777
FXUS63 KBIS 042308
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
608 PM CDT SUN MAY 4 2025
KEY MESSAGES
- CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE ACROSS MOST OF
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THIS EVENING.
- GUSTY SOUTHERLY WINDS ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THIS EVENING, CONTINUING IN SOUTH CENTRAL AND EASTERN
NORTH DAKOTA ON MONDAY. STRONGER NORTHERLY WINDS IN NORTHWEST
NORTH DAKOTA ON MONDAY.
- ISOLATED SHOWERS AND THUNDERSTORMS COULD DEVELOP IN WESTERN
NORTH DAKOTA THIS EVENING. HIGHER CHANCES FOR SCATTERED
SHOWERS AND STORMS INCREASE MONDAY AFTERNOON THROUGH THE
EVENING.
- COOLER ON TUESDAY, WITH A FEW LINGERING SHOWERS IN THE
SOUTHWEST. THEN MOSTLY DRY WITH ABOVE NORMAL TEMPERATURES AND
BREEZY CONDITIONS AT TIMES THROUGH THE END OF THE WEEK.
UPDATE
ISSUED AT 607 PM CDT SUN MAY 4 2025
LATE AFTERNOON SATELLITE IMAGERY SHOWS AGITATED CUMULUS CLOUDS
BUILDING ALONG A SURFACE WIND SHIFT FROM NEAR GLENDIVE, MT TO
BELLE FOURCHE, SD. A FEW UPDRAFTS HAVE BEEN ABLE TO GROW INTO
THUNDERSTORMS, MAINLY SOUTH OF HIGHWAY 12. LATEST SPC
MESOANALYSIS SHOWS UP TO 1000 J/KG SBCAPE BUT ONLY 500 J/KG
MLCAPE IN SOUTHWEST NORTH DAKOTA. EFFECTIVE BULK SHEAR IS ALSO
ONLY AROUND 20-25 KTS. STORMS ARE NOT EXPECTED TO BECOME SEVERE,
BUT THE STRONGLY MIXED BOUNDARY LAYER COULD PROMOTE CONVECTIVE
WIND GUSTS ENHANCED BEYOND THE BACKGROUND SYNOPTIC WINDS.
FURTHER NORTH, A LESS-AGITATED CUMULUS FIELD IS FILLING IN OVER
NORTHWEST NORTH DAKOTA. THIS COULD EVENTUALLY LEAD TO A FEW
SHOWERS AND PERHAPS A WEAK THUNDERSTORM, BUT BOTH CAPE AND SHEAR
ARE MUCH LOWER IN THAT PART OF THE STATE.
DISCUSSION
ISSUED AT 325 PM CDT SUN MAY 4 2025
DEVELOPING SURFACE LOW IN EASTERN MT AND EXITING HIGH PRESSURE
TO OUR EAST WILL CONTINUE TO BRING A WARM, DRY, AND WINDY FLOW
THROUGH THIS EVENING. ISOLATED ADVISORY WINDS HAVE BEEN NOTED
ALREADY THIS AFTERNOON, ALTHOUGH ARE NOT WIDESPREAD ENOUGH FOR A
HIGHLIGHT AT THIS TIME. THE BIGGER CONCERN IS WIDESPREAD
CRITICAL FIRE WEATHER CONDITIONS EXPECTED THROUGH THIS EVENING.
A RED FLAG WARNING CONTINUES FOR MOST OF THE CWA. SEE THE FIRE
WEATHER DISCUSSION BELOW FOR MORE DETAILS. THIS EVENING THROUGH
TONIGHT, A BOUNDARY OF UP TO 1000 J/KG MUCAPE STILL LOOKS TO SET
UP IN THE WEST. SHEAR IN THIS AREA LOOKS OVERALL LOW. HOWEVER,
WITH THE LOW APPROACHING AND ISOLATED THUNDERSTORM IS POSSIBLE
THROUGH TONIGHT. SPC HAS ALSO ADDED IN GENERAL THUNDER FOR THIS
THREAT. THE CHANCE FOR SEVERE WEATHER IS OVERALL LOW. THE STRONG
LOW LEVEL JET ALOFT AND INVERTED V SOUNDING COULD BRING A
MAINLY SUB SEVERE WIND THREAT WITH ANY STORMS THAT CAN DEVELOP.
