Area Forecast Discussion
Issued by NWS Aberdeen, SD

Home | Current Version | Previous Version | Text Only | 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 KABR 280947
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
447 AM CDT SAT MAR 28 2015

.SHORT TERM...(TODAY THROUGH MONDAY AFTERNOON)
ISSUED AT 442 AM CDT SAT MAR 28 2015

RETURN FLOW WINDS HAVE SET UP ACROSS THE REGION AHEAD OF THE NEXT
APPROACHING SURFACE TROUGH. GIVEN THE WARM AIR ADVECTION
PATTERN...UNCERTAIN OF HOW THE AREA OF STRATUS CURRENTLY ACROSS
THE EASTERN CWA WILL EVOLVE. TOOK AN OPTIMISTIC APPROACH AND
GRADUALLY TRENDED TOWARD CLEAR SKIES...BUT OBVIOUSLY...IF CLOUDS
STICK AROUND IT WILL EFFECT TEMPERATURES ACROSS THE EAST TODAY.
WINDS WILL INCREASE TO THE 20 TO 30 MPH RANGE THIS AFTERNOON...SO
WILL HAVE TO KEEP TRACK OF FIRE WEATHER CONDITIONS. MODELS DO
SUGGEST THAT MIN RH VALUES WILL REMAIN AT 30 PERCENT OR
GREATER...BUT THE FAR WESTERN EDGE OF THE CWA COULD BE DROPPING TO
THE 20 PERCENT RANGE. MAY ALSO SEE ENHANCED WINDS IN THE DOWNSLOPE
REGION OF THE SISSETON HILLS GIVEN THE FAVORABLE SOUTHWEST WIND
DIRECTION AND WARM AIR ADVECTION PATTERN....ESPECIALLY LATER THIS
EVENING AND OVERNIGHT.

THE DYNAMIC LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
MOVE ACROSS THE REGION TONIGHT. THERMAL PROFILES SUGGEST
ALL RAIN WITH THIS SYSTEM...AND MODELS EVEN SHOW WEAK CAPE ACROSS
THE WESTERN DAKOTAS. WENT AHEAD AND ADDED A MENTION OF THUNDER
ACROSS THE NORTHWEST CWA. QPF VALUES RANGE FROM A FEW HUNDREDTH TO
POSSIBLY UP TO A TENTH OF AN INCH ACROSS THE FAR NORTHERN CWA
OVERNIGHT. THE MAJOR CONCERN WITH THE SYSTEM HOWEVER IS THE STRONG
NORTHWEST WINDS EXPECTED IN THE STRONG COLD AIR ADVECTION AND
SUBSIDENCE REGIME. MODELS SHOW LAPSE RATES NEAR 8 C/KM ACROSS THE
WESTERN CWA THIS EVENING...AND BUFKIT SOUNDINGS SUGGEST AROUND 50
KTS OF WIND AT THE TOP OF THE MIXED LAYER. PEAK WINDS ARE EXPECTED
TO OCCUR DURING THE OVERNIGHT HOURS...SO SOME SPECULATION ON HOW
HIGH GUSTS WILL GET...BUT WENT AHEAD WITH A HIGH WIND WARNING FOR
THE FAR WESTERN CWA REGARDLESS...AND SURROUNDED THE WARNING WITH A
WIND ADVISORY. THE WIND ADVISORY WILL LIKELY NEED TO BE EXTENDED
INTO THE FUTURE WITH SUBSEQUENT FORECAST UPDATES...BUT AT LEAST IT
IS A START.

FIRE WEATHER WILL REMAIN A CONCERN SUNDAY AND MONDAY AS WELL.
NORTHWEST WINDS WILL REMAIN GUSTY THROUGH THE DAY SUNDAY...AND
MIN RH VALUES WILL BE DROPPING INTO THE MID 20S. BY MONDAY THE
WINDS WILL BE LIGHTER...BUT DRIER AIR WILL PUSH IN...SO MIN RH
VALUES MAY BE LOWER. WILL DEFINITELY HAVE TO KEEP FIRE WEATHER IN
THE FOREFRONT OVER THE NEXT SEVERAL DAYS.

