445 
FXUS63 KBIS 042044
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
344 PM CDT TUE JUN 4 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 CDT TUE JUN 4 2013

THE HIGHLIGHT OF THE SHORT TERM IS CONTINUED HYDROLOGIC IMPACTS
FROM MODERATE TO HEAVY RAINFALL THROUGH TONIGHT. SEE THE
HYDROLOGIC DISCUSSION BELOW FOR DETAILS.

THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT WITH THE SURFACE
LOW ACROSS SOUTHEAST NORTH DAKOTA THIS AFTERNOON PROPAGATING INTO
MINNESOTA ON WEDNESDAY. THUS HAVE USED A BLEND OF THE 12 UTC
GUIDANCE FOR ALL FIELDS.

FOR THIS EVENING PRIOR TO SUNSET...WILL HAVE TO CLOSELY WATCH THE
I-94 CORRIDOR EAST OF BISMARCK AND POINTS SOUTH AS A SIMILAR
ENVIRONMENT IS SETTING UP AS WAS SEEN LAST NIGHT ACROSS THE
SOUTHWEST...FAVORABLE FOR NON-SUPERCELL/LANDSPOUT TORNADOES. THIS
AREA HAS SEEN SUNSHINE THROUGH MUCH OF THE DAY...RESULTING IN
SURFACE DESTABILIZATION UNDER THE COLD CORE ALOFT. WITH LARGE
AMOUNTS OF BOUNDARY LAYER RELATIVE VORTICITY AND LOW LCLS...ANY
SURFACE BASED CONVECTION WOULD HAVE THE POTENTIAL TO STRETCH THE
ENVIRONMENTAL VORTICITY INTO A POSSIBLE FUNNEL CLOUD OR PERHAPS A
WEAK TORNADO. 

OTHERWISE FOR TONIGHT...DID ADD A MENTION OF PATCHY FOG TO THE
WEST WITH UPSLOPE FLOW WITH NEAR SATURATED BOUNDARY LAYER
CONDITIONS WHICH PERHAPS RADIATION FOG ACROSS THE NORTHWEST AS
SKIES CLEAR AND WINDS BECOME LIGHT TONIGHT. FOR WEDNESDAY ISOLATED
TO SCATTERED DIURNALLY DRIVEN SHOWERS ARE POSSIBLE WITH THE COLD
TEMPERATURES ALOFT...ESPECIALLY SOUTH OF US HIGHWAY 2. 

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 CDT TUE JUN 4 2013

THE FOCUS IN THE LONG TERM WILL BE PRECIPITATION FRIDAY INTO THE 
WEEKEND. 

THE 12 UTC GFS AND 12 UTC ECMWF ARE IN GOOD AGREEMENT ON THE UPPER 
LEVEL PATTERN THE REST OF THIS WEEK INTO EARLY NEXT WEEK. THE LATEST 
12 UTC ECMWF HAS ALSO COME INTO BETTER AGREEMENT ON THE TIMING OF 
THE PRECIPITATION ON FRIDAY WITH PAST GFS MODEL RUNS. THE GFS IS 
STILL FASTER WITH MOVING THE SHORT WAVE AND FRONTAL BOUNDARY OVER 
WESTERN NORTH DAKOTA...HOWEVER THE RECENT MODEL AGREEMENT GIVES A 
LITTLE MORE CONFIDENCE THAT CHANCES FOR PRECIPITATION WILL START 
FRIDAY LATE AFTERNOON INTO NIGHT IN WESTERN NORTH DAKOTA AND MOVE EAST. 
MODEL DIVERGENCE ON THIS SYSTEM BEGINS SATURDAY AT 18 UTC WHEN THE 
GFS DEVELOPS A CUT OFF UPPER LEVEL LOW JUST NORTH OF NORTH 
DAKOTA...WHILE THE ECMWF DOES NOT DEVELOP A CUT OFF UPPER LEVEL LOW 
UNTIL THE SYSTEM IS EXITING THE NORTHERN PLAINS AT 12 UTC SUNDAY. 
DESPITE THIS DIFFERENCE THE MODELS STILL HAVE CHANCES FOR 
PRECIPITATION LINGERING OVER CENTRAL AND PERHAPS WESTERN NORTH DAKOTA 
INTO SUNDAY. 

THE BEST CHANCE FOR THUNDERSTORMS OVER THIS TIME PERIOD WILL BE 
FRIDAY AFTERNOON AND NIGHT. THE GFS AND ECMWF ARE IN AGREEMENT ON 
THE POSSIBILITY OF THUNDERSTORMS...HOWEVER SINCE THE GFS BRINGS IN 
THE FRONTAL BOUNDARY EARLIER ON FRIDAY THAN THE ECMWF THE GFS 
SOLUTION HAS THE BEST CHANCE FOR STRONG TO SEVERE STORMS. GFS SEVERE 
PARAMETERS OF DEEP LAYER SHEAR AND SURFACED BASED CAPE ARE ALSO 
CONSIDERABLY HIGHER THAN THAT OF THE ECMWF FOR FRIDAY EVENING. THIS 
SITUATION WILL HAVE TO BE MONITORED THE NEXT FEW DAYS...AS HEAVY 
DOWN POURS FROM THUNDERSTORMS ON THE ALREADY SATURATED 
SOILS...ESPECIALLY OVER THE SOURIS RIVER BASIN...MAY CAUSE 
ADDITIONAL FLOODING ISSUES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 343 CDT TUE JUN 4 2013

WIDESPREAD MVFR TO IFR CONDITIONS IN STRATUS...FOG AND RAIN ARE
EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH
TONIGHT AS LOW PRESSURE ACROSS SOUTHEAST NORTH DAKOTA SLOWLY MOVES
IN WESTERN MINNESOTA. KISN IS EXPECTED TO BE THE FIRST TERMINAL TO
BE SUSTAINED IN THE VFR CATEGORY BEGINNING AFTER 03 UTC.

&&

.HYDROLOGY...
ISSUED AT 343 CDT TUE JUN 4 2013

AREAL FLOOD ADVISORIES REMAIN IN EFFECT FOR
WARD...RENVILLE...MCLEAN...MCHENRY...BOTTINEAU...BURKE AND
MOUNTRAIL COUNTIES...WITH THE FLOOD WATCH REMAINING IN EFFECT
THROUGH 12 UTC WEDNESDAY FOR ROLLETTE...PIERCE...SHERIDAN...WELLS
AND FOSTER COUNTIES. FOR THE WATCH AREA...AN ADDITIONAL ONE TO ONE
AND A HALF INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS IS POSSIBLE
AND WILL HAVE TO MONITOR FOR POSSIBLE UPGRADES THROUGH THE
EVENING.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NDZ005-013-022-023-025.

&&

$$

SHORT TERM...AYD
LONG TERM...MM
AVIATION...AYD
HYDROLOGY...AYD