400
FXUS63 KGLD 071733
AFDGLD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
1033 AM MST SAT NOV 7 2009
DISCUSSION
223 AM MST SAT NOV 7 2009
MAIN FORECAST PROBLEM WILL BE CHANCE OF PRECIPITATION SUNDAY NIGHT
INTO MONDAY FOLLOWED BY HOW MUCH TO COOL MAXES OFF THE NEXT THREE
DAYS...ESPECIALLY ON MONDAY. SATELLITE SHOWING THAT MID/UPPER RIDGE
THAT WAS OVER OUR AREA HAS BEEN FLATTENED AND PUSHED EAST. FAST
WESTERLY FLOW IS IN PLACE FROM THE CENTRAL PACIFIC INTO THE CENTRAL
PORTION OF THE COUNTRY. ONE STRONG SHORTWAVE TROUGH PUSHING ACROSS
SOUTH CENTRAL CANADA WITH ANOTHER ONE MOVING INTO THE PACIFIC
NORTHWEST. AS OF 06Z COLD FRONT HAS PUSHED INTO NORTHERN WYOMING
AND THROUGH MOST OF SOUTH DAKOTA.
AT JET LEVEL...MODELS INITIALIZED WELL ON THE STRONG JET SEGMENT
ACROSS THE NORTHWEST AND NORTH CENTRAL PORTION OF THE COUNTRY. AT MID
LEVELS...MODELS INITIALIZED WELL AGAIN. AT LOW LEVELS...MODELS
HAVING A REALLY BAD TIME IN DEPICTING SURFACE WIND/PRESSURE FIELD IN
ADVANCE OF THE FRONT. THEY ALSO APPEAR TO BE A LITTLE TOO FAR SOUTH
WITH THE FRONT. OVERALL THE ECMWF DID THE BEST. THE UKMET AND ECMWF
ARE HANDLING THE LOW LEVEL TEMPERATURE FIELD THE BEST. CONSIDERING
WHAT THE ANALYSIS IS SHOWING...WILL BE BASING THIS FORECAST MOSTLY
ON THE ECMWF.
TODAY/TONIGHT...A WEAK PIECE OF THE UPPER JET STARTS OVER THE
NORTHWEST PORTION OF THE FORECAST AREA AND THEN QUICKLY MOVES AWAY.
THIS MAY BRING SOME CLOUDS EARLY ON. OTHERWISE MAIN JET AXIS
REMAINS WELL NORTH OF THE AREA. NOT SURE HOW COOLING WILL RECEIVE
TODAY. SERIES OF PREFRONTAL TROUGHS IN ADVANCE OF FRONT. MAIN
COOLING INITIALLY MAY BE JUST BECAUSE OF THE UNFAVORABLE SURFACE
WIND DIRECTION. MSAS 3 HOUR PRESSURE CHANGE ANALYSIS INDICATES THAT
MOST OF THE BIGGER PRESSURE RISES ARE STAYING WELL NORTH AND ARE
MOVING MORE WEST TO EAST. ALSO FLOW ALOFT REMAINS RATHER STRONG
FROM WEST TO SOUTHWEST WHICH WILL SERVE ENHANCE THE LEE TROUGH.
SO A SLOWER ARRIVAL OF THE FRONT/MAIN COOLING LOOKS TO BE THE WAY TO
GO. EVEN DESPITE THAT...NUMERICAL GUIDANCE LOOKS WARM. INTERESTING
LOW TEMPERATURE FORECAST. WHATEVER BOUNDARY PUSHES THROUGH TODAY...
LIFTS BACK TO THE NORTH INITIALLY AND THEN SURGES BACK SOUTH LATE IN
THE NIGHT. DOWNSLOPE WINDS SHOULD KEEP WARM...ESPECIALLY IN THE
SOUTHEAST HALF.
