Area Forecast Discussion Issued by NWS Aberdeen, SD
000
FXUS63 KABR 202009
AFDABR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
309 PM CDT MON MAY 20 2013
.SHORT TERM...THROUGH TUESDAY
AXIS OF SHOWERS HAS SHIFTED INTO THE EASTERN CWA THIS
AFTERNOON...WITH A BREAK FOR COUNTIES WEST OF ABERDEEN. THIS
BREAK WILL BE SHORT LIVED AS RADARS UPSTREAM IN NORTH DAKOTA ARE
QUITE ACTIVE...WITH WIDESPREAD LIGHT/MODERATE RAINFALL. HRRR AND
RUC GUIDANCE PIVOTS THIS MOISTURE BACK OVER THE CWA THIS EVENING
AND PERSISTS WELL INTO TUESDAY. MOST OF THE AREA HAS BEEN ABLE TO
HANDLE THE MOISTURE THUS FAR...WITH A FEW SPOTS REPORTING RISING
WATER IN DITCHES/CREEKS BUT NOT MUCH IMPACT OTHERWISE. SREF
PROBABILITIES FOR GREATER THEN A QUARTER INCH ARE HIGHEST ACROSS
OUR NORTHER MISSOURI COUNTIES...AN AREA THAT HAS NOT RECEIVED MUCH
DROUGHT RELIEF THIS SPRING...AND THUS THINK AREA CAN HANDLE THE
ADDITIONAL 1/2 INCH RAIN. SOILS FARTHER SOUTH AND EAST MAY BE LESS
FORGIVING AND WILL NEED TO BE MONITORED THIS EVENING/OVERNIGHT FOR
WATER ISSUES.
AS THE STACKED LOW CONTINUES TO DRIFT EAST TUESDAY...LIFT WEAKENS
WITH SOME DRIER AIR ENTRAINMENT RESULTING IN LOWER PROBABILITY FOR
PRECIPITATION AND QPF. TEMPERATURES THIS PERIOD WILL REMAIN BELOW
NORMAL AND CHANGE LITTLE THANKS TO CLOUD COVER.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
AS THE PERIOD OPENS...A DECAYING UPPER LOW CIRCULATION OVER THE
REGION WILL BE SLOWLY DRIFTING SOUTHEAST OUT OF THE AREA.
CONTINUED WRAP-AROUND MOISTURE COMBINED WITH SOME WEAK TROWALESQUE
FORCING/LIFT WILL KEEP POPS/RAIN SHOWERS MENTION GOING TUESDAY
NIGHT INTO WEDNESDAY AS THIS LOW PULLS AWAY FROM THE REGION.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT SHOULD BE DRY FORECAST
PERIODS WHILE A TRANSIENT HIGH-AMPLITUDE LONGWAVE HIGH PRESSURE
RIDGE WORKS THROUGH THE REGION.
BY FRIDAY...LOW LEVEL RETURN FLOW IS IN FULL SWING AND POPS FOR
SHOWERS AND THUNDERSTORMS MAKE THEIR RETURN TO THE FORECAST AS MID
AND UPPER LEVEL FLOW TAKES ON A RATHER PROLONGED PERIOD OF SWRLY
FLOW...THAT IS CURRENTLY PROGGED BY THE GFS AND ECMWF TO LAST
RIGHT INTO MONDAY.
THE COOLEST TEMPS DURING THE PERIOD LOOK TO BE TUESDAY NIGHT AND
WEDNESDAY BEFORE THE WARMING TREND ENSUES. BY THE
WEEKEND...TEMPERATURES SHOULD BE MUCH CLOSER TO CLIMO NORMAL.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AREA OF RAIN PIVOTING THROUGH KABR AND KPIR...EXITING KMBG...WITH
A SECOND AREA OF SHOWERS OVER/NORTH OF KATY. MOST OF THE RAIN IS
LIGHT WITH VFR VISBY AND MVFR CIGS...THOUGH HEAVIER POCKETS ARE
RESULTING IN IFR CIGS. THIS LINE IS CLEARING KMBG SO EXPECT
IMPROVING CONDITIONS...HOWEVER ANOTHER BAND OF MODERATE RAIN IS
SET TO PIVOT DOWN OUT OF NORTH DAKOTA THIS EVENING. FOR
KATY...BEING IN A WARMER/UNSTABLE AIRMASS...A FEW WEAK
THUNDERSTORMS COULD POP FOR A FEW HOURS THIS AFTERNOON.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...CONNELLY
LONG TERM...DORN
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN