989
FXUS66 KMFR 301109
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
409 AM PDT THU APR 30 2026
DISCUSSION
UPDATED AVIATION DISCUSSION.
AVIATION...30/12Z TAFS
IFR CEILINGS ARE IMPACTING ALMOST ALL
THE COASTAL WATERS AND BEACHES THIS MORNING WITH SOME ALSO PRESENT
IN THE COASTAL VALLEYS JUST INLAND. THESE SHOULD CLEAR TO VFR AT
LEAST BRIEFLY THIS AFTERNOON. THE REMAINDER OF THE AREA IS VFR,
THOUGH SOME HIGH AND MID CLOUDS WILL DRIFT THROUGH THIS MORNING
INTO THIS AFTERNOON. A FEW CUMULUS COULD ALSO BUILD NEAR THE
MOUNTAINS THIS AFTERNOON. VFR PREVAILS TONIGHT INTO FRIDAY MORNING
FOR MOST, BUT MARINE STRATUS WILL RETURN TO COASTAL LOCATIONS,
INCLUDING NORTH BEND WITH A MIX OF IFR/MVFR CEILINGS. A BIT DEEPER
OF A MARINE PUSH TONIGHT INTO FRIDAY MORNING COULD RESULT IN SOME
MVFR CEILINGS NEAR ROSEBURG AROUND SUNRISE. -SPILDE
PREV DISCUSSION
/ISSUED 259 AM PDT THU APR 30 2026/
KEY MESSAGES...
-WARM AND DRY TODAY INTO FRIDAY.
-REMAINING WARM WITH INCREASING HUMIDITY FRIDAY THROUGH SUNDAY.
-SHOWER/T-STORM CHANCES INCREASE LATE FRIDAY, PERSIST THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK, FOCUSED ON SUNDAY/MONDAY.
-BRIEFLY COOLER MONDAY.
-HIGH PRESSURE REBUILDS TUESDAY/WEDNESDAY WITH A WARM-UP, THOUGH
SHOWERS COULD LINGER FROM CASCADES EAST ON TUESDAY.
DISCUSSION...AN UPPER RIDGE WILL BRING DRY WEATHER TODAY. COASTAL
AREAS WILL ENDURE SOME MORNING STRATUS, BUT THESE CLOUDS SHOULD
BREAK UP FOR AT LEAST A FEW HOURS THIS AFTERNOON (HIGHS IN THE
UPPER 50S BEACHES TO MID OR UPPER 60S JUST INLAND). THE REST OF
THE AREA WILL BE SUNNY WITH HIGH CIRRUS AT TIMES AND PERHAPS A FEW
CUMULUS NEAR THE MOUNTAINS DURING THE AFTERNOON. HIGH
TEMPERATURES WILL BE ABOUT 6-12F ABOVE NORMAL (UPPER 60S/LOW 70S
EAST OF THE CASCADES AND 75-85F FOR WEST SIDE VALLEYS).
THE RIDGE WILL MOVE EAST OF THE CASCADES TONIGHT INTO FRIDAY. A
BIT DEEPER OF A MARINE PUSH WILL BRING MARINE STRATUS BACK TO
COASTAL AREAS TONIGHT AND PERHAPS ALSO INTO PORTIONS OF THE UMPQUA
BASIN. NOT SURE IF IT REACHES QUITE TO ROSEBURG, BUT THERE IS A
DECENT SHOT AT SOME LOWER CLOUDS AROUND THE AIRPORT FRIDAY
MORNING. CLEAR SKIES PERSIST ELSEWHERE.
FRIDAY AFTERNOON, WITH THE RIDGE BREAKING TO THE EAST, AN UPPER
TROUGH WILL CLOSE OFF JUST OFF THE PACNW COAST AND MOVE SOUTHWARD
(INSIDE 130W, BUT JUST OFFSHORE). INCREASING SOUTHERLY FLOW IN
ADVANCE OF THIS DISTURBANCE WILL BRING HIGHER MOISTURE (PWS OF
0.5-0.8") AND INSTABILITY (CAPE 200-500 J/KG) OVER THE AREA
DURING THE AFTERNOON/EVENING. HI-RES GUIDANCE SHOWS DECENT SOME
CUMULUS BUILDING DURING THE LATE AFTERNOON OVER THE MOUNTAINS,
ESPECIALLY FROM WESTERN SISKIYOU COUNTY, UP ACROSS JACKSON COUNTY
AND INTO THE CASCADES. THESE AREAS STAND A DECENT CHANCE (20-40%)
OF SHOWERS ALONG WITH A SLIGHT CHANCE (15-20%) OF THUNDERSTORMS.