SUNDAY...THE SOUTHWEST HALF OF THE AREA WILL NOT SEE THE FRONT MOVE
THROUGH UNTIL 18Z AND AFTER. THERE IS INDICATIONS THERE COULD BE A
LOT OF HIGH LEVEL CLOUD COVER...THICKEST IN THE AFTERNOON. COOLED
OFF THE NORTHWEST HALF AND WARMED UP THE SOUTHEAST PORTION. TENDED
TO STAY BELOW GUIDANCE WHICH WAS THE 2 METER.
SUNDAY NIGHT/MONDAY...THE NAM AND UKMET ARE MORE AMPLIFIED WITH THE
INCOMING TROUGH AND FURTHER SOUTH WITH THE MAIN JET AXIS MOVING INTO
THE AREA ON SUNDAY NIGHT...WITH THE UKMET FURTHEST SOUTH. THE GFS IS
MORE LIKE THOSE TWO MODELS BUT IS FURTHER NORTH WITH THE ECMWF
FURTHEST NORTH. THE NAM PUTS AREA IN LEFT FRONT QUADRANT WITH
POSSIBLE COUPLED RIGHT REAR QUADRANT OF THE NORTHERN JET. THE GFS HAS
THE AREA IN A RIGHT REAR QUADRANT LATE IN THE NIGHT.
THIS SAME TREND CONTINUES THROUGH THE DAY. THE NAM AND GFS KEEP THE
AREA IN A LEFT FRONT QUADRANT OF THE JET...WHICH IS NOT TOO STRONG...
THROUGH MOST OF THE DAY. THE UKMET AND ESPECIALLY THE ECMWF KEEP THE
MAIN JET LIFT WELL NORTH. CONSIDERING THE PROGRESSIVE FLOW ALOFT
LIKE THE FLATTER FURTHER NORTH SOLUTIONS. UPPER AIR ANALYSIS
INDICATES A DRY AIR MASS UPSTREAM AT MID LEVELS AND CONSIDERING THE
FLOW ALOFT...WHAT MOISTURE THERE IS WILL GET RUNG OUT BY THE
MOUNTAINS. ALSO A SERIES OF SURFACE TROUGHS/FRONTS AND RESULTING
SURFACE WIND FLOW WILL ALLOW FOR LITTLE IF ANY LOW LEVEL MOISTURE
RETURN. FORECAST POINT SOUNDINGS WOULD CONFIRM WHAT REALITY IS NOW
INDICATING. SO REDUCED POPS ACROSS THE BOARD...ESPECIALLY ON
MONDAY...AND ADDED SPRINKLES. THE BEST LIFT...AVAILABLE MOISTURE...
AND QPF FAVOR THE NORTHERN PORTION OF THE AREA...AND CONFIGURED THE
POPS THAT WAY. IF CANADIAN VERIFIES WILL RECEIVE NO PRECIPITATION.
NO MATTER HOW MUCH PRECIPITATION OCCURS...LOOK TO HAVE THICK CLOUD
COVER AND NORTH TO NORTHEAST WINDS. MAXES FROM NEAR 50 TO MAYBE 55
LOOK TO BE REASONABLE.
MONDAY NIGHT...CLOUDS WILL CLEAR AND WINDS WILL BECOME LIGHT...
ESPECIALLY IN THE EAST HALF. THAT SUPPORTS GOING TOWARD THE COOLER
GUIDANCE.
NO CHANGES PLANNED BEYOND THIS PERIOD. THANKS TO ALL FOR
COLLABORATION
BULLER
AVIATION
1027 AM MST SAT NOV 7 2009
FOR THE 18Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGHOUT THE VALID
PERIOD. WINDS WILL UNDERGO A GRADUAL SHIFT THROUGH THE PERIOD...LIGHT
FROM THE EAST/SOUTHEAST THIS AFTERNOON TO SOUTHWEST DURING THE OVERNIGHT
HOURS...BEFORE BECOMING NORTH/NORTHWESTERLY AROUND THE 15G20KT RANGE
AFTER ABOUT 15Z SUNDAY MORNING BEHIND A SURFACE COLD FRONT PASSAGE.
50
GLD WATCHES/WARNINGS/ADVISORIES
KS...NONE.
NE...NONE.
CO...NONE.
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