High Wind in Montana, February 18 to 19, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1032 AM MST THU FEB 18 2016

...UPDATE TO AVIATION...

.UPDATE...HAVE MADE MINOR CHANGES TO POPS/WEATHER AND SNOW
ACCUMULATIONS BASED ON LATEST OBSERVATIONS AND MORNING MODEL
RUNS. OVERALL FORECAST APPEARS TO BE IN FAIRLY GOOD SHAPE. AM
SOMEWHAT CONCERNED ABOUT THE POSSIBILITY OF STRONG WINDS
DEVELOPING IN CHOUTEAU AND HILL COUNTIES BUT WILL HOLD OFF ON
EXPANDING THE HIGH WIND WARNING FOR NOW AS CONFIDENCE IN
VERIFICATION IS LOW TO MODERATE. MPJ

&&

.AVIATION...
UPDATED 1732Z.
UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE COLD FRONT MOVE
THROUGH THE FORECAST AREA THIS AFTERNOON. SCATTERED RAIN AND SNOW
SHOWERS OVER WESTERN MONTANA SPREAD EAST THROUGH 00Z FRIDAY. WINDS
INCREASE BEHIND THE FRONT AND BECOME STRONG WITH GUSTS IN EXCESS OF
60 KNOTS, ESPECIALLY NEAR KLWT AND OVER HIGHER TERRAIN. VFR
CONDITIONS PREVAIL WITH AREAS MVFR DUE TO LOW CEILINGS AND
PRECIPITATION. MOUNTAINS OBSCURED AT TIMES. SKIES BECOME MOSTLY
CLEAR TO PARTLY CLOUDY AFTER 12Z FRIDAY.

&&

.PREV DISCUSSION...
/ISSUED 500 AM MST THU FEB 18 2016/

TODAY THROUGH SATURDAY...A STRONG AND DEEPLY OCCLUDED PACIFIC
STORM SYSTEM CONTINUES TO SPIN INTO THE PAC-NW. THE ASSOCIATED
COLD FRONT IS ADVANCING THROUGH WESTERN ID AT THIS HOUR AND WILL
CROSS CENTRAL AND SOUTHWEST MT THIS AFTERNOON. INCREASING MOISTURE
WILL BRING SNOW INTO THE NORTHERN ROCKIES AND ACROSS SOUTHWEST
MONTANA. SNOW LEVELS ARE WELL ABOVE PASS LEVEL BUT WILL LOWER
QUICKLY AS THE FRONT MOVES BY. A FEW INCHES OF SNOWFALL ARE
EXPECTED THROUGH THIS EVENING ON SOUTHWEST PASSES...SO A WINTER
WEATHER ADVISORY IS IN EFFECT FOR THIS AREA. RAIN SHOWERS WILL
SPREAD ACROSS THE NORTH CENTRAL PLAINS. NOT EVERYONE WILL SEE
RAIN...WHILE OTHERS COULD EXPERIENCE BRIEF AND LOCALLY HEAVY RAIN
SHOWERS MORE TYPICAL OF EARLY SPRING. THE POTENTIAL FOR HIGH WINDS
PRESENTS A SIGNIFICANT FORECAST CHALLENGE TONIGHT. LEESIDE TROUGHING
WILL PRODUCE A STRONG PRESSURE GRADIENT AND GUSTY WINDS ALONG THE
ROCKY MOUNTAIN FRONT, BUT MODELS SUGGEST 700 MB WINDS WILL NOT
INCREASE UNTIL THE UPPER LEVEL TROUGH MOVES EAST OF THE
CONTINENTAL DIVIDE. PRESSURE RISES BEHIND THE FRONT WILL PRODUCE
STRONG PRESSURE GRADIENTS DOWNWIND OF THE CENTRAL MT RANGES BY
AFTERNOON. AT THIS TIME..AND THROUGH THE OVERNIGHT PERIOD...MODEL
GUIDANCE SUPPORTS STRONG SYNOPTIC SUBSIDENCE ALIGNING WITH THE
SURFACE GRADIENTS. THEREFORE, HAVE POSTED A HIGH WIND WARNING
ANTICIPATING WIND GUSTS NEAR 60 MPH FOR LOCATIONS INCLUDING
GEYSER...FORT BELKNAP..AND PORTIONS OF EASTERN FERGUS COUNTY.
MODELS ALSO SUGGEST POST-FRONTAL WIND GUSTS NEAR 50 MPH WILL BE
POSSIBLE FROM AROUND CUT BANK EAST TO HAVRE. WILL HAVE TO MONITOR
THIS AREA CLOSELY TODAY. QUIETER CONDITIONS PREVAIL FRIDAY WITH A
PASSING SHORTWAVE RIDGE. ANOTHER SHORTWAVE CRUISES THROUGH THE
STATE FRIDAY NIGHT AND EARLY SATURDAY, CAUSING CHANCE FOR
SCATTERED SHOWERS AND ANOTHER ROUND OF WIND. PN

