Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
475
FXUS63 KUNR 062048
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
248 PM MDT FRI MAY 6 2016

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 229 PM MDT FRI MAY 6 2016

LATEST SURFACE ANALYSIS SHOWS A TROUGH EXTENDING FROM DULUTH TO
DENVER. THE COLD FRONT IS CURRENTLY LAGGING SLIGHTLY TO THE WEST
OF THE TROUGH...FROM NORTHEASTERN TO SOUTHWESTERN SOUTH DAKOTA. A
LINE OF THUNDERSTORMS HAS DEVELOPED ALONG THE FRONT BETWEEN
ABERDEEN AND WATERTOWN. RADAR IS ALSO SHOWING SOME WEAK RETURNS
ALONG THE FRONT IN SOUTHERN JACKSON COUNTY. BANDS OF SHOWERS AND
THUNDERSTORMS CONTINUE TO STREAM NORTHWARD TOWARD THE FORECAST
AREA FROM SERN WYOMING AND THE NEBRASKA PANHANDLE. THIS EVENING
UP TO 1500J/KG MLCAPE WILL BE AVAILABLE AS LOW LEVEL MOISTURE
INCREASES AHEAD OF THE COLD FRONT. MODEST INSTABILITY AND 0-6KM
EFFECTIVE SHEAR MAY BE ENOUGH TO PRODUCE AN ISOLATED SEVERE TSRA
OR TWO MAY OVER THE SOUTHWEST QUARTER OF THE FORECAST AREA.
MARGINAL HAIL/SEVERE WIND GUSTS POSSIBLE.

NORTHWARD UPPER FLOW WILL INCREASE TO THE EAST OF THE
SOUTHWESTERN CONUS UPPER LOW TONIGHT. THE UPPER LOW WILL MOVE
NORTHEASTWARD...BECOMING LOCATED OVER THE FOUR CORNERS AREA BY
12Z SATURDAY. UPPER DIVERGENCE ALONG THE NOSE OF A 120KT JET
ROUNDING THE UPPER LOW WILL INCREASE SYNOPTIC SCALE LIFT OVER THE
FORECAST AREA THIS EVENING. THE SFC FRONT WILL CONTINUE TO MOVE
SLOWLY SOUTHWARD TONIGHT. NORTHEASTERLY UPSLOPE SFC FLOW TO THE
NORTH OF THE FRONT WITH COMBINE WITH THE INCREASING SYNOPTIC SCALE
LIFT TO PRODUCE RELATIVELY HIGH POPS FROM EASTERN WYOMING INTO
SOUTHWESTERN SOUTH DAKOTA TONIGHT.

ON SATURDAY...THE UPPER LOW WILL MOVE INTO SOUTH CENTRAL WY.
UPPER FORCING WILL DECREASE RAPIDLY DURING THE MORNING AS DRIER
AIR CIRCULATES INTO CWA FROM THE EASTERN DAKOTAS. DURING THE AFTERNOON...
A SURFACE LOW WILL DEVELOP OVER WESTERN NEBRASKA IN RESPONSE TO
ENERGY ROTATING AROUND UPPER LOW. FLOW TURNS SOUTHEAST WITH
MOISTURE RETURN. POPS INCREASE LATER IN THE DAY AND INTO THE NIGHT
ACROSS SOUTHERN PORTIONS OF THE CWA AS WEAK INSTABILITY COMBINES
WITH SYNOPTIC SCALE LIFT. TEMPERATURES WILL BE NEAR GUIDANCE.

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 229 PM MDT FRI MAY 6 2016

UPPER LOW WILL BE LOCATED OVER THE CENTRAL HIGH PLAINS
SUNDAY MORNING...SLOWLY TRACKING EASTWARD ACROSS THE CENTRAL PLAINS
THROUGH EARLY NEXT WEEK. RIDGE TO THE NORTH AND EAST OF THE REGION
WILL HELP TO KEEP THE HEAVIER RAINFALL POTENTIAL MOSTLY TO THE SOUTH
AND EAST OF THE CWA SUNDAY INTO MONDAY. THE BEST CHANCES FOR
RAINFALL DURING THIS TIME WILL GENERALLY BE ACROSS SOUTHWEST SD INTO
SOUTH CENTRAL SD.

GFS AND EC IN BETTER AGREEMENT NOW ON BRINGING ANOTHER UPPER LEVEL
SYSTEM ACROSS THE NORTHERN PLAINS LATE MONDAY NIGHT AND TUESDAY.
THIS SYSTEM WILL TRACK FURTHER NORTH ACROSS THE REGION AND SHOULD
BRING THE BETTER CHANCES FOR RAINFALL FROM NORTHEAST WY TO NORTHWEST
SD. THIS SYSTEM LOOKS TO EXIT THE AREA LATER TUESDAY NIGHT OR EARLY
WEDNESDAY. NORTHWEST FLOW ALOFT IS PROGGED FOR THE REST OF THE WORK
WEEK. WEAK ENERGY IN THE FLOW COULD BRING SOME SHOWERS TO PORTIONS
OF THE AREA LATE IN THE WEEK...BUT TIMING AND LOCATIONS RATHER
UNCERTAIN AT THIS POINT. TEMPS WILL BE NEAR OR A BIT BELOW SEASONAL
AVERAGES DURING THE WEEK...WITH HIGHS IN THE 50S TO 60S AND LOWS IN
THE 30S TO MID 40S.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 229 PM MDT FRI MAY 6 2016

CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
INCREASE ACROSS NORTHEAST WY...THE BLACK HILLS...AND FAR SOUTHWEST
SD LATE THIS AFTERNOON AS AN UPPER LEVEL DISTURBANCE APPROACHES.
SHOWERS AND EVENING THUNDERSTORMS WILL SPREAD SLOWLY EAST-NORTHEAST
ACROSS THE REST OF SOUTHWEST AND SOUTH CENTRAL SD TONIGHT...WITH
CHANCES DECREASING NORTHWARD ACROSS NORTHWEST SD. AREAS OF MVFR
CONDITIONS ARE MAINLY EXPECTED ACROSS NORTHEAST WY AND THE BLACK
HILLS TONIGHT. BREEZY NORTH TO NORTHEAST WINDS WILL PERSIST ACROSS
MUCH OF THE PLAINS THROUGH THIS EVENING AS A COLD FRONT PASSES SOUTH
AND EAST OF THE CWA LATE THIS AFTERNOON.

&&

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

$$

SHORT TERM...10
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.