441 
FXUS63 KBIS 282208
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
508 PM CDT FRI MAR 28 2014

.UPDATE...
ISSUED AT 508 PM CDT FRI MAR 28 2014

KMBX RADAR AND SURFACE OBS INDICATE AN AREA OF SNOW SHOWERS OVER
NORTH CENTRAL NORTH DAKOTA MOVING EAST AT 20 KNOTS. UPDATED THE
FORECAST TO INCREASE POPS TO CATEGORICAL OVER THE AFFECTED AREAS 
BASED ON CURRENT RADAR OBS/TRENDS. NEW SNOW ACCUMULATIONS SHOULD
REMAIN LESS THAN ONE INCH BY THE END OF THIS EVENING.

THIS ACTIVITY APPEARS TO BE ASSOCIATED WITH AN AREA OF 700MB-300MB
LAYER Q-VECTOR CONVERGENCE AND ISENTROPIC ASCENT ALONG THE 280K-
285K THETA SURFACES. THE SHORT RANGE MODELS PROG THE GREATEST
SYNOPTIC ASCENT TO SHIFT EAST INTO WESTERN MINNESOTA BY 06Z
TONIGHT AS THE STRONGEST ISENTROPIC ASCENT SHIFTS NORTH INTO
SOUTHERN MANITOBA AFTER 06Z. AS A RESULT...THINK THERE WILL BE A
RAPID END TO SNOW SHOWER ACTIVITY LATER THIS EVENING AS THESE TWO
FEATURES BREAK APART FROM EACH OTHER.

THE UPDATED PRODUCTS HAVE BEEN SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 251 PM CDT FRI MAR 28 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE SKY COVER
AND PRECIPITATION LATE THIS AFTERNOON INTO TONIGHT. THEN
TEMPERATURES ON SATURDAY. 

CURRENTLY...SCATTERED LIGHT SNOW CONTINUES ACROSS CENTRAL AND
NORTHWEST NORTH DAKOTA. MESOSCALE MODEL HAVE HAD A HARD TIME
PICKING UP ON THE LIGHT PRECIPITATION TODAY...BUT WILL CARRY SOME
SLIGHT CHANCE TO CHANCE POPS THROUGH THE LATE AFTERNOON. IN
ADDITION...WILL KEEP THE SLIGHT CHANCE POPS ACROSS THE NORTH
CENTRAL THIS EVENING AS MID LEVEL WARM ADVECTION CONTINUES OVER
THIS AREA THROUGH THE EVENING.

THE SURFACE HIGH THAT IS CURRENTLY SITUATED OVER EASTERN NORTH
DAKOTA GETS SHUNTED EAST TONIGHT AS UPPER LEVEL RIDGING BUILDS
OVER THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS. LOW LEVEL
MOISTURE SITUATED OVER WESTERN NORTH DAKOTA TODAY WILL SHIFT
SLOWLY EAST TONIGHT...AND THEN LIFT NORTHWARD ON SATURDAY AS A
WARM FRONT MOVES THROUGH THE AREA. WITH THE PASSAGE OF THE WARM
FROM MOST MODEL GUIDANCE IS PROGGING LOW TO MID 60S ACROSS MUCH OF
CENTRAL AND WESTERN NORTH DAKOTA. THE PROBLEM IS THAT A GOOD
PORTION OF THE WEST RECEIVED 1 TO 2 INCHES OF SNOW TODAY.

THINK THAT THE SNOW SHOULD INHIBIT TEMPERATURES ON SATURDAY ACROSS
THE WEST...SO CUT A FEW DEGREES OFF MAX TEMPERATURES ON SATURDAY
WHERE THE SNOW ACCUMULATED TODAY. ALSO A BIT WORRIED ABOUT
POSSIBLE LOW STRATUS AND FOG DEVELOPMENT LATE TONIGHT OR SATURDAY
MORNING. BUT INCREASING SOUTHERLY WINDS WILL BE AN INHIBITING
FACTOR. WILL PASS THIS ALONG BUT NOT ADD TO THE FORECAST AT THIS
TIME. 

.LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 251 PM  CDT FRI
MAR 28 2014

FOCUS FOR THE LONG TERM PERIOD REMAINS IN THE SUNDAY NIGHT THROUGH 
MONDAY AFTERNOON TIMEFRAME. A SPECIAL WEATHER STATEMENT WAS ISSUED 
AND WILL LET SUBSEQUENT SHIFTS CONTINUE TO ANALYZE THE LATEST DATA 
FOR POSSIBLE HEADLINES IN THE NEAR FUTURE. 

