840
FXUS63 KBIS 071229
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
729 AM CDT THU JUL 7 2022
UPDATE
ISSUED AT 720 AM CDT THU JUL 7 2022
FOG HAS DEVELOPED FROM EMMONS TO DICKEY COUNTY, HOWEVER THE FOG
LAYER IS SHALLOW AT THE SURFACE IS EXPECTED TO DISPATE IN THE NEXT
HOUR. A LINE OF THUNDERSTORMS OVER SOUTH CENTRAL NORTH DAKOTA
WILL CONTINUE TO MOVE EASTWARD BRINGING BRIEF HEAVY RAIN AND
FREQUENT LIGNTING. OTHER THEN ADDING FOG TO THE GRIDS, NO OTHER
CHANGES WERE MADE.
UPDATE ISSUED AT 633 AM CDT THU JUL 7 2022
SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE EAST ACROSS PORTIONS OF
THE SOUTHWEST AND SOUTH CENTRAL. ANOTHER AREA OF SHOWERS AND
STORMS IS CURRENTLY ONGOING IN THE NORTHWEST, MAINLY OVER DIVIDE
COUNTY. THIS SECOND AREA IS BARELY MOVING, SO SOME HIGHER RAINFALL
TOTALS MAY BE SEEN HERE WHEN ALL IS SAID AND DONE. MRMS FLASH
CREST UNIT STREAMFLOW IS STARTING TO HIGHLIGHT THE CENTRAL PART OF
DIVIDE COUNTY FOR SOME HIGHER RATES, SO WE WILL CONTINUE
MONITORING THIS AREA FOR ANY FLOODING CONCERNS SHOULD STORMS
CONTINUE TO STICK AROUND. FOR THIS UPDATE, INCREASED PRECIPITATION
CHANCES OVER THESE TWO AREAS TO BETTER ACCOUNT FOR RADAR
OBSERVATIONS AND TRENDS. OTHERWISE, JUST BLENDED THE LATEST
OBSERVATIONS TO THE GOING FORECAST.
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT THU JUL 7 2022
CHANCES FOR STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND THEN
AGAIN TONIGHT HIGHLIGHT THE SHORT TERM FORECAST PERIOD.
EARLY THIS MORNING, AN ENERGETIC MID-LEVEL SHORTWAVE WAS MAKING
ITS WAY THROUGH RIDGING IN THE VICINITY OF THE MONTANA/NORTH
DAKOTA BORDER. THIS HAS PROMPTED SCATTERED THUNDERSTORM
DEVELOPMENT OVER MUCH OF EASTERN MONTANA AND INTO SOUTHWESTERN
NORTH DAKOTA. THIS ACTIVITY WILL CONTINUE TO SLOWLY SPREAD EAST
AND NORTH. THE HEAVIEST THUNDERSTORMS WILL GENERALLY RESIDE ALONG
AND SOUTH OF A NEARLY STATIONARY WEST TO EAST ORIENTED FRONT OVER
THE SOUTHERN THIRD OF THE STATE. ACROSS THE SOUTHWEST, 07Z SPC
MESOANALYSIS SUGGESTS THAT SOME POCKETS OF MUCAPE UP TO 2000 J/KG
ARE PRESENT. HOWEVER, SHEAR REMAINS WEAK WITH 0-6 KM VALUES ONLY
TOPPING OUT AROUND 20-25 KNOTS. THUS, CONVECTION THIS MORNING
SHOULD REMAIN MULTICELLULAR, BRIEFLY PULSING UP WITH SOME SMALL
HAIL FOLLOWED BY GUSTY WINDS THAT COULD GUST TO 40 TO 50 MPH AS
THE STRONGER CORES COLLAPSE. STORMS THIS MORNING SHOULD REMAIN
BELOW SEVERE LIMITS, BUT MOST CAMS WILL KEEP AT LEAST SOME OF THIS
ACTIVITY GOING THROUGH THE DAY AS THE WAVE MOVES EAST.
LATER THIS AFTERNOON THERE WILL LIKELY BE SOME REJUVENATION OF
CONVECTION ALONG THE QUASI STATIONARY FRONT, MAINLY ALONG AND
SOUTH OF A LINE FROM NEAR WATFORD CITY TO AROUND GLEN ULLIN. THE
BEST CAPE/SHEAR OVERLAP WILL BE RIGHT ALONG THE INSTABILITY
GRADIENT NEAR THE FRONT. HERE, MLCAPE WILL RANGE FROM 1000 TO 2000
J/KG AND DEEP LAYER SHEAR WILL APPROACH 25 TO 35 KNOTS. THIS COULD
LEAD TO SOME ORGANIZED SEVERE MULTICELL/TRANSIENT SUPERCELL
STRUCTURES. THE MAIN THREATS FOR THESE STORMS WOULD BE HAIL TO THE
SIZE OF PING PONG BALLS AND WIND GUSTS TO 60 MPH. UNCERTAINTY
STILL REMAINS ABOUT WHETHER THE WAVE MOVES OUT OF THE AREA TOO
QUICKLY, AND IF MID LEVEL LAPSE RATES WILL BE ENOUGH TO SUSTAIN
ORGANIZED CONVECTION.
IN THE WAKE OF TODAY'S EARLIER WAVE, RIDGING WILL POP BACK UP
ACROSS THE WEST AND WE SHOULD HAVE A LITTLE BIT OF A BREAK IN
ACTIVITY. THE NEXT EMBEDDED WAVE THEN APPROACHES THE WEST LATE
TONIGHT. MOST GUIDANCE SHOW STORMS PROPAGATING IN FROM MONTANA BY
AROUND 06Z FRIDAY OR SO, WITH MOST OF THE ACTIVITY ALONG THE SAME
SURFACE BOUNDARY ACROSS THE SOUTHWEST. SEVERE POTENTIAL IS EVEN
MORE UNCERTAIN WITH THIS WAVE AS SHEAR WILL REMAIN RATHER
MARGINAL, BUT SMALL HAIL AND WIND GUSTS TO 60 MPH WILL BE POSSIBLE
IF THE AFOREMENTIONED STORMS CAN REMAIN ORGANIZED AS THEY MOVE
INTO THE AREA.
