690
FXUS66 KMFR 240303
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
803 PM PDT WED APR 23 2025
UPDATE
UPDATED MARINE DISCUSSION.
MARINE
MODERATE NORTH WINDS WILL GRADUALLY LOWER OVERNIGHT.
WINDS SHOULD DROP BELOW SMALL CRAFT LEVELS BY EARLY THURSDAY
MORNING, BUT SEAS WILL REMAIN JUST ELEVATED ENOUGH FOR SMALL CRAFT
CONDITIONS TO CONTINUE THROUGH LATE THURSDAY MORNING. CALMER
CONDITIONS ARE LIKELY THURSDAY AFTERNOON THROUGH FRIDAY AS LOW
PRESSURE MOVES TO THE SOUTH. SHOWERS ARE LIKELY DURING THIS TIME
PERIOD, THEN STRONGER NORTH WINDS AND STEEP SEAS ARE POSSIBLE
AGAIN BY SATURDAY AFTERNOON.
PREV DISCUSSION
/ISSUED 437 PM PDT WED APR 23 2025/
UPDATED AVIATION DISCUSSION...
AVIATION...24/00Z TAFS...ISOLATED SHOWERS AND THUNDERSTORMS
WILL CONTINUE THROUGH THIS EVENING IN SE PORTIONS OF THE AREA, BUT
MAINLY SE OF OUR TAF SITES. EXPECT WIDESPREAD VFR THROUGH LATE THIS
AFTERNOON FOR KLAMATH FALLS, MEDFORD, ROSEBURG AND NORTH BEND. GUSTY
NORTH WINDS ARE EXPECTED (~25KT) AT NORTH BEND INTO THIS EVENING.
MODELS SHOW MARINE STRATUS INFILTRATING THE COAST AGAIN THIS EVENING
AND OVERNIGHT WITH MVFR/IFR DEVELOPING AT NORTH BEND AND LASTING
INTO THURSDAY MORNING. HI-RES GUIDANCE IS NOT SHOWING THIS STRATUS
ADVANCING FAR ENOUGH INLAND TO IMPACT ROSEBURG, BUT THERE IS ABOUT
20% CHANCE OF OCCURRENCE (MVFR/IFR) AROUND SUNRISE THERE. AFTER DRY
WEATHER OVERNIGHT INTO THURSDAY MORNING, THERE IS A HIGHER
PROBABILITY OF SHOWERS THURSDAY AFTERNOON AND EVENING WITH LOW
THUNDER CHANCES (15-25%) AT BOTH MEDFORD AND ROSEBURG.
-SPILDE/BR-Y
PREV DISCUSSION... /ISSUED 154 PM PDT WED APR 23 2025/
DISCUSSION...SATELLITE IMAGERY SHOWS A MID-LEVEL DISTURBANCE
MOVING EAST OF THE CASCADES THIS AFTERNOON WITH SOME
CONVECTIVE/CONGESTED CUMULUS ACROSS SE PORTIONS OF THE CWA. THESE
EXTEND FROM SOUTHERN KLAMATH AND EASTERN SISKIYOU COUNTIES EASTWARD
ACROSS MODOC AND SOUTHERN LAKE COUNTIES. ANY SHOWERS AND ISOLATED
THUNDERSTORMS THAT MANAGE TO DEVELOP THIS AFTERNOON WILL DIMINISH
AND END THIS EVENING AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE
AREA. BEST CHANCE FOR THUNDER (STILL LESS THAN 20%) WILL BE OVER
THE WARNER MTNS SOUTH OF LAKEVIEW. OTHERWISE, IT'S A NICE
AFTERNOON OUT THERE IN MOST OTHER AREAS WITH SUNNY SKIES AND
TEMPERATURES ABOUT 5-8F ABOVE NORMAL. A WEAK UPPER SHORT WAVE RIDGE
WILL MOVE IN OVERNIGHT INTO EARLY THURSDAY MORNING WITH DRY
CONDITIONS, THOUGH MARINE STRATUS WILL LIKELY REVISIT COASTAL
LOCATIONS/COQUILLE BASIN (IT'S ALREADY FORMING NEAR CAPE ARAGO).
THE NEXT UPPER TROUGH DIGGING OFFSHORE WILL ALLOW THE FLOW TO BACK
TO THE SSE ON THURSDAY. IT'LL REMAIN MILD IN ADVANCE OF THIS
SYSTEM, SO HIGH TEMPS WILL BE SIMILAR TO WHERE THEY ARE TODAY. A
SHORT WAVE DISTURBANCE IN THE SSE FLOW ALOFT WILL ARRIVE ACROSS
NORCAL THURSDAY AFTERNOON. INSTABILITY PARAMETERS ARE MODEST WITH
ABOUT 100-500 J/KG OF MUCAPE, BUT ALSO SOME DECENT MID-LEVEL
MOISTURE MOVING IN ALOFT. THIS WILL PROVIDE ENOUGH LIFT TO
GENERATE SOME SHOWERS, ESPECIALLY FROM THE CASCADES WESTWARD
(SISKIYOU COUNTY NORTH-NORTHWESTWARD) DURING THURSDAY AFTERNOON
AND INTO THURSDAY EVENING. THESE PROBABLY GET GOING AROUND 2-4 PM
AND PROPAGATE OFF TOWARD THE NNW THROUGH EARLY THURSDAY EVENING.
PROBABILITY OF SHOWERS DURING THIS TIME FRAME IS 40-60% ACROSS THE
WEST SIDE, WITH THUNDER CHANCES MOSTLY IN THE 20-40% CHANCE
RANGE. ACTIVITY SHOULD BE MORE ISOLATED OVER THE EAST SIDE
THURSDAY AFTERNOON/EVENING.
THE UPPER TROUGH WILL DEVELOP INTO A CLOSED LOW OFF THE NORCAL
COAST THURSDAY NIGHT, WHICH WILL MAINTAIN SHOWERS OVER OUR AREA
THURSDAY NIGHT THROUGH SATURDAY, BUT ALSO WITH A COOLING TREND
(HIGH TEMPS BACK TO NEAR OR EVEN BELOW NORMAL). THE LOW
EVENTUALLY MOVES EASTWARD ACROSS CALIFORNIA AND INTO SOUTHERN
NEVADA BY SUNDAY MORNING. SHOWERS WILL BE MOST NUMEROUS IN THE
AFTERNOONS/EVENINGS COINCIDING WITH PEAK HEATING/INSTABILITY AND
THERE IS STILL A SLIGHT CHANCE OF THUNDERSTORMS. THE FOCUS WILL BE
NEAR THE MOUNTAINS AND WEST OF THE CASCADES THROUGH FRIDAY, THEN
SOUTH AND EAST OF THE CASCADES ON SATURDAY. CONVECTIVE SHOWERS ARE
QUITE DIFFICULT TO ASSESS JUST