MODEL SUMMARY...NOT A LOT OF CHANGE FROM PREVIOUS MODEL RUNS. THE 
ECMWF CONTINUES AS THE MOST DIRE/AGGRESSIVE WITH WIDESPREAD HEAVY 
SNOW AND BLIZZARD CONDITIONS SUNDAY NIGHT THROUGH MONDAY AFTERNOON.  
THE GFS MAINTAINS A SWATH OF SNOW ALONG AND SOUTH OF INTERSTATE 94 
WITH THE HEAVIEST SNOW ACROSS THE FAR SOUTH INCLUDING THE SOUTHERN 
JAMES RIVER VALLEY. THE 12Z GEM...WHICH PREVIOUSLY WAS IN LINE WITH 
THE GFS...IS NOW IN BETWEEN THE ECMWF AND GFS IN TERMS OF AREAL 
COVERAGE OF THE SNOW. AFTER COLLABORATING WITH SURROUNDING 
OFFICES...USED A BLEND OF THE GFS/GEM AND LIMITED THE NORTHERN 
EXTENT OF SNOW MUCH BEYOND INTERSTATE 94 AT THIS TIME. 

THERE IS VERY GOOD AGREEMENT WITH THE TIMING AND LOCATION OF THE 
SOUTHERN STREAM SHORTWAVE THAT MOVES INTO CENTRAL CALIFORNIA 12Z 
SUNDAY. A CONSOLIDATED UPPER TROUGH BECOMES DISJOINTED AS IT 
ADVANCES EAST WITH A SPLIT IN THE NORTHERN AND SOUTHERN BRANCH JET 
STREAM DEVELOPING. THE MAIN CHALLENGE IS FORECASTING A SHORTWAVE 
SKIPPING ACROSS THE INTERMOUNTAIN WEST AND INTO THE NORTHERN HIGH 
PLAINS SUNDAY/SUNDAY NIGHT...AND TRYING TO NAIL DOWN EXACTLY WHERE 
DOES THIS SHORTWAVE DEVELOP INTO AN UPPER LOW. THE GFS CONTINUES TO 
DEVELOP THE UPPER LOW OVER SOUTH DAKOTA...WHILE THE ECMWF DEVELOPS 
AN UPPER LOW IN CENTRAL AND EASTERN NORTH DAKOTA...HENCE SUPPORTING 
A MORE NORTHERN SOLUTION. THE LATEST 12Z GEM WHICH HAD BEEN IN  
TANDEM WITH THE GFS THE LAST FEW DAYS IS NOW IN BETWEEN THE ECMWF 
AND GFS UPPER LOW FORECAST...WHICH WOULD BE ALONG THE ND/SD BORDER. 
WENT WITH A BLEND OF THE GFS/GEM IN THE GRIDDED DATA WHICH SUGGESTS 
A SHARP TRANSITION FROM A DRY/COLD NORTHEAST FLOW TO CATEGORICAL 
POPS DEVELOPING JUST SOUTH OF INTERSTATE 94 SUNDAY NIGHT INTO 
MONDAY. THIS WILL LIKELY NEED SOME ADJUSTMENT IN THE NEXT DAY OR TWO 
AS BETTER DATA BECOMES AVAILABLE ONCE THE SHORTWAVE REACHES THE 
COAST. WILL HAVE TO WATCH FOR GUSTY WINDS IN CONJUNCTION WITH THE 
FALLING SNOW RESULTING IN SOME BLOWING SNOW. 

BEYOND MONDAY...UNCERTAINTY IN THE REST OF EXTENDED REMAINS HIGH. 
THE ECMWF DEVELOPS ANOTHER POTENTIAL SNOWSTORM BEGINNING LATE 
WEDNESDAY AND POTENTIALLY LINGERING INTO FRIDAY. THE GFS IS MUCH 
FARTHER SOUTH WITH THIS IDEA. HAVE NOT DEVIATED FROM THE THE 
ALLBLEND WHICH KEEPS SOME MENTION OF SNOW IN THE WEDNESDAY THROUGH 
FRIDAY TIMEFRAME.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 251 PM CDT FRI MAR 28 2014

MVFR CEILINGS REMAINING AROUND KISN...KDIK AND KMOT THIS
AFTERNOON..WITH SCATTERED LIGHT SNOW SHOWERS. IMPROVING CONDITIONS
EXPECTED THIS EVENING AS SOUTH TO SOUTHWEST WINDS INCREASE AND
LIFT LOWER CEILINGS OUT OF THE AREA. WILL NEED TO MONITOR FOR
PATCHY FOG TONIGHT AS SKIES CLEAR...BUT NO MENTION OF FOG AT THIS
TIME. VFR CONDITIONS ARE EXPECTED SATURDAY AS A WARM FRONT LIFTS
THROUGH THE AREA.


&&

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

$$

UPDATE...TM
SHORT TERM...TWH
LONG TERM...KS
AVIATION...TWH