Red Flag Warning 2, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
1137 AM CDT THU APR 23 2009

.UPDATE...
LITTLE CHANGE REQUIRED TO GOING FORECAST. MAIN CONCERN HAS BEEN
DEWPOINT TEMPERATURES...WHICH...WILL BE QUITE THE TRICK. SOUNDING
SUGGESTS WE SHOULD MIX OUT THE MORNING MOISTURE FAIRLY
WELL...HOWEVER FETCH FROM SOUTH/SOUTHWEST FEEDING HIGHER DEWPOINT
AIR INTO THE EAST. THUS WE HAVE SEEN MAINTENANCE OF DEWPOINTS IN
THE MID 40S. HAVE TRENDED THE PREVIOUS NUMBERS DOWN A LITTLE...BUT
NOT SIGNIFICANTLY ENOUGH TO SIGNIFICANTLY EFFECT THE FIRE WEATHER
NUMBERS FROM THIS MORNING FORECAST. WILL BE CLOSE TO RED FLAG
CONDITIONS IN THE FAR EAST...BUT MIN RH AND WINDS ARE NOT QUITE
THERE.

&&
.PREV DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY.
ISOLATED RW/TRW- DEVELOPING ON LOW LEVEL JET THIS MORNING. DO NOT
EXPECT MUCH FROM THESE AS MOISTURE IS LIMITED...BUT HAVE ADDED
THEM TO THE GRIDS. NEW MODEL RUNS ARE SLOWING THE SYSTEM DOWN A
FEW HOURS...AND IT LOOKS LIKE THE STRONG COLD FRONTAL PASSAGE
WILL BE DELAYED. WITH THAT SAID...TEMPS WILL RISE TO THE WARMEST
LEVELS THIS YEAR ACROSS FORECAST AREA. EXPECT SOME GOOD PRE-
FRONTAL HEATING AHEAD OF THE FRONT AS WELL AS DOWNSLOPE AREAS
EAST OF SISSETON HILLS. HAVE LEANED ON THE WARMER SIDE OF
GUIDANCE. WINDS WILL BE STRONGEST IN THE EAST...AND BE LESS OF A
PROBLEM IN THE WEST AS AREA WILL BE SITTING IN THE SFC TROUGH
THIS AFTERNOON. SHOWERS AND THUNDERSTORMS WILL DEVELOP ON THE
COLD SIDE OF THE FRONT THIS EVENING AND TONIGHT. THE BEST AREA
FOR SHOWERS AND THUNDERSTORMS TONIGHT WILL BE IN ND WHERE JET IS
STRONGEST.

MAIN BAND OF SHOWERS WILL SLOWLY SHIFT SOUTH FROM NORTH DAKOTA ON
FRIDAY. FRONTOGENESIS STRENGTHENS ALONG A BAND FROM SOUTHWEST SD
TO SOUTHEAST ND. THIS BAND WILL BRING A GOOD CHANCE OF SHOWERS TO
MOST OF FORECAST AREA FRIDAY NIGHT AND SATURDAY MORNING. AIRMASS
COLD ENOUGH FOR SOME SNOW IN NORTH CENTRAL SD...BUT FEEL
ACCUMULATIONS WILL REMAIN ON THE LIGHT SIDE AS PRECIP WILL BE
ENDING AS COLDER AIR ARRIVES. COOL HIGH PRESSURE WILL SETTLE IN
AREA SATURDAY...BUT PATTERN WILL REMAIN UNSETTLED WITH A CHANCE
OF SHOWERS.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE MAIN FORECAST CHALLENGE IN THE EXTENDED CENTERS AROUND PCPN
CHANCES AND TYPE FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT.

