875  
FXUS66 KMFR 131126  
AFDMFR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEDFORD OR  
426 AM PDT THU JUN 13 2024  
   
..NEW AVIATION SECTION
 
 
   
AVIATION (12Z TAFS)
 
 
CURRENT OBSERVATION AT NORTH BEND (KOTH) DOESN'T INDICATE LOW  
CLOUDS, BUT SATELLITE SUGGEST THIS IS A POSSIBILITY THIS MORNING,  
SO WENT AHEAD AND ADDED SOME IFR CEILINGS BASED ON SATELLITE  
TRENDS. OTHERWISE, THE INLAND TAF SITES ARE EXPECTED TO REMAIN IN  
VFR THROUGHOUT THIS CYCLE, BUT EXPECTING HIGH CLOUDS TO INFILTRATE  
OVER THE REGION TONIGHT. KOTH WILL LIKELY SEE SOME RELIEF AND VFR  
CONDITIONS LATER TODAY, BUT ANOTHER ROUND OF LOW STRATUS IS  
ANTICIPATED FRIDAY MORNING. LASTLY, BREEZY AFTERNOON WIND SPEEDS  
ARE EXPECTED TODAY.  
 
-GUERRERO  
 

 
   
PREV DISCUSSION
 
/ISSUED 258 AM PDT THU JUN 13 2024/  
 
DISCUSSION...FOG IS BUILDING IN THE COQUILLE VALLEY AND CURRENT  
EXPECTATIONS ARE FOR THERE AND PORTIONS OF CURRY COUNTY AROUND  
BROOKINGS TO BE THE ONLY PLACES WHERE FOG FORMS.  
 
THE THERMAL TROUGH ALONG THE COAST WILL SHIFT INLAND TODAY. THIS  
WILL BRING A SMALL 1 TO 3 DEGREE BUMP UP IN TEMPERATURES FROM  
YESTERDAY AND DRIER CONDITIONS ALONG THE I-5 CORRIDOR. THE  
DISPLACEMENT OF THE THERMAL TROUGH IS BEING DRIVEN BY THE  
OVERSPREADING OF A MID-LEVEL TROUGH OVER THE PACIFIC COAST. IN  
ADDITION TO THE SMALL FLUCTUATIONS IN TEMPERATURE AND HUMIDITY,  
THE LARGER IMPACT WILL BE TO WINDS. THE WEST EAST PRESSURE  
GRADIENT WILL AMPLIFY, CAUSING THE TYPICAL DIURNAL WINDS TO BE A  
BIT STRONGER THAN NORMAL (10-20 MPH, GUSTS AROUND 30-35 MPH). THIS  
WILL BE ESPECIALLY TRUE IN THE LEE OF THE CASCADES, WHERE THE  
DOWNSLOPE WINDS AND HUMIDITIES BELOW 15% COULD LEAD TO BRIEF  
CRITICAL FIRE WEATHER CONDITIONS FOR 1 TO 2 HOURS IN MODOC, LAKE,  
AND EASTERN KLAMATH COUNTY. CRITICAL FIRE WEATHER CONDITIONS MAY  
ALSO EXIST FOR AN HOUR OR TWO AROUND THE SCOTT VALLEY TODAY.  
HOWEVER, IT'S IMPORTANT TO NOTE THAT THESE CONDITIONS ARE FAIRLY  
TYPICAL IN THE SUMMER AND NOT REALLY UNCOMMON.  
 
FRIDAY, A NOTICEABLE COOLDOWN IS EXPECTED AS THE TROUGH MOVES A  
COOLER POLAR AIR MASS INTO THE REGION. CONDITIONS WILL AGAIN BE  
WINDY IN THE AFTERNOON AS THE DIURNAL WINDS GET AN ENHANCEMENT,  
BUT WITH HUMIDITIES TRENDING UP A FEW PERCENTAGES, NO FIRE WEATHER  
CONCERNS ARE EXPECTED. PERHAPS THE BIGGER CONCERN WILL BE THE  
COLD TEMPERATURES IN THE MOUNTAINS AND AREAS EAST OF THE CASCADES.  
NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED FRIDAY NIGHT AND  
CONTINUING THROUGH THE WEEKEND. ANYONE IN THESE AREAS WITH PLANTS  
OUTSIDE WILL WANT TO CONSIDER COVERING THEM, AND CAMPERS WILL  
WANT TO MAKE SURE THEY PLAN APPROPRIATELY FOR THESE COLD  
TEMPERATURES.  
 
