600
FXUS63 KBIS 130242
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
942 PM CDT SAT APR 12 2025
KEY MESSAGES
- WIDESPREAD MEDIUM TO HIGH CHANCES (60-95%) FOR RAIN TONIGHT
THROUGH SUNDAY NIGHT, WITH PRECIPITATION CHANCES DECREASING
THROUGH MONDAY.
- STRONG WEST-NORTHWEST WINDS AROUND 30 TO 35 MPH WITH GUSTS UP
TO 55 MPH ARE EXPECTED IN FAR SOUTHWEST NORTH DAKOTA LATE
SUNDAY MORNING THROUGH SUNDAY EVENING.
- SOME SNOW MAY MIX IN WITH THE RAIN SUNDAY NIGHT THROUGH MONDAY
MORNING, WITH LITTLE TO NO IMPACTS EXPECTED.
- DRY CONDITIONS WITH TEMPERATURES TRENDING WARMER ARE FORECAST
TOWARDS THE MIDDLE OF NEXT WEEK, FOLLOWED BY COOLER
TEMPERATURES AND INCREASING CHANCES FOR PRECIPITATION TO END
THE WEEK.
UPDATE
ISSUED AT 942 PM CDT SAT APR 12 2025
RAIN IS BEGINNING TO INCREASE IN COVERAGE AND INTENSITY ALONG A MID
LEVEL VORTICITY STREAK FROM THE SOUTHWEST CORNER OF THE STATE TO
NEAR BISMARCK. SOME LIGHTNING ACTIVITY HAS ALSO BEEN OBSERVED NEAR
BOWMAN COUNTY, THOUGH HAS YET TO BECOME FULLY ESTABLISHED WITHIN
STATE BOUNDARIES. OVERALL, THE FORECAST FOR TONIGHT INTO TOMORROW
REMAINS IN GOOD SHAPE. RADAR TRENDS ARE FOLLOWING THE HRRR QUITE
NICELY, SO THE POP FORECAST WAS TRENDED IN ITS DIRECTION
UPDATE
ISSUED AT 732 PM CDT SAT APR 12 2025
CURRENT CONDITIONS AND TRENDS ALONG WITH THE MOST RECENTLY
INITIALIZED HIGH-RESOLUTION ENSEMBLE DATA WERE BLENDED INTO THE
FORECAST FOR THIS UPDATE. ONE ASPECT OF THE PRECIPITATION FORECAST
THAT IS NOW MORE PROMINENT IS A LOWERING OF PROBABILITIES ASSOCIATED
WITH AN EXPECTED DRY SLOT MOVING FROM WEST TO EAST ACROSS SOUTHERN
NORTH DAKOTA DURING THE DAY SUNDAY. WE ALSO INCREASED OUR WIND GUST
FORECAST FOR SUNDAY AFTERNOON, WITH CONCERN OF APPROACHING WARNING-
CRITERIA GUSTS (58 MPH) IN THE FAR SOUTHWEST. THE RAP HAS BEEN
CONSISTENTLY PROJECTING A +50 KT LOW LEVEL JET WRAPPING AROUND THE
DEEPENING LOW OVER NORTH DAKOTA, WITH THE JET CUTTING THROUGH
THE SOUTHWEST CORNER OF THE STATE. THE 18Z HRRR CONFIRMS THIS
POTENTIAL WITH SIMULATED SURFACE GUSTS AROUND 50 TO 55 KTS. BUT
THERE ARE STILL CONCERNS ABOUT THE STRENGTH OF BOUNDARY LAYER
MIXING AND WHAT ROLES CLOUD COVER AND PRECIPITATION COULD PLAY.
THEREFORE, WE ARE BUMPING UP OUR WIND GUST FORECAST TO AS HIGH
AS 55 MPH FOR THE WIND ADVISORY.
DISCUSSION
ISSUED AT 343 PM CDT SAT APR 12 2025
QUASI-ZONAL UPPER LEVEL FLOW CONTINUES ACROSS THE NORTHERN
PLAINS WITH A WAVE PASSING OVER EASTERN MONTANA. SHOWERS
CONTINUE ACROSS THE NORTHWEST THIS AFTERNOON WITH AN AREA OF
SHOWERS ARE MOVING INTO THE SOUTHWEST. PRECIPITATION CHANCES
WILL INCREASE THIS AFTERNOON ACROSS THE WEST AND CENTRAL AS THE
WAVE APPROACH THE STATE. THERE IS A LOW CHANCE FOR THUNDERSTORMS
IN THE SOUTHWEST THIS AFTERNOON AS SOME INSTABILITY CREEPS INTO
THE REGION. SEVERE WEATHER IS NOT LIKELY IN THE SOUTHWEST. THE
UPPER LEVEL LOW WILL MOVE ACROSS THE STATE TOMORROW CONTINUING
WIDESPREAD PRECIPITATION ACROSS THE REGION. THERE IS AROUND
AROUND A 70 PERCENT CHANCE FOR 0.5 INCH IN THE SOUTH CENTRAL AND
AROUND A 50 PERCENT CHANCE FOR 1 INCH OF RAIN IN THE NORTHWEST
THROUGH MONDAY. THERE MAY BE SOME SNOW MIXED IN THE BACKSIDE OF
THIS SYSTEM, BUT ACCUMULATIONS REMAIN LOW. ANOTHER SYSTEM WILL
TRAIL THIS SYSTEM BRINGING A CHANCE OF RAIN TO THE STATE MONDAY
AS CYCLONIC FLOW ALOFT LINGERS FROM THE PASSAGE OF THE UPPER
LOW. THESE TWO SYSTEM WILL LIKELY BLEND TOGETHER SUNDAY NIGHT
INTO MONDAY MORNING.