TODAY'S HIGHS WILL BE COOLER NORTH AS WIDESPREAD STRATUS IS
FORECAST TO STREAM DOWN FROM CANADA (MAINLY IN THE 70S). WARMER
TEMPERATURES WILL BE SEEN SOUTH OF THE FRONT WHERE THERE SHOULD
BE FEWER CLOUDS (LOW TO MID 80S). TONIGHT'S LOWS WILL RANGE FROM
THE MID 50S TO LOWER 60S.
LONG TERM
(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 404 AM CDT THU JUL 7 2022
CHANCES FOR THUNDERSTORMS CONTINUE INTO THE LONG TERM FORECAST
PERIOD WITH THE BEST CHANCES FOR SEVERE WEATHER TRENDING TOWARDS
SATURDAY AFTERNOON AND NIGHT.
SOME STRONG TO SEVERE STORMS MAY BE ONGOING ACROSS THE SOUTHWEST
FRIDAY MORNING AS THE PREVIOUSLY MENTIONED WAVE CONTINUES TO MOVE
THROUGH. SIMILAR TO TODAY, THIS CONVECTION SHOULD GRADUALLY
WEAKEN, BUT THERE MAY BE SOME REDEVELOPMENT ACROSS PORTIONS OF
THE CENTRAL IN THE AFTERNOON. HOWEVER, IT IS WORTH NOTING THAT
ONLY A COUPLE OF CAMS ARE CURRENTLY REDEVELOPING CONVECTION IN OUR
AREA WITH THIS WAVE. THE ROBUST PRECIPITATION SIGNALS IN THE
DETERMINISTIC GLOBAL MODELS VERY LIKELY HAVE SOME CONVECTIVE
FEEDBACK ISSUES. STILL, IF STORMS CAN FORM OVER PORTIONS OF THE
CENTRAL, DEEP SHEAR SHOULD BE A BIT STRONGER (35 TO 40 KNOTS) AND
INSTABILITY WILL BE SUFFICIENT FOR A STRONG TO SEVERE STORM OR
TWO. LIKE CLOCKWORK, THE NEXT WAVE THEN COMES THROUGH FRIDAY NIGHT
WITH MORE CHANCES OF NOCTURNAL CONVECTION.
BROAD RIDGING AND STRONG CAPPING SHOULD KEEP MOST OF SATURDAY
AFTERNOON DRY. A STRONGER WAVE WILL THEN EJECT FROM A BROAD
PACIFIC NORTHWEST TROUGH INTO THE NORTHERN PLAINS IN THE EVENING,
APPROACHING OUR WEST FROM MONTANA. IT IS STILL A BIT EARLY FOR
SPECIFICS, BUT THE PARAMETER SPACE COULD BE CHARACTERIZED BY
STRONG SHEAR AND PLENTY OF INSTABILITY. THE BEST CHANCE FOR
DISCRETE STORMS WOULD BE DURING THE AFTERNOON IF A COUPLE OF WARM
SECTOR CELLS CAN DEVELOP ON THE NORTHERN PERIPHERY OF CAPPING. A
MORE LINEAR STORM MODE IS FAVORED AT NIGHT WITH AN MCS LIKELY
APPROACHING FROM MONTANA.
MORE THUNDERSTORMS ARE POSSIBLE ON SUNDAY, BUT HIGH PRESSURE
SLIDES IN ON MONDAY WITH A HIGHER AMPLITUDE RIDGE POPPING BACK UP
TO OUR WEST. THIS SHOULD GIVE US A BREAK FROM THE ACTIVE PATTERN
INTO MIDWEEK.
SATURDAY SHOULD BE THE WARMEST DAY OF THE LONG TERM WHEN HIGHS
WILL RANGE FORM THE MID 80S ACROSS THE NORTHEAST TO THE LOWER 90S
SOUTHWEST AND SOUTH CENTRAL. OTHERWISE, HIGHS WILL GENERALLY BE IN
THE MID 70S TO MID 80S FOR THE REST OF THE PERIOD.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 633 AM CDT THU JUL 7 2022
THERE WILL BE MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH
THE PERIOD. A FEW COULD BECOME STRONG TO SEVERE THIS AFTERNOON OR
TONIGHT, WITH HAIL TO THE SIZE OF PING PONG BALLS AND WIND GUSTS
TO 60 MPH AS THE PRIMARY THREATS. GUIDANCE HAS BACKED OFF A BIT
WITH STRATUS ACROSS THE NORTH TODAY, BUT WE WILL LIKELY STILL SEE
SOME LOWER SCATTERED CLOUDS ACROSS THE NORTH WITH SOME POSSIBLE
INTERMITTENT MVFR CEILINGS. MORE MVFR CEILINGS MAY MOVE INTO THE
SOUTHWEST TONIGHT, ALONG WITH MORE CHANCES OF THUNDERSTORMS. BRIEF
MVFR/IFR CONDITIONS WILL BE POSSIBLE UNDER ANY OF THE HEAVIER
THUNDERSTORMS THROUGH THE PERIOD, ALONG WITH GUSTY ERRATIC WINDS.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...JOHNSON
SHORT TERM...ZH
LONG TERM...ZH
AVIATION...ZH
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