199
FXUS63 KBIS 130530
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1230 AM CDT SUN APR 13 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 1224 AM CDT SUN APR 13 2025
RAIN CONTINUES TO EXPAND ACROSS THE AREA, WITH A FEW HIGHER
REFLECTIVITY RETURNS TRACKING ACROSS THE CENTRAL PART OF THE
STATE. SOME LIGHTNING CONTINUES ACROSS THE CLUSTER OF SHOWERS IN
FAR EASTERN MONTANA, NUDGING INTO FAR SOUTHWESTERN NORTH DAKOTA
OVER THE NEXT HOUR. NO MAJOR CHANGES WERE MADE TO THE FORECAST
FOR THIS UPDATE.
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 /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1224 AM CDT SUN APR 13 2025
VFR CEILINGS AND VISIBILITIES ARE PRESENT AT THE MOMENT, THOUGH
CONDITIONS WILL DETERIORATE AS THE NIGHT PROGRESSES. AS THE
SYSTEM CONTINUES MOVING THROUGH THE AREA, CEILINGS WILL DROP TO
MVFR ACROSS THE SOUTHERN HALF OF THE STATE, AND IFR ACROSS THE
NORTHERN HALF BY EARLY SUNDAY MORNING. LATER SUNDAY AFTERNOON,
IFR CEILINGS ARE EXPECTED ACROSS THE ENTIRE AREA. RAIN SHOWERS
WILL CONTINUE FOR MOST LOCATIONS THROUGH THE TAF PERIOD, THOUGH
A BRIEF DRY PERIOD WILL BE POSSIBLE IN THE SOUTHWEST AND FAR
SOUTH CENTRAL, IMPACTING KDIK, FROM AROUND 11Z TO 20Z. INITIALLY
LIGHT WINDS WILL QUICKLY PICK UP THROUGH THE DAY TODAY, WITH
SUSTAINED WEST-NORTHWESTERLY WINDS AROUND 20 TO 25 KTS POSSIBLE,
AND GUSTS UP TO 35 KTS. THE FAR SOUTHWEST MAY SEE EVEN STRONGER
WINDS.
BIS WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 1 AM
CDT /MIDNIGHT MDT/ MONDAY FOR NDZ040>045.
UPDATE...BESSON
DISCUSSION...JOHNSON
AVIATION...BESSON
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