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 270938
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
238 AM MST TUE JAN 27 2015

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 224 AM MST TUE JAN 27 2015

WATER VAPOR SHOWS LARGE AMPLITUDE RIDGE OVER THE
ROCKIES/PLAINS. AT THE SFC...HIGH PRESSURE HAS SHIFTED INTO THE
UPPER MIDWEST WITH DEEPENING LEE TROF ALONG THE ROCKY MOUNTAIN
FRONT.

TODAY...LEE TROF WILL ADVANCE EWD INTO THE WRN DAKOTAS BY AFTN.
THICKNESS RIDGE PASSING OVERHEAD ALONG WITH DOWNSLOPE FLOW WILL
RESULT IN ANOTHER WARM DAY WITH PLENTY OF RECORD HIGHS EXPECTED.
THERMAL PROFILES SUGGEST TEMPS SHOULD BE AT LEAST AS WARM AS
MONDAY IF NOT A FEW DEGREES WARMER...BUT THAT WILL BE DEPENDENT ON
THE AMOUNT OF CIRRUS OVERHEAD.

WEDNESDAY...THE UPPER RIDGE WILL FLATTEN OVER THE NRN PLAINS AS A
STRONG DISTURBANCE MOVES THROUGH. MAJORITY OF GUIDANCE SUGGESTING
ENOUGH ENERGY FOR A FEW -SHRA ACROSS NERN WY...THE BLKHLS...AND
SWRN SD...ALTHOUGH MOISTURE WILL BE RATHER LIMITED. GUSTY NW WINDS
EXPECTED GIVEN COLD ADVECTION AND STEEP LO LVL LAPSE RATES...WITH
SOME AREAS ON THE SD PLAINS POSSIBLY REACHING NEAR ADVISORY
CRITERIA. WINDS WILL DECREASE WED EVENING WITH SFC HIGH BUILDING
IN OVERNIGHT.

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 224 AM MST TUE JAN 27 2015

TEMPERATURES WILL GRADUALLY LOWER TO NEAR OR BELOW
AVERAGE LEVELS BY THE WEEKEND AS NORTHWEST FLOW BRINGS COLDER AIR
INTO THE REGION. MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT ON
THIS...BUT STILL SOME ISSUES WITH REGARD TO HOW COLD IT COULD BE AND
HOW LONG THE COLDER AIR REMAINS OVER THE REGION...WITH ECMWF STILL A
BIT MORE AGGRESSIVE THAN THE GFS AND GEM. WILL KEEP TRENDING COLDER
FOR THE WEEKEND...ESPECIALLY SUNDAY. CHANCES FOR SNOWFALL SHOULD
HOLD OFF UNTIL SATURDAY INTO SATURDAY NIGHT AS A STRONGER SHORTWAVE
MOVES ACROSS THE REGION AND BRINGS IN THE COLDEST AIR. ANY
ACCUMULATIONS SHOULD BE LIGHT ACROSS THE AREA...WITH THE BEST
CHANCES OVER THE NORTHERN BLACK HILLS. SOME MILDER AIR COULD SLIDE
BACK EASTWARD INTO THE REGION EARLY NEXT WEEK...BUT THAT IS VERY
UNCERTAIN AT THIS POINT.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING
ISSUED AT 224 AM MST TUE JAN 27 2015

VFR CONDITIONS CAN BE EXPECTED THROUGH THE FORECAST
PERIOD.

&&

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

$$

SHORT TERM...JOHNSON
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.