SATURDAY NIGHT THROUGH THURSDAY...PROGRESSIVE PATTERN CONTINUES
THROUGH THE MEDIUM RANGE PERIOD. AN UPPER TROF EXITS THE AREA
SATURDAY NIGHT LEAVING BEHIND A FEW LINGERING SHOWERS ACROSS
NORTHEAST MONTANA. AN UPPER RIDGE THEN REBUILDS OVER THE WESTERN
U.S. SUNDAY RETURNING DRY CONDITIONS TO THE AREA. MONDAY FINDS
SHORT WAVE ENERGY FLATTENING THE RIDGE AND PUSHING IT EAST. AN
ASSOCIATED COLD FRONT WILL ALSO MOVE ACROSS THE AREA BRINGING
SCATTERED MOUNTAIN SNOW SHOWERS AND RAIN AND SNOW SHOWERS TO THE
PLAINS. DRY NORTHWESTERLY FLOW ALOFT WILL SET UP OVER THE AREA
TUESDAY THROUGH THURSDAY THOUGH THE MODELS DIFFER IN THEIR
RESPECTIVE SOLUTIONS. THE GFS DEVELOPS A CLOSED UPPER LOW OVER THE
FOUR CORNERS AREA WHILE THE ECMWF PLACES THE CLOSED LOW OVER
SOUTHERN IDAHO. REGARDLESS OF THE LOW'S POSITION, DRY CONDITIONS
WILL PREVAIL OVER THE AREA. TEMPERATURES WILL DECLINE DURING THE
PERIOD BUT REMAIN ABOVE SEASONAL AVERAGES. THE EXCEPTION BEING
SOUTHWEST MONTANA WHERE AFTERNOON HIGHS WILL BE NEAR TO SLIGHTLY
BELOW AVERAGES.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  55  36  53  35 /  50  10  10  20
CTB  51  35  51  32 /  50  10  10  10
HLN  48  34  49  31 /  50  20  10  20
BZN  45  27  45  26 /  50  20  10  20
WEY  36  23  33  21 /  90  60  30  40
DLN  44  30  43  26 /  50  20  10  20
HVR  55  35  54  33 /  40  20   0  20
LWT  55  33  48  31 /  30  30   0  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 2 PM THIS AFTERNOON TO 11 AM MST FRIDAY
FOR MTZ047-050-051.

WINTER WEATHER ADVISORY UNTIL 10 PM MST THIS EVENING FOR MTZ008-
015-055.

&&

WEATHER.GOV/GREATFALLS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1239 PM MST THU FEB 18 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1226 PM     NON-TSTM WND GST 7 NE CRAIG              47.14N 111.86W
02/18/2016  M57 MPH          CASCADE            MT   DEPT OF HIGHWAYS

            57 MPH WIND GUST WIND THE COLD FRONT AND RAIN SHOWER
            MOVED THROUGH. REPORT VIA THE DOT SENSOR NEAR DEARBORN
            ON I15.

&&

BRUSDA