Frost Advisory 41, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
914 AM PST TUE NOV 24 2015

.DISCUSSION...CURRENT SATELLITE IMAGE SHOWS THE UPPER LOW MAKING
ITS WAY SOUTH ALONG THE OREGON COAST. THE COLD FRONT IS STARTING
TO CROSS THE CASCADES AND SNOW LEVELS ARE DROPPING. THE VISIBLE
IMAGE IS ALREADY SHOWING COLDER AIR MOVING IN AS EVIDENCE BY
INSTABILITY CLOUDS MOVING INTO COOS, CURRY AND WESTERN DOUGLAS
COUNTY. A LOOK AT SOME WEBCAMS AND SOME REPORTS INDICATE WET SNOW
IS FALLING NEAR 2000 FEET, BUT SO FAR ROADS ARE WET. MEANWHILE
ROADS ARE ALREADY SNOW COVERED OVER THE HIGHER PASSES ALONG THE
CASCADES. SISKIYOU SUMMIT HAS ROADSIDE SLUSH WITH SNOW COVERING
THE GROUND. THE COLD AIR MASS WILL CONTINUE TO MOVE OVER THE AREA
TODAY WITH PLENTY OF INSTABILITY SHOWERS. SNOW LEVELS ARE EXPECTED
TO REMAIN AROUND 2000 FEET TODAY WEST OF THE CASCADES, BUT COULD
LOWER TO 1500 FEET WHERE THERE ARE HEAVIER SHOWERS.

ROADS ARE SNOW COVERED EAST OF THE CASCADES, MAINLY OVER THE
NORTHERN PORTIONS OF LAKE AND KLAMATH COUNTIES, BUT THE CONCERN
FOR SNOW COVERED ROADS WILL SHIFT SOUTH THIS AFTERNOON AS COLDER
AIR MOVES IN AND SHOWERS INCREASE.

TONIGHT, THE MODELS ARE IN FAIRLY GOOD AGREEMENT SHOWING A
DEFORMATION ZONE SETTING UP EAST OF THE CASCADES. IN ADDITION
GUSTY WINDS WILL CONTINUE WITH BRIEF BLIZZARD CONDITIONS FOR PARTS
OF THE AREA TONIGHT INTO WEDNESDAY MORNING.

MADE A FEW ADJUSTMENTS TO THE FORECAST TODAY. WE INCREASED POPS,
QPF AND SNOW AMOUNTS FOR THIS AFTERNOON.

THE CONCERN WILL SHIFT FROM SNOW TO COLD TEMPERATURES WEDNESDAY
NIGHT THROUGH THANKSGIVING FOR THE ENTIRE AREA. THIS INCLUDES THE
COASTAL AREAS WHERE TEMPERATURES COULD DROP BELOW FREEZING.
THEREFORE A FREEZE WARNING MAY BE NEEDED FOR MOST OF THESE AREAS
BECAUSE OF THE POTENTIAL FOR FREEZING PIPES. -PETRUCELLI

&&

.AVIATION...FOR THE 24/12TAF CYCLE...RAIN AND SNOW ASSOCIATED WITH A
FRONTAL PASSAGE WILL BE THE MAIN CONCERN TODAY AS THIS COULD PRODUCE
SOME ISSUES WITH ICING...TURBULENCE...AND TERRAIN OBSCURATION. MVFR
CIGS AND VSBYS WILL DOMINATE AREAWIDE TODAY WITH PERIODS OF VFR CIGS
AND VSBYS DURING BREAKS IN IN PRECIPITATION...PARTICULARLY WEST OF
THE CASCADES AND ESPECIALLY NEAR THE COAST. RAIN IS EXPECTED AT THE
AIRPORTS WEST OF THE CASCADES...BUT WILL QUICKLY CHANGE TO ICE AND
SNOW WITH ANY ALTITUDE. EAST OF THE CASCADES...RAIN SHOWERS WILL
TURN TO SNOW SHOWERS BETWEEN 15Z AND 18Z AND VSBYS WILL DROP TO IFR
AS LONG AS IT IS SNOWING. -SCHAAF

&&

.MARINE...UPDATED 850 AM PST, TUESDAY 24 NOV 2015...A MODERATE
NORTHWEST SWELL HAS ALREADY ARRIVED IN THE WATERS AND HAS REACHED
BUOY 15. THE FORECAST WAS UPDATED TO ACCOUNT FOR THIS TIMING. A COLD
FRONT HAS MOVED ASHORE, AND LOW PRESSURE WILL MOVE ACROSS THE WATERS
TODAY. MODERATE NORTH WINDS WILL DEVELOP BEHIND THE LOW TODAY AND
CONTINUE THROUGH TOMORROW MORNING. WINDS TURN MORE NORTHEAST AND
STRENGTHEN POSSIBLY TO GALES TOMORROW. THE SWELL DIMINISHES TOMORROW
BUT SEAS REMAIN HIGH AS THEY BECOME WIND WAVE DOMINATED. -WRIGHT

