (mph)   E 17                      E 26
Vent Rate (kt-ft)     42150                     92690
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ027-250930-
Southwest Coastal Plains and Mona Island-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     20           10           0
Temp (24h trend)      94 (+6)      73 (-4)      93
RH % (24h trend)      58 (-6)      96 (+3)      55
Wind 20ft/early(mph)  E 16 G24     E 12         E 19 G28
Wind 20ft/late(mph)   E 16 G24     E 12         E 19 G28
Mixing Hgt(ft-agl/msl)4270                      5570
Transport Wnd (mph)   E 14                      E 18
Vent Rate (kt-ft)     51240                     89120
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$

VIZ001-250930-
Saint Thomas and Saint John-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      None         Showers
Chance Precip (%)     20           0            10
Temp (24h trend)      88 (+3)      76 (-3)      88
RH % (24h trend)      66 (-11)     97 (0)       66
Wind 20ft/early(mph)  E 19 G23     E 19 G23     E 20 G24
Wind 20ft/late(mph)   E 19 G23     E 19 G23     E 20 G24
Mixing Hgt(ft-agl/msl)2770                      3850
Transport Wnd (mph)   E 24                      E 26
Vent Rate (kt-ft)     58170                     88550
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

VIZ002-250930-
St Croix-
523 AM AST Sun Aug 24 2025

                      Today        Tonight      Mon

Cloud Cover           Mclear       Mclear       Pcldy
Precip Type           Showers      None         Showers
Chance Precip (%)     10           0            20
Temp (24h trend)      90 (+4)      77 (-1)      89
RH % (24h trend)      64 (-11)     94 (-4)      66
Wind 20ft/early(mph)  E 17 G21     E 18 G22     E 19 G23
Wind 20ft/late(mph)   E 17 G21     E 18 G22     E 19 G23
Mixing Hgt(ft-agl/msl)3680                      4440
Transport Wnd (mph)   E 21                      E 26
Vent Rate (kt-ft)     66240                     102120
Dispersion            1                         1
DSI
RH Recovery                        Excellent

Remarks...None.

$$


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