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

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FNCA52 TJSJ 170844
FWFSJU

Fire Weather Planning Forecast for Puerto Rico
National Weather Service San Juan PR
444 AM AST Thu Jul 17 2025

.DISCUSSION...

Lingering moisture from a tropical wave will result in showers and
isolated thunderstorms today, especially across the interior and
western Puerto Rico during the afternoon hours. Minimum relative
humidities are expected to generally remain above critical fire
weather levels, however, in some areas across the southern coastal
plains of Puerto Rico values in the mid 50s are possible. Accompanied
with breezy winds may increase the fire risk if those areas do not
receive heavy rain.

PRZ014-180845-
Southeast Coastal Plains-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Mclear       Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     20           10           10
Temp (24h trend)      92 (+2)      75 (-2)      92
RH % (24h trend)      52 (-10)     90 (-1)      54
Wind 20ft/early(mph)  E 17 G23     E 14 G20     E 17 G22
Wind 20ft/late(mph)   E 17 G23     E 14 G20     E 17 G22
Mixing Hgt(ft-agl/msl)4600                      5560
Transport Wnd (mph)   E 18                      E 16
Vent Rate (kt-ft)     73600                     77840
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ015-180845-
Southern Hills-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Tstms        Showers      Tstms
Chance Precip (%)     40           10           30
Temp (24h trend)      88 (+4)      71 (-3)      88
RH % (24h trend)      56 (-14)     94 (0)       61
Wind 20ft/early(mph)  E 13         E 11         E 12
Wind 20ft/late(mph)   E 13         E 11         E 12
Mixing Hgt(ft-agl/msl)5100                      5660
Transport Wnd (mph)   E 17                      E 14
Vent Rate (kt-ft)     76500                     67920
Dispersion            5                         5
DSI                   6            3            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ016-180845-
North Coastal Plains-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     50           40           30
Temp (24h trend)      89 (+2)      75 (-2)      89
RH % (24h trend)      58 (-16)     93 (-4)      66
Wind 20ft/early(mph)  E 20         E 18         E 17 G20
Wind 20ft/late(mph)   E 20         E 18         E 17 G20
Mixing Hgt(ft-agl/msl)4060                      4500
Transport Wnd (mph)   E 20                      E 15
Vent Rate (kt-ft)     69020                     58500
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ017-180845-
Northern Hills-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Tstms
Chance Precip (%)     60           20           40
Temp (24h trend)      89 (+4)      72 (-2)      87
RH % (24h trend)      58 (-17)     96 (-3)      69
Wind 20ft/early(mph)  E 18         E 16         NE 16
Wind 20ft/late(mph)   E 18         E 16         NE 16
Mixing Hgt(ft-agl/msl)5040                      5200
Transport Wnd (mph)   E 16                      E 12
Vent Rate (kt-ft)     70560                     52000
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ018-180845-
West Coast-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Mclear       Pcldy
Precip Type           Tstms        Showers      Tstms
Chance Precip (%)     50           20           60
Temp (24h trend)      92 (+2)      72 (-2)      92
RH % (24h trend)      54 (-13)     99 (+2)      62
Wind 20ft/early(mph)  E 14         E 12         E 12
Wind 20ft/late(mph)   E 14         E 12         E 12
Mixing Hgt(ft-agl/msl)4120                      4960
Transport Wnd (mph)   E 12                      E  9
Vent Rate (kt-ft)     41200                     39680
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ019-180845-
Eastern Interior-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     50           40           40
Temp (24h trend)      87 (+3)      72 (-3)      88
RH % (24h trend)      62 (-13)     94 (-3)      65
Wind 20ft/early(mph)  E 13         E 13         E 11
Wind 20ft/late(mph)   E 13         E 13         E 11
Mixing Hgt(ft-agl/msl)5210                      5590
Transport Wnd (mph)   E 16                      E 13
Vent Rate (kt-ft)     72940                     61490
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ022-180845-
Luquillo Mountain Range-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     60           60           60
Temp (24h trend)      82 (+4)      70 (-3)      83
RH % (24h trend)      71 (-15)     98 (-1)      74
Wind 20ft/early(mph)  E 11         E 11         E 10
Wind 20ft/late(mph)   E 11         E 11         E 10
Mixing Hgt(ft-agl/msl)3320                      4230
Transport Wnd (mph)   E 17                      E 13
Vent Rate (kt-ft)     49800                     46530
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ023-180845-
Central Mountain Range-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Mclear       Pcldy
Precip Type           Tstms        Showers      Tstms
Chance Precip (%)     60           0            70
Temp (24h trend)      86 (+5)      69 (-2)      86
RH % (24h trend)      56 (-21)     96 (-3)      69
Wind 20ft/early(mph)  E 10         E 10         E  9
Wind 20ft/late(mph)   E 10         E 10         E  9
Mixing Hgt(ft-agl/msl)6120                      6260
Transport Wnd (mph)   E 13                      E  8
Vent Rate (kt-ft)     67320                     43820
Dispersion            5                         5
DSI                   5            2            5
RH Recovery                        Excellent

