Weather Service Report


976 
FXUS65 KGGW 302049
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
249 PM MDT THU OCT 30 2014

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
BIGGEST CHALLENGE DURING THIS PERIOD WILL BE WHAT HAPPENS OVER THE 
NEXT 6 TO 12 HOURS WITH THE LOW CLOUDS. THESE LOW CLOUDS HAVE 
COVERED THE NE TWO-THIRDS OF THE CWA AND EXTEND EAST INTO THE 
DAKOTAS. MODELS CONTINUE TO DIFFER ON THE SCENARIOS ON WHEN WE CLEAR 
OUT WITH THE NAM FAMILIES SEEMING TO VERIFY SO FAR. WILL LEAN 
HEAVILY ON THE NAM AND CONCEPTUAL MODELS.

OTHERWISE...UPPER RIDGE BUILDING OVER THE NORTHERN ROCKIES WHILE 
CANADIAN SURFACE HIGH PUSHES INTO THE DAKOTAS. THIS WILL CREATE A 
TIGHT PRESSURE GRADIENT TONIGHT AND FRIDAY. THUS A LAKE WIND 
ADVISORY IS IN EFFECT FROM THIS EVENING THROUGH FRIDAY.

ON SATURDAY...A THERMAL RIDGE MOVES EAST ACROSS THE AREA WITH 850 MB 
TEMPS REACHING THE MID TEENS *C BUT LACK OF MIXING WILL NOT 
TRANSLATE MUCH OF THAT WARMTH TO THE GROUND. THEREFORE TEMPS ARE 
EXPECTED TO REACH THE 50S NORTH WITH 60S SOUTH. TFJ

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...

SPENT SOME TIME UPDATING THE FORECAST TODAY FOR THIS COMING LATE
WEEKEND STORM SYSTEM AS EXTENDED MODELS SHOW THE BEST CONSENSUS
THEN AND IT COULD BE OF SOME IMPACT TO THE AREA. 

SOMEWHAT SIMILAR TO THE LAST STORM SYSTEM WHICH MOVED THROUGH THE
REGION LAST WEEKEND...THIS NEXT STORM SYSTEM MIGHT HAVE JUST A
LITTLE MORE STRENGTH TO IT. THE UPPER-LEVEL TROUGH SEEMS STRONGER
AND DIGS DEEPER INTO THE WEST COAST AND INTER-MOUNTAIN WEST
REGIONS ON SATURDAY...THEN EJECTS NORTHEAST-WARD OVER CENTRAL
MONTANA BY SUNDAY MORNING. THE NORTHWESTERN SECTOR OF THIS STORM
SYSTEM WILL BE THE AREA MOST FAVORED FOR SNOW POTENTIAL AND THIS
IS EXPECTED TO TRACK MAINLY OVER OUR WESTERN...NORTHWESTERN...AND
NORTHERN ZONES THROUGH MONDAY MORNING. IT WILL LIKELY BEGIN AS A
RAIN AND SNOW MIX OVERNIGHT SATURDAY NIGHT INTO VERY EARLY SUNDAY
MORNING WITH THE BEST CHANCES FOR SNOW COMING IN BY OVERNIGHT SUNDAY
NIGHT. A SHORT-WAVE RIDGE MOVES THE STORM SYSTEM EAST OF NORTHEAST
MONTANA BY MONDAY NIGHT. BEST ESTIMATES FOR SNOW AT THIS TIME PLACES
2 TO 4 INCHES OVER THE HIGHER ELEVATIONS OF THE LITTLE ROCKIES...1
TO 3 INCHES NEAR OPHEIM...AND UNDER 1 INCH ELSEWHERE. MAY BE
ENOUGH TO CONSIDER A WINTER WEATHER ADVISORY FOR SOME LOCATIONS...BUT
IT IS STILL 4 DAYS AWAY FROM NOW AND TOO EARLY TO CALL. BMICKELSON

PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD BEGINS
SATURDAY EVENING WITH A LONG WAVE RIDGE ENTERED OVER THE
MISSISSIPPI RIVER VALLEY AND AN UPPER LEVEL TROUGH DIGGING INTO
THE WEST. A COLD FRONT AND SURFACE CLOSED LOW WILL MOVE INTO
NORTHEAST MONTANA SATURDAY NIGHT TO INITIATE A PATTERN CHANGE.
BOTH THE EC AND THE GFS SUGGEST A WET AND COLD SUNDAY AND SUNDAY
NIGHT WITH THE STORM MOVING OUT OF THE AREA MONDAY AFTERNOON AND
EVENING. COLD ARCTIC AIR GETS WRAPPED IN BEHIND THE FRONT TO
CHANGE SOME OF THE RAIN OVER TO SNOW SUNDAY NIGHT. SO TEMPERATURES
WILL DROP ABOUT 15F DEGREES ON SUNDAY AND FURTHER ON MONDAY.
READJUSTED QPF AND SNOW AMOUNTS. SOUTHWEST PHILLIPS AND NORTHERN
VALLEY COUNTIES NOW ARE SHOWING SEVERAL INCHES OF SNOW AND MAY
NEED A WATCH WHEN IT SHIFTS INTO THE SHORT TERM.

AS THE CLOSED SURFACE LOW MOVES OVER NEMONT EASTERLY WIND WILL
BACK TO THE NORTH AND RAMP UP SATURDAY NIGHT AND BECOME
NORTHWESTERLY ON SUNDAY AND MONDAY. CAA WILL LIKELY PUSH WIND
HIGHER THAN MODEL GUIDANCE CURRENTLY SUGGESTS.

MODELS THEN SUGGEST WEAK RIDGING OR ZONAL FLOW THROUGH MID WEEK
WITH TEMPERATURES TRENDING TO NEAR NORMAL. 

&&

.AVIATION...

VISIBLE AND SATELLITE IMAGERY SHOW THE PERSISTENT LOW-LEVEL CLOUD
DECK STILL IN PLACE OVER THE TAF SITES. MODELS CONTINUE TO SHOW
THIS MVFR STRATUS DECK BURNING OFF THIS AFTERNOON TO VFR UNDER A
MOSTLY A CLEAR SKY THROUGH TONIGHT.

WINDS WILL CONTINUE A SLOW BUT STEADY INCREASE FROM THE EAST-
SOUTHEAST THROUGHOUT THE TAF CYCLE. SOME LOCATIONS COULD
EXPERIENCE WINDS IN THE 25G35 KT RANGE BY FRIDAY MID-DAY. BMICKELSON

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 9 PM THIS EVENING TO 6 PM MDT FRIDAY FOR 
FORT PECK LAKE FOR CENTRAL AND SOUTHERN VALLEY...GARFIELD...
MCCONE.

&&

$$

WEATHER.GOV/GLASGOW



Return to Home page


Western Regional Climate Center, wrcc@dri.edu