SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
AFDLOX 300 AM PST SUN MAR 14 2004
.SHORT TERM...
MARINE LAYER PROBLEMS PERSIST. MDLS REMAIN STYMIED AND EVEN THE 06Z
ETA MISSES 95 PERCENT OF THE MARINE LAYER THAT IS ALREADY IN PLACE.
THIS DOES NOT BODE WELL FOR FUTURE FORECASTS. ACARS SHOWS MARINE LAYER
SQUASHED ABOUT 1000 FEET OVER THE LAST 18 HOURS AND THIS TREND SHOULD
CONTINUE AS HIGH PRESSURE BUILDS IN ALOFT. THIS SHOULD KEEP THE CLOUDS
OUT OF THE VALLEYS. NEW ETA LIKES THE IDEA OF A MORE ROBUST MARINE
LAYER MONDAY AND THIS MAKES MORE SENSE AS THERE JUST ARE NOT MANY
MECHANISMS IN PLACE TO CLEAR THE MARINE LAYER. A LITTLE NORTH FLOW MAY
KEEP IT AWAY FROM SBA S CST. SO WILL ADD SOME CLOUDS TO CENTRAL COAST
AND VTA COUNTY. CLEARING SHOULD BE BETTER AND TEMPS WILL WARM ESP IN
THE VLYS. MONDAY NIGHT AND TUE WILL ONLY KEEP MENTION OF CLOUDS IN
L.A. COAST AS MDLS SHOULD OFFSHORE FLOW SETTING UP ELSEWHERE.
.LONG TERM...
VERY STATIC PATTERN THROUGH NEXT SUNDAY WITH ERN PAC HIGH PRESSURE IN
CONTROL. GFS A LITTLE MORE AGRESSIVE WITH MORNING OFFSHORE FLOW EACH
DAY THROUGH FRIDAY. HGTS AND THKNS DELTAS ARE SMALL SO SEE LITTLE
REASON TO CHANGE TEMPS MUCH OR INTRODUCE A MARINE LAYER. THE LATE WEEK
COOL DOWN IS NO LONGER ADVERTISED SO BUMPED UP FRIDAY AND SATURDAYS
TEMPS TO THURSDAY LEVELS.
IF ...A BIG IF... ONE IS TO BELIVE THE GFS IT WILL RAIN ON DAY TEN AS
RIDGE BREAKS DOWN TO MORE OF A ZONAL FLOW AND SAGS STORM TRACK OVER
CENTRAL CA.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
RORKE
AREA FORECAST DISCUSSION
NWS MISSOULA MT
AFDMSO 905 AM MST SUN MAR 14 2004
.UPDATE...MINOR TIMING UPDATES TO IDAHO ZONE FORECAST...NO CHANGES
NEEDED TO STATE PRODUCT. SKIES ARE OVERCAST OVER MOST OF THE AREA
THIS MORNING...BUT PRECIPITATION HAS GENERALLY NOT STARTED YET.
STRONG JET MAXIMA IS CURRENTLY OVER WESTERN WASHINGTON AND SHOULD
START MOVING INTO IDAHO AND WESTERN MONTANA LATE THIS MORNING. IN
ADDITION...AIRCRAFT OBSERVATIONS AT JET LEVEL INDICATE THAT WINDS ARE
ABOUT 20-30 KNOTS STRONGER THAN MODELS INDICATE. FINALLY...ISENTROPIC
LIFT INDICATED OVER THE CLEARWATERS THIS AFTERNOON. SO AREAS OF RAIN
& SNOW DEVELOPING THIS AFTERNOON LOOKS GOOD AT THIS POINT...
PARTICULARLY OVER CENTRAL MOUNTAINS OF IDAHO AND BITTERROOT MOUNTAINS
IN MONTANA.
&&
.PREVIOUS DISCUSSION...TODAY THROUGH TUESDAY...NORTHWEST FLOW WILL
CONTINUE THROUGH TUESDAY AS A WEAK RIDGE REMAINS ALONG THE WEST
COAST. A SHORTWAVE WILL MOVE ACROSS THE INTERMOUNTAIN WEST TODAY.
BEST CHANCE OF PRECIPITATION WITH THIS SHORTWAVE WILL BE ACROSS NORTH
CENTRAL IDAHO AND THE BITTERROOT MOUNTAINS LATER THIS MORNING AND
THROUGH THE AFTERNOON. THE SHORTWAVE QUICKLY MOVES OUT OF THE AREA
SUNDAY NIGHT. VERY WEAK DISTURBANCES WILL CONTINUE TO EFFECT
NORTHWEST MONTANA THROUGH TUESDAY. GIVEN THE NORTHWEST FLOW AND
STRONGER JET MAXIMA MOVING INTO THE AREA MONDAY INTO TUESDAY THE
PRECIPITATION WILL BE CONFINED TO MAINLY THE MOUNTAINS. HAVE LOWERED
PROBABILITY OF PRECIPITATION ACROSS THE VALLEYS OF IDAHO AND EXTREME
NORTHWEST MONTANA TO ACCOUNT FOR THIS. TEMPERATURES WILL REMAIN AT
NORMAL THROUGH THE PERIOD.
TUESDAY NIGHT THROUGH SATURDAY...MODELS ARE STARTING TO TREND BACK TO
THE SOLUTION THAT EARLIER RUNS HAD. A STRONGER RIDGE OFF OF THE
PACIFIC COAST PRODUCING A NORTHWEST UPPER LEVEL FLOW FOR WESTERN
MONTANA...WITH THE JET BEING PUSHES A LITTLE FURTHER NORTH. THIS
PATTERN IS A LITTLE BETTER FOR PRODUCING OROGRAPHIC SHOWERS ACROSS
THE MOUNTAINS OF NORTHWEST MONTANA. WHICH IS WHERE WE ALREADY HAD THE
HIGHEST POPS FOR THE PERIOD...WILL TREND POPS DOWN ACROSS THE REST OF
THE FORECAST AREA...BUT STILL HOLD ON TO AT LEAST SOME SLIGHT CHANCES
THROUGH THE PERIOD...AS WEAK DISTURBANCES ARE STILL MOVING ACROSS THE
AREA EACH DAY. &&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
ID...NONE.
&&
$$
UPDATE/MWJ
PREVIOUS DISCUSSION/KOCH/KOLATA