873
FXUS63 KUNR 260936
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
336 AM MDT SAT APR 26 2025
KEY MESSAGES
- WARMING UP THIS WEEKEND WITH GUSTY SOUTHEAST WINDS TODAY.
- STRONG LOW PRESSURE WILL CROSS THE REGION LATE SUNDAY AND MONDAY,
BRINGING POTENTIALLY SEVERE WEATHER LATE SUNDAY, ALONG WITH
BENEFICIAL RAIN AND GUSTY WINDS TO MOST AREAS LATER SUNDAY NIGHT AND
MONDAY.
- MILD AND DRIER PATTERN FOR THE REST OF NEXT WEEK.
DISCUSSION
(TODAY THROUGH FRIDAY)
ISSUED AT 336 AM MDT SAT APR 26 2025
CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED TO THE EAST
OF THE REGION, WITH LOW PRESSURE OVER NORTHERN UT. FRONTAL
BOUNDARY EXTENDS EAST-SOUTHEAST OF THE LOW FROM THE CENTRAL
ROCKIES TO THE SOUTHERN PLAINS. UPPER LEVEL ANALYSIS SHOWS
SHORTWAVE RIDGING OVER THE PLAINS, WITH A STRONG LOW JUST OFF THE
CENTRAL CA COAST. SOUTHWESTERLY FLOW EXTENDS ACROSS THE WESTERN US
AND INTO THE ROCKIES. SKIES ARE MAINLY CLOUDY ACROSS THE FORECAST
AREA, WITH TEMPS GENERALLY IN THE MID 30S TO MID 40S. SOME LOW
CLOUDS AND PATCHY FOG PERSIST ACROSS THE AREA, ESPECIALLY OVER THE
BLACK HILLS AND NORTHEAST WY. WINDS ARE SOUTHEASTERLY, BREEZY
ACROSS NORTHEAST WY.
WARMER AIR WILL BUILD INTO THE AREA TODAY, ESPECIALLY NORTHEAST WY
INTO FAR WESTERN SD, AS FRONTAL BOUNDARY OVER THE ROCKIES PUSHES
BACK NORTHEAST AS A WARM FRONT. THE FRONT WILL LIKELY REACH EASTERN
WY THIS AFTERNOON. CLOUDS WILL GRADUALLY DECREASE ACROSS NORTHEAST
WY AND AT LEAST FAR WESTERN SD LATER THIS MORNING INTO THE
AFTERNOON, WHILE CLOUDS COULD LINGER MOST OR ALL DAY TOWARD CENTRAL
SD. HIGHS WILL GENERALLY RANGE FROM THE 50S ACROSS PORTIONS OF
NORTHWEST TO CENTRAL SD TO THE 70S ACROSS THE NORTHEAST WY PLAINS
AND POSSIBLY FAR SOUTHWEST SD. GUSTY SOUTHEASTERLY WINDS WILL
DEVELOP ACROSS MUCH OF THE AREA TODAY, ESPECIALLY THE NORTHWESTERN
SD PLAINS, WHERE SOME GUSTS ARE LIKELY TO REACH 40 TO 50 MPH LATER
THIS MORNING AND AFTERNOON. HAVE ISSUED A WIND ADVISORY FOR HARDING,
PERKINS, BUTTE, AND NORTHERN MEADE COUNTIES. NOT TOTALLY CONVINCED
THAT WINDS WILL REACH ADVISORY CRITERIA ACROSS NORTHWEST SD FOR AN
EXTENDED PERIOD WITH WARM ADVECTION AND POTENTIAL FOR CLOUD COVER TO
LINGER INTO THE AFTERNOON, BUT THE POTENTIAL LOOKS HIGH ENOUGH FOR
AT LEAST SOME AREAS. A FEW LIGHTER SHOWERS/SPRINKLES COULD LINGER
ACROSS AREAS EAST OF THE BLACK HILLS TODAY, BUT MOST AREAS SHOULD
GENERALLY BE DRY. ANY CHANCES FOR SHOWERS TONIGHT SHOULD MOSTLY BE
CONFINED TO SOUTH CENTRAL SD, WITH LOWS MOSTLY IN THE 40S. BREEZY
CONDITIONS WILL LINGER ACROSS PORTIONS OF THE SD PLAINS TONIGHT AS
LOW LEVEL JET INTENSIFIES OVER THE AREA.
WARMEST AIR PUSHES ACROSS THE AREA ON SUNDAY, AS UPPER LOW MOVES
ACROSS THE GREAT BASIN REGION. HIGHS WILL REACH THE 70S AND LOWER
80S. SOUTHERLY WINDS WILL BRING INCREASING MOISTURE ACROSS THE SD
PLAINS, WITH DEWPOINTS RISING INTO THE 50S EAST OF THE BLACK HILLS.