Remarks...None.

$$

PRZ024-180845-
Cayey Mountain Range-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Mclear
Precip Type           Tstms        Showers      Showers
Chance Precip (%)     50           30           20
Temp (24h trend)      83 (+3)      71 (-2)      83
RH % (24h trend)      67 (-11)     97 (-3)      70
Wind 20ft/early(mph)  E 11         E 10         E 10
Wind 20ft/late(mph)   E 11         E 10         E 10
Mixing Hgt(ft-agl/msl)4290                      5380
Transport Wnd (mph)   E 18                      E 15
Vent Rate (kt-ft)     68640                     69940
Dispersion            5                         5
DSI                   6            4            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ025-180845-
Vieques-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Mclear       Pcldy
Precip Type           Showers      Showers      Showers
Chance Precip (%)     40           20           60
Temp (24h trend)      89 (+2)      77 (-1)      88
RH % (24h trend)      61 (-8)      85 (-7)      61
Wind 20ft/early(mph)  E 14 G19     E 16 G20     E 13
Wind 20ft/late(mph)   E 14 G19     E 16 G20     E 13
Mixing Hgt(ft-agl/msl)2520                      3030
Transport Wnd (mph)   E 20                      E 16
Vent Rate (kt-ft)     42840                     42420
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ026-180845-
Culebra-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Pcldy
Precip Type           Showers      Showers      Showers
Chance Precip (%)     40           30           40
Temp (24h trend)      91 (+3)      79 (0)       90
RH % (24h trend)      58 (-12)     84 (-7)      62
Wind 20ft/early(mph)  E 16 G19     E 17 G21     E 13 G17
Wind 20ft/late(mph)   E 16 G19     E 17 G21     E 13 G17
Mixing Hgt(ft-agl/msl)2610                      3110
Transport Wnd (mph)   E 20                      E 15
Vent Rate (kt-ft)     44370                     40430
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

PRZ027-180845-
Southwest Coastal Plains and Mona Island-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Mclear       Mclear       Mclear
Precip Type           Showers      None         Showers
Chance Precip (%)     10           0            30
Temp (24h trend)      92 (+2)      75 (-2)      92
RH % (24h trend)      53 (-8)      92 (+4)      56
Wind 20ft/early(mph)  SE 20 G26    E 16 G21     E 17 G22
Wind 20ft/late(mph)   SE 20 G26    E 16 G21     E 17 G22
Mixing Hgt(ft-agl/msl)4570                      5500
Transport Wnd (mph)   E 18                      E 17
Vent Rate (kt-ft)     73120                     82500
Dispersion            5                         5
DSI                   6            5            6
RH Recovery                        Excellent

Remarks...None.

$$

VIZ001-180845-
Saint Thomas and Saint John-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Pcldy        Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     30           30           30
Temp (24h trend)      86 (+1)      76 (-3)      86
RH % (24h trend)      66 (-8)      88 (-7)      67
Wind 20ft/early(mph)  E 17 G21     E 17 G21     E 13 G17
Wind 20ft/late(mph)   E 17 G21     E 17 G21     E 13 G17
Mixing Hgt(ft-agl/msl)2650                      3140
Transport Wnd (mph)   E 21                      E 17
Vent Rate (kt-ft)     47700                     47100
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$

VIZ002-180845-
St Croix-
444 AM AST Thu Jul 17 2025

                      Today        Tonight      Fri

Cloud Cover           Pcldy        Mclear       Mclear
Precip Type           Showers      Showers      Showers
Chance Precip (%)     30           20           10
Temp (24h trend)      89 (+3)      77 (-2)      87
RH % (24h trend)      62 (-11)     82 (-10)     65
Wind 20ft/early(mph)  E 17 G20     E 16 G19     E 13
Wind 20ft/late(mph)   E 17 G20     E 16 G19     E 13
Mixing Hgt(ft-agl/msl)3740                      4520
Transport Wnd (mph)   E 22                      E 15
Vent Rate (kt-ft)     71060                     58760
Dispersion            5                         5
DSI                   6            6            6
RH Recovery                        Excellent

Remarks...None.

$$


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