Damaging Winds in North Dakota, June 21, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
938 PM CDT SUN JUN 21 2015

.UPDATE...
ISSUED AT 938 PM CDT SUN JUN 21 2015

THERE ARE CURRENTLY TWO AREAS OF STORMS...DEVILS LAKE BASIN AND
SOUTH CENTRAL NORTH DAKOTA. MINIMAL INSTABILITY ACROSS THE DEVILS
LAKE BASIN LEADING TO MORE GENERAL THUNDER HERE...ALTHOUGH WIND
GUSTS TO 40-50MPH LIKELY THE MAIN THREAT.

SPC MESO-ANALYSIS INDICATES MUCAPE 1000-1500 J/KG ACROSS THE FAR
SOUTHERN FA (SE ND/WC MN)...WITH APPROACHING STORMS AND STRONG
DEEP LAYER SHEAR. STRONGEST PART OF THE APPROACHING STORM MAY
DRIVE INTO GREATEST INSTABILITY AND MISS THE FORECAST AREA...BUT
WILL BE CLOSE. STRONG WIND (BOW ECHO) THE MAIN THREAT.

INSTABILITY AND ANOTHER UPPER WAVE SHOULD LEAD TO ADDITIONAL
ACTIVITY CLOSER TO 12Z...MAINLY ACROSS THE SOUTHERN FA. ALTHOUGH
SEVERE STORMS ARE POSSIBLE (BRIEF MARGINAL WIND GUSTS POSSIBLY
SOME SMALLER HAIL)...GREATEST SEVERE THREAT WILL BE ACROSS SOUTH
DAKOTA WITHIN THE STRONGER INSTABILITY.

UPDATE ISSUED AT 703 PM CDT SUN JUN 21 2015

INCREASED POPS AS CONFIDENCE THAT MOST AREAS WILL RECEIVE
MEASURABLE PRECIP HAS INCREASED. THE MAIN CONCERN WILL REMAIN THE
SEVERE THREAT THIS EVENING INTO THE OVERNIGHT HOURS. LATEST CAM
GUIDANCE SUGGESTS STRONGER WIND GUSTS WILL BE THE MAIN
THREAT...WHICH MAKES SENSE GIVEN RELATIVELY HIGH FREEZING
LEVELS...WITH WEAKER INSTABILITY AND VERY STRONG DEEP LAYER SHEAR.
IN FACT...CURRENT MESO-ANALYSIS SHOWS MLCAPE 1000-2000 J/KG ACROSS
WESTERN/CENTRAL NORTH DAKOTA...WHICH QUICKLY DROPS TO A STABLE
ATMOSPHERE INTO THE RED RIVER VALLEY. THERE IS A RATHER STRONG
INSTABILITY GRADIENT SET UP FROM CENTRAL NORTH DAKOTA INTO THE
SOUTHERN RED RIVER VALLEY...AND WOULD IMAGINE THE STRONGER STORMS
WILL TRACK ALONG THIS FEATURE. THIS SETS THE STAGE FOR THE
ACTIVITY TO ORGANIZE ACROSS CENTRAL NORTH DAKOTA...AND TRACK SOME
SORT OF STRONGER MCS INTO SE ND. CURRENT HRRR DEPICTS THIS
SCENARIO...WITH A BOW TYPE FEATURE TRACKING INTO SE ND OR POSSIBLY
JUST SOUTH OF THIS FA. TO THE NORTH...INTO THE MORE STABLE
ATMOSPHERE...GIVEN THE STRONG DEEP LAYER SHEAR AND STRONG MID-
LEVEL WINDS IT WILL NOT TAKE MUCH TO GENERATE NEAR SEVERE WIND
GUSTS...HOWEVER THESE REPORTS WOULD LIKELY BE MOSTLY SUB-SEVERE
AND NOT AS WIDESPREAD GIVEN THE VERY WEAK INSTABILITY.