SOUTHWESTERLY WINDS FURTHER WEST WILL BRING DRY AIR AND LOW HUMIDITY
INTO NORTHEAST WY AND PORTIONS OF THE BLACK HILLS. SURFACE LOW IS
PROGGED TO MOVE ACROSS SOUTHEAST MT AND INTO WESTERN SD SUNDAY INTO
SUNDAY NIGHT. MUCAPE VALUES ARE EXPECTED TO RANGE FROM ABOUT 500 TO
AROUND 1500 J/KG ACROSS MOST OF THE AREA BY LATE SUNDAY, HIGHEST
OVER EASTERN PORTIONS OF THE CWA. SHEAR IS NOT FORECAST TO BE VERY
FAVORABLE, ESPECIALLY WHERE THE BETTER CAPE IS EXPECTED, BUT LIKELY
SUFFICIENT FOR A FEW ORGANIZED STORMS TO POTENTIALLY DEVELOP. MAIN
CONCERN IS THE TIMING OF STRONGER FORCING THAT EVENTUALLY MOVES INTO
THE AREA. AT THIS POINT, IT LOOKS LIKE IT WILL HOLD OFF UNTIL AT
LEAST LATE DAY, AND MORE LIKELY DURING THE EVENING HOURS. THIS WOULD
AT LEAST LIMIT THE SEVERE POTENTIAL A BIT ACROSS THE AREA. THE BEST
POTENTIAL RIGHT NOW LOOKS TO BE ACROSS PORTIONS OF SOUTHWEST SD INTO
SOUTH CENTRAL SD DURING THE EVENING AS STRONGER SHORTWAVE ENERGY
MOVES INTO THAT AREA FROM THE SOUTHWEST. STRONGER STORMS COULD
PRODUCE LARGE HAIL AND STRONG WIND GUSTS. ISOLATED STRONG TO
MARGINALLY SEVERE STORMS ARE POSSIBLE ELSEWHERE ACROSS WESTERN SD
DURING THE LATE DAY AND EVENING, WITH HAIL AND GUSTY WINDS. SEVERE
THREAT SHOULD TAPER OFF OVERNIGHT AS BOUNDARY LAYER STABILIZES.
UPPER LOW WEAKENS AND LIKELY FALLS APART AS IT MOVES ACROSS THE
ROCKIES SUNDAY NIGHT. HOWEVER, STRONG NORTHERN STREAM SHORTWAVE WILL
CROSS THE NORTHERN PLAINS LATE SUNDAY NIGHT AND MONDAY, BRINGING
RAINFALL TO MOST OR ALL OF THE AREA, SOME OF IT ON THE HEAVIER SIDE.
BENEFICIAL RAINS ARE EXPECTED ACROSS MUCH OF THE FORECAST AREA FROM
THIS SYSTEM. LREF PROBS FOR A HALF INCH OR MORE OF PCPN LATE SUNDAY
NIGHT INTO MONDAY EVENING RANGE FROM 50 TO 90 PERCENT ACROSS MOST OF
THE FORECAST AREA, LOWER ACROSS MOST OF FAR SOUTHERN SD. LREF PROBS
FOR AN INCH OR MORE ARE 30 TO 70 PERCENT ACROSS A GOOD PORTION OF
NORTHWEST SD, THE NORTHERN BLACK HILLS AREA, AND FAR NORTHWEST SD.
COLDER AIR PUSHES INTO THE AREA ON THE BACK SIDE OF THE SYSTEM
MONDAY AND MONDAY NIGHT. RAIN IS LIKELY TO CHANGE OVER TO SOME SNOW
OVER THE HIGHER BLACK HILLS, ESPECIALLY ABOVE 5500 FEET, LATER
MONDAY INTO MONDAY NIGHT BEFORE PCPN TAPERS OFF. ACCUMULATIONS WOULD
MOSTLY BE LIGHT AT THAT POINT. GUSTY NORTHWEST WINDS CAN BE EXPECTED
MONDAY, POTENTIALLY ADVISORY CRITERIA OVER THE WESTERN SD PLAINS.
THE REST OF THE WEEK LOOKS MOSTLY MILD AND DRIER AS RIDGING
EVENTUALLY BUILDS OVER THE WESTERN US. A WEAKER DISTURBANCE OR TWO
COULD BRING SOME SHOWERS AND A FEW STORMS DURING THE MIDWEEK PERIOD
BEFORE THE RIDGE MOVES OVER THE REGION LATE WEEK. WELL ABOVE AVERAGE
TEMPS WILL LIKELY RETURN LATE NEXT WEEK AND ESPECIALLY NEXT WEEKEND.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 540 PM MDT FRI APR 25 2025
PREDOMINATELY MVFR CONDITIONS WITH INTERMITTENT IFR CONDITIONS
WILL PERSIST ACROSS THE KRAP AND KGCC TERMINALS THROUGH 15Z.
EXPECT PERIODS OF -DZ THROUGH 06Z AT KRAP TERMINAL. CONDITIONS
WILL IMPROVE ACROSS THE TERMINALS BY 19Z BUT STRONG SOUTH WINDS
ARE PROGGED TO IMPACT THE TERMINAL BEGINNING AROUND 15Z WHERE
WINDS COULD GUST UP TO 40 KNOTS.
FIRE WEATHER
ISSUED AT 336 AM MDT SAT APR 26 2025
ELEVATED FIRE WEATHER CONDITIONS ARE LIKELY ACROSS NORTHEAST WY
INTO PORTIONS OF THE BLACK HILLS SUNDAY AFTERNOON AS HUMIDITY
DROPS TO 12 TO 20 PERCENT. AT THIS TIME, SOUTHWESTERLY WINDS LOOK
TO REMAIN BELOW RED FLAG CRITERIA, BUT WILL CONTINUE TO MONITOR.
UNR WATCHES/WARNINGS/ADVISORIES
SD...WIND ADVISORY FROM 8 AM THIS MORNING TO 5 PM MDT THIS AFTERNOON
FOR SDZ001-002-012-013-078.
WY...NONE.
DISCUSSION/KEY MESSAGES...26
AVIATION...WOODWARD
FIRE WEATHER...26
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