FXUS65 KTFX 260106
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
606 PM MST FRI DEC 25 2009
.UPDATE...
QUICK UPDATE TO ZONE AND STATE FORECASTS. PATCHY FOG HAS DEVELOPED
THIS EVENING ACROSS THE EASTERN AND SOUTHWEST PORTION OF THE TFX
CWA. HAVRE ASOS REPORTING LESS THAN ONE MILE VISIBILITY...BUT HILL
COUNTY SHERIFF DOES NOT REPORT WIDESPREAD DENSE FOG.
THEREFORE...WILL HOLD OFF ON A DENSE FOG ADVISORY AT THIS TIME.
FOG ALSO REPORTED BY BOZEMAN ASOS...BUT VISIBILITY THERE IS
BETWEEN 3 AND 5 MILES. WEB CAMS SHOW SOME FOG BUT AGAIN NOT
WIDESPREAD DENSE FOG. WILL ALSO HOLD OFF ON AN ADVISORY THERE FOR
NOW. WILL CONTINUE TO MONITOR THE SITUATION THROUGHOUT THE
EVENING. WILL KEEP MENTION OF FOG IN THROUGH TOMORROW MORNING.
COULSTON
&&
.AVIATION...
UPDATED 0005Z.
VFR CONDITIONS WILL PREVAIL AT TAF SITES ALONG THE ROCKY MOUNTAIN
FRONT...WITH PATCHY FOG AFFECTING TAF SITES OF KHVR/KBZN AND
POSSIBLY KHLN TONIGHT. UPPER LEVEL CLOUDS FROM THE WINTER STORM
CURRENTLY AFFECTING THE DAKOTAS WILL CONTINUE TO MOVE ACROSS KLWT
AND KBZN. CONDITIONS SHOULD IMPROVE TO VFR AT ALL TAF SITES BY
18Z ON THE 26TH. SUK
&&
.PREV DISCUSSION...
/ISSUED 505 PM MST FRI DEC 25 2009/
FRIDAY NIGHT THROUGH SUNDAY...NORTHERLY FLOW CONTINUES ACROSS THE
AREA WITH WEAK DISTURBANCES MOVING THROUGH FLOW. SOME SNOW HAS
BEEN FALLING OVER HIGHER ELEVATIONS OVER SOME SOUTHWEST
MOUNTAINS...BUT IT HAS BEEN LIMITED TO THE MOUNTAINOUS LOCATIONS.
THIS SHOULD BE DIMINISHING SOMEWHAT OVERNIGHT...BUT HAVE KEPT SOME
LOWER POPS IN THESE AREAS. HIGH PRESSURE WILL CONTINUE TO MAINTAIN
LIGHT WINDS AND COOL TO COLD TEMPS ACROSS THE AREA. EXPECT TEMPS
TO FALL TO NEAR -20 IN THE MILK RIVER VALLEY AGAIN TONIGHT. WITH
HIGH PRESSURE REMAINING...TEMPERATURES WILL CONTINUE TO SLOWLY
WARM...TO HIGHS BREAKING FREEZING IN SOME LOCATIONS ALONG THE
PLAINS ADJACENT TO THE ROCKIES ON SUNDAY. HIGH PRESSURE WILL ALSO
LIMIT PRECIP ACROSS THE AREA THROUGH THIS PERIOD. DB
SUNDAY NIGHT THROUGH FRIDAY NIGHT...HIGH PRESSURE WILL BEGIN TO PUSH
EASTWARD EARLY IN THE PERIOD WITH WESTERLY FLOW ALOFT DEVELOPING.
DRY CONDITIONS WILL PERSIST THROUGH TUESDAY BEFORE NEXT SHORTWAVE
TROUGH MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE CONSISTENT IN
BRINGING THIS WEAK SHORTWAVE THROUGH WESTERN MONTANA AND THEN INTO
SOUTHWEST MONTANA TUESDAY NIGHT...THUS INCREASED POPS ACROSS
SOUTHWEST MT THROUGH WEDNESDAY. IN ADDITION...STRONG
WEST-NORTHWESTERLY FLOW ALOFT MAY BRING STRONG AND GUSTY DOWNSLOPING
WINDS ALONG THE ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS. UNSETTLED
NORTHWEST FLOW IS EXPECTED THROUGH THURSDAY...THEN MODELS DIVERGE IN
TRENDS FOR THE NEW YEAR WEEKEND. LATEST EC INDICATES A BUILDING
RIDGE OF HIGH PRESSURE AND ABOVE AVERAGE TEMPERATURES THROUGH THE
END OF THE FORECAST PERIOD WHILE GFS AND GEM MODELS BRING A STRONG
TROUGH OF LOW PRESSURE AND COLDER TEMPERATURES TO THE REGION. GIVEN
THE UNCERTAINTY...KEPT TEMPERATURES ONLY SLIGHTLY ABOVE AVERAGE WITH
POPS NEAR CLIMATOLOGY. MLS/EMANUEL
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 8 24 9 32 / 0 0 0 0
CTB 2 26 8 33 / 0 0 0 0
HLN 4 19 1 11 / 0 0 0 0
BZN 5 21 0 18 / 0 0 0 0
WEY -2 23 -2 24 / 10 10 0 0
DLN 2 19 3 26 / 0 0 0 0
HVR -15 9 -8 18 / 0 0 0 0
LWT -1 22 6 30 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON/DB
LONG TERM...MLS/EMANUEL
AVIATION...SUK
WEATHER.GOV/GREATFALLS