WHILE CONVECTIVE PARAMETERS AREN'T BULLISH ON SEVERE POTENTIAL
(BULK SHEAR ONLY IN THE 20-30KT RANGE), ANY CELLS THAT DO FORM
COULD PRODUCE GUSTY WINDS, CG LIGHTNING AND SMALL HAIL. SOME
ACTIVITY (MOSTLY JUST SHOWERS) COULD LINGER NEAR AND WEST OF THE
CASCADES INTO THE NIGHT SINCE THE CORE OF THE CLOSED LOW WILL BE
JUST OFF THE OREGON COAST AT THAT TIME. SHOWERS AND STORMS WILL
BE IN THE SAME GENERAL AREAS SATURDAY, BUT WITH THE FLOW BECOMING
MORE SSE AS THE CLOSED LOW HEADS DOWN THE COAST, ACTIVITY COULD
BECOME MORE WIDESPREAD AND INCLUDE EAST SIDE AREAS DURING THE
AFTERNOON/EVENING. THE LOW SETTLES SOUTHWARD TO A POSITION ABOUT
~300 MILES WSW OF SAN FRANCISCO SATURDAY NIGHT INTO SUNDAY MORNING
AND SHOWERS SHOULD WIND DOWN OVER OUR AREA WITH THE LOSS OF
INSTABILITY.
SUNDAY INTO MONDAY, MUCH WILL DEPEND OF THE ULTIMATE TRACK OF THE
LOW. LATEST GUIDANCE HAS THE LOW JUST A BIT FARTHER SOUTH THAN IT
DID YESTERDAY, WHICH WOULD KEEP THE FOCUS FOR SHOWERS AND STORMS
AS BIT FARTHER SOUTH AS WELL (MORE DIRECTED INTO NORCAL THAN
SOUTHERN OREGON). EVEN SO, THERE SHOULD BE ENOUGH MOISTURE,
INSTABILITY AND FORCING FOR MORE WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS SUNDAY AFTERNOON/EVENING. BY MONDAY, WE'LL BE
DECIDEDLY ON THE NORTHERN PERIPHERY OF THE LOW WITH UPPER RIDGING
TO THE NORTH AND MID-LEVEL FLOW AROUND THE LOW FROM THE ENE. MOST
AREAS WILL BE COOLER, BUT ESPECIALLY NORCAL WHERE CLOUDS/SHOWERS
WILL BE MOST PERSISTENT. THERE'S STILL A CHANCE OF THUNDERSTORMS,
BUT BEST CHANCE IS EAST OF THE CASCADES. RAIN AMOUNTS WITH THIS
ENTIRE SYSTEM WILL LIKELY VARY QUITE A BIT, BUT HAVE COME DOWN
COMPARED TO YESTERDAY DUE TO THE SOUTHWARD SHIFT OF THE LOW. BEST
GUESS IS 0.25-0.50 OF AN INCH (LESSER FOR AREAS N&W) WITH UP TO
AN INCH IN AREAS WHERE SHOWERS ARE MOST PERSISTENT OR MANAGE TO
GET BENEATH A THUNDERSTORM CORE FOR A WHILE.
TUESDAY INTO WEDNESDAY, THE UPPER RIDGE TO THE NORTH WILL WIN OUT
AS THE CLOSED LOW SETTLES INTO THE GREAT BASIN AND DESERT
SOUTHWEST. THIS WILL ALLOW THINGS TO WARM UP AGAIN, THOUGH A
CHANCE OF SHOWERS CONTINUES FOR AREAS MOSTLY TO THE SOUTH AND EAST
OF THE CASCADES. -SPILDE
AVIATION...30/06Z TAFS...IFR CEILINGS HAVE BUILT IN ALONG THE COAST
THIS EVENING AND THEY WILL CONTINUE THROUGH THE NIGHT. OTHERWISE,
VFR CONDITIONS WILL PERSIST ELSEWHERE THROUGH THE TAF PERIOD WITH
SOME FAIR WEATHER CUMULUS BUILD UPS EAST OF THE CASCADES THURSDAY
AFTERNOON. -SMITH
MARINE...UPDATED 250 AM PDT THURSDAY, APRIL 30, 2026....A
THERMAL TROUGH PATTERN WILL BRING GUSTY NORTH WINDS THROUGH
SATURDAY. THE STRONGEST WINDS AND VERY STEEP SEAS ARE EXPECTED SOUTH
OF OPHIR TODAY AND AGAIN ON FRIDAY. SEAS WILL BE STEEP ELSEWHERE.
WINDS START TO EASE ON SATURDAY BUT UNSETTLED SEAS MAY CONTINUE.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT
SATURDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING FROM 2 PM THIS AFTERNOON TO 11 AM PDT
FRIDAY FOR PZZ356-376.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page