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

000
FXUS63 KUNR 262047
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
247 PM MDT TUE APR 26 2016

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 240 PM MDT TUE APR 26 2016

UPPER LEVEL ANALYSIS SHOWS TROUGH OVER THE ROCKIES...WITH 100-KT
JET ROUNDING THE BASE...AND LOW OVER SOUTHEASTERN WY. INITIAL
SWATH OF MOISTURE/PRECIP HAS DISSIPATED AS IT MOVED NORTHWARD.
WATER VAPOR INDICATES ANOTHER ROUND OF MOISTURE PUSHING IN FROM
THE SOUTH...AND RADAR SHOWS SOME SCATTERED SHOWERS ACROSS WESTERN SD
AND NORTHEASTERN WY. AT THE SURFACE...WINDS ARE NORTHEASTERLY
5-10KTS...AND TEMPS ARE IN THE 30S TO LOWER 40S.

NAM/GFS/ECMWF ARE IN FAIRLY GOOD AGREEMENT ABOUT CURRENT UPPER LOW
WEAKENING TONIGHT AS IT SHIFTS NORTHWESTWARD...WHILE A NEW LOW
DEVELOPS AT THE BASE OF THE TROUGH AND STRENGTHENS OVER CENTRAL
KANSAS/NEBRASKA TONIGHT. UPPER DIVERGENCE ASSOCIATED WITH THE
NORTHERN LOW...AS WELL AS SOME WEAK ENERGY AND LINGERING
MOISTURE...WILL KEEP RAIN/SNOW SHOWERS AROUND TONIGHT. MAY BE AN
ISOLATED THUNDERSTORM ACROSS SOUTH CENTRAL SD. HOWEVER...AS THIS LOW
WEAKENS...RAIN/SNOW IS EXPECTED TO DIMINISH ACROSS THE WESTERN HALF
OF THE CWA. MEANWHILE AS SOUTHERN LOW STRENGTHENS...PRECIP WILL
BECOME MORE ORGANIZED ACROSS CENTRAL/EASTERN SD/NE BY EARLY
WEDNESDAY MORNING. STRONG FORCING ASSOCIATED WITH THIS LOW SPINS
WESTWARD INTO WESTERN SD WEDNESDAY...WITH GFS/ECM/GEM IN GOOD
AGREEMENT ABOUT AREA OF PRECIP SHIFTING WEST NEAR THE WY/SD BORDER.
HOWEVER...NAM IS THE OUTLIER AND KEEPS THE WESTERN CWA MOSTLY DRY
WEDNESDAY...NOT BRINGING BAND OF PRECIP WEST UNTIL WED NIGHT. SIDED
WITH THE MAJORITY ON POPS...WITH GREATEST CHANCES ACROSS CENTRAL
SD...ALONG WITH HIGHEST QPF. LOW PRESSURE WILL BRING COLDER AIR INTO
THE REGION ON WEDNESDAY AS WELL...AND SO WITH HIGHS NEAR
40...EXPECTING BOTH RAIN AND SNOW ACROSS MUCH OF THE AREA...WITH
RAIN FOR SOUTH CENTRAL SD. AS PRECIP BECOMES ALL SNOW WED
NIGHT...THE PLAINS MAY PICK UP AN INCH OR SO OF SNOW ACCUMULATION.

OVERALL THROUGH WED NIGHT...EXPECTING QPF TO RANGE FROM ANOTHER
QUARTER OF AN INCH ACROSS NORTHEASTERN WY...TO 2.5 INCHES OVER SOUTH
CENTRAL SD. SINCE MODELS HAVE SHIFTED HEAVIEST PRECIP FARTHER
EAST...JUST ANOTHER 1-2 INCHES OF SNOW IS EXPECTED ACROSS
NORTHEASTERN WY...WITH 2-4 INCHES OF ADDITIONAL ACCUMULATION OVER
THE BLACK HILLS. THEREFORE CONSIDERED DOWNGRADING ALL HEADLINES TO
ADVISORIES. HOWEVER...WITH BURSTS OF HEAVY SNOW CONTINUING ACROSS
SOUTHERN CAMPBELL COUNTY AND THE BLACK HILLS...WILL LET WINTER STORM
WARNINGS CONTINUE FOR NOW...ESPECIALLY SINCE SNOW MAY START STICKING
BETTER OVERNIGHT. ONCE RADAR/OBS/REPORTS SUGGEST SNOW IS
DIMINISHING...LATER SHIFTS COULD POSSIBLY CANCEL WARNINGS/ADVISORIES
EARLY.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 240 PM MDT TUE APR 26 2016

COOL/WET WEATHER EXPECTED THROUGH THE LONG TERM. AFOREMENTIONED
UPPER LOW MOVES INTO THE UPPER MIDWEST THURSDAY AND WEAKENS
CONSIDERABLY. NEXT UPPER LOW/TROUGH OVER THE FOUR CORNERS AREA
THURSDAY EVENING MOVES INTO THE CENTRAL PLAINS FRIDAY NIGHT AND
THEN SPINS OVER NE THROUGH THE WEEKEND. PLENTIFUL MOISTURE AND
LIFT ASSOCIATED WITH THESE SYSTEMS WILL BRING PERIODS OF
RAIN/SNOW. SNOW CHANCES MAINLY DIURNAL/IN THE WEST...AND AT THE
HIGHER ELEVATIONS...ESPECIALLY FOR EARLY NEXT WEEK. TEMPERATURES
WILL BE 5-15F BELOW NORMAL THROUGH THE PERIOD.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 240 PM MDT TUE APR 26 2016

WIDESPREAD IFR CONDITIONS EXPECTED THROUGH THE PERIOD AS
ST/RA/SN/BR CONTINUES. AREAS LIFR/LOCAL VLIFR CONDITIONS EXPECTED IN
THE BANDS OF HEAVIEST SNOW/FOG AND OVER THE HIGHER TERRAIN OF THE
BLACK HILLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM MDT WEDNESDAY FOR SDZ024-028-029.

WY...WINTER STORM WARNING UNTIL 6 PM MDT WEDNESDAY FOR WYZ057.

     WINTER WEATHER ADVISORY UNTIL 6 AM MDT WEDNESDAY FOR WYZ054-056-
     058.

     WINTER STORM WARNING UNTIL 6 AM MDT WEDNESDAY FOR WYZ055.

&&

$$

SHORT TERM...POJORLIE
LONG TERM...HELGESON
AVIATION...HELGESON



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