Frost Advisory 11, NWS Medford, OR

236 
WWUS76 KMFR 070910
NPWMFR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MEDFORD OR
210 AM PDT SAT APR 7 2012

...ANOTHER NIGHT OF COLD TEMPERATURES WILL BRING FROST TO NORTH
   BEND AND AREAS JUST INLAND FROM THE IMMEDIATE COAST...

ORZ021-022-071500-
/O.CON.KMFR.FR.Y.0011.000000T0000Z-120407T1500Z/
SOUTH CENTRAL OREGON COAST-CURRY COUNTY COAST-
INCLUDING THE CITIES OF...COOS BAY...NORTH BEND...COQUILLE
210 AM PDT SAT APR 7 2012

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

A FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING. 

* LOW TEMPERATURES...33 TO 38.

* TEMPERATURE INVERSION...AN INVERSION IS EXPECTED...AND WARMER 
  AIR WILL EXIST ABOVE THE SURFACE.

* LOCATIONS INCLUDE: COOS BAY...NORTH BEND...COQUILLE.

* IMPACTS...SENSITIVE VEGETATION MAY BE DAMAGED IN COLD
  TEMPERATURES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$

STOCKTON

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
847 AM PDT FRI APR 6 2012

.DISCUSSION...A COUPLE DRY AND PARTLY SUNNY DAYS ARE EXPECTED THE
NEXT COUPLE DAYS. A GENERAL WARMING TREND WILL BRING HIGH
TEMPERATURES INTO THE 50S ON THE WEST SIDE TODAY...THEN THE 60S ON
SATURDAY. HIGH TEMPERATURES ON THE EAST SIDE WILL GENERALLY BE 40S
ON THE EAST SIDE TODAY AND 50S TOMORROW. TONIGHT...TEMPERATURES
WILL LIKELY DROP INTO THE 30S IN WEST SIDE VALLEYS...BUT A WARMING
OF THE AIR MASS AND INCREASING HIGH CLOUDS OVERNIGHT SHOULD PREVENT
TEMPERATURES FROM REACHING CRITICAL READINGS THAT IMPACT LOCAL
AGRICULTURE.

RAIN CHANCES ARE NOT A BIG PART OF THE FORECAST UNTIL SATURDAY
NIGHT WHEN AN OFFSHORE UPPER LOW WILL GENERATE SOME SHOWERS ALONG
THE COAST. EASTER MORNING RAIN CHANCES WILL BE PRIMARILY OVER
NORTHERN CALIFORNIA...THE COAST...AND THE CASCADES. WEST SIDE
VALLEYS SHOULD BE PARTLY TO MOSTLY CLOUDY BUT DRY.

PLEASE SEE PREVIOUS DISCUSSION BELOW FOR MORE DETAILS ON THE
FORECAST FOR NEXT WEEK.

&&

.AVIATION...MORNING IFR AND MVFR CEILINGS IN PLACES LIKE ROSEBURG
AND KLAMATH FALLS WILL LIFT TO VFR EARLY THIS AFTERNOON...WITH SOME
LINGERING LOW CLOUDS EAST OF THE CASCADES THROUGH LATE THIS
AFTERNOON. MOUNTAIN OBSCURATION WILL AFFECT THE FORECAST AREA
THROUGH EARLY AFTERNOON. TONIGHT...CONDITIONS SHOULD BE MAINLY
VFR...LASTING INTO SATURDAY.

&&

.PREV DISCUSSION... /ISSUED 106 AM PDT FRI APR 6 2012/

DISCUSSION...06/00Z NAM/GFS IN.

THE OMEGA BLOCK CURRENTLY ALONG THE WEST COAST AND OFFSHORE IS NOW
WEAKENING. THE EASTERN ANCHOR LOW OVER THE WESTERN U.S. WILL
WEAKEN AND MOVE EAST FRIDAY INTO FRIDAY EVENING...AND THE WESTERN
ANCHOR LOW WILL CUT OFF AND MOVE UNDER THE SOUTHEAST ALASKA HIGH
TO FORM A REX BLOCK.

EXPECT THE AIRMASS OVER THE PACIFIC NORTHWEST TO BE LESS UNSTABLE
TODAY AS A SHORT WAVE RIDGE BUILDS OVER THE AREA AND TEMPERATURES
AT THE SURFACE AND ALOFT WARM UP A BIT. IT WILL STILL BE COLD THIS
MORNING. WILL KEEP THE FREEZE WARNING GOING THIS MORNING...BUT THE
MINIMUM TEMPERATURES FOR SATURDAY MORNING WILL BE SIGNIFICANTLY
WARMER. WILL LIKELY CANCEL THE THE FREEZE WATCH FOR SATURDAY
MORNING LATER THIS MORNING.