LOWS TONIGHT WILL BE MILD AND MAINLY IN THE 50S. LOW AND
ASSOCIATED COLD FRONT IS STILL EXPECTED TO MOVE THROUGH MONDAY,
ALTHOUGH PRECIPITATION AND COLD FRONT TIMING MAY BE SLIGHTLY
DELAYED. BECAUSE OF THIS, WARM, DRY, AND BREEZY CONDITIONS MAY
LINGER ACROSS THE EAST AND PERHAPS BRING SOME NEAR CRITICAL FIRE
WEATHER CONDITIONS. MEANWHILE, IN THE WEST COLD FRONT PASSAGE
WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS. STRONG NORTH
WINDS BEHIND THE FRONT COULD ALSO BE FOUND, AND PERHAPS BE AT
ADVISORY LEVELS. AS THE FRONT ENTERS CENTRAL NORTH DAKOTA LATER
IN THE DAY, MODEST MUCAPE AND SHEAR WILL BE FOUND. THERE IS SOME
CAPPING CONCERNS AND THE BETTER SHEAR IS NOT FULLY ALIGNED WITH
THE HIGHEST INSTABILITY. SPC HAS MAINTAINED A GENERAL RISK FOR
THUNDERSTORMS ON MONDAY. OF NOTE ARE LOW CHANCES FOR SEVERE HAIL
IN THE CSU-MLP GUIDANCE. IF SHEAR AND INSTABILITY CAN BETTER
ALIGN, THEN PERHAPS AN ISOLATED STRONG TO SEVERE STORM IS
POSSIBLE, ALTHOUGH CONFIDENCE IS NOT HIGH ENOUGH TO MESSAGE
SEVERE WEATHER AT THIS POINT. HIGHS ON MONDAY WILL SEE A WIDE
RANGE DUE TO THE MENTIONED COLD FRONT. LOOK FOR HIGHS NEAR 60 IN
THE NORTHWEST TO NEAR 80 IN THE SOUTHEAST. WIDESPREAD SHOWERS
WITH A FEW THUNDERSTORMS ARE THEN EXPECTED FOR MONDAY NIGHT.
MOST AREAS WILL SEE WINDS BECOME NORTHERLY AND BECOME BREEZY.
LOWS WILL DIP INTO THE UPPER 30S TO UPPER 40S.
POST FRONTAL CONDITIONS TO BE FOUND ON TUESDAY. LINGERING
SHOWERS COULD BE FOUND THROUGH THE DAY. BREEZY NORTHEAST WINDS
COULD BE FOUND CENTRAL AND EAST, ALTHOUGH COOLER TEMPERATURES IN
THE UPPER 50S TO UPPER 60S WILL BRING IMPROVED HUMIDITY VALUES.
WINDS AND PRECIPITATION CHANCES WILL DIMINISH TUESDAY NIGHT.
OVERNIGHT LOWS COULD BE QUITE COOL AND IN THE 30S TO LOWER 40S
ACROSS MUCH OF THE AREA. RIDGE TO FLAT RIDGING THEN FORECAST FOR
THE MID TO LATE WEEK PERIOD. THIS BRINGS WARMING TEMPERATURES
BACK INTO THE 70S TO PERHAPS LOWER 80S. BREEZY WINDS AT TIMES
MAY ALSO ACCOMPANY THIS PATTERN THROUGH THE END OF THE WEEK.
HUMIDITY VALUES COULD LOWER AGAIN DURING THIS TIME PERIOD, AND
MAY NEED TO BE MONITORED FOR THE RETURN OF FIRE WEATHER
CONCERNS. CHANCES FOR PRECIPITATION ARE LIMITED RIGHT NOW. THERE
COULD BE A WEAK WAVE IN THE FLOW THURSDAY EVENING INTO FRIDAY.
NBM PUTTING A SLIGHT CHANCE OF SHOWERS AS A RESULT DURING THIS
TIME PERIOD.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1250 PM CDT SUN MAY 4 2025
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE FORECAST
PERIOD. TODAY EXPECT MAINLY CLEAR SKIES AND GUSTY SOUTHERLY
WINDS. TONIGHT, BREEZY SOUTHERLY WINDS MAY LINGER. MAINLY CLEAR
SKIES WILL ALSO BE FOUND. THERE IS A LOW CHANCE FOR ISOLATED
THUNDERSTORMS IN THE NORTHWEST THIS EVENING THROUGH TONIGHT
ALONG WITH SOME INCREASED CLOUDS STILL AT VFR LEVELS. CONFIDENCE
WAS NOT HIGH ENOUGH TO INCLUDE PRECIPITATION MENTION. LOW LEVEL
WIND SHEAR IS ALSO FORECAST TONIGHT, MAINLY FROM KDIK TO KBIS TO
KMOT. SHOWER AND THUNDERSTORM CHANCES MAY LINGER ACROSS THE
NORTHWEST AND MOVE INTO THE NORTHCENTRAL MONDAY MORNING.
CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN TAFS AT THIS TIME.
A COLD FRONT COULD CHANGE WINDS TO THE NORTH AND BECOME BREEZY
ACROSS NORTHWESTERN AREAS INCLUDING KXWA ON MONDAY MORNING. THIS
FRONT MAY ALSO BRING LOW VFR TO PERHAPS MVFR CEILINGS. THIS WAS
ALSO INCLUDED IN THE KXWA TAF. OTHERWISE VFR CONDITIONS CAN BE
EXPECTED FOR THE REMAINING SITES THROUGH MONDAY MORNING.
FIRE WEATHER
ISSUED AT 325 PM CDT SUN MAY 4 2025
RED FLAG WARNING NOW IN EFFECT FOR MOST OF THE CWA. LAMOURE AND
DICKEY COUNTIES REMAIN AT NEAR CRITICAL FIRE WEATHER CONDITIONS
FOR TODAY GIVEN UNCERTAINTY IN FUELS AS A GREENUP IS MORE
APPARENT HERE, YET UNCERTAIN IF THAT IS ENOUGH TO OVERCOME
REMAINING TALL DEAD GRASSES FROM LAST SEASON. SOUTH WINDS UP TO
30 MPH WITH GUSTS UP TO 40 MPH ARE STILL FORECAST THIS
AFTERNOON THROUGH THIS EVENING. AFTERNOON RH VALUES WILL FALL
INTO THE MID TEENS TO MID 20S. THUS ANYWHERE IN THE RED FLAG
WARNING COULD SEE RAPID GROWTH AND SPREAD OF WILDFIRES. THE MORE
CONCERNING AREAS WITHIN THE RED FLAG WARNING WOULD BE IN
SOUTHWESTERN NORTH DAKOTA AND CENTRAL NORTH DAKOTA, GENERALLY
ALONG THE HIGHWAY 83 CORRIDOR. THESE AREAS SEE LOW LEVEL LAPSE
RATES OVER 8 C/KM OVERLAP WITH THE STRONGER 850 MB LEVEL WINDS
ALOFT. FOR THOSE INTERESTED, MUCH OF THE NORTHERN PLAINS IS NOW
COVERED UNDER GOES EAST 19 MESO SECTOR 1 TO HELP MONITOR FOR
HOT SPOTS USING SATELLITE DATA.
TONIGHT, A STEADY SOUTHERLY WIND MAY LINGER THROUGH THE NIGHT
WITH RH RECOVERIES 50 TO 80 PERCENT. CHANCES FOR PRECIPITATION
MOVE ACROSS THE REGION FROM WEST TO EAST ON MONDAY. THIS
INCREASED MOISTURE MAY DELAY ACROSS THE EAST, AND WARM
TEMPERATURES COULD ALLOW AFTERNOON RH VALUES TO DROP INTO THE
20S. BREEZY SOUTHERLY WINDS WILL ALSO BE FOUND ACROSS THE EAST
ON MONDAY, WHILE WINDS BECOME NORTH AND BREEZY ACROSS THE WEST.
A FEW THUNDERSTORMS ARE ALSO POSSIBLE FOR MONDAY. THE
COMBINATION OF LOWER HUMIDITY VALUES AND BREEZY WINDS MAY BRING
SOME NEAR CRITICAL FIRE WEATHER CONCERNS IN THE EAST, MAINLY
ALONG AND EAST OF HIGHWAY 83, THROUGH MONDAY AFTERNOON. BREEZY
NORTH WINDS WITH WIDESPREAD SHOWER AND THUNDERSTORM CHANCES ARE
THEN EXPECTED FOR MONDAY NIGHT. COOLER TEMPERATURES, IMPROVED
HUMIDITY VALUES, AND SOME LINGERING BREEZY NORTHERLY WINDS ARE
THEN EXPECTED FOR TUESDAY. SOME SHOWERS MAY LINGER IN THE WEST AS
WELL ON TUESDAY.
BIS WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ001>005-009>013-017>023-025-031>037-040>047-050.
UPDATE...HOLLAN
DISCUSSION...ANGLIN
AVIATION...ANGLIN
FIRE WEATHER...ANGLIN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page