FPCN39 CWLW 171322
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 7:00 AM PDT SUNDAY 17 MAY 1998 FOR TODAY.

VENTILATION INDICES (TEMPERATURE) AND MIXING HEIGHTS.
MIXING HEIGHTS IN METRES ABOVE SEA LEVEL.
AVERAGE WINDS IN KNOTS.

SPOT INDICES ARE DETERMINED BY THE ASPECT AND ELEVATION OF THE SITES.
COMPARE WINDS, TEMPERATURES AND ELEVATION WITH THE SITES HERE
TO DETERMINE THE INDEX IN ANY OTHER AREA.

SOUTHERN INTERIOR

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
FRSR CANYN   KEL      12   14     700   1    100   21    2550  12
KAMLOOPS     KEL      38   14    1100   5    100   21    2900  12
OKANAGAN     KEL      11   12     650   1    100   20    2700  12
CASTLEGAR    SPOK     32    9     990   2     92   19    3400   8
CRANBROOK    SPOK     17    7    1040   2     ##   20    3350   8
REVELSTOKE   KEL      18   12     850   2    100   19    2700  12

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    NW   9   N   20   N   33
CRANBROOK             E    9   E   24

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          580 m         12 C
SPOKANE          MISG

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD.


CENTRAL INTERIOR/NORTHEAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
WILLIAMS L   P.G.      9   10     950   4    100   18    3950   9
PR. GEORGE   P.G.     13   11     850   3    100   19    3700   8
SMITHERS     P.G.     33   14    1250   4    100   20    3500   7
WELLS GRAY   P.G.     63   12    2000   7    100   19    4000   9
FT NLSN      F.N.     15   14     500   5     79   22    2050   6
FT STJOHN    F.N.      9   12     700   5     12   17     750   5

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            VR   5   VR   5
SMITHERS              VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       860 m         13 C
FT. NELSON       752 m         20 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     83   13    1200  10     88   16    1500   9
FRASER VLY   QUIL     87   13    1200  11     88   16    1500   9
SRN VRISL    QUIL     74   13    1100   9     88   18    1700   8
CNTRL VRISL  QUIL     12   11     300   1     82   16    1500   8
NRN VRISL    HRDY     60   12    1000   7     74   15    1300   7
TERRACE      ANT      47   14    1550   3     56   20    2550   3
STEWART      ANT      25   14     750   2     50   20    2200   2

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   24   W   19   NW  11
PORT HARDY   NW  17   VR   5   VR   5
SANDSPIT     NW  31   NW  13   S   13

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE        NONE
PORT HARDY        NONE
ANNETTE          200 m         10 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD

VENTILATION GUIDELINES:
          0-33.....POOR
          34-54.....FAIR
          55-100.....GOOD.
VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET.


END/MWSO