FXUS63 KOAX 132038
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
238 PM CST THU JAN 13 2011
.SHORT TERM...TONIGHT THROUGH SUNDAY. SURFACE TROUGH MOVING INTO
THE CWFA WILL ESSENTIALLY WASH OUT THIS EVENING OR EARLY OVERNIGHT
RESULTING IN LIGHT OR CALM WINDS IN SOME AREAS. THIS COULD ALLOW
SOME FOG TO DEVELOP...ALTHOUGH MID/HIGH CLOUDS STREAMING OVERHEAD
COULD ALSO PREVENT THAT. CERTAINLY TEMPS SHOULD NOT BOTTOM OUT
LIKE LAST NIGHT DUE TO THE HIGH CLOUDS ALSO.
FOCUS SHIFTS TO A FAST MOVING WAVE COMING OUT OF THE PACIFIC
NORTHWEST THAT MOVES DOWN THE MISSOURI RIVER VALLEY LATE TONIGHT
AND ACROSS THE AREA ON FRIDAY. ALL 12Z MODEL SUITES FROM
NAM/GFS/ECMWF/GEM AND 09Z SREF ALL SUGGESTED SOME VERY LIGHT
PRECIP POTENTIAL WITH THE WAVE MOVING THROUGH...BUT PRECIP TYPE IN
QUESTION AS WARMING ALOFT COULD RESULT IN A SLEETY MIX. 18Z
NAM/15Z SREF STILL SUGGEST SOME PRECIP...BUT KEEP IT NORTH OF THE
CWFA ACROSS SOUTH DAKOTA AND NORTHERN IOWA. OPTED TO EXPAND THE
PREVIOUSLY MENTIONED AREA OF SLEET A LITTLE FURTHER SOUTH...
EXTENDING FROM KOFK TO KTQE TO KHNR AS THE WAVE MOVES THROUGH...
BUT KEPT IT OUT OF THE KOMA/KLNK METRO AREAS. HPC WINTER WEATHER
DESK INDICATED A SLIGHT POTENTIAL FOR SOME FREEZING RAIN IN THIS
SAME AREA AS WELL. IF ANYTHING DOES DEVELOP...IT WOULD BE VERY
LIGHT AND SHOULD NOT CAUSE ANY PROBLEMS. FLOW RETURNING SOUTHERLY
FRIDAY SHOULD HELP BOOST TEMPS TOO...ALTHOUGH CONSIDERABLE LOW
CLOUDINESS COULD HINDER A DECENT WARMUP ALSO.
A SECONDARY FRONT IS FORECAST TO PUSH INTO THE CWFA FRIDAY NIGHT.
THERE ARE SIGNIFICANT MODEL DISCREPANCIES ON THE STRENGTH OF THE
COLD AIR AND HOW FAST IT WILL SURGE ACROSS THE REGION. MOS GUIDANCE
WAS ONLY OFF BY ABOUT 14 TO 18 DEGREES FOR LOWS FRIDAY NIGHT AND
HIGHS SATURDAY. FELT THE GFS WAS TOO COLD AS IT SEEMED TO BE THE
ONLY MODEL WITH MUCH COLDER SURGE...BUT NAM MAY BE TOO WARM...SO
USED A CONSENSUS OF ALL AVAILABLE SOURCES. THE NAM THE LAST COUPLE
OF RUNS HAS ALSO SUGGESTED THERE COULD BE SOME FREEZING DRIZZLE
POTENTIAL AS THE FRONT MOVES IN FRIDAY NIGHT. HAVE NOT ADDED THAT TO
THE FORECAST YET...BUT WILL HAVE TO CONTINUE TO MONITOR FOR POTENTIAL
DEVELOPMENT.
FOR SATURDAY/SUNDAY...NORTHWEST FLOW PREVAILS WITH A COUPLE OF
WAVES MOVING THROUGH THE REGION. BACKED OFF CONSIDERABLY ON THE
SNOW CHANCES DURING THE DAY SATURDAY AS THE FIRST WAVE APPEARS TO
DAMPEN OUT QUITE A BIT WITH A HIGH PRESSURE RIDGE SETTLING SOUTH
OUT OF THE DAKOTAS...AND HAVE DOUBTS THAT SNOW CAN PENETRATE VERY
FAR INTO THE RIDGE LOOKS LIKE THE SECONDARY WAVE COULD HAVE SOME
POTENTIAL TO BRING SOME LIGHT SNOW TO THE AREA SATURDAY NIGHT AND
SUNDAY AS THE SURFACE RIDGE GETS PUSHED EAST...BUT IT DOESNT APPEAR
TO BE CAPABLE OF PRODUCING A LOT OF SNOW. AGAIN...GFS REMAINS
LIKELY TOO COLD THROUGH THE WEEKEND...SO USED A MODEL CONSENSUS
BLEND OF ALL AVAILABLE SOURCES FOR HIGHS/LOWS.
DEWALD
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. MODELS MAINTAIN AN
ACTIVE NWRLY FLOW ACROSS THE REGION IN THE EXTENDED PERIOD WITH
INTERMITTENT CLOUDS AND POTENTIAL FOR LIGHT SNOW. BEST CHANCE FOR
SNOW LOOKS TO BE AROUND MONDAY WITH SLIGHT CHANCE WEDNESDAY INTO
WEDNESDAY NIGHT AS A COUPLE OF COLD FRONTS SURGE THROUGH THE
REGION. TEMPERATURES STAY ON THE COLD SIDE WITH EXTENT AND
PERSISTENCE OF CLOUD COVER EXPECTED TO HAVE A LARGE IMPACT ON
TEMPS. NEW 12Z EURO SHOWING SPLIT FLOW DEVELOPING BY END OF THE
PERIOD AS UPPER LOW CUTS OFF NEAR BAJA WHILE WEAKER WAVES CONTINUE
TO RIPPLE THROUGH THE NORTHERN STREAM OVER THE NORTHERN PLAINS AND
UPPER MIDWEST.
FOBERT
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
NO SIGNIFICANT AVN CONCERNS THRU THIS FCST PD WITH MOSTLY VFR CIGS
GENERALLY FL050 AGL PREVAILING AFT 14/00Z. HAVE DECIDED THOUGH TO
ADD TEMPO GROUP FOR MVFR COND AT ALL TERMINALS BTWN 14/10-14Z.
APPEARS THAT SMALL LLVL POCKET OF COLD AIR WILL BE ENOUGH TO ALLOW
FOR SATURATION/CONDENSATION WITH CIGS FORMING AROUND FL015 AGL
DURING THAT TIME.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$