.LONG TERM...(MONDAY EVENING THROUGH FRIDAY)
ISSUED AT 442 AM CDT SAT MAR 28 2015

GOOD AGREEMENT WITH THE MODELS EARLY ON WITH SOME DIFFERENCES LATER
ON BUT WERE NOT IMPORTANT ENOUGH TO MAKE A BIG CHANGE IN THE FORECAST.
TUESDAY WILL BE MUCH ABOVE NORMAL ACROSS THE CWA AS SOUTH WINDS IN
ADVANCE OF THE NEXT UPPER LOW PRESSURE TROUGH WILL BRING IN THE
WARMER AIR. TEMPERATURES WILL BE IN THE 60S AND 70S WITH MAYBE 80
DEGREES SOUTHWEST IN THE CWA. THE MODELS THEN AGREE WELL WITH
BRINGING A COLD FRONT ACROSS THE REGION LATE TUESDAY NIGHT AND
WEDNESDAY. THIS WILL BRING STRONG WEST TO NORTHWEST WINDS FOR
WEDNESDAY. ALTHOUGH...TEMPERATURES WILL STILL BE ABLE TO MIX OUT
INTO THE 60S FOR HIGHS ON WEDNESDAY BEFORE THE STRONGER CAA KICKS
IN. THE MODELS SHOW LOWERING THICKNESSES WITH PREDOMINANTLY NORTHWEST
FLOW AT THE SURFACE FOR THURSDAY AND FRIDAY. THUS...THURSDAYS HIGHS
WILL BE MOSTLY IN THE 50S WITH 40S AND 50S FOR FRIDAY. THE EC WAS
SHOWING COOLER AIR ACROSS THE CWA ON FRIDAY AND THUS LOWER
GUIDANCE TEMPERATURES THAN THE GFS/MEX GUIDANCE. OTHERWISE...A FEW
WEAK SYSTEMS WILL MOVE ACROSS THE REGION WITH VERY LITTLE MOISTURE
AVAILABLE. THUS...HAVE IT DRY FOR NOW THROUGH THE ENTIRE PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1229 AM CDT SAT MAR 28 2015

VFR CONDITIONS AT KPIR AND KMBG COULD TEMPORARILY DROP TO IFR IN
GROUND FOG OR LOW STRATUS BETWEEN NOW AND SUNRISE SATURDAY.
OTHERWISE...VFR WILL REMAIN AS SOUTHERLY WINDS BECOME BREEZY TO
WINDY. LATER SATURDAY EVENING...A VERY STRONG COLD FRONT IS
FORECAST TO SWEEP THROUGH CENTRAL SOUTH DAKOTA...TURNING WINDS
AROUND TO THE NORTHWEST AND BECOMING VERY STRONG. SOME GUSTS COULD
REACH 50 KNOTS. ALSO...LATER SATURDAY EVENING...RAIN CHANCES ARE
INCREASING SUBSTANTIALLY FOR SEVERAL HOURS.

MVFR STRATUS /1500-2500FT AGL/ IS EXPECTED TO PERSIST AT KABR FOR
THE REST OF TONIGHT. ON SATURDAY...CONDITIONS WILL GRADUALLY
IMPROVE TO VFR AS SOUTHERLY WINDS BECOME BREEZY TO WINDY. LATER
SATURDAY EVENING...RAIN CHANCES ARE INCREASING SUBSTANTIALLY FOR
SEVERAL HOURS.

VFR STRATUS /APPX 3500FT AGL/ AT KATY COULD GRADUALLY LOWER INTO
MVFR STRATUS /2000-3000FT AGL/ OVER THE NEXT SEVERAL HOURS. ON
SATURDAY...CONDITIONS WILL GRADUALLY IMPROVE TO VFR AS SOUTHERLY
WINDS BECOME BREEZY TO WINDY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 1 AM TO 7 AM CDT SUNDAY FOR SDZ004-005-009-010-
     016-017-034>036-045-048.

     HIGH WIND WARNING FROM 9 PM THIS EVENING TO 6 AM MDT SUNDAY FOR
     SDZ003-015-033.

MN...NONE.
&&

$$

SHORT TERM...SERR
LONG TERM...MOHR
AVIATION...MOHR





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