Freeze Warning 27, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
207 PM PST SAT DEC 3 2011

.SHORT TERM...THE LONGWAVE PATTERN WILL HARDLY CHANGE AT ALL
THROUGH THE SHORT TERM WITH A BIG RIDGE REMAINING PARKED OVER THE
NORTHEAST PACIFIC AND DRY NORTHERLY FLOW ALOFT OVER THE WEST COAST
THROUGH TUESDAY. IN A NUTSHELL, THIS MEANS THAT WHAT WE HAVE IN
MOST LOCATIONS TODAY WILL BE WHAT WE GET OVER THE NEXT SEVERAL
DAYS, AT LEAST.

STRATUS AND FOG HAS ERODED FROM THE WESTERN VALLEYS SOMEWHAT THIS
AFTERNOON, BUT THE UPPER ROGUE AND THE UMPQUA FROM ROSEBURG NORTH
REMAIN SOCKED IN. WE HAVE REACHED PEAK SUN, SO FOG AND STRATUS
WILL START TO FILL IN AGAIN. I CAN'T FIND ANYTHING TO DISRUPT THIS
PATTERN THROUGH WEDNESDAY AT LEAST AND THUS HAVE EXTENDED THE AIR
STAGNATION ADVISORY THROUGH WEDNESDAY. FOR TONIGHT, I EXPECT A
REPEAT OF LAST NIGHT WHICH MEANS STRATUS/FG IN THE INLAND WEST
SIDE VALLEYS. WE WILL ALSO SEE SUB-FREEZING LOWS OVER PARTS OF
COOS COUNTY AND THUS I UPGRADED THE FREEZE WATCH TO A WARNING FOR
LATE TONIGHT AND TOMORROW MORNING.

THERE WILL BE A FEW DISTURBANCES TOPPING THE RIDGE, BUT RIGHT NOW
NONE OF THEM LOOKS SIGNFICANT ENOUGH TO CLEAR OUT THE STRATUS. THE
FIRST SUCH SHORT WAVE WILL PUSH INTO THE NORTHERN ROCKIES TONIGHT
AND DIG INTO THE CENTRAL ROCKIES AND EASTERN GREAT BASIN TOMORROW.
IT IS FAR ENOUGH EAST TO HAVE LITTLE EFFECT WEST OF THE CASCADES,
BUT IT WILL BRING COLDER AIR TO THE EAST SIDE AND REINFORCE THE
GRADIENT TO KEEP THINGS MIXED THERE. THIS COLDER AIR WILL FILTER
INTO THE WEST SIDE AS WELL. THE MODELS ARE COLD SUNDAY NIGHT ON
THE EAST SIDE WITH LOWS IN THE LOWER TEENS AND EVEN SOME SINGLE
DIGITS. WE COULD SEE PRETTY COLD TEMPERATURES ON THE WEST SIDE,
AND IN FACT THE GFS MOS SHOWS LOWS IN THE UPPER TEENS IN MEDFORD
MONDAY MORNING. HAVE NOT GONE THAT COLD, BUT DID LOWER TEMPS
ACROSS THE BOARD FOR SUNDAY NIGHT. THAT SAID, I ALSO OPTED TO GO
STRAIGHT TO A FREEZE WARNING FOR PORTIONS OF COOS COUNTY SUNDAY
NIGHT AND MONDAY MORNING. I ALSO ADJUSTED CLOUDS AND TEMPERATURES
TO ACCOUNT FOR MORE PERSISTENT FOG AND STRATUS ON THE WEST SIDE
THROUGH TUESDAY. -WRIGHT