TEMPERATURES SUNDAY ARE FORECAST TO COOL OFF IN THE UPPER 40S
NORTHWEST TO THE LOWER 60S SOUTHEAST. MONDAY TEMPERATURES ARE
FORECAST TO SIT IN THE 40S TO LOWER 50S.
STRONG NORTHWEST WINDS ARE FORECAST TO PICK UP SUNDAY ACROSS
THE SOUTHWEST. THERE IS A 40 TO 45 KTS 850 MBS WINDS THAT ARE
FORECAST TO MIXED DOWN TO THE SURFACE ACROSS THE SOUTHWEST AND
PORTIONS OF THE SOUTH CENTRAL. A TIGHT PRESSURE GRADIENT FROM
THE SURFACE LOW WILL HELP SUSTAIN ADVISORY LEVEL WINDS ACROSS
THE SOUTHWEST. CLOUD COVER COULD INHIBIT SOME MIXING TOMORROW
AFTERNOON LIMITING GUSTS BUT SUSTAINS WINDS SHOULD NOT BE
IMPACTED AS MUCH. THEREFORE, A WIND ADVISORY HAS BEEN ISSUED
FOR SOUTHWEST AND PORTIONS OF SOUTH CENTRAL NORTH DAKOTA LATE
TOMORROW MORNING INTO THE EARLY EVENING HOURS. MONDAY ANOTHER
ROUND OF A WINDY CONDITIONS IS POSSIBLE AS A NORTHWEST TO
SOUTHEAST ORIENTATED PRESSURE GRADIENT COULD LEAD TO ADVISORY
LEVEL WINDS IN THE JAMES RIVER VALLEY.
TEMPERATURES WILL BEGIN TREND WARMER BY THE MIDDLE OF THE WEEK BACK
INTO THE 60S WITH A SLIGHT CHANCE OF RAIN. HOWEVER, COOLER
TEMPERATURES WILL FOLLOW THIS WARM UP AS THE UPPER LEVEL PATTERN
BEGINS TO BECOME MORE ACTIVE BY THE END OF THE WEEK.
PRECIPITATION CHANCES WILL ALSO RETURN BY THE END OF NEXT AS
ANOTHER SYSTEM IS FORECAST TO MOVE THROUGH THE NORTHERN PLAINS.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 942 PM CDT SAT APR 12 2025
A LOW PRESSURE SYSTEM WILL BRING PERIODS OF RAIN, MVFR TO IFR
CEILINGS, AND SHIFTING AND STRENGTHENING WINDS ACROSS WESTERN AND
CENTRAL NORTH DAKOTA THROUGH THE FORECAST PERIOD.
PRECIPITATION: RAIN IS EXPECTED TO BECOME WIDESPREAD ACROSS WESTERN
AND CENTRAL NORTH DAKOTA THIS EVENING THROUGH TONIGHT. THERE WILL
LIKELY BE A BREAK IN THE RAIN FOR SOUTHWEST (MORNING) AND SOUTH
CENTRAL (AFTERNOON) NORTH DAKOTA ON SUNDAY, WITH SHOWERS
CONTINUING ACROSS THE NORTH THROUGHOUT MUCH OF THE DAY. A FEW
THUNDERSTORMS ARE POSSIBLE IN SOUTHWEST NORTH DAKOTA LATER THIS
EVENING. THERE IS ALSO A LOW CHANCE OF SNOW MIXING WITH RAIN IN
WESTERN PARTS OF THE STATE ON SUNDAY.
CEILINGS: MVFR TO IFR CEILINGS WILL SPREAD ACROSS THE STATE FROM
WEST TO EAST LATER TONIGHT, PERSISTING ACROSS THE NORTH THROUGH THE
DAY SUNDAY WHERE PROBABILITIES FOR IFR ARE HIGHEST. SOUTHWEST AND
SOUTH CENTRAL NORTH DAKOTA COULD EXPERIENCE A BREAK IN THE LOW
CLOUDS FROM WEST TO EAST SUNDAY MORNING AND AFTERNOON.
WINDS: MOST AREAS WILL SEE EAST-NORTHEAST WINDS AROUND 10 KTS THIS
EVENING. A LOW PRESSURE CENTER MOVING THROUGH THE STATE TONIGHT AND
SUNDAY WILL CAUSE VARYING WIND DIRECTIONS. THE STRONGEST WINDS ON
SUNDAY ARE EXPECTED IN SOUTHWEST NORTH DAKOTA, WITH WEST-NORTHWEST
WINDS AROUND 20 TO 30 KTS GUSTING TO AROUND 35 TO NEAR 50 KTS.
BIS WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ SUNDAY TO 1 AM CDT
/MIDNIGHT MDT/ MONDAY FOR NDZ040>045.
UPDATE...HOLLAN
DISCUSSION...JOHNSON
AVIATION...HOLLAN
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