THERE IS ANOTHER UPPER WAVE THAT WILL LIKELY LEAD TO ANOTHER
CONVECTIVE COMPLEX LATER TONIGHT...BUT TRACK SOUTH OF THIS
FORECAST AREA.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 304 PM CDT SUN JUN 21 2015

FCST THINKING ON TRACK. INITIAL SUPERCELLS DEVELOPING IN ERN MT
AND FAR NW ND IN AREA OF DEEP LAYERED SHEAR WITH ASSOCIATED SHORT
WAVE. THESE STORMS WILL MOVE EAST AND DEVELOP SOUTH AS IT MOVES
INTO WRN ND AND THEN INTO CNTRL ND LATE AFTN/EARLY EVENING. MAIN
THREAT WILL EVOLVE INTO A SQUALL LINE WITH WIND POTENTIAL AS IT
MOVES INTO PARTS OF ERN ND LATE EVENING/OVERNIGHT. EXACTLY
WHERE/WHEN THIS HAPPENS IS AS USUAL UNCERTAIN. MAIN EMPHASIS AFTER
MIDNIGHT SEEMS TO TRANSITION A BIT INTO SOUTH DAKOTA WITH WIND
EVENT THAT WILL TRANSLATE INTO CNTRL/SRN MN. PREV FCST WAS PRETTY
GOOD WITH THIS AND ONLY MINOR TWEEKS NEEDED. PRECIP CHANCES WILL
END MONDAY MORNING IN ERN ND AND IN NW MN IN THE AFTN AS SOME
SHOWERS REMAIN IN THE MOISTURE BEHIND THE SHORT WAVE.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 304 PM CDT SUN JUN 21 2015

ON TUESDAY GENERALLY DRY....BUT ENOUGH COOL AIR ALOFT COMBINED
WITH TEMPS CLOSE TO 80 IN THE NRN FCST AREA WILL BRING ISOLD CHC
OF STORMS. BETTER CHANCE COMES WEDNESDAY AS NEXT WAVE MOVES
THROUGH.

FOR WEDNESDAY THROUGH SUNDAY... SPLIT FLOW REMAINS ACROSS
NORTHAMERICA WITH NORTHERN STREAM OVER CENTRAL AND EASTERN CANADA
AND SOUTHERN STREAM OVER THE NORTHERN STATES. LONG WAVE PATTERN
AMPLIFIES THIS PERIOD WITH LONG WAVE RIDGE BUILDING OVER WESTERN
NORTH AMERICA AND TROUGH OVER EASTERN CANADA/GREAT LAKE STATES.

THE ECMWF WAS THE FASTER SOLUTION COMPARED TO THE GFS THROUGH THE
PERIOD. HOWEVER THE ECMWF WAS TRENDING FASTER OVER THE LAST COUPLE
RUNS WHILE THE GFS WAS TRENDING SLOWER. WILL BLEND THE ECMWF AND
GFS. UPPER AIR PATTERN EXPECTED TO AMPLIFY AFTER A SHORT WAVE DIGS
INTO THE CENTRAL US ON FRI NIGHT/SAT.

HIGH TEMPS WERE DECREASED ABOUT TWO DEGREES FOR THU. LITTLE CHANGE
FOR FRI AND SAT AND HIGH TEMPS INCREASED ONE TO TWO DEGREES FOR SUN
COMPARED TO THIS MORNINGS FORECAST PACKAGE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 703 PM CDT SUN JUN 21 2015

SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH MOST TAF SITES THIS
EVENING AND OVERNIGHT. THERE COULD BE BRIEF PERIODS OF MVFR
CONDITIONS...BUT NOT LONG LIVED. GUSTY NORTHWEST WINDS ON MONDAY.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...TG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND FORKS ND
430 AM CDT SUN JUN 21 2015

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-221100-
WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS-
WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE-
EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN-
SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN-
WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER-
PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON-
GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-
RICHLAND-WESTERN WALSH COUNTY-
430 AM CDT SUN JUN 21 2015

...THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY AND
TONIGHT IN EASTERN NORTH DAKOTA AND PORTIONS OF WEST CENTRAL
MINNESOTA...

...THERE IS A MARGINAL RISK FOR SEVERE THUNDERSTORMS TODAY AND
TONIGHT IN THE NORTHERN RED RIVER VALLEY AND PORTIONS OF
NORTHWEST MINNESOTA...

 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH
DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS WILL INCREASE ALONG AND WEST OF THE RED RIVER
VALLEY AFTER 7 PM AND CONTINUE THROUGH TONIGHT. THE MAIN THREAT
WILL BE LARGE HAIL AND DAMAGING WINDS. A LARGER MORE INTENSE
COMPLEX OF THUNDERSTORMS MAY MOVE ACROSS THE EXTREME SOUTHERN RED
RIVER VALLEY AFTER MIDNIGHT...WITH DAMAGING WINDS AND HEAVY RAIN
THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS A CHANCE FOR THUNDERSTORMS ON TUESDAY NIGHT AND WEDNESDAY
AND AGAIN ON FRIDAY AND SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.