Wildfire in Montana, August 8 to 18, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
832 PM MDT WED AUG 8 2007

.SHORT TERM...VALID FOR THU AND FRI...

UPDATE...
ONLY MINOR ADJUSTMENTS TO MAINLY WINDS AND CLOUD COVER FOR UPDATE
THIS EVENING. WEAK SHORT WAVE ENERGY LIFTING OUT OF NORTHERN IDAHO
AND FAR WESTERN MONTANA PROVIDING JUST ENOUGH LIFT FOR ISOLATED
SHOWERS AND THUNDERSTORMS TO THE WEST OF OUR REGION. THIS ENERGY
WORKS ACROSS OUR AREA OVERNIGHT. DYNAMICS AND INSTABILITY ARE
WEAK AND MOISTURE LIMITED SO ANY FURTHER DEVELOPMENT SHOULD BE
VERY LIMITED. CLOUDS HAVE DEVELOPED INTO OUR AREA FROM LIVINGSTON
TO BILLINGS EARLY THIS EVENING WITH SOME VIRGA VISIBLE. LOW LEVELS
REMAIN VERY DRY AND SO WITH ANY DEVELOPMENT THAT DOES OCCUR...NOT
ANTICIPATING MORE THAN A FEW SPRINKLES REACHING THE GROUND. HAVE
MAINTAINED THE DRY FORECAST. FRIEDERS

PREVIOUS DISCUSSION...
UPPER TROUGH OFF THE BRITISH COLUMBIA COAST WAS DEEPENING THIS
AFTERNOON AND THIS IS EXPECTED TO CONTINUE THURSDAY. THIS PROCESS
WILL CAUSE MID LEVEL WINDS TO BACK AND PROVIDE SOUTHWEST FLOW
OVER THE STATE. MOISTURE AVAILABILITY HAS BEEN DROPPED QUITE A
BIT FROM THE LAST SEVERAL WEEKS AS DEEP MONSOON MOISTURE HAS BEEN
SHOVED INTO THE CENTRAL PLAINS. SOUTHWEST FLOW WILL ALLOW THE
ATMOSPHERE TO BECOME MORE UNSTABLE THURSDAY THROUGH FRIDAY. WILL
KEEP THE LOW POPS OVER THE WEST THURSDAY AFTERNOON AND SPREAD
THEM EAST THURSDAY NIGHT.

FRIDAY LOOKS A LITTLE MORE INTERESTING AS THE BRITISH COLUMBIA
TROUGH MOVES INLAND AND WORKS INTO SOUTHERN ALBERTA FRIDAY
AFTERNOON. MID LEVEL FLOW WILL INCREASE AS THE GRADIENT TIGHTENS
THE MID LEVEL ISOBARS BETWEEN THE TROUGH OVER SOUTHERN CANADA AND
THE STRONG HIGH TRYING TO BUILD BACK INTO THE SOUTHERN ROCKIES.
THIS WILL SEND PROGRESSIVELY STRONGER CHUNKS OF ENERGY INTO THE
FORECAST AREA. ALONG WITH THAT...A COLD FRONT WILL PUSH INTO THE
WEST FRIDAY AFTERNOON AND ACROSS THE REST OF THE AREA FRIDAY
NIGHT. THIS FRONT WILL PROVIDE A STRONG WIND SHIFT AND
THUNDERSTORMS SHOULD DEVELOP ALONG AND JUST BEHIND IT. MOISTURE
AVAILABILITY WILL BE LIMITED...SO KEPT THE LOW POPS IN FOR THIS.

FOR FIRE WEATHER...WEST WINDS HAVE BEEN A BIT BREEZY OVER THE
AREA EARLY THIS AFTERNOON WITH THE STRONGEST WINDS OVER SOUTH
CENTRAL MONTANA. CONDITIONS HAVE BEEN BORDERLINE RED FLAG WITH A
FAR MAJORITY OF SITES STAYING BELOW CRITERIA. AS MENTIONED
ABOVE...POCKET OF MID LEVEL WINDS WILL SLIDE EAST THIS AFTERNOON
AND EVENING AND WINDS SHOULD DECREASE THROUGH EARLY EVENING. WILL
CONTINUE TO HIT THE WORDING STRONG FOR WEST WINDS AND LOW
HUMIDITIES. HUMIDITIES WILL REMAIN QUITE LOW THE NEXT FEW DAYS.
ISOLATED THUNDERSTORMS ARE EXPECTED OVER WESTERN AND CENTRAL
ZONES THURSDAY AND THURSDAY NIGHT. A SLIGHT CHANCE OF
THUNDERSTORMS WILL BE IN THE FORECAST FOR FRIDAY AND FRIDAY NIGHT
AS A COLD FRONT MOVES IN. STORMS WILL BE DRIER THEN THEY HAVE
BEEN RECENTLY. A COLD FRONT AND ASSOCIATED WIND SHIFT WILL MOVE
INTO THE WEST FRIDAY AND ACROSS THE REST OF THE AREA FRIDAY
NIGHT. A FIRE WEATHER WATCH MAY BE NEEDED FOR THIS FEATURE IN
FUTURE FORECASTS. HUMPHREY

