000
FXUS63 KBIS 060738
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
138 AM CST THU MAR 6 2014

.UPDATE...
ISSUED AT 138 AM CST THU MAR 6 2014

ISSUED A FREEZING RAIN ADVISORY FOR NORTH CENTRAL NORTH DAKOTA AND
THE UPPER JAMES RIVER VALLEY THROUGH 5 AM CST THIS MORNING AHEAD
OF THE BAND OF PRECIPIATION FROM NEAR BOWBELLS THROUGH GARRISON.
BASED UPON MULITPLE OBSERVATIONS OF LIQUID PRECIPITATION REAHCING
THE SURFACE UNDER THE BAND...THE STRONGER AND FURTHER NORTH WARM
LAYER OFFERED ON THE 00 UTC NAM APPEARS TO VERIFYING BEST. ANOTHER
FREEZING RAIN ADVISORY MAY BE NEEDED ACROSS NORTHWEST AND NORTH
CENTRAL NORTH DAKOTA LATER THIS MORNING AND INTO THE EARLY
AFTERNOON FOR THE NEXT ROUND OF PRECIPITATION.

UPDATE ISSUED AT 1255 AM CST THU MAR 6 2014

AS OF 0650 UTC...A BAND OF PRECIPITATION WAS LOCATED FROM CROSBY
AND ESTEVAN...SOUTHEAST TO NEAR HAZEN AND MAX. SURFACE
OBSERVATIONS INDICATE LIQUID WATER IS REACHING THE GROUND UNDER
THE MAJORITY OF THE BAND...MIXING WITH LIGHT SNOW/SLEET NEAR THE
INTERNATIONAL BORDER. NEAR TERM POPS AND PRECIPITATION TYPE GRIDS
UPDATED TO REFLECT THIS TREND. GIVEN THE SHORT DURATION OF THE
FREEZING RAIN THREAT...WILL HOLD OFF ON AN ADVISORY WITH A SPECIAL
WEATHER STATEMENT ALREADY OUT.

UPDATE ISSUED AT 1019 PM CST WED MAR 5 2014

CONTINUED TO TRIM POPS ACROSS CENTRAL ND TONIGHT AS BEST CHANCES
WILL REMAIN CLOSER TO CANADIAN BORDER. BASED ON LATEST MODEL
GUIDANCE ALSO INTRODUCED POPS ACROSS THE NORTHWEST AROUND 15Z
THURSDAY AND SPREAD EAST THROUGH THE AFTERNOON. PRECIP AMOUNTS ARE
GENERALLY LIGHT AND HIGHEST NORTH...MAINLY BELOW A TENTH OF AN
INCH. COLDER AIR ADVECTING IN FROM THE NORTH BEHIND THE FRONT SHOULD
SUPPORT SNOW ACROSS THE NORTH WITH A POSSIBLE MIX OVER CENTRAL
ND.

UPDATE ISSUED AT 825 PM CST WED MAR 5 2014

ISSUED QUICK UPDATE TO LOWER POPS TONIGHT ACROSS PORTIONS OF
CENTRAL ND AND DELAY TIMING SLIGHTLY ACROSS THE NORTHWEST...BASED
ON RADAR/OBS TRENDS UPSTREAM AS WELL AS SHORT TERM MODEL DATA
(HRRR/RUC/00Z NAM).

UPDATE ISSUED AT 703 PM CST WED MAR 5 2014

NO SIGNIFICANT CHANGES MADE TO FORECAST. WILL NEED TO FURTHER EVALUATE
PRECIP CHANCES FOR TONIGHT AS NEXT SYSTEM APPROACHES FROM THE WEST
OVERNIGHT. SOMEWHAT DISORGANIZED LOW PRESSURE/COLD FRONT WILL PUSH
ACROSS ND BY 00Z FRIDAY WITH SURFACE WINDS EVENTUALLY TURNING
NORTHWEST. 18Z MODELS SHOW BEST CHANCE OF PRECIP OVERNIGHT NEAR
THE CANADIAN BORDER WHILE 18Z NAM AND LATEST RUC ARE FARTHER
NORTH WITH SOUTHERN EXTENT OF MEASURABLE PRECIP COMPARED TO
GFS/12Z ECMWF. SOME WEAK RADAR RETURNS OBSERVED UPSTREAM ACROSS
MONTANA...BUT STILL NOT SEEING MUCH REACH THE GROUND. WILL
CONTINUE TO MONITOR TRENDS THE NEXT COUPLE HOURS...BUT MAY NEED TO
LOWER POPS OR REMOVE THEM ACROSS CENTRAL ND FOR THE OVERNIGHT
PERIOD.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)

ISSUED AT 325 PM CST WED MAR 5 2014

MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE
PRECIPITATION TYPE TONIGHT AND THURSDAY. MODELS HAVE NOT BEEN VERY
CONSISTENT SO CONFIDENCE IS NOT HIGH WITH PRECIPITATION TYPES.

LOW PRESSURE OVER MONTANA IS FORECAST TO MOVE EAST INTO CENTRAL
NORTH DAKOTA BY THURSDAY MORNING...AND INTO MINNESOTA BY LATE
THURSDAY AFTERNOON. STRONG WARM ADVECTION ALONG AND NORTH OF THE LOW
PRESSURE SYSTEM WILL RESULT IN A BAND OF PRECIPITATION TRACKING
ALONG THE INTERNATIONAL BORDER TONIGHT. AS THE SURFACE LOW TRACKS
EAST COLD ADVECTION WILL BEGIN TO DROP SOUTH BEHIND THE LOW.
STRONG WARM ADVECTION PRODUCING WARM TEMPERATURES ALOFT WILL
TRANSITION TO COLD ADVECTION AND THE MIXED PRECIPITATION WILL
TRANSITION TO ALL SNOW FROM NORTH TO SOUTH THURSDAY AFTERNOON AND
COLD AIR CONTINUES TO DROP OVER THE AREA.

UTILIZED THE GFS FOR THE MAX TEMPERATURE ALOFT. THE GFS HAS BEEN
THE MOST CONSISTENT KEEPING BELOW ZERO CELSIUS TEMPERATURES ALONG
THE INTERNATIONAL BORDER. THE ECMWF WAS SIMILAR TO THIS ON THE 04
MARCH 12 UTC RUN...BUT IS NOW QUITE A BIT WARMER AND CLOSER TO THE
NAM. THE MAIN REASON FOR GOING WITH THE GFS IS THAT EVEN THE WARM
NAM DOES NOT HAVE A REAL DEEP LAYER OF +3C TEMPERATURES ALOFT THIS
IF THERE WERE A PERIOD OF FREEZING RAIN...THE THINKING NOW IS THAT
IT WOULD BE BRIEF...AND THE MAIN PRECIPITATION TYPE WOULD BE SNOW.
NOW AS YOU GO FARTHER SOUTH...SAY SOUTH OF HIGHWAY 2...THE THREAT
OF FREEZING RAIN INCREASES WITH A DEEPER WARM LAYER ALOFT...BUT
THE PROBABILITY OF PRECIPITATION DECREASES RAPIDLY AS YOU MOVE
SOUTH. WE WILL ALSO HAVE THE UNCERTAINTY OF SURFACE TEMPERATURES
SOUTH OF THE HIGHWAY 2 CORRIDOR. NORTH OF HERE...SURFACE
TEMPERATURES WILL LIKELY REMAIN BELOW FREEZING. HOWEVER...THE
THREAT OF SNOW ALSO INCREASES AS YOU GO NORTH. SOUTH OF HIGHWAY
2...IN THE WESTERN THIRD...SURFACE TEMPERATURES WILL LIKELY REMAIN
ABOVE FREEZING UNTIL PRECIPITATION CHANCES BEGIN TO DROP OFF.

CURRENTLY...SKIES ARE MAINLY CLEAR ACROSS EASTERN MONTANA THUS WE
SHOULD HAVE A GOOD AMOUNT OF TIME TO SEE HOW THINGS DEVELOP THIS
EVENING...AND EVENING OR MID SHIFT WILL HAVE A BETTER IDEA ON IF A
FREEZING RAIN ADVISORY IS NEEDED...AND WHERE IT WOULD GO.

ON THURSDAY...A LIGHT WINTRY MIX WILL BE POSSIBLE THROUGH THE DAY
AS COLDER AIR DROPPING SOUTH WILL BE SLOW TO DROP COMPLETELY
THROUGH THE STATE.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)

ISSUED AT 325 PM CST WED MAR 5 2014

THE LONG TERM BEGINS THURSDAY EVENING WITH A COLD FRONT PUSHING
SOUTH THROUGH THE NORTHERN PLAINS. WILL MAINTAIN LIKELY POPS
NORTHEAST ON THE TAIL END OF A MID LEVEL S/WV.
OTHERWISE...LINGERING LIGHT SNOW A POSSIBILITY THROUGH THURSDAY
NIGHT WITH MODELS PORTRAYING LOW STRATUS IN ADVANCE OF SURFACE
HIGH PRESSURE.

COLD SURFACE HIGH PRESSURE BUILDS OVER THE DAKOTAS ON
FRIDAY...WITH NOTICEABLY COOLER AIR WITH HIGHS FRIDAY AROUND 20F
DEGREES COLDER THAN THURSDAY. MODELS STILL DEPICT LIGHT QPF ACROSS
MONTANA AND AS FAR EAST AS WESTERN NORTH DAKOTA...PICKING UP ON
WEAK EMBEDDED MID LEVEL ENERGY AND RETURN FLOW WEST OF THE SFC
HIGH.

BROAD UPPER LEVEL RIDGING MATERIALIZES FOR THE WEEKEND...RESULTING
IN DRY CONDITIONS AND TEMPERATURES WARMING EACH DAY. HIGHS SUNDAY
ARE CURRENTLY PROJECTED TO HIT 40 DEGREES IN THE TURTLE MOUNTAIN
REGION AND THE LOW/MID 50S IN THE SOUTHWEST.

RIDGE FLATTENS MONDAY AS A STRONG MID LEVEL S/WV TROUGH MOVES INTO
THE PACIFIC NORTHWEST...WITH THIS FEATURE ADVANCING EAST-SOUTHEAST
TUESDAY. TEMPERATURES WILL COOL WITH THIS TRANSITION...ALONG WITH
SOME CHANCES FOR PRECIPITATION. AT THIS TIME DO NOT ANTICIPATE
ANYTHING HIGH IMPACT AS FAR AS PRECIPITATION AMOUNTS WITH MODELS
SUGGESTING A SPLIT FLOW REGIME SETTING UP...KEEPING THE BEST STORM
TRACKS WELL TO OUR SOUTH AND NORTH.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 138 AM CST THU MAR 6 2014

FREEZING RAIN IS EXPECTED TO IMPACT KMOT BETWEEN 07-09 UTC
TONIGHT. ANOTHER ROUND OF MIXED PRECIPITATION IS POSSIBLE LATE
THURSDAY MORNING AND INTO THE AFTERNOON AT KISN AND KMOT WITH
MVFR/IFR CONDITIONS. MVFR STRATUS OVERTAKES KDIK/KBIS/KJMS LATE
THURSDAY AFTERNOON INTO THE EVENING.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 5 AM CST EARLY THIS MORNING FOR
NDZ003>005-011>013-021>023-025.

&&

$$

UPDATE...AYD
SHORT TERM...TWH
LONG TERM...NH
AVIATION...AYD