865
FXUS63 KUNR 222311
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
511 PM MDT TUE APR 22 2025
KEY MESSAGES
-SEMI-ZONAL ACTIVE PATTERN WILL BRING NEAR DAILY CHANCES FOR
PRECIPITATION, WITH A STRONGER SYSTEM EXPECTED THURSDAY AND
ANOTHER SUNDAY INTO MONDAY
-TEMPS WILL FLUCTUATE IN THE PERIOD AS A FRONTAL BOUNDARY WAVERS
OVER THE REGION, WITH THE COOLEST DAY THUR
DISCUSSION
(THIS EVENING THROUGH TUESDAY)
ISSUED AT 154 PM MDT TUE APR 22 2025
PERTURBED SEMI-ZONAL FLOW CONTINUES ACROSS THE REGION AS A SERIES
OF IMPULSES CONTINUE TO EJECT OUT OF THE PAC. A COUPLE STRONGER
SYSTEMS WILL AFFECT THE REGION THUR AND SUNDAY-MONDAY, BRINGING
WIDESPREAD CHANCES FOR RAIN AND SOME SNOW AS WELL (THUR). STEEP
LAPSE RATES HAVE ALLOWED FOR SOME HIGH BASED SHOWERS OVER THE BH,
WITH MOST OF THE PRECIP NOT REACHING THE GROUND PER VERY DRY SUB
CLOUD LAYER PROFILES. OTHERWISE, A WEAK SYSTEM WILL MOVE THROUGH
REGION TONIGHT AND SUPPORT SOME SHOWERS ACROSS MAINLY SCENTRAL SD.
A COUPLE HIRES MODELS DO INDICATE THAT SOME ELEVATED SHOWERS ARE
POSSIBLE OVER THE BH AND EAST ON THE SD PLAINS LATE TONIGHT, BUT
GIVEN MARGINAL PROFILES AND LACK OF DEEP MOISTURE, HAVE LEFT POPS
OUT ATTM. STRONG SYSTEM WILL APPROACH THE REGION WED WITH SOME
AFTERNOON SHOWERS POSSIBLE ONCE AGAIN OVER THE BH AND ACROSS
PORTIONS OF THE SD PLAINS. HOWEVER, BETTER CHANCES FOR PRECIP WILL
ARRIVE LATER WED NIGHT AS BETTER LIFT AND MOISTURE MOVE INTO THE
REGION. EVEN BETTER CHANCES FOR PRECIP WILL BE ON THUR AS THE MAIN
LOBE OF LIFT PUSHES THROUGH THE REGION. TEMPS WILL BE COLD ENOUGH
FOR RAIN TO CHANGE TO SNOW IN THE HIGHER ELEVATIONS OF THE BH,
WITH SOME POTENTIAL FOR RAIN TO SNOW OVER PORTIONS OF NORTHEAST WY
AND NW SD. RIGHT NOW, ONLY AN INCH OR TWO IS EXPECTED. HOWEVER,
IF COLDER TEMP PROFILES MATERIALIZE, SNOW COULD CHANGE OVER
EARLIER WITH A FEW INCHES POSSIBLE. SHOWER CHANCES CONTINUE
THROUGH THE WEEKEND, WITH THE BEST CHANCE SUNDAY AFTERNOON AS A
DECENT LOW PRESSURE SYSTEM IS EXPECTED TO TRACK RIGHT OVER THE
REGION. THERE WILL ALSO BE THE POTENTIAL FOR SEVERE WEATHER SUNDAY
ON THE SD PLAINS AS THE WARM SECTOR PUSHES IN TO WESTERN AND
CENTRAL SD. DEFINITIVELY CONDITIONAL, BUT SOMETHING TO KEEP AN EYE
ON. AS FOR TEMPS, EXPECT COOLER CONDS WED AND ESP THUR, WITH A
WARMING TREND THIS WEEKEND, AS TEMPS SURGE INTO THE 70S AND A FEW
80S BY SAT AND SUNDAY.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 510 PM MDT TUE APR 22 2025
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...JC
AVIATION...HELGESON
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