663
FXUS63 KUNR 230442
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1042 PM MDT FRI AUG 22 2025
KEY MESSAGES
- ISOLATED THUNDERSTORMS POSSIBLE TONIGHT.
- MILD TEMPERATURES AND WITH MOSTLY DRY CONDITIONS THIS WEEKEND
AND INTO NEXT WEEK.
DISCUSSION
(THIS EVENING THROUGH FRIDAY)
ISSUED AT 1256 PM MDT FRI AUG 22 2025
WATER VAPOR IMAGERY SHOWS THE LOW ACROSS SOUTH CENTRAL CANADA
CONTINUING TO PUSH OF TO THE EAST WITH THE BROAD TROUGH AXIS
DRAPED ACROSS THE NORTHERN PLAINS. THIS TROUGH AXIS HAS PUSHED
SOME DRIER AIR INTO THE REGION TODAY AND HAS PUSHED THE BULK OF
THE DEEPER MOISTURE SOUTH INTO NEBRASKA. RESIDUAL MOISTURE IS
STILL POOLED WITHIN THE BLACK HILLS AS EVIDENT BY AN EXPANSIVE
CUMULUS FIELD THAT IS DEVELOPING THIS AFTERNOON OVER THE BLACK
HILLS. RADAR AND VIS SATELLITE SHOW A FEW CONVECTIVE TOWERS TRYING
TO INITIATE AND THIS TREND WILL CONTINUE INTO THE EVENING HOURS
WITH THE POSSIBLE OF SOME ISOLATED THUNDERSTORMS DEVELOPING.
STORMS THAT DO DEVELOP WILL PRIMARILY STICK TO THE TERRAIN AS
UPPER LEVEL FORCING IS QUITE WEAK WITH THE EXITING TROUGH TO THE
EAST AND A BUILDING RIDGE AND INCREASING HEIGHTS PROGGED TO COME
INTO THE REGION FROM THE WEST, SO ANY ONGOING CONVECTION TONIGHT
SHOULD COME TO AN END QUICKLY.
THE AFOREMENTIONED RIDGE AXIS BUILDS ACROSS THE SOUTHERN ROCKIES
AND PER MODEL GUIDANCE LOOKS TO BE THE MAIN WEATHER DRIVER THIS
WEEKEND AND INTO MUCH OF NEXT WEEK. PERSISTENT NORTHWEST FLOW WILL
USHER IN BOTH COOLER AND DRIER AIR INTO THE REGION ALLOWING FOR
TEMPERATURES TO DROP TO SEASONAL NORMALS. A FEW MODELS HAVE SOME
WEAK DISTURBANCES COMING THROUGH THE NW FLOW THAT COULD INITIATE
SOME PRECIPITATION CHANCES BUT WITH THE DRIER AIR WORKING ITS WAY
INTO THE REGION THE FORECAST WILL ONLY ADVERTISE ISOLATED, LOW END
(<20%) POP CHANCES THROUGHOUT THE WEEK.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1042 PM MDT FRI AUG 22 2025
VFR CONDITIONS WILL PREVAIL AT BOTH TAF SITES NEXT 24HRS. BROKEN
MID CLOUDS STILL PREVAIL AT BOTH SITES, BUT RAP WILL SEE CLOUDS
BECOMING SCATTERED AROUND 3AM. HOWEVER, BROKEN MID CLOUDS AROUND
10KFT WILL RETURN FOR THE DAY TIME HOURS. SKIES WILL BECOME
SCATTERED CIRRUS AT RAP AFTER 00Z. GCC WILL HAVE BROKEN MID
CLOUDS AROUND 10KFT THROUGH MOST OF THE PERIOD BUT THEN SHOULD
BECOME SCATTERED CIRRUS AT 00Z TOMORROW EVENING. NORTHERLY WINDS
WILL PREVAIL AT BOTH SITES BUT EXPECTING GCC TO BECOME SOUTHEAST
TOMORROW, THEN BACK TO NORTHEAST TOMORROW EVENING. NORTH TO
NORTHEAST WINDS WILL CONTINUE FOR RAP THROUGH TOMORROW AND
TOMORROW EVENING.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...WOODWARD
AVIATION...AUTEN
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