792  
FXUS66 KMFR 141201  
AFDMFR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEDFORD OR  
401 AM PST SAT DEC 14 2019  
   
DISCUSSION
 
RAIN AND SNOW HAS MOVED EAST WITH THE SHORT WAVE AND  
BRIEF RIDGING WILL KEEP THE AREA DRY THROUGH THE REMAINDER OF THE  
MORNING HOURS. INFRARED SATELLITE IMAGERY SHOWS ANOTHER SYSTEM  
OFFSHORE THAT HAS MOVED INSIDE OF 130W. MODELS HAVE STRUGGLED FOR  
CONSISTENCY WITH THIS SHORT WAVE RELATED TO THE EXTENT OF INLAND  
PRECIPITATION TODAY THROUGH EARLY SUNDAY. HAVE STUCK CLOSE TO  
EARLIER FORECASTS IN KEEPING LIKELY TO CATEGORICAL POPS COASTWARD  
MAINLY THIS AFTERNOON WITH CHANCE POPS INLAND TO ABOUT THE  
CASCADES. THE LEAST CONFIDENCE HERE IS BASICALLY EVERYWHERE INLAND  
FROM THE COAST RANGE. THIS SYSTEM WILL CONTINUE TO PRODUCE SOME  
CHANCES FOR LIGHT RAIN AND SNOW ACROSS THE REGION TONIGHT. THEN,  
DESPITE RIDGING BUILDING IN, SOME LIGHT OVERRUNNING PRECIPITATION  
REMAINS POSSIBLE SUNDAY INTO SUNDAY NIGHT. CHANCES SUNDAY WILL BE  
FAIRLY LOW - ON THE ORDER OF 20 OR 30 PERCENT, INCREASING A BIT  
SUNDAY NIGHT MAINLY ALONG AND WEST OF THE CASCADES. NOTHING  
SIGNIFICANT.  
 
THE REGION SHOULD REMAIN DRY MONDAY AFTERNOON THROUGH TUESDAY  
UNDER WEAK HIGH PRESSURE. THEREAFTER, THE ONSET OF A POTENTIALLY  
SIGNIFICANT RAIN EVENT LOOMS STARTING LATE-WEEK.  
 
THERE IS GOOD AGREEMENT AT THIS TIME THAT A PROLONGED ATMOSPHERIC  
RIVER WILL IMPACT THE REGION STARTING LATE WEDNESDAY OR THURSDAY.  
CURRENT GFS AND EC ARE IN AGREEMENT WITH THE GENERAL ENSEMBLE CAMP  
OF A DEEP TROUGH MOVING INTO THE GULF OF ALASKA ALLOWING FOR A  
MOIST SOUTHWEST FLOW ROOTED NORTH OF HAWAII AIMED INTO THE PACNW.  
TOUGH TO BE CONFIDENT WITH RAIN AMOUNTS AT THIS LEAD TIME,  
HOWEVER, DUE TO THE POTENTIAL DURATION OF ABOUT 3 DAYS, A 5-10  
INCH EVENT FOR THE SOUTH COAST LOOKS REASONABLE AT FIRST GLANCE.  
WE'LL NEED TO SEE HOW THIS SHAPES UP OVER THE NEXT COUPLE DAYS  
BEFORE WE RAMP UP MESSAGING. STAVISH  
 

 
   
AVIATION...FOR THE 14/12Z TAFS
 
THE FRONT WILL CONTINUE EAST  
TONIGHT AND DRIER AIR WILL MOVE IN BEHIND THE FRONT. EXPECT  
WIDESPREAD IFR CIGS TO PERSIST OVERNIGHT. MVFR TO IFR CEILINGS ARE  
IN PLACE OVER MOST OF THE REGION.THE SOLID DECK IS KEEPING  
VISIBILITIES UP, EXCEPT FOR NEAR ROSEBURG. CONDITIONS ARE EXPECTED  
TO RISE TO MVFR TO VFR BY EARLY AFTERNOON, DROPPING AGAIN TO MVFR TO  
IFR AS THE NEXT FRONT MOVES IN LATE AFTERNOON INTO THE EVENING.  
 

 
   
MARINE...UPDATED 345 AM PST SATURDAY, 14 DECEMBER 2019
 
HEAVY  
AND STEEP LONG PERIOD SWELL WILL REMAIN HIGH INTO SUNDAY, WITH WINDS  
REMAINING BELOW ADVISORY CRITERIA THROUGH AT LEAST WEDNESDAY. SEAS  
WILL GRADUALLY DIMINISH THIS WEEKEND, SUBSIDING BELOW ADVISORY  
CRITERIA LATE SUNDAY INTO MONDAY. THIS WILL BE SHORT-LIVED, HOWEVER,  
AS ANOTHER SWELL TRAIN MOVES INTO THE WATERS TUESDAY AHEAD OF THE  
NEXT FRONTAL SYSTEM. THIS FRONT WILL BRING INCREASING SOUTHERLY  
WINDS WEDNESDAY, AND WITH BUILDING SEAS, CONDITIONS WILL LIKELY  
BECOME HAZARDOUS TO SMALL CRAFT. IN THE MEANTIME, PERIODS OF  
MODERATE TO HEAVY RAIN WILL CONTINUE WITH A RELATIVE BREAK EXPECTED  
MONDAY INTO TUESDAY. /BR-Y/SVEN  
 

 
   
MFR WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
 
CA...NONE.  
 
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 10 PM PST SUNDAY  
FOR PZZ350-356-370-376.  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab OR Page
The Nexlab CA Page Main Text Page