THERE IS A SMALL CHANCE FOR RAIN AMOUNTS LESS THAN 0.05" FRIDAY  
NIGHT ACROSS COOS, DOUGLAS, AND NORTHERN KLAMATH COUNTY,  
ESPECIALLY IN THE HIGHER TERRAIN. THE MORE MOIST FRONT IS  
EXPECTED SUNDAY INTO MONDAY. CHANCES ARE PEAKING AROUND 40%, SO  
NOTHING IS CERTAIN WITH THIS FRONT OTHER THAN SOME ELEVATED WIND  
SPEEDS AND A GOOD MARINE PUSH LEADING TO INCREASING HUMIDITIES.  
IF ENOUGH MOISTURE DOES ARRIVE WITH THE FRONT TO PRODUCE  
PRECIPITATION, AMOUNTS ARE GENERALLY EXPECTED TO BE LESS THAN  
0.1", EXCEPT IN THE COAST RANGE AND THE CASCADES, WHERE UP TO 0.2"  
SEEMS REASONABLE. THERE COULD ALSO BE A THUNDERSTORM THREAT WITH  
THIS SYSTEM, BUT FOR RIGHT NOW, THE GREATEST INSTABILITY IS AHEAD,  
NOT ALONG, THE FRONT AND THE CORE OF THE TROUGH IS TOO FAR NORTH  
TO ADD THUNDERSTORMS TO THE FORECAST. THAT SAID, SOME SHOWERS WILL  
STILL BE STRONG AND THEIR HEAVIER PRECIPITATION RATES COMBINED  
WITH SNOW LEVELS NEAR OR BELOW BELOW 6KFT, THE PEAKS OF THE  
CASCADES (INCLUDING AT CRATER LAKE NP) COULD PICK UP SOME NEW WET  
SNOW COVER.  
 
WE WILL REMAIN IN THIS COOLER, UNSETTLED WEATHER PATTERN INTO THE  
START OF NEXT WEEK.  
 
-MILES  
 
AVIATION...13/06Z TAFS...VFR CONTINUES NEARLY EVERYWHERE LATE THIS  
EVENING. FOR MOST OF THE AREA, IT WILL REMAIN THAT WAY FOR THE NEXT  
24 HOURS. PATCHY MVFR CEILINGS ARE DEVELOPING IN PORTIONS OF  
NORTHERN CURRY COUNTY AND ALONG THE COAST NORTH OF CAPE BLANCO. WITH  
THE WIND EXPECTED TO BE SLIGHTLY E OF DUE NORTH, THE CLOUDS THAT  
CONTINUE TO FORM OVERNIGHT MAY JUST HUG THE IMMEDIATE COASTLINE. AT  
NORTH BEND, WE'RE MAINTAINING SCT010 AFTER 10Z, WITH THE IDEA THAT  
PERHAPS IT COULD GO EITHER WAY (50/50 CHANCE OF BKN OR SKC) IN THE  
EARLY MORNING HOURS THURSDAY. SIMILARLY, PATCHY MVFR CEILINGS ARE  
POSSIBLE IN THE UMPQUA BASIN, THOUGH AGAIN, CONFIDENCE IN A BKN  
CEILING IS LOW. AS SUCH, THE ROSEBURG TAF CONTINUED WITH SCT020 FOR  
A FEW HOURS (14-17Z) THURSDAY MORNING (WITH ABOUT A 30% CHANCE OF  
BKN). GUSTY NORTHERLY WINDS WILL REDEVELOP ALONG THE COAST THURSDAY  
AFTERNOON, BUT WON'T BE AS STRONG AS TODAY. BREEZES SIMILAR TO  
TODAY'S WILL DEVELOP OVER THE INLAND VALLEYS, THOUGH IT'LL PROBABLY  
BE A BIT GUSTIER OVER THE EAST SIDE, INCLUDING AT KLAMATH FALLS.  
 
-SPILDE  
 
MARINE...UPDATED 230 AM THURSDAY, JUNE 13, 2024...STEEP SEAS WILL  
CONTINUE ACROSS ALL WATERS THROUGH FRIDAY MORNING, WITH AREAS OF  
VERY STEEP SEAS (HAZARDOUS SEAS WARNING) CONTINUING SOUTH OF PORT  
ORFORD THIS MORNING ACROSS THE OUTER WATERS. THEREAFTER, RELATIVELY  
CALMER SEAS ARE EXPECTED THROUGH SUNDAY MORNING. BY SUNDAY  
AFTERNOON, THERE IS A LOT OF UNCERTAINTY WITH MODEL GUIDANCE, AND  
THERE IS AT LEAST SOME POTENTIAL FOR A STRONG CLOSED LOW TO PASS  
ALOFT. THIS COULD BRING IN A STRONG FRESH SWELL IN ADDITION TO  
STRONGER WIND SPEEDS THAN WE CURRENTLY HAVE FORECAST AT THE MOMENT.  
WE ESSENTIALLY HAVE A SCENARIO WHERE EITHER AN UPPER LEVEL LOW TAKES  
A NORTHERN TRACK OR A SOUTHERN TRACK THROUGH THE PACNW SUN-MON. AS  
THE TRACK BECOMES CLEARER, WE SHOULD HAVE A MUCH BETTER IDEA OF  
POTENTIAL HAZARDS (OR LACK THEREOF) OVER THE WATERS.  
 
-GUERRERO  
 

 
   
MFR WATCHES/WARNINGS/ADVISORIES
 
 
OR...CA...NONE.  
 
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 2 AM PDT FRIDAY  
FOR PZZ350-356-370.  
 
HAZARDOUS SEAS WARNING UNTIL 11 AM PDT THIS MORNING FOR PZZ376.  
 
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 2 AM PDT FRIDAY  
FOR PZZ376.  
 

 
 

 
 
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