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 271728 AAC
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1228 PM CDT WED AUG 27 2014

.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.


&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
SURFACE HIGH PRESSURE CONTINUES TO BACK OUT OF THE CWA...AND A
COUPLE OF WEAK SHOWERS/STORMS HAVE DEVELOPED ON THE NORTHERN
FRINGE OF WARM ADVECTION ACROSS FAR SOUTHERN COUNTIES THIS AM.

MAIN THREAT THIS FORECAST PERIOD IS THE POTENTIAL FOR HEAVY
RAIN TONIGHT/THURSDAY...UNFORTUNATELY WITH LOW CONFIDENCE THANKS
TO RATHER STRIKING DIFFERENCES BETWEEN THE NAM AND GFS.

NAM PROVIDES A MUCH BETTER JET SIGNATURE AND STRONGER MID LEVEL
FRONTOGENISIS...ALONG WITH A DEEPER LOW...AND A MORE NORTHERLY
TRACK. THIS PUSHES THE QPF BULLSEYE WELL INTO THE CWA. THE NAM
TREND HAS EXISTED SINCE 18Z AND IS CURRENTLY ENCOMPASSED WITHIN THE
06Z RUN. SREF AND GEM/ECMWF HAVE A SOMEWHAT LESS NORTHERLY EXTREME
BUT THE SREF HAS PROBABILITIES GREATER THEN 2 INCHES FOR THE
SOUTHERN TIER OF THE CWA AND BOTH THE GEM/ECMWF BRING THE
PRECIPITATION BULLSEYE CLOSE ENOUGH TO THE CWA TO BE CONCERNED.
THE GFS IS THE SOUTHERLY OUTLIER.

NAM SUGGEST GENERALLY WEAK CONVECTION WITH MOIST ADIABATIC
PROFILES...AND LESS THEN 500 J/KG CAPE. THERE WILL BE ABOUT 20 TO
30 MICROBARS OF LIFT ALONG A NARROW EAST WEST AXIS WITH A SLOW
NORTHEAST MOVEMENT. SINCE STORMS ARE LIKELY DOMINATED BY WARM
CLOUD PROCESSES WITH SLOW EXPECTED MOTION...ADDED THE MENTION OF
HEAVY RAIN ACROSS FAR SOUTHEAST COUNTIES. AS THIS AREA OF THE CWA
HAS ESCAPED HEAVY RAIN IN THE PAST COUPLE OF DAYS...AND THE
UNCERTAINTY OVER EXACT LOCATIONS FOR STORMS...WILL OPT OUT OF ANY
FLOOD HEADLINES.


.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
MODELS REMAIN RELATIVELY SIMILAR AND MAINTAIN DECENT 24 HOUR
CONTINUITY. POPS CONTINUE TO BE SPRINKLED THROUGHOUT THE EXTENDED
WHILE FLATTER...MORE ZONAL-TYPE...UPPER FLOW PERSISTS. STILL
WATCHING SUNDAY AFTERNOON/EVENING AS A POSSIBLE ROUND OF STRONG
CONVECTION WITH A COLD FROPA AND MODERATELY STRONG MID-LEVEL
SHORTWAVE PROGGED. TEMPERATURES SHOULD BE RUNNING GENERALLY CLOSE
TO NORMAL FOR THIS TIME OF YEAR.


&&

.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

IFR CIGS CONTINUE TO LINGER OVER THE SOUTHWESTERN CWA...WITH SOME
SCATTERED MVFR CIGS PUSHING FURTHER NORTH. PRECIPITATION CHANCES
WILL BEGIN TO INCREASE OVER MAINLY THE SOUTHERN AND EASTERN CWA
OVERNIGHT AND THROUGH THE MORNING HOURS THURSDAY. FOR NOW...WILL
INTRODUCE MVFR VSBYS IN RAIN AT KABR AND KATY LATE TONIGHT...WITH
CIGS LIKELY FALLING INTO THE IFR CATEGORY WITH THE PRECIPITATION.


&&

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

$$
SHORT TERM...CONNELLY
LONG TERM...DORN
AVIATION...PARKIN

WEATHER.GOV/ABERDEEN





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