FXUS63 KEAX 031130
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
530 AM CST THU DEC 3 2009

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...
COLDER AIR CONTINUES TO SURGE SOUTHEAST WITH THE AID OF BRISK NW WINDS.
HAVE TRENDED A LITTLE BELOW FOR TEMP GUIDANCE TODAY GIVEN TEMPS AND
CLOUD COVER UPSTREAM. THE CLOUD COVER SPREADING SOUTH INTO NRN
NEBRASKA WILL SHIFT SOUTH INTO THE CWFA...ESP THE NRN GRIDS TODAY.
FCST SOUNDINGS SUGGEST THAT THERE IS SUFFICIENT DEEP OF SC LAYER FOR
THE DEVELOPMENT OF FLURRIES FOR NRN MO. IN ADDITIONS THERE IS A SHALLOW
LAYER OF VERY WEAK INSTABILITY WITHIN THE SC LAYER. THE UPPER LEVEL
LOW/UPR TROUGH AXIS WILL BEGIN TO SHEAR NE WITH THE SC LAYER
GRADUALLY LIFTING TO THE NE. HOWEVER...WL HOLD A FEW FLURRIES FOR
EXTREME NRN MO FOR TONIGHT. OTHERWISE...CHILLY TEMPS ARE EXPECTED
THROUGH FRIDAY...BEFORE TEMPS BEGIN TO RISE ON SATURDAY.

IN THE EXTENDED...HAVE MADE COLLABORATED CHANGES IN THE EXTENDED AS
THE MODELS HAVE BEEN RELATIVELY CONSISTENT IN SHOWING THE POTENTIAL
FOR WINTRY PRECIP FOR SUNDAY AND TUESDAY. THE ECMWF/GFS AND UKMET
CONTINUE TO INDICATE THAT A DEEP TROUGH WILL DROP SOUTH INTO THE WRN
US WITH A STG AND COLD SFC HIGH BUILDING OVER WRN CANADA EARLY THIS
WEEKEND. A PORTION OF THE UPPER TROUGH WILL SHEAR ENE INTO THE
CENTRAL PLAINS ON SUNDAY WITH THE TRACK SUGGESTING THE POTENTIAL FOR
A BAND OF LIGHT SNOW...MAINLY FOR NRN MO. GIVEN THE LACK OF
SIGNIFICANT MOISTURE...SNOW AMOUNTS APPEAR TO BE LIGHT.

OF MORE CONCERN IS THE POTENTIAL FOR A MORE SIGNIFICANT WINTER
WEATHER EVENT FOR TUESDAY. ONCE THE SHORTWAVE PASSES ON SUNDAY...THE
COLD SFC RIDGE WILL BUILD SOUTH INTO KANSAS AND MISSOURI.
THEREFORE...A COLD AIR MASS WILL BE FIRMLY IN PLACE BEFORE THE
ARRIVAL OF THE UPPER SYSTEM TO PROGRESS ACROSS THE SRN AND CNTRL
PLAINS ON TUESDAY. ALTHOUGH THIS SYSTEM IS STILL FIVE DAYS AWAY...MODELS
HAVE BEEN AMAZINGLY SIMILAR THE LAST COUPLE OF DAYS. ABUNDANT DEEP
TROPOSPHERIC MOISTURE ALONG WITH AN EXTENDED PERIOD OF ISENTROPIC
LIFT COULD PRODUCE SIGNIFICANT AMOUNTS OF SNOW. WOULD NOT BE
SURPRISED IF THE UPPER SYSTEM BECOMES STGR ON FUTURE RUNS GIVEN THE
STG BAROCLINIC ENVIRONMENT IN OKLAHOMA AND ARK. HAVE DOUBTS ABOUT THE
MODELS TRYING TO KEEP THE SRN BRANCH SYSTEM IN PHASE WITH THE NRN
BRANCH. THIS IS A TYPICAL MODEL ERROR THIS FAR IN THE FUTURE. THE
CANADIAN MODEL MAY BE THE BETTER MODEL AT THIS TIME AS IT SHOWS A
CONSIDERABLY STGR SRN SOLUTION. THE STGR SOLUTION MAY ALSO SUGGEST
THAT THE SYSTEM MAY BE SLOWER TO SHIFT ENE.

AT THIS TIME...HAVE BUMPED POPS A LITTLE FOR SUNDAY AND TUESDAY AND
LOWERED TEMPS A CATEGORY FOR SUNDAY THROUGH WEDNESDAY. WILL BEGIN TO
ADVERTISE THE WINTER EVENTS IN THE MORNING HWO. 

DB

&&

.AVIATION...

FOR THE 12Z TAFS...VFR CONDITIONS WILL PREVAIL AT THE TERMINALS OVER
THE NEXT 24 HOURS ALONG WITH GUSTY NORTHWEST WINDS. CLOUDS TO THE
NORTHWEST WILL ADVECT IN...ESPECIALLY ACROSS THE KSTJ TERMINAL...BUT
ANY CEILINGS FROM THESE CLOUDS ARE EXPECTED TO STAY AT OR ABOVE 4000
FT. PRESSURE GRADIENT WILL RELAX AS THE SUN SETS THIS EVENING AND
WINDS WILL START TO BACK TO THE WEST.

CUTTER

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

$$