.LONG TERM...THE OPERATIONAL MODELS REMAIN IN FAIRLY GOOD AGREEMENT
FROM NEXT WEDNESDAY INTO NEXT WEEKEND. THE OMEGA BLOCK WILL REMAIN
IN PLACE WHICH MEANS MUCH OF THE SAME WITH COLD MORNINGS AND COOL
AFTERNOONS IN THE VALLEYS AND MILDER OVER THE RIDGETOPS. THE CONCERN
IS THAT WE COULD CONTINUE TO HAVE FREEZING FOG IN THE WESTSIDE
VALLEYS IN THE EVENING INTO MOST OF THE MORNING HOURS. THE EC AND
GFS SHOW A SHORTWAVE MOVING IN FROM THE NORTH EARLY THURSDAY MORNING
WHICH MAY BE STRONG ENOUGH TO MIX THINGS OUT. THERE ARE SOME
INDICATIONS THAT THE OVERALL PATTERN WILL NOT CHANGE MUCH FOR THE
NEXT 7 TO 10 DAYS. MAP

&&

.AVIATION...THE MAIN IMPACT WILL BE FREEZING FOG IN THE ROGUE AND
ILLINOIS VALLEY AND UMPQUA BASIN AGAIN LATER THIS EVENING THROUGH
SUNDAY MORNING. THE LOW CLOUDS AND FOG CONTINUE TO HANG TOUGH IN
THE ROGUE VALLEY. CONFIDENCE IS HIGH THAT CIGS/VIS REMAIN IFR AT
KMFR THROUGH THIS EVENING. THE FOG MAY LIFT TO A LOW OVERCAST FOR A
FEW HOURS LATE THIS AFTERNOON INTO EARLY EVENING...THEN FOG AND LOW
CIGS RETURN EARLY THIS EVENING AND LASTING THROUGH SUNDAY MORNING.
MEANWHILE...THERE IS A CHANCE FOR VFR CONDITIONS TO DEVELOP FOR A
COUPLE OF HOURS AT KRBG...BUT MOST LIKELY FOG AND LOW CLOUDS WILL
RE DEVELOP AGAIN BETWEEN 3-4Z. ELSEWHERE SKIES SHOULD REMAIN CLEAR
WITH VFR CONDITIONS PREVAILING. MAP

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZE WARNING FROM 2 AM TO 8 AM PST SUNDAY FOR ORZ021.
     FREEZE WARNING FROM 2 AM TO 8 AM PST MONDAY FOR ORZ021.
     AIR STAGNATION ADVISORY UNTIL 4 PM PST WEDNESDAY FOR
     ORZ023-024-026.

CA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
     FOR PZZ356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
     FOR PZZ350.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY
     FOR PZZ370.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST MONDAY FOR PZZ376.
     HAZARDOUS SEAS WARNING UNTIL 10 PM PST SUNDAY FOR PZZ376.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MEDFORD OR
216 PM PST SAT DEC 3 2011

ORZ023-024-026-041615-
CENTRAL DOUGLAS COUNTY-EASTERN CURRY COUNTY AND JOSEPHINE COUNTY-
JACKSON COUNTY-
216 PM PST SAT DEC 3 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
OREGON.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THE AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST
WEDNESDAY. PLEASE SEE THE LATEST WEATHER MESSAGE FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST
WEDNESDAY. NO OTHER SIGNIFICANT WEATHER IS EXPECTED DURING THIS
PERIOD.

.SPOTTER INFORMATION STATEMENT...

NO SPOTTER ACTIVATION WILL BE NECESSARY.

ORZ021-041615-
SOUTH CENTRAL OREGON COAST-
216 PM PST SAT DEC 3 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
OREGON.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A FREEZE WARNING HAS BEEN ISSUED EFFECTIVE FROM 2 AM TONIGHT UNTIL 8
AM PST SUNDAY. PLEASE SEE THE LATEST WARNING MESSAGE FOR FURTHER
DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM PST SUNDAY. A
FREEZE WARNING WILL ALSO BE IN EFFECT FROM 2 AM TO 8 AM PST MONDAY
MORNING. THE CLEAR AND COLD PATTERN WILL CONTINUE UNTIL AT LEAST
MID WEEK.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

MSO