THE 0Z MODEL RUN OF THE GFS AND ECMWF ARE EXTRAORDINARILY SIMILAR
THROUGHOUT THE EXTENDED. THE PERIOD BEGINS WITH A BROAD UPPER LEVEL
TROF OVER THE WESTERN CONUS. THIS LEAVES THE NORTH PLAINS UNDER SW
FLOW ALOFT. MODELS SHOW A SURFACE LOW ROUNDING THE BASE OF THE
TROF AND QUICKLY MOVING NORTHEAST INTO IOWA. BASED OF THE CURRENT
TRACK OF THE LOW PRESSURE...BELIEVE CAA WILL FILTER INTO THE CWA.
HAVE LOWERED OVER NIGHT LOWS ON SATURDAY NIGHT A FEW DEGREE...AND
EXTENDED THE AREAL COVERAGE OF SNOW AND RAIN OR SNOW. THE ECMWF IS
JUST A BIT FASTER WITH PUSHING THIS SYSTEM EAST OF THE REGION BY
SUNDAY AFTERNOON. THE GFS HOLDS SOME WRAP AROUND PCPN IN THE
EASTERN PORTION OF THE CWA...WITH A SHORT WAVE APPROACHING FROM
THE WEST. BELIEVE THE GFS IS A BIT TOO AGGRESSIVE WITH THIS SHORT
WAVE...BUT WILL KEEP POPS AS IS FOR NOW ON SUNDAY. THE REST OF THE
EXTENDED LOOKS DRY AS THE WESTERN CONUS TROF DEEPENS TOWARD THE
END OF THE PERIOD. WITH THIS DEEPENING...AN UPPER LEVEL RIDGE
FORMS OVER AREA. TEMPERATURES THROUGHOUT THE EXTENDED WILL BE
BELOW CLIMO.

&&

.AVIATION...
VFR CONDITIONS CONTINUE ACROSS THE REGION. SOME MID LEVEL CLOUDS
ARE MOVING ACROSS THE STATE TONIGHT BUT WILL NOT HAVE A BIG EFFECT
ON AVIATION. THROUGH TOMORROW EVENING EXPECT VFR CONDITIONS WITH
ANY CEILINGS ABOVE 8K FT AGL AND UNRESTRICTED VISIBILITY.

&&

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

UPDATE...CONNELLY
SHORT TERM...SCARLETT
LONG TERM...SD
AVIATION...HINTZ

WEATHER.GOV/ABERDEEN

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE ABERDEEN SD
400 AM CDT THU APR 23 2009

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-240900-
TRAVERSE-BIG STONE-CORSON-CAMPBELL-MCPHERSON-BROWN-MARSHALL-
ROBERTS-WALWORTH-EDMUNDS-DAY-DEWEY-POTTER-FAULK-SPINK-CLARK-
CODINGTON-GRANT-HAMLIN-DEUEL-STANLEY-SULLY-HUGHES-HYDE-HAND-JONES-
LYMAN-BUFFALO-
400 AM CDT THU APR 23 2009 /300 AM MDT THU APR 23 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL
MINNESOTA...CENTRAL SOUTH DAKOTA...NORTH CENTRAL SOUTH DAKOTA AND
NORTHEAST SOUTH DAKOTA.

.DAY ONE...TODAY AND TONIGHT
VERY HIGH TO EXTREME FIRE DANGER IS EXPECTED FOR ALL OF CENTRAL
AND NORTHEAST SOUTH DAKOTA...AS WELL AS WEST CENTRAL MINNESOTA.
TEMPERATURES WILL RISE INTO THE MID 80S TO NEAR 90 IN SOME
LOCATIONS ALONG WITH STRONG SOUTHERLY WINDS ALONG AND EAST OF
INTERSTATE 29.

A STRONG COLD FRONT WILL MOVE INTO THE AREA TONIGHT BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS. SEVERE WEATHER IS NOT
ANTICIPATED AT THIS TIME.

FLOODING WILL CONTINUE ALONG THE JAMES RIVER FOR THE FORESEEABLE
FUTURE. PLEASE SEE THE LATEST ISSUED FLOOD STATEMENTS FOR MORE
DETAILED INFORMATION.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE FRIDAY. NO SEVERE
WEATHER IS EXPECTED.

SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.