Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 251754
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1152 AM MDT MON APR 25 2016

UPDATED AVIATION SECTION

.UPDATE...

MADE SOME MINOR ADJUSTMENTS TO ONGOING FORECAST. WENT WITH
CATEGORICAL POPS FOR MUCH OF NORTH CENTRAL MONTANA TO BETTER
REFLECT RADAR ECHO COVERAGE. HAVE ALSO LOWERED TEMPERATURES A FEW
DEGREES MOST LOCATIONS DUE TO PERSISTENT PRECIPITATION AND CLOUD
COVER.  COULSTON

&&

.AVIATION...
UPDATED 1752Z.

MOISTURE WRAPPING AROUND A LOW PRESSURE SYSTEM OVER THE DAKOTAS WILL
CONTINUE WIDESPREAD MVFR/IFR CONDITIONS WITH MOUNTAIN OBSCURATION
ACROSS NORTH CENTRAL AND CENTRAL MONTANA THROUGH 18Z TUESDAY.
WIDESPREAD RAIN/SNOW WILL CONTINUE ACROSS THAT AREA THROUGH AROUND
00Z, BUT ANY LINGERING PRECIPITATION AFTER THEN WILL LIKELY BE MORE
SHOWERY. IN SOUTHWEST MONTANA SKIES WILL BE MOSTLY CLOUDY WITH VFR
CONDITIONS WITH MORE SCATTERED PRECIPITATION AND ONLY OCCASIONAL
MVFR CONDITIONS.  COULSTON

&&

.PREV DISCUSSION...
/ISSUED 745 AM MDT MON APR 25 2016/

QUICK UPDATE TO THIS MORNING`S FORECAST. SPOTTER NEAR FORT
BELKNAP HAS REPORTED BETWEEN 8 AND 9 INCHES OF WET HEAVY SNOW
OVERNIGHT, WHICH HAS CAUSED A POWER OUTAGE IN THAT AREA. HAVE
THEREFORE UPGRADED THE ADVISORY FOR BLAINE COUNTY TO A WINTER
STORM WARNING. HAVE KEPT THE EXPIRATION TIME AT NOON FOR NOW AND
WILL RE-EVALUATE THE SITUATION THEN. THE OTHER ADVISORY AREAS ARE
SHOWING LESSER ACCUMULATIONS ON WEB CAMS THIS MORNING, SO WILL
LEAVE THEM AS IS. COULSTON

TODAY THROUGH WEDNESDAY...WATER VAPOR SATELLITE IMAGERY THIS
MORNING SHOWS UPPER LEVEL LOW SPINNING OVER SD WITH DEFORMATION
AXIS EXTENDING TO ITS NW ACROSS N-CENTRAL MT WHILE ANOTHER
MID/UPPER LEVEL LOW DIGS INTO THE GREAT BASIN REGION. WIDESPREAD
RAIN/SNOW WRAPPING INTO NORTH-CENTRAL MT FROM THE EAST WILL SPREAD
WEST GRADUALLY THROUGH TODAY WITH A GRADUAL DECREASE IN
PRECIPITATION INTENSITY EXPECTED THROUGH THE DAY. PRECIPITATION
TYPE WILL BE SNOW THROUGH MOST OF THIS MORNING ACROSS
HILL/BLAINE/FERGUS COUNTIES WHERE A WINTER WX ADVISORY CONTINUES
THROUGH NOON TODAY. BY LATE THIS MORNING DIMINISHING PRECIPITATION
INTENSITY AND DAYTIME HEATING WILL REDUCE ACCUMULATION OF SNOW
AND LIMIT IMPACTS, THOUGH SNOW MAY CONTINUE TO ACCUMULATE ACROSS
THE HIGHER ELEVATIONS OF THE BEARS PAW MTNS. TONIGHT THROUGH
WEDNESDAY, THE MID/UPPER LEVEL LOW IN THE GREAT BASIN TRACKS EAST
ACROSS UT/CO WITH WEAKENING ENERGY AND A MOIST AIRMASS LINGERING
TO THE NORTH ACROSS MT WITH ANOTHER UPPER TROUGH DIGGING INTO THE
INTERMOUNTAIN WEST LATE WEDNESDAY. WITH LITTLE FORCING, BUT
CONTINUED MOIST CONDITIONS IN PLACE ACROSS MT, PRECIPITATION WILL
BE SCATTERED AND DISORGANIZED ACROSS THE REGION. TEMPERATURES
REMAIN BELOW SEASONAL AVERAGES THROUGH MID-WEEK. HOENISCH

WEDNESDAY NIGHT THROUGH MONDAY...MEDIUM RANGE PERIOD CONTINUES TO
LOOK UNSETTLED WITH PERIODS OF SHOWERS. THE PERIOD BEGINS WITH A
CLOSED UPPER LOW OVER NEBRASKA/SOUTH DAKOTA PROVIDING LIFT AND GOOD
MOISTURE TRANSPORT ACROSS THE AREA RESULTING IN SCATTERED SHOWERS
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. BY THURSDAY AFTERNOON,
ANOTHER UPPER TROF MAKES ITS WAY ACROSS THE WESTERN U.S. BUT MOST OF
THE ENERGY ASSOCIATED WITH THIS FEATURE WILL DIG WELL SOUTH OF THE
AREA RESULTING IN ISOLATED TO SCATTERED SHOWERS ACROSS SOUTHERN AND
CENTRAL MONTANA THROUGH FRIDAY. MODELS BEGIN TO DIVERGE WITH THEIR
SOLUTIONS SATURDAY. THE ECMWF MAINTAINS THE CLOSED LOW AND MOVES IT
TO SOUTHEAST NEBRASKA. CIRCULATION AROUND THIS LOW THEN PROVIDES
SPOTTY PRECIPITATION ACROSS THE AREA. THE GFS MAINTAINS A BROAD
UPPER TROF ACROSS THE INTERIOR WESTERN STATES AND HAS A STRONGER
FEED OF MOISTURE ACROSS MONTANA RESULTING IN A BIT MORE ORGANIZED
PATTERN OF SHOWER ACTIVITY. AN UPPER RIDGE BUILDS ALONG THE WEST
COAST SUNDAY AND THIS WILL RESULT IN A NORTH TO NORTHWEST FLOW ALOFT
AND THE POSSIBILITY OF SCATTERED SHOWERS CONTINUING. TEMPERATURES
WILL BE BELOW SEASONAL AVERAGES TO START THE PERIOD BUT WILL
GRADUALLY WARM THROUGH THE WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  31  49  32 /  80  50  50  10
CTB  44  31  50  30 /  80  60  50  10
HLN  53  36  54  35 /  40  40  40  10
BZN  51  33  53  32 /  50  40  40  30
WEY  44  30  46  27 /  70  60  50  30
DLN  49  34  53  32 /  50  50  40  20
HVR  38  31  48  30 / 100  70  60  20
LWT  40  31  45  32 / 100  60  60  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON MDT TODAY FOR MTZ047.

WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR MTZ011-051.

&&

$$

WEATHER.GOV/GREATFALLS



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