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

MODELS IN MUCH BETTER AGREEMENT WITH THE EXTENDED FORECAST THIS
MORNING. THE SOLUTION IS A BIT ODD IN THAT IT INVOLVES A PACIFIC
LOW ON THE WASHINGTON/BC COAST MOVING OUT INTO THE PACIFIC AND A
SUBTROPICAL HIGH RETROGRADING FROM EAST TO WEST...CURRENTLY CAUSING
ALL THE HEAT RELATED HIGHLIGHTS OVER THE SOUTHEAST...PULLING WEST
INTO COLORADO AND THEN NORTHWARD INTO THE NORTHERN PLAINS TUESDAY
INTO WEDNESDAY. THE GFS...ECMWF...UKMET...AND DGEX ARE ALL IN GOOD
AGREEMENT WITH THIS PATTERN.

A STRONG UPPER WAVE EJECTS OUT OF THE PACIFIC NORTHWEST AND ACROSS
SOUTHERN CANADA AND NORTHERN MONTANA LATE FRIDAY. THIS WILL DROP A
COLD FRONT THROUGH THE AREA RESULTING IN HIGHS NEAR TO SLIGHTLY
BELOW NORMAL TO START THE WEEKEND. TEMPERATURES WARM SOMEWHAT
SUNDAY IN THE WEST AS NEXT PACIFIC SYSTEM DROPS DOWN THE NORTHWEST
COAST BACKING FLOW ALOFT TO THE SOUTHWEST AND ALLOWING WARMER AIR
TO SURGE BACK TO THE NORTH. THE EASTERN ZONES WILL SEE ONE MORE
NEAR NORMAL TEMPERATURE DAY. MONDAY THE SUB TROPICAL HIGH
RETROGRADES INTO COLORADO...BRINGING A +32C 850 MB AIRMASS OVER
THE AREA FOR MONDAY AND TUESDAY...RESULTING IN POTENTIAL HIGHS
BACK NEAR THE CENTURY MARK. ONE SAVING GRACE MAY BE THAT THE RIDGE
WILL LIKELY BE ACTIVE WEATHERWIZE...WITH PACIFIC MOISTURE AND
ASSORTED UPPER LEVEL DISTURBANCES KICKING OUR WAY...SUPPRESSING MAX
POTENTIAL HEATING SOME.

PERSISTENCE IS BEST DESCRIPTION FOR POPS. MANY FOCUSES FOR
CONVECTION WITH DECENT MID LEVEL MOISTURE AROUND ALONG WITH
PERIODS OF HIGHER DEW POINT AIR ADVECTING IN FROM THE PLAINS FROM
TIME TO TIME. WITH SOUTHWEST FLOW OVER THE AREA WILL SEE AT LEAST
SOME MOUNTAIN INITIATED CONVECTION EACH AFTERNOON. CHAMBERS/GILSTAD

&&

.AVIATION...

VFR CONDITIONS WILL PREVAIL OVERNIGHT AND INTO THURSDAY. SOME
CUMULUS DEVELOPMENT THIS EVENING WITH SOME ISOLATED VIRGA WILL
GRADUALLY DISSIPATE THROUGH THE NIGHT AS IT DRIFTS EAST. BT

&&

.PRELIMINARY POINT TEMP/POPS...

    THU     FRI     SAT     SUN     MON     TUE     WED
-----------------------------------------------------------
BIL 059/090 059/090 060/087 060/090 063/092 063/091 064/087
    00/U    22/T    22/T    22/T    22/T    22/T    22/T
LVM 049/087 050/088 049/082 050/089 052/090 055/089 054/083
    00/U    23/T    32/T    22/T    22/T    22/T    22/T
HDN 058/092 059/096 058/089 059/096 060/099 062/099 060/096
    00/U    22/T    22/T    22/T    22/T    22/T    22/T
MLS 060/094 064/096 064/089 063/091 064/096 066/094 065/093
    00/U    02/T    22/T    22/T    20/U    22/T    22/T
4BQ 057/096 060/095 060/091 061/095 063/098 064/099 062/099
    00/U    02/T    22/T    22/T    22/T    22/T    22/T
BHK 057/093 060/094 061/087 058/088 060/093 061/092 061/093
    00/U    22/T    22/T    22/T    20/U    22/T    22/T
SHR 052/090 054/092 054/086 055/092 058/093 058/095 059/092
    00/U    02/T    22/T    22/T    22/T    22/T    22/T

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

WEATHER.GOV/BILLINGS