162  
FXUS66 KMFR 051935  
AFDMFR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEDFORD OR  
1235 PM PDT SUN APR 5 2026  
   
DISCUSSION
 
 
HIGH CLOUDS CONTINUE TO MOVE THROUGH THE REGION THIS AFTERNOON.  
HOWEVER, PLENTY OF SUN IS STILL FILTERING THROUGH THOSE HIGHER  
CLOUDS AND WE'RE ANTICIPATED TO WARM UP INTO THE LOWER 70'S AGAIN  
TODAY. A THERMAL TROUGH IS ALONG THE CASCADES AND THAT TROUGH  
WILL RETREAT FARTHER TO THE EAST DURING THE AFTERNOON HOURS.  
OVERALL, NOT MUCH GOING ON EXCEPT FOR THE ABOVE NORMAL  
TEMPERATURES TODAY.  
 
THE FLOW PATTERN WILL BECOME MORE ONSHORE BY TOMORROW, ALTHOUGH  
TEMPERATURES WILL REMAIN WARM IN THE VALLEYS WITH MORE UPPER 70'S  
WEST OF THE CASCADES AND LOWER 70'S EAST OF THE CASCADES. THE  
VERY LOW(10-20%) CHANCE OF THUNDERSTORMS PERSIST ON MONDAY.  
LOOKING AT SOUNDINGS THE AMOUNT OF CONVECTIVE AVAILABLE POTENTIAL  
ENERGY(CAPE) IS LOW AND ONLY 100-200 J/KG. THE SPC HREF  
CALIBRATED THUNDER ALGORITHM IS GOING WITH A 10-20% CHANCE, SO  
FELT THAT WAS FAIR. DON'T BE SURPRISED IF NOTHING HAPPENS AND WE  
JUST GET SOME SHOWERS ALONG AND EAST OF THE CASCADES MONDAY  
AFTERNOON AND EVENING.  
 
BY TUESDAY MORNING, AN UPPER LEVEL TROUGH IN CANADA STARTS TO DIG  
DOWN INTO WASHINGTON AND IDAHO WITH A CUT OFF LOW OFF THE COAST OF  
NORTHERN CALIFORNIA. IN ADDITION, A COLD FRONT SHOULD BE MOVING  
SOUTH DURING THE DAY AS WELL. THIS FRONT STALLS OUT OVER CENTRAL  
OREGON DURING THE DAY WITH HIGHS IN THE MID 70'S IN SOUTHERN  
OREGON AND MID 60'S FARTHER NORTH OF EUGENE AND BEND. THE FORECAST  
HAS ALSO TRENDED DRIER COMPARED TO YESTERDAY WITH A 5-10% CHANCE  
OF RAIN DURING THE DAY. IT SEEMS 500 MB HEIGHTS ARE AMPLIFYING  
AHEAD OF THE CUT OFF LOW, SO THAT CUTS OFF MOISTURE AND ENHANCES  
THE SINKING MOTION.  
 
AS THAT DEEPER TROUGH DIGS FURTHER INTO THE CONUS, THE CUTOFF LOW  
REMAINS OFF OUR COAST BY WEDNESDAY. THE CHANCE OF RAIN IS ABOUT 20  
TO 30 PERCENT OVER OUR FORECAST AREA, ALTHOUGH THAT COULD VERY  
WELL TREND LOWER DEPENDING ON HOW THIS UPPER LEVEL LOW BEHAVES.  
MOST ENSEMBLE MEMBERS ALSO SEEM TO BE TARGETING NORTHERN  
CALIFORNIA, SO THE PROBABILITY FOR PRECIPITATION IS HIGHER THERE  
COMPARED TO PARTS OF OREGON.  
 
THIS CUTOFF LOW BEGINS TO TRAVEL SOUTH ALONG THE CALIFORNIA  
COASTLINE WITH SOME STRONG 500 MB DIVERGENCE OVER OUR FORECAST  
AREA ON THURSDAY. THIS SHOULD RESULT IN SHOWERS AND PERHAPS MORE  
THUNDERSTORMS DEPENDING ON CAPE. HOWEVER, THE POP FORECAST  
SUGGESTS A WET DAY WITH A 50-60% CHANCE OF RAIN THURSDAY MORNING  
AND AFTERNOON.  
 
THE EXTENDED FORECAST IS LOOKING WET AROUND FRIDAY INTO NEXT WEEK  
WITH THE VAST MAJORITY OF ENSEMBLE MEMBERS WITH PRECIPITATION IN  
THE FORECAST.  
 
-SMITH  
 

 
   
AVIATION...05/18Z TAFS
 
VFR CONDITIONS WILL PERSIST THROUGH THE  
TAF PERIOD FOR MOST THE AREA. LIFR CEILINGS ARE POSSIBLE ALONG THE  
COAST(KOTH) LATER TONIGHT AS SOME WEAK ONSHORE FLOW DEVELOPS.  
 
-SMITH  
 

 
   
MARINE...UPDATED 1200 PM PDT SUNDAY, APRIL 5, 2026
 
RELATIVELY  
CALM CONDITIONS ARE EXPECTED THROUGH THIS WEEK. ANOTHER THERMAL  
TROUGH DEVELOPS AROUND TUESDAY AFTERNOON, BRINGING A PERIOD OF  
STRONG NORTH WINDS AND STEEP SEAS STARTING AROUND TUESDAY  
AFTERNOON AND POTENTIALLY FOR MOST OF THE WEEK.  
 

 
   
MFR WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
 
CA...NONE.  
 
PACIFIC COASTAL WATERS...NONE.  
 

 
 

 
 
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