Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 160242
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
942 PM CDT TUE APR 15 2014

.UPDATE...
ISSUED AT 942 PM CDT TUE APR 15 2014

REGIONAL RADARS CONTINUE TO INDICATE AN AREA OF ELEVATED
PRECIPITATION EXTENDING FROM NORTH CENTRAL NORTH DAKOTA INTO
SOUTHEASTERN NORTH DAKOTA. SURFACE OBS CONTINUE TO INDICATE DRY
SURFACE CONDITIONS. HOWEVER...CEILINGS ARE BEGINNING TO LOWER AND
TEMP/DEWPOINT SPREADS ARE BEGINNING TO CONVERGE TO NEAR SATURATED
CONDITIONS.

WILL CONTINUE TO INDICATE DRY CONDITIONS EAST FOR THE NEXT FEW
HOURS...THEN HAVE CHANCE TO LIKELY POPS FOR THE REMAINDER OF THE
OVERNIGHT HOURS AS BOUNDARY LAYER CONDITIONS SHOULD BECOME
SATURATED BY THEN. NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING
FORECAST. THE UPDATED PRODUCTS HAVE BEEN SENT.

UPDATE ISSUED AT 656 PM CDT TUE APR 15 2014

REGIONAL RADARS ARE DEPICTING A SWATH OF ELEVATED PRECIPITATION
EXTENDING FROM MINOT TO HARVEY...JAMESTOWN TO LISBON. NONE OF THIS
ACTIVITY IS REACHING THE GROUND AS BOUNDARY LAYER CONDITIONS ARE
TOO DRY (TEMP/DEWPOINT SPREADS OF 10-20 DEGREES). THINK THE
BOUNDARY LAYER WILL MOISTEN UP OVERNIGHT WITH TEMPERATURES
DECREASING DUE TO BOTH WET BULBING EFFECTS AND LOSS OF DAYTIME
HEATING. HOWEVER...STILL THINK SATURATION IS A FEW HOURS OFF FROM
NOW. AS A RESULT...UPDATED THE FIRST PERIOD POP FORECAST TO COME
MORE IN LINE WITH PRECIPITATION CHANCES INCREASING FROM WEST TO
EAST TONIGHT COINCIDENT WITH THE BEST UPPER LEVEL FORCING
ASSOCIATED WITH A SHORTWAVE CURRENTLY OVER MONTANA MOVING OVER
NORTH DAKOTA. THE HEAVIEST PRECIPITATION SHOULD REMAIN OVER SOUTH
DAKOTA...WITH PRECIPITATION LIKELY DEVELOPING SOUTH OF I-94 AFTER
MIDNIGHT.

FURTHERMORE...GIVEN THE EXPECTED WINDS AND CLOUD COVER...INCREASED
OVERNIGHT LOWS BY A CATEGORY. THE UPDATED PRODUCTS HAVE BEEN SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT TUE APR 15 2014

THE MAIN FORECAST ISSUES IN THE SHORT TERM PERIOD ARE
PRECIPITATION TRENDS AND SNOWFALL AMOUNTS OVERNIGHT AND WEDNESDAY.

PRECIPITATION IS EXPECTED TO BEGIN ACROSS THE NORTHEAST LATE THIS
AFTERNOON...A GENERAL RAIN/SNOW MIX...BEFORE TURNING TO ALL SNOW
THIS EVENING. THERE ARE STILL SOME VARIATIONS AMONG MODEL QPF
FIELDS. HOWEVER...THE GENERAL THINKING IS THE INITIAL SNOWFALL
WILL OCCUR NORTHEAST ASSOCIATED WITH A LEAD SHORT WAVE AND
BAROCLINIC ZONE. OVERNIGHT...THE MAIN UPPER LOW WILL EXERT ITS
INFLUENCE...WITH THE BULK OF THE SNOW ACROSS THE FAR SOUTH INTO
THE JAMES RIVER VALLEY. TOTAL AMOUNTS OF 1 TO 2 INCHES ARE
EXPECTED FROM THE TURTLE MOUNTAINS...SOUTH THROUGH THE JAMES RIVER
VALLEY. TO THE WEST...AMOUNTS SHOULD BE LIMITED TO AN INCH OR
LESS. HEADLINES ARE NOT WARRANTED...HOWEVER SOME AREAS WILL HAVE A
SLICK MORNING COMMUTE WEDNESDAY. HIGHS WILL ONLY REACH THE 30S
WEDNESDAY AFTERNOON...SOME 20 TO 25 DEGREES BELOW NORMAL FOR MID APRIL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 243 PM CDT TUE APR 15 2014

