Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KUNR 040824
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
224 AM MDT FRI SEP 4 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 224 AM MDT FRI SEP 4 2015

LEE SIDE TROUGH WILL REMAIN NEARLY STATIONARY OVER THE REGION AS
TWO WEAK SW FLOW IMPULSES TRAVERSE THE REGION...BEFORE THE PAC NW
UPPER TROUGH FINALLY EJECTS EAST AND SUPPORTS A COLD FRONT INTO
THE NORTHERN PLAINS. THE FIRST WEAK IMPULSE IS SUPPORTING SCT-
ISOLD SHRA/TS THIS MORNING...WITH THE HIGHEST COVERAGE OVER
SCENTRAL SD. WEAK SUBSIDENCE WILL FOLLOW IN ITS WAKE...SUPPORTING
DRY CONDS ACROSS THE FA THIS AFTERNOON. SOME VERY WEAK INDICATION
FOR PERHAPS A SHOWER OVER THE NORTHERN BLACK HILLS THIS AFTERNOON.
HOWEVER...GIVEN DRY SW FLOW...LEFT THE FORECAST DRY THERE. SFC LOW
WILL WANDER OVER THE FA...AFFECTING MIXING POTENTIALS ACROSS THE
NORTHERN HALF OF THE FA AND RESULTANT TEMPERATURES. DEEPEST MIXING
WILL BE ACROSS SW THROUGH SCENTRAL SD...WHERE UPPER 90S ARE ON
TRACK ONCE AGAIN IN SOUTHERLY FLOW. WARM...BUT SLIGHTLY COOLER
CONDS EXPECTED MOST OTHER PLACES. THE NEXT WEAK IMPULSE WILL
TRAVERSE THE REGION TONIGHT...WITH GENERALLY ISOLD CONVECTION
EXPECTED. THIS SYSTEM WILL LINGER INTO SAT MORNING...SIMILAR TO
TODAY/S SYSTEM...WITH PRECIP CHANCES SHIFTING EAST THROUGH THE DAY
SAT. OVERALL WEAK FORCING AND LACK OF APPRECIABLE INSTABILITY WILL
HIGHLY LIMIT COVERAGE. OPTED FOR MAINLY SLIGHT CHANCE POPS. MAIN
LOBE OF LSA AND DEEP LAYER FORCING WILL BE CONFINED WITH THE PAC
NW UPPER TROUGH...WHICH WILL EJECT NE TOWARD THE CANADIAN PRAIRIE
PROVINCES SAT. A PORTION OF DEEP LAYER FORCING WILL CLIP THE FAR
NW ZONES...POSSIBLY SUPPORTING ISOLD TO WIDELY SCT SHRA/TS SAT
NIGHT. THE MAIN IMPACT FROM THIS SYSTEM WILL BE AN ASSOCIATED COLD
FRONT WHICH WILL SLIDE INTO THE REGION SUNDAY MORNING. SLIGHTLY
COOLER TEMPS CAN BE EXPECTED SAT GIVEN POOR MIXING POTENTIALS WITH
LINGERING MID/HIGH CLOUD. MUCH COOLER CONDS EXPECTED SAT NW HALF
AS THE SFC COLD FRONT ADVECTS THROUGH THE REGION.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 224 AM MDT FRI SEP 4 2015

MEDIUM RANGE MODELS STILL IN VERY GOOD AGREEMENT ON
UPPER LOW PASSING TO THE NORTH AND WEST OF THE AREA LATER THIS
WEEKEND...WITH THE AREA BEING DRY SLOTTED ON SUNDAY. COOLER AIR WILL
PUSH INTO THE AREA ON SUNDAY BEHIND PASSING COLD FRONT...WITH BRISK
WEST TO NORTHWEST WINDS. LOW AFTERNOON HUMIDITIES CAN BE EXPECTED
ACROSS NORTHEAST WY INTO THE BLACK HILLS AND FAR SOUTHWEST SD...WITH
ELEVATED FIRE WEATHER CONDITIONS POSSIBLE IF WINDS END UP A BIT
STRONGER.

AFTER THIS SYSTEM PASSES NORTH AND EAST OF THE REGION ON MONDAY...
ZONAL FLOW WILL DEVELOP FOR THE EARLY PART OF NEXT WEEK...
TRANSITIONING TO NORTHWESTERLY FLOW FOR THE LATTER PART OF THE WEEK.
THIS SHOULD RESULT IN SEASONABLY WARM AND MOSTLY DRY CONDITIONS FOR
MUCH OF THE WEEK. WEAK DISTURBANCES IN THE FLOW COULD BRING A FEW
SHOWERS FROM TIME TO TIME...ESPECIALLY EARLY IN THE WEEK. WILL KEEP
LOW POPS FOR THE SOUTH CENTRAL SD AREA FOR MONDAY INTO MONDAY
NIGHT...THEN ACROSS MOSTLY SOUTHERN PORTIONS OF THE CWA TUESDAY AND
TUESDAY NIGHT. WILL GO DRY FOR THE REST OF THE WEEK AT THIS POINT.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT
ISSUED AT 224 AM MDT FRI SEP 4 2015

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE ACROSS MUCH OF THE AREA THIS MORNING...ESPECIALLY OVER THE
WESTERN AND SOUTH CENTRAL SD PLAINS. BRIEF MVFR CONDITIONS ARE
POSSIBLE WITH HEAVIER SHOWERS. ISOLATED SHOWERS AND THUNDERSTORMS
ARE POSSIBLE AGAIN TONIGHT AS ANOTHER DISTURBANCE MOVES THROUGH.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...JC
LONG TERM...26
AVIATION...26


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.