Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 270548 AAC
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1248 AM CDT WED MAY 27 2015

.UPDATE...
ISSUED AT 915 PM CDT TUE MAY 26 2015

JUST A FEW LINGERING SHOWERS STILL OVER THE CWA...BUT COVERAGE HAS
DIMINISHED QUITE A BIT AND EXPECT ALL THE PRECIPITATION TO BE GONE
BY 10 PM OR SO. NO OTHER CHANGES MADE TO THE FORECAST AT THIS
TIME.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 323 PM CDT TUE MAY 26 2015

INSTABILITY SHOWERS HAVE DEVELOPED OVER NORTH DAKOTA THIS AFTERNOON.
THESE SHOWER WILL SLOWLY TRACK SOUTHWARD AND POSSIBLE AFFECT THE
NORTHERN HALF OF THIS CWA THIS EVENING. THESE STORMS WILL DIMINISH
SHORTLY AFTER SUNSET WITH DRY CONDITIONS LIKELY THROUGH WEDNESDAY
AFTERNOON. A STRONGER STORM SYSTEM CROSS THE CWA LATE WEDNESDAY
AFTERNOON THROUGH THURSDAY MORNING. WHILE ALL MODELS SHOW DECENT
PCPN CHANCES FOR THE MISSOURI RIVER VALLEY BETWEEN 0-6Z...THERE IS
SIGNIFICANT DISAGREEMENT AMONG MODELS FOR THE EASTERN CWA BETWEEN 6-
12Z. FAVORED THE HI-RES MODELS OF THE ARW/NMM...WHICH HAS SUPPORT
FROM THE NAM FOR POPS WEDNESDAY NIGHT. THESE MODELS SHOW WIDE
COVERAGE OF STORMS ALONG THE MISSOURI RIVER AROUND 0Z. THESE STORMS
WOULD TRACK EASTWARD AND WEAKEN WITH LITTLE PCPN EXPECTED FOR THE
I29 CORRIDOR. THAT SAID...WILL KEEP CHANCE POPS GOING AS THE
ECMWF/GFS AND CANADIAN ALL SUPPORT CONVECTION HOLDING TOGETHER. AM A
BIT SURPRISED THE GFS STILL SHOWS THIS AS THE LLJ SURGES INTO FAR
NORTHEASTERN ND AFTER 6Z.

AN UPPER LEVEL TROUGH AND SURFACE FRONTAL BOUNDARY WILL SLIDE ACROSS
THE REGION THURSDAY AFTERNOON BRINGING ADDITIONAL CHANCES FOR
SHOWERS AND THUNDERSTORMS. SOME THUNDERSTORMS ON THURSDAY COULD
PRODUCE LOCALLY HEAVY RAINFALL AS PWATS AND SPECIFIC HUMIDITY VALUES
AROUND ONE TO TWO STANDARD DEVIATIONS ABOVE NORMAL AND THE STORM
MOTION IS 5 TO 10 KNOTS.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 323 PM CDT TUE MAY 26 2015

THE WEEKEND FORECAST WILL BE DOMINATED BY PERSISTENT WEAK FLOW ALOFT
AND CANADIAN HIGH PRESSURE. INITIALLY...WE MAY SEE SOME LIGHT QPF
SHOWERS AROUND...HOWEVER THE PUSH OF DRIER/COOLER AIR INTO THE CWA
WILL HELP CLEAR US OUT DURING THE DAY FRIDAY. COLD ADVECTION WILL
CAUSE 850MB TEMPERATURES TO FALL INTO THE SINGLE DIGITS BY SATURDAY
AM...AROUND 1 STANDARD DEVIATION BELOW CLIMO...WITH THE RIDGE AXIS
LINGERING OVERHEAD INTO EARLY SUNDAY BEFORE RETURN FLOW DEVELOPS.
ZONAL FLOW/WEAK RIDGING WITH AN EMBEDDED WAVE...ALONG WITH A WEAK
LOW LEVEL JET...MAY PROMOTE CONVECTION WITH A FEW HUNDRED J/KG CAPE
LATE SUNDAY/EARLY MONDAY. THE PATTERN LOOKS TO BE MORE ACTIVE INTO
THE MIDDLE OF NEXT WEEK AS ANOTHER WESTERN CONUS TROF DEVELOPS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1245 AM CDT WED MAY 27 2015

VFR CONDITIONS WILL PREVAIL OVERNIGHT AND THROUGH THE DAY WEDNESDAY.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL PUSH OVER
THE WESTERN HALF OF THE CWA DURING THE LATE AFTERNOON AND EVENING
HOURS...LIKELY AFFECTING KPIR AND KMBG. NO SEVERE WEATHER IS
ANTICIPATED. CIGS AND VSBYS MAY FALL INTO THE MVFR CATEGORY WITH
ANY THUNDERSTORMS THAT DEVELOP.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

$$

UPDATE...PARKIN
SHORT TERM...SD
LONG TERM...CONNELLY
AVIATION...DORN


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