ONCE THE REX BLOCK SETS UP...THE KEY TO THE LOCAL FORECAST WILL BE
THE LOCATION OF THE CUTOFF LOW. INITIALLY...IT WILL SET UP FAR
ENOUGH OFFSHORE TO PUMP UP A RIDGE OVER THE PACIFIC NORTHWEST.
THIS WILL MAKE FOR A WARMER AND DRY SATURDAY. HOWEVER...IT WILL
SLOWLY EDGE CLOSER TO THE COAST AND EVENTUALLY THE SHORT WAVES
ROTATING AROUND THE LOW WILL MOVE OVER COASTAL AND INLAND AREAS.
THE LATEST GFS/NAM/EC RUNS ALL AGREE THAT THIS WILL START
HAPPENING SATURDAY NIGHT WHEN ONE OF THE SHORT WAVES PUSHES A WEAK
OCCLUDED FRONT ONSHORE. THIS WON'T BE A BIG PRECIPITATION OR WIND
PRODUCER AS IT APPEARS TO BE THE SECOND OR THIRD WRAPAROUND FROM
THE PARENT SURFACE LOW...WHICH TRACKS NORTH OUT AROUND 135W SUNDAY
AND SUNDAY NIGHT. HOWEVER...THE PRECIPITATION WILL LAST A
WHILE...SATURDAY NIGHT THROUGH SUNDAY NIGHT...WITH THE HEAVIEST
AMOUNTS OVER WESTERN AND SOUTH CENTRAL SISKIYOU COUNTY...WHERE IT
WILL BE AUGMENTED BY UPSLOPE FLOW. VERY LITTLE PRECIPITATION WILL
FALL EAST OF THE CASCADES.

LONG TERM DISCUSSION FROM THE THURSDAY AFTERNOON AFD...MONDAY THROUGH
THURSDAY...THE EXTENDED MODELS MAINTAIN A LOW OFF THE PACNW COAST
EARLY NEXT WEEK WITH A FRONT ALONG THE COAST...THIS IS FOLLOWED BY
AN UPPER TROUGH MOVING OVER THE REGION WEDNESDAY THEN ANOTHER
STRONG LOW MOVING TOWARDS THE COAST ON THURSDAY.

MONDAY INTO TUESDAY...EXPECT THE LOW TO REMAIN OFFSHORE WITH A FRONT
NEAR THE COAST OR JUST INLAND BRINGING RAIN AND MOUNTAIN SNOW TO
AREAS FROM THE CASCADES WEST. THE 12Z ECMWF HAS COME INTO BETTER
AGREEMENT WITH THE GFS. BOTH MODELS BRING THE FRONT INTO THE COAST
SATURDAY NIGHT INTO SUNDAY THEN LINGER IT OVER THE AREA ON MONDAY
INTO TUESDAY. THIS FRONT IS EXPECTED TO BRING RAIN TO COASTAL AREAS
WITH A CHANCE FOR RAIN AND MOUNTAIN SNOW INTO AREAS FROM THE
CASCADES WEST. UNCERTAINTY REMAINS ON HOW QUICKLY AND HOW FAR THE
FRONT WILL PUSH INLAND. THE ECMWF IS SLOWER TO MOVE THE FRONT INLAND
THAN THE GFS AND THEN WEAKENS THE FRONT MONDAY NIGHT TUESDAY WHILE
THE GFS MAINTAINS A MOIST BOUNDARY OVER THE AREA.

LATE TUESDAY INTO TUESDAY NIGHT... MODELS SHOW A SHORTWAVE MOVING
AROUND THE LOW AND INTO THE AREA WHILE THE  LOW OFFSHORE MOVES
NORTHEAST WEAKENS. EXPECT PRECIPITATION CHANCES TO INCREASE FOR
INLAND AREAS TUESDAY AFTERNOON INTO TUESDAY NIGHT. BY WEDNESDAY...A
SHORTWAVE TROUGH IS FORECAST TO MOVE OVERHEAD WITH CONTINUED SHOWERS
OVER THE AREA.

THEN...LATE IN THE WEEK...ANOTHER STRONG LOW SETS UP OFFSHORE.
MODELS SHOW THIS LOW MOVING TOWARDS THE NORTHERN CALIFORNIA COAST
LATE THURSDAY INTO EARLY FRIDAY WITH PRECIPITATION SPREADING INLAND.

SNOW LEVELS ARE EXPECTED TO REMAIN HIGH THROUGH TUESDAY AROUND 5000
TO 6000 FEET THEN LOWERING TO 3500 TO 4500 FEET WEDNESDAY AND
THURSDAY.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.

CA...NONE.

PZ...NONE.

SK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MEDFORD OR
528 PM PDT THU APR 5 2012

ORZ021>024-026-061100-
SOUTH CENTRAL OREGON COAST-CURRY COUNTY COAST-
CENTRAL DOUGLAS COUNTY-EASTERN CURRY COUNTY AND JOSEPHINE COUNTY-
JACKSON COUNTY-
528 PM PDT THU APR 5 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
OREGON.

.DAY ONE...TONIGHT

FREEZE WARNINGS AND FROST ADVISORIES ARE IN EFFECT BEGINNING AT 2
AM TONIGHT. PLEASE SEE THE WEATHER MESSAGES FOR MORE SPECIFIC
DETAILS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE FREEZE WARNINGS AND FROST ADVISORIES ARE IN EFFECT UNTIL 8 AM
FRIDAY. A FREEZE WATCH IS THEN IN EFFECT FROM LATE FRIDAY NIGHT
THROUGH EARLY SATURDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT NEEDED.