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000
FXUS63 KBIS 172353
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
653 PM CDT THU APR 17 2014

.UPDATE...
ISSUED AT 653 PM CDT THU APR 17 2014

SOUTHEAST FLOW WILL CONTINUE OVER THE FORECAST AREA THIS EVENING
AS LOW PRESSURE IN THE LEE OF THE NORTHERN ROCKIES DEEPENS AND
BEGINS TO MOVE EAST INTO THE NORTHERN HIGH PLAINS. A VORT LOBE
LIFTING THROUGH THE AREA COMBINED WITH ISENTROPIC ASCENT MAY
PRODUCE SCATTERED SHOWERS OVER THE NORTHWEST TONIGHT. LATEST
MESOSCALE MODELS ARE HINTING AT THE BEST CHANCES BETWEEN AROUND
06-10 UTC. MAINLY MID AND HIGH LEVEL CLOUDINESS OVER THE AREA
TONIGHT AS THE LOWER LEVELS OF THE ATMOSPHERE REMAIN DRY. UPDATED
LATEST SENSIBLE WEATHER GRIDS WITH ONLY MINOR ADJUSTMENTS. DID
BUMP UP OVERNIGHT LOWS A BIT WITH THE EXPECTED WINDS AND CLOUDS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 420 PM CDT THU APR 17 2014

FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD INCLUDE INCREASING
PRECIPITATION CHANCES ACROSS THE WEST...ESPECIALLY FRIDAY AFTERNOON.

IN THE NEAR TERM...SNOW SHOWERS IN THE FAR SOUTHWEST HAVE
DISSIPATED WHILE CLOUDS CONTINUE TO INCREASE FROM WEST TO EAST
ACROSS THE FORECAST AREA. THE HIGH PRESSURE RIDGE HAS MOVED INTO
THE RED RIVER VALLEY WITH AN INCREASING PRESSURE GRADIENT AND
BRISK SE FLOW ACROSS THE WEST. HIGH RESOLUTION MODELS...INCLUDING
THE RAP AND HRRR..INDICATING A 500MB SHEARED VORTICITY AXIS
PUSHING INTO WESTERN NORTH DAKOTA THIS EVENING AND PUSHING EAST
OVERNIGHT. A SWATH OF ENHANCED LIFT MAY SUPPORT SOME LIGHT
RAIN/SNOW SHOWERS FROM NORTHWEST TO SOUTHEAST TONIGHT AND HAVE
MADE SOME MINOR ADJUSTMENTS TO POPS.

ON FRIDAY...EXPECT BREEZY CONDITIONS BUT WIDESPREAD ADVISORY
CRITERIA (SUSTAINED 30 MPH) IS NOT EXPECTED TO BE REACHED.
INCREASING WARM AIR ADVECTION WILL BOOST AFTERNOON TEMPERATURES
INTO THE 50S TO LOWER 60S. AN UPPER LEVEL LOW WILL PUSH INTO
MONTANA WITH DIFFLUENT SOUTHWEST FLOW SUPPORTING RAIN ACROSS
NORTHWEST NORTH DAKOTA...ESPECIALLY DURING THE AFTERNOON HOURS.
SOME ISOLATED THUNDERSTORMS CAN`T BE RULED OUT WITH A SHOWALTER
INDEX NEAR OR JUST BELOW ZERO.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 420 PM CDT THU APR 17 2014

THE HIGHLIGHT OF THE EXTENDED FORECAST IS A TRANSITION TO A MORE
ACTIVE WEATHER PATTERN INTO NEXT WEEK.

THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A
PROGRESSIVE SHORTWAVE TO IMPACT THE NORTHERN PLAINS FRIDAY EVENING
INTO SATURDAY MORNING. PRECIPITATION ASSOCIATED WITH ISENTROPIC
LIFT IS EXPECTED TO BEGIN AS RAIN...AND POSSIBLY TRANSITIONING TO
SNOW LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING. LITTLE TO NO
ACCUMULATION IS ANTICIPATED AT THIS TIME. THEREAFTER...A
SIGNIFICANT TROUGH PROPAGATES INTO THE WESTERN CONUS TUESDAY INTO
THURSDAY...POTENTIALLY PLACING THE NORTHERN PLAINS UNDER SOUTHWEST
FLOW ALOFT. WHILE DIFFERENCES EXIST AMONGST THE GUIDANCE REGARDING
THE EVOLUTION OF THE SYSTEM AS IT PROPAGATES ONTO THE
PLAINS...INCREASING MOISTURE TRANSPORT AND INSTABILITY SUPPORTS
THE POTENTIAL FOR THUNDERSTORMS TUESDAY INTO WEDNESDAY. THE
GUIDANCE BEGINS TO DIVERGE THE MOST THURSDAY...WITH THE 12 UTC
GFS CLOSING OFF A POTENT LOW ACROSS NORTH DAKOTA...WITH THE 12 UTC
ECMWF ACROSS SOUTHERN SASKATCHEWAN. WHILE SIGNIFICANT QPF IS
EXPECTED SOMEWHERE IN THE NORTHERN PLAINS AND CANADIAN
PRAIRIES...PRECIPITATION TYPE AND PLACEMENT WILL REMAIN HIGHLY
UNCERTAIN FOR THE COMING DAYS. IN LIGHT OF MOIST
SOILS...HYDROLOGIC IMPACTS WILL ALSO NEED TO BE CONSIDERED.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 653 PM CDT THU APR 17 2014

MAINLY VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD WITH A
SOUTHEAST FLOW. MODERATE FLOW THROUGH THE NIGHT WITH MODERATE TO
STRONG SOUTHEAST FLOW ON FRIDAY. STRONGEST WINDS WILL BE OVER
CENTRAL NORTH DAKOTA WITH SUSTAINED WINDS AROUND 20 MPH AND GUST
TO 35 MPH. FLOW WILL BEGIN TO DIMINISH OVER THE WEST FRIDAY
AFTERNOON AS LOW PRESSURE APPROACHES. MAINLY SLIGHT CHANCE TO
CHANCE POPS TONIGHT ACROSS THE NORTHWEST INTO THE NORTH CENTRAL.
HAVE OPTED TO LEAVE PRECIPITATION OUT OF THE TAFS TONIGHT FOR NOW
UNTIL WE GET A BETTER IDEA ON PRECIPITATION PLACEMENT. BETTER
CHANCES MOVE INTO THE WEST LATE FRIDAY WITH A MENTION OF RAIN AT
WILLISTON AROUND 22 UTC FRIDAY.

&&

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

$$

UPDATE...TWH
LONG TERM...AYD
AVIATION...TWH