&&

.PREV DISCUSSION... /ISSUED 513 AM PST TUE NOV 24 2015/

DISCUSSION...A COLD FRONT IS PRODUCING RAIN AND SNOW WITH SHARPLY
FALLING SNOW LEVELS. THE SNOW LEVEL RANGES FROM AROUND 2500 TO
3500 FEET BEHIND THE FRONT IN THE KALMIOPSIS WILDERNESS AND UMPQUA
DIVIDE...AND IS AROUND 5500 FEET AHEAD OF THE FRONT. DAY-TIME
HEATING WILL HAVE A COUNTER EFFECT ON THE FALLING SNOW
LEVELS...WHICH IS EXPECTED TO RESULT IN SNOW LEVELS HOVERING
AROUND 2500 FEET THIS AFTERNOON WHILE THE FOCUS OF PRECIPITATION
SHIFTS TO EAST OF THE CASCADES. THE BOTTOM LINE IS THAT THE MAIN
TRAVEL PROBLEMS THIS MORNING WILL BE OVER THE MAJOR PASSES OF THE
SOUTHERN OREGON CASCADES AND SISKIYOUS AND INTO KLAMATH COUNTY AND
SISKIYOU COUNTY AS WELL...INCLUDING SISKIYOU SUMMIT...LAKE OF THE
WOODS/HIGHWAY 140...DIAMOND LAKE...HIGHWAY 66 AND MUCH OF HIGHWAY
97. THE PASSES BETWEEN GRANTS PASS AND ROSEBURG ON INTERSTATE 5
ARE AT AROUND 2000 FEET AND WILL BE MONITORED CLOSELY BUT ARE
EXPECTED TO BARELY CONTINUE WITH EXCLUSIVELY RAINFALL TODAY.
THE MOUNT SHASTA CITY AREA IS EXPECTED TO TRANSITION TO SNOW
DURING THE AFTERNOON.

SNOWFALL WILL OCCUR MAINLY FROM THE CASCADES EASTWARD THIS
AFTERNOON INTO WEDNESDAY MORNING AS THE COLD UPPER LEVEL LOW
MOVES INLAND ACROSS OUR AREA INTO WESTERN NEVADA. THE CLOSE
PROXIMITY OF THE LOW WILL BRING INCREASED WIND SPEEDS TO THE EAST
SIDE THAT WILL PRODUCE AREAS OF BLOWING SNOW. THE BULK OF THE SNOW
THAT FALLS TONIGHT WILL OCCUR EAST OF THE CASCADES...ESPECIALLY IN
AND NEAR LAKE COUNTY WITH A MAJORITY OF THEIR EXPECTED 3 TO 10
INCH TOTAL TO FALL DURING THOSE 12 HOURS. BUT THE MOIST NORTH TO
NORTHEAST FLOW WILL ALSO PRODUCE SNOW SHOWERS OVER THE SISKIYOU
MOUNTAINS...CASCADES AND CASCADE FOOTHILLS WITH SOME ACCUMULATION
AS FAR WEST AS THE COASTAL RANGE. THE SNOW LEVEL WILL FALL TO
AROUND 1500 FEET OVERNIGHT. AMOUNTS AT 1500 FEET WILL PROBABLY NOT
BE MUCH MORE THAN JUST ENOUGH TO COVER THE GROUND. BUT THIS COULD
PRODUCE SLICK ROADS OVER HAYES HILL...THE AFOREMENTIONED PASSES
NORTH OF GRANTS PASS INTO DOUGLAS COUNTY AND PORTIONS OF JACKSON
AND SISKIYOU COUNTIES AS WELL.

ACTIVITY WILL TAPER ON WEDNESDAY. UPSLOPE NORTHERLY FLOW WILL
CONTINUE TO PRODUCE FLURRIES ON AND NEAR SISKIYOU SUMMIT AND THE
UMPQUA DIVIDE ON WEDNESDAY MORNING WHILE MEASUREABLE SNOW SHOWERS
CONTINUE IN LAKE AND MODOC COUNTIES. THE LAST OF THE SNOW SHOWERS
IS EXPECTED TO END OVER SISKIYOU SUMMIT BY NOON AND OVER THE
WARNER MOUNTAINS BY THE END OF THE DAY.

VERY COLD TEMPERATURES WILL ACCOMPANY DRY WEATHER INTO THE
WEEKEND. THIS INCLUDES THE LIKELIHOOD OF FREEZING TEMPERATURES
OVERNIGHT AT MUCH OF THE COAST WEDNESDAY NIGHT AND THURSDAY
NIGHT...FREEZING TEMPERATURES CERTAIN OVERNIGHT IN WEST SIDE
VALLEYS WEDNESDAY NIGHT THROUGH THE WEEKEND...AND SINGLE DIGIT
LOWS WITH THE POSSIBILITY OF BELOW ZERO READINGS ON THE EAST SIDE
WEDNESDAY NIGHT THROUGH THE WEEKEND.

OUR WEATHER PATTERN WILL LIKELY TURN WARMER AND WETTER EARLY NEXT
WEEK.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST WEDNESDAY FOR
     ORZ029-030.
     WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY ABOVE 4500 FEET
     FOR FOR ORZ029-030.
     WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY FOR ORZ031.
     WINTER WEATHER ADVISORY UNTIL 4 AM PST WEDNESDAY FOR ORZ021>026.
     WINTER WEATHER ADVISORY UNTIL 4 AM PST WEDNESDAY FOR ORZ027-028.

CA...WINTER WEATHER ADVISORY UNTIL 10 AM PST WEDNESDAY FOR
     CAZ084-085.
     WINTER WEATHER ADVISORY UNTIL 4 AM PST WEDNESDAY FOR CAZ080-081.
     WINTER WEATHER ADVISORY UNTIL 10 AM PST WEDNESDAY FOR
     CAZ082-083.
     WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY ABOVE 4500 FEET
     FOR FOR CAZ083-085.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 4 AM PST THURSDAY FOR
     PZZ350-356-370-376.
     GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE WEDNESDAY NIGHT
     FOR PZZ370-376.
     HAZARDOUS SEAS WARNING UNTIL 4 PM PST WEDNESDAY FOR PZZ370-376.

MAP/MAP/MAP

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>