Frost Advisory 30, NWS Medford, OR

509 
WWUS76 KMFR 240938
NPWMFR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MEDFORD OR
238 AM PDT FRI AUG 24 2012

ORZ029>031-241500-
/O.CON.KMFR.FZ.W.0015.000000T0000Z-120824T1500Z/
/O.CON.KMFR.FR.Y.0030.000000T0000Z-120824T1500Z/
KLAMATH BASIN-
NORTHERN AND EASTERN KLAMATH COUNTY AND WESTERN LAKE COUNTY-
CENTRAL AND EASTERN LAKE COUNTY-
INCLUDING THE CITIES OF...BEATTY...CHEMULT...CRESCENT...
GILCHRIST...SPRAGUE RIVER
238 AM PDT FRI AUG 24 2012

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

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

* TEMPERATURES: MINIMUM TEMPERATURES WILL BE IN THE MID 20S TO
  LOWER 30S IN THE FREEZE WARNING AREA. MINIMUM TEMPERATURES IN
  THE FROST ADVISORY AREA WILL BE 32 TO 36 DEGREES.

* TIMING: THE COLDEST TEMPERATURES ARE EXPECTED AROUND SUNRISE.

* LOCATIONS IN THE FREEZE WARNING INCLUDE: CHEMULT...CRESCENT...
   GILCHRIST...AND BEATTY. 

* LOCATIONS IN THE FROST ADVISORY INCLUDE: SPRAGUE RIVER...
  AREAS JUST NORTHEAST OF DAIRY ALONG HIGHWAY 140...AND SILVER 
  LAKE. 

* IMPACTS: SENSITIVE VEGETATION COULD BE DAMAGED OR KILLED IF
  LEFT UNPROTECTED. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.

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
357 AM PDT THU AUG 23 2012

.DISCUSSION...IN THE MORNING FORECAST ISSUANCE, THERE WAS VERY LITTLE
CHANGE TO THE THREE MAIN SHORT-TERM CONCERNS. FIRST IS THE BREEZY
TO WINDY CONDITIONS THAT WILL DEVELOP INLAND THIS AFTERNOON.
WESTERLY WINDS WILL BE STRONGEST OVER LAKE AND MODOC COUNTIES AT
10 TO 20 MPH WITH GUSTS OF 20 TO 30 MPH WITH THE HIGH END OF THE
RANGE OVER THE HIGHER TERRAIN. THESE WINDS WILL HEIGHTEN THE FIRE
DANGER AND ARE IN RESPONSE TO A BROAD AND DEEPER THAN NORMAL UPPER
LEVEL LOW MOVING ACROSS BRITISH COLUMBIA WHILE HIGH PRESSURE
BUILDS OVER THE EASTERN PACIFIC AND A THERMAL TROUGH PERSISTS OVER
NORTHERN CALIFORNIA. THE SECOND CONCERN IS THAT THE PATTERN WILL
ALSO RESULT IN NORTHERLY WINDS OVER THE MARINE WATERS AND AT THE
COAST. STRONG COASTAL WINDS WILL PERSIST INTO FRIDAY NIGHT WITH
GALE FORCE WINDS SOUTH OF CAPE BLANCO. THE THIRD SHORT-TERM
CONCERN IS ALSO RELATED TO FIRE WEATHER AS THE THERMAL TROUGH
ALONG THE COAST WILL INDUCE NORTHEAST WINDS OF 10 TO 20 MPH
TONIGHT THROUGH FRIDAY NIGHT OVER THE HIGHER TERRAIN OF CURRY AND
JOSEPHINE COUNTIES WITH POOR TO MODERATE NIGHT-TIME RECOVERY OF
RELATIVE HUMIDITY.

THE PASSAGE OF THE CANADIAN TROUGH WILL ALSO LEAD TO SEVERAL
DEGREES OF COOLING TODAY AND NOTICEABLY COOLER LOW TEMPERATURES ON
FRIDAY MORNING. LOWS WILL BE COLDEST IN NORTHERN KLAMATH AND LAKE
COUNTIES WHERE FREEZING TEMPERATURES ARE POSSIBLE.

AT THIS TIME, THE AIR MASS LOOKS TO REMAIN STABLE DURING THE NEXT
7 DAYS, MOST STABLE AS BUILDING HIGH PRESSURE BRINGS A BRIEF WARMING
TREND FRIDAY INTO SATURDAY.

THE WEATHER DURING THE FIRST HALF OF NEXT WEEK IS STILL QUITE
UNCERTAIN BUT WILL CERTAINLY BE MOST SIGNIFICANTLY INFLUENCED BY
THE APPROACH OF A COLD CLOSED UPPER LOW MOVING SOUTHEAST FROM THE
GULF OF ALASKA. THE 00Z GFS SOLUTION IS SIGNIFICANTLY SLOWER THAN
THE ECMWF SOLUTION. HPC RECOMMENDS LEANING TOWARD THE ECMWF AS IT
IS IN CLOSER AGREEMENT TO NAM, CANADIAN AND UKMET MODELS.

THIS WOULD LEAD TO A SIGNIFICANTLY COOLER SOLUTION THAN THE GFS
WITH STRONGER WINDS AND TEMPERATURES NOTICEABLY BELOW NORMAL FOR
THE FIRST TIME SINCE JULY 16TH-18TH. AND ALSO LEAD TO A SLIGHT
CHANCE TO CHANCE OF RAIN NEAR THE COAST SUNDAY AND SLIGHT CHANCE
OF SHOWERS MONDAY...WITH HIGHEST POPS NORTH OF COOS BAY. WITH SUCH
DISPARITY BETWEEN THE GFS AND ECMWF, WILL STICK WITH MENTION OF A
SLIGHT CHANCE JUST OVER THE MARINE WATERS AND COOS/DOUGLAS BEACHES
FOR NOW.

THE ECMWF SOLUTION FOLLOWS WITH VERY WEAK RIDGING TOWARD MID-WEEK
THEN ANOTHER TROUGH AROUND DAY 7 OR 8 WITH CONDITIONS THAT WOULD
BE SIMILAR TO THOSE TODAY.

&&

.AVIATION...A PATCH OF MARINE STRATUS WITH IFR CEILINGS AND
VISIBILITIES EXTENDS FROM CAPE BLANCO INTO SOUTHERN COOS COUNTY.
THIS IS EXPECTED TO EXPAND INTO COOS BAY EARLY THIS MORNING THEN
BEGIN TO DISSIPATE AROUND 8 AM. ELSEWHERE, VFR CONDITIONS CONTINUE
WITH GUSTY WINDS IN THE AFTERNOON EAST OF THE CASCADES.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR
     ORZ029>031.

CA...NONE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SATURDAY FOR
     PZZ350-356-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT FRIDAY
     FOR PZZ350-370.
     HAZARDOUS SEAS WARNING UNTIL 11 PM PDT FRIDAY FOR PZZ356.
     GALE WARNING UNTIL 11 PM PDT FRIDAY FOR PZZ376.
     HAZARDOUS SEAS WARNING UNTIL 2 AM PDT SATURDAY FOR PZZ376.

DW