Damaging Wind in Oregon, May 29, 2003

SOUTHWEST OREGON AND NORTHERN CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD, OR
135 PM PDT THU MAY 29 2003

PRIMARY FORECAST FOCUS IS ON THE CONVECTION DEVELOPING ACROSS
NORTHERN CALIFORNIA. AT 2030Z A LIGHTNING STRIKE WAS DETECTED SOUTH
OF SUSANVILLE. IN THE SHORT TERM...THE DURATION...LOCATION...AND
STRENGTH OF THE RESULTING THUNDERSTORMS WILL BE THE FORECAST
CHALLENGE.

CLASSIC NEGATIVELY TILTED UPPER LOW WITH STRONG JET LEVEL WINDS AND
DIFFLUENCE WILL DRIVE THE CONVECTION TONIGHT. AN 80 KNOT 250 MB JET
EXTENDING FROM NORTHERN CALIFORNIA INTO THE CASCADES WILL SHIFT
SLOWLY EAST OVERNIGHT. THE JET WILL EXIT THE EAST SIDE SHORTLY AFTER
12Z FRIDAY. SURFACE DEWPOINTS MAINLY RANGED FROM 50 TO 55 F AT THIS
TIME AND THERE WAS SUFFICIENT INSTABILITY ONCE THE CAP IS BROKEN BY
LATE AFTERNOON. MID LEVEL STEERING FLOW SHOULD BE NEARLY DUE NORTH
OVERNIGHT...A GOOD DIRECTION TO BRING STORMS INTO THE WESTERN
VALLEYS OF OREGON. EXPECT CIRRUS AND MARINE AIR TO KEEP THE COAST
FREE OF THUNDERSTORMS.

ISOLATED SEVERE STORMS POSSIBLE ESPECIALLY MOUNT SHASTA AREA NORTH
TO THE CASCADES AND EAST OF THIS AREA THIS EVENING AS THE GREATEST
INSTABILITY AND STRONGEST JET ENERGY COINCIDE. THE PRIMARY SHORT
WAVE MOVING ACROSS NORTHERN CALIFORNIA OVERNIGHT WILL SUPPORT
CONTINUED THUNDERSTORMS INTO FRIDAY MORNING.

THUNDERSTORM POSSIBILITIES ON FRIDAY ARE MORE MURKY. THE SHORT WAVE
PASSAGE WILL END THE THUNDERSTORM CHANCE ON FRIDAY. THE ETA SHOWS
THIS WAVE EXITING OUR EAST SIDE BY 00Z SATURDAY. HOWEVER...WILL
HEDGE A BIT WITH SLOWER TIMING BASED ON THE AVN AND KEEP A CHANCE OF
THUNDERSTORMS ON THE EAST SIDE THROUGH THE AFTERNOON.

THE REST OF THE FORECAST IS RELATIVELY SIMPLE WITH DRY CONDITIONS
AND A WARMING TREND. COULD SEE A GOOD MARINE PUSH FRIDAY NIGHT AND
THEN MARINE AIR AGAIN INTO THE UMPQUA SATURDAY NIGHT. AFTERWARD...
THE MARINE LAYER SHOULD BECOME MUCH MORE SHALLOW WITH OFFSHORE FLOW
DEVELOPING AS THE THERMAL TROUGH EXPANDS NORTH.

.MFR...SMALL CRAFT ADVISORY PT. ST. GEORGE, CA TO CAPE BLANCO, OR.

SANDLER

ORZ021>031-CAZ080>085-301330-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MEDFORD OR
630 AM PDT THU MAY 29 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN OREGON AND
NORTHERN CALIFORNIA

.DAY ONE...TODAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

JACOBS

CAZ080>085-ORZ024-026>031-300600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MEDFORD OR
558 PM PDT THU MAY 29 2003

...A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED UNTIL 11 PM PDT
FOR PORTIONS OF SOUTHERN OREGON AND NORTHERN CALIFORNIA...

THE STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH
UNTIL 11 PM PDT FOR A PORTION OF SOUTHERN OREGON AND NORTHERN
CALIFORNIA. THIS WATCH IS IN EFFECT UNTIL 11 PM PDT AND INCLUDES
THE FOLLOWING COUNTIES IN SOUTHERN OREGON:

JOSEPHINE...JACKSON...KLAMATH AND LAKE

THE WATCH INCLUDES THE FOLLOWING COUNTIES IN NORTHERN CALIFORNIA:

SISKIYOU AND MODOC

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 55
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS THIS
EVENING.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

IF SEVERE WEATHER IS OBSERVED IN YOUR AREA...PLEASE CONTACT THE
NATIONAL WEATHER SERVICE IN MEDFORD...OR YOUR LOCAL LAW ENFORCEMENT.

STAVISH