114
FXUS63 KUNR 020434
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1034 PM MDT FRI MAY 1 2026
KEY MESSAGES
- ISOLATED HIGH-BASED SHOWERS WILL DEVELOP OVER THE SOUTHERN BLACK
HILLS AND SOUTHERN SD THIS AFTERNOON.
- CLEARER SKIES AND MILD TEMPS RETURN FOR THE WEEKEND.
- CHANCE FOR SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON. SEVERE
WEATHER ISN'T EXPECTED.
UPDATE
ISSUED AT 1034 PM MDT FRI MAY 1 2026
LOOKING AT THINGS THIS EVENING...COLD FRONT LOOKS TO CROSS THE
REGION FROM NORTHWEST TO SOUTHEAST SATURDAY AFTERNOON. ON THE FIRE
WEATHER SIDE OF THINGS...THIS MAY BE A SCENARIO WHERE LOWEST RHS
ARE REALIZED DURING THE EARLY- TO MID-AFTERNOON HOURS AHEAD OF THE
FRONT, BUT MAY STALL OR START TO RECOVER/INCREASE A BIT BEHIND
THE FRONT AS THE NEW AIRMASS AND SOME CLOUDS PUSH THROUGH. WE DID
MASSAGE THE WIND/WIND GUST FORECAST POST-FRONT, MOSTLY TO
BROADBRUSH THE SLIGHTLY HIGHER NBM SPEEDS OUT OVER ADDITIONAL REAL
ESTATE ACROSS THE NORTHWEST SOUTH DAKOTA PLAINS DOWN TO ABOUT
I-90 USING ADJMAV. WHILE WE HAVE HAD SOME RECENT MOISTURE AND
SOME GREEN- UP OF FUELS, THE COMBINATION OF MINIMUM RHS OF 15-25%
AND WIND GUSTS 20-40 MPH WILL STILL SPELL "ELEVATED" FIRE WEATHER
CONDITIONS. ON THE PRECIP SIDE OF THINGS...A FEW CAMS ARE TRYING
TO FIRE A FEW SHOWERS OR EVEN A THUNDERSTORM ALONG THE FRONT, BUT
NEARLY ALL RAW MODEL GUIDANCE IN ADDITION TO BLENDS LIKE CONSSHORT
AND THE NBM ARE DRY (POPS GENERALLY 10% OR LESS), AND SPOT
CHECKING A FEW MODEL FORECAST SOUNDINGS, MOISTURE AT THE TOP OF
THE BOUNDARY LAYER ALONG THE FRONT SEEMS QUITE SHALLOW WITH THE
LOW-LEVELS DRY. HAVE THUS HELD WITH THE NBM AND KEPT ANY MENTION
OF PRECIP OUT OF THE FORECAST FOR NOW. BETTER CHANCES STILL APPEAR
TO ARRIVE SUNDAY. NO MAJOR UPDATES/CHANGES MADE FROM SUNDAY
ONWARD.
DISCUSSION
(THIS EVENING THROUGH FRIDAY)
ISSUED AT 1251 PM MDT FRI MAY 1 2026
MOST RECENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS SHOWS
RIDGE AXIS EXTENDING FROM ID/MT INTO NORTHERN CA/NV. MEANWHILE, AN
UPPER LOW SITS OVER ONTARIO/QUEBEC. THE NORTHERN PLAINS SITS
UNDER NORTH/NORTHWEST FLOW WITH WEAK UPPER WAVE MOVING THROUGH SD.
RECENT KUDX SCANS ARE PICKING UP ON SCATTERED HIGH-BASED SHOWERS
OVER BENNETT COUNTY, THOUGH WEBCAMS IN THAT AREA AREN'T SHOWING
ANY PRECIP MAKING IT TO THE GROUND. CAMS ALSO HAVE HINTED AT
SHOWERS DEVELOPING IN THE CONVERGENCE ZONE OVER THE SOUTHERN
HILLS. HAVE PAINTED LIGHT/ISOLATED POPS FOR SOUTHWESTERN SD FOR
THIS AFTERNOON.
RIDGE BUILDS INTO THE REGION THROUGH EARLY THIS WEEKEND, BRINGING
DRY AND WARM CONDITIONS TO THE CWA LATE TONIGHT INTO SATURDAY.
SATURDAY WILL BE WARM WITH HIGHS IN THE 70S ACROSS MUCH OF THE
AREA. HUMIDITIES SATURDAY AFTERNOON WILL DROP TO ~15% ACROSS
SOUTHWESTERN SD WITH WINDS GUSTING UP TO ~25 MPH. THIS WOULD PUT
US NEAR OR AT RED FLAG CRITERIA; HOWEVER, THE RECENT PRECIP AND
FUELS IN GREEN UP PRECLUDE ANY CRITICAL FIRE WEATHER CONCERNS.
RIDGE BREAKS DOWN BY SUNDAY, BRINGING NORTHWEST FLOW BACK TO THE
REGION. UPPER LEVEL WAVE SLIDES SOUTHEASTWARD FROM CANADA AND
GRAZES THE CWA ON SUNDAY. SOME SHOWERS/STORMS MAY DEVELOP ACROSS
THE BLACK HILLS AND WESTERN SD ON SUNDAY AFTERNOON AS THIS WAVE
MOVES THROUGH, THOUGH NOT EXPECTING ANYTHING SEVERE. DETERMINISTIC
GUIDANCE IN GOOD CONSENSUS OF A REX BLOCK DEVELOPING OVER THE
WESTERN US FOR THE BEGINNING OF NEXT WEEK. THIS WOULD KEEP OUR
NECK OF THE WOODS UNDER UNSETTLED NORTHWEST FLOW WITH MILD
TEMPERATURES AND PERIODIC CHANCES FOR SOME LIGHT PRECIP AS A
RESULT.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1034 PM MDT FRI MAY 1 2026
VFR CONDITIONS ARE EXPECTED AT BOTH TAF SITES THROUGH THE FORECAST
PERIOD. A COLD FRONT WILL MOVE IN FROM THE NW SATURDAY AFTERNOON,
BRINGING WINDY CONDITIONS. PRECIPITATION IS NOT EXPECTED.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
UPDATE...KSMITH
DISCUSSION/KEY MESSAGES...WONG
AVIATION...SCHWEIGERT
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