FXUS63 KOAX 270907
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
307 AM CST MON DEC 27 2010
.DISCUSSION...
QUIET AND CLEARER WEATHER IS FINALLY TAKING HOLD IN THE AREA.
SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES STUFF UPPER RIDGE
CENTERED STRAIGHT THROUGH THE CENTRAL PLAINS...WITH 500MB HEIGHT
FALLS UP TO 140M IN MT AS AN UPPER-LEVEL TROUGH IS ERODING THE
RIDGE. 850MB TEMPERATURE ADVECTION IS MAINLY STILL NEUTRAL...BUT
WARMER TEMPS LURK TO THE WEST...UP TO 10C IN WRN DAKOTAS/ERN MT. AS
SURFACE HIGH SLIDES EAST INTO TO MID-MS RIVER VALLEY...SFC LOW IS
DEVELOPING IN WRN ND...WITH SECONDARY LOW IN SERN CO.
MAIN FORECAST CONCERN IS ASSOCIATED WITH MID TO LATE WEEK
SYSTEM...WITH BENIGN WEATHER IN THE INTERIM AS PATTERN SHIFTS FROM
CENTRAL US RIDING TO A DEEPENING WRN US UPPER LOW. PERIODS OF
CLOUDS ARE STILL POSSIBLE TODAY AS A WEAK AND MOISTURE-STARVED FRONT
MOVES THROUGH THE REGION...BUT SHOULD SEE MORE SUN TODAY THAN
PREVIOUS FEW DAYS...AND TEMPS SHOULD RESPOND ACCORDINGLY. WINDS
WILL VEER AROUND TO SOUTHWESTERLY THROUGH TUESDAY...BEGINNING THE
MODERATING TREND THAT WILL CONTINUE THROUGH THURSDAY NIGHT. STRONG
WARM AIR ADVECTION AND ISENTROPIC LIFT BEGINS ON WEDNESDAY...THOUGH
STRONGER DYNAMICAL FORCING REMAINS WELL WEST. THINK A GOOD PART OF
THE MOISTURE ADVECTION AND LIFT ON WEDNESDAY WILL GO TOWARD
INCREASING CLOUDINESS...BUT TEMPS SHOULD MODERATE WELL INTO THE 40S
DESPITE CLOUDS GIVEN STRONG WARM PUSH.
UPPER LOW BEGINS TO EJECT INTO THE PLAINS ON WEDNESDAY
NIGHT/THURSDAY...INCREASING THE POTENTIAL FOR MEASURABLE PRECIP.
HAVE INCLUDED LITTLE TEMPERATURE FALL-OFF ON WEDNESDAY NIGHT AS WARM
AIR ADVECTION CONTINUES AND LOW-LEVEL MOISTURE INCREASES...WITH
COVERAGE OF RAIN INCREASING THROUGH WEDNESDAY NIGHT. FIRST SIGNS OF
DRY SLOTTING BEGIN TO POKE IN THE SRN CWA AS EARLY AS THURSDAY...AND
HAVE LOWERED POPS DURING THE DAY. PRECIP IS PROGGED TO RETURN AS
THE SHARP ARCTIC COLD FRONT SURGES THROUGH THE CWA THURSDAY
NIGHT/FRIDAY. GFS UPPER LOW TRACK IS SOUTH AND EAST OF ECMWF...AND
HAVE LEANED TOWARD MORE CONSISTENT ECMWF SOLUTION FOR FRONT TIMING
AND TEMPERATURE PROFILE. COLD AIR SWEEPS IN FAIRLY QUICKLY...AND
WHILE A QUICK MIX OF RA/FZRA/SN IS POSSIBLE DURING THE
TRANSITION...THINK ICING POTENTIAL IS ON THE LOWER END WITH SUCH A
RAPID COLD AIR PUSH. DID MENTION MIX OF ALL THREE ON THURSDAY
NIGHT...BUT JUST SN OR RA/SN ON FRIDAY AS FRONT CONTINUES ITS
PUSH. TEMPS WILL CERTAINLY DROP THROUGH THE DAY FRIDAY AS THE
FRONT MOVES THROUGH...WITH 850MB TEMPS FALLING FROM AROUND 10C TO
AROUND -20C IN 24 HRS...AND HAVE HELD MAX TEMPS FRIDAY TO
ESSENTIALLY THE SAME VALUES AS MIN TEMPS ON THURSDAY NIGHT. AFTER
THE FRONT MOVES THROUGH...DRY ARCTIC AIR MOVES IN RAPIDLY AS THE
DEEPENING LOW PULLS NORTHEASTWARD..LEAVING THE CWA IN A DISTINCT
DRY SLOT. HAVE SCALED BACK POPS QUITE A BIT ON FRIDAY NIGHT...AND
COULD SEE PULLING THEM ALTOGETHER. SYSTEM WILL LEAVE A SHARPLY
COLDER AIRMASS BEHIND IN THE CNTRL PLAINS. COULD SEE SOME WIND AND
CLOUDS ON SATURDAY NIGHT THAT WOULD PREVENT A TEMPERATURE
CRASH...BUT WITH SUCH A STRONG ARCTIC PUSH...WAS NOT COMFORTABLE
LEAVING MIN TEMPS AROUND 10 DEGREES ABOVE GUIDANCE...AND HAVE
SLASHED THEM TO JUST A COUPLE OF DEGREES ABOVE FOR NOW.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
TERMINALS WILL BE HIGHLY VARIABLE THIS MRNG AS ALL 3 SITES ARE ON
THE WRN EDGE OF AN EXPANSIVE STRATUS AND FOG DECK. THIS IS MOST
LIKELY TO MOV INTO THE OMA TERMINAL BEFORE MRNG /ARND 9-10Z/ WITH
LIFR TO IFR CIGS AND VISBY CONDS INTO MID MRNG BEFORE MIXING CLEARS
OUT THE LO LVL RH. THE DECK MAY ALSO MOV AS FAR WWD AS LNK AND OFK
WITH SIMILAR CONDS...BUT GIVEN THE FARTHER WEST LOCATION...IT
APPEARS A LITTLE LESS LIKELY THAN OMA. OTHERWISE...ONCE MRNG CONDS
CLEAR...VFR CONDS ARE THEN EXPECTED THRU THE REST OF THE TAF CYCLE
WITH LO LVL SRLY FLOW INCREASING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MAYES/BOUSTEAD