FOCUS IN THE LONG TERM WILL BE ON THE CLOSED 500MB LOW BRINGING
CHANCES FOR PRECIPITATION INTO CENTRAL AND WESTERN NORTH DAKOTA
FRIDAY AFTERNOON INTO SATURDAY.

LATEST 12 UTC GFS AND ECMWF MODEL RUNS HAVE COME INTO AGREEMENT BOTH
ON TIMING AND PLACEMENT OF THE CLOSED 500MB LOW PRESSURE SYSTEM
FROM FRIDAY 18 UTC THROUGH 00 UTC SUNDAY. LATEST 12 UTC OF THE
NH-GEM APPEARS TO BE THE OUTLIER. THE 12 UTC NH-GEM SHOWS A DEEPER
500 MB TROUGH AND HAS THE CLOSED LOW OVER NORTHWEST NORTH DAKOTA 12
UTC SATURDAY...WHEREAS THE 12 UTC GFS AND ECMWF HAVE THE CLOSED LOW
WELL NORTH OF THE INTERNATIONAL BORDER. WHILE I BELIEVE OVER TIME
THE NH-GEM WILL COME MORE INTO LINE WITH THE 12 UTC GFS AND ECMWF
SOLUTIONS...THE NH-GEM FORECAST FOR NOW HAS MUCH HEAVIER PRECIP OVER
NORTHERN NORTH DAKOTA...INCLUDING MUCH OF THE SOURIS RIVER BASIN.
THIS WILL HAVE TO BE MONITORED OVER THE COMING DAYS.

AS FOR PRECIPITATION TYPE FROM THIS FRIDAY AND SATURDAY
SYSTEM...PRECIPITATION WILL START AS RAIN AND SWITCH TO SNOW FRIDAY
NIGHT AND SATURDAY MORNING AND THEN BACK TO RAIN LATE MORNING AND
AFTERNOON SATURDAY. OVER THE PAST DAY OR SO THE GFS SOLUTIONS HAVE
BEEN COOLER THAN THE ECMWF SOLUTIONS. HOW THIS DIFFERENCE PLAYS OUT
OVER THE COMING DAYS WILL PLAY A LARGE ROLE IN HOW MUCH IF ANY SNOW
WESTERN AND CENTRAL NORTH DAKOTA RECEIVES AS FORECAST LOWS FRIDAY
NIGHT ARE HOVERING AROUND THE FREEZING MARK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 656 PM CDT TUE APR 15 2014

VFR CONDITIONS WILL PREVAIL THIS EVENING. LIGHT SNOW WILL MAINLY
DEVELOP OVER SOUTHWEST NORTH DAKOTA (KDIK) AND MOVE EAST ALONG THE
I-94 CORRIDOR AND INTO KBIS AND KJMS AFTER MIDNIGHT. MVFR
CONDITIONS/TEMPO IFR CONDITIONS ARE EXPECTED WITH THIS ACTIVITY.
VFR CONDITIONS WILL THEN DEVELOP FROM WEST TO EAST LATE WEDNESDAY
MORNING...WITH VFR CONDITIONS PREVAILING AREAWIDE WEDNESDAY
AFTERNOON.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

UPDATE...TM
SHORT TERM...RP KINNEY
LONG TERM...MM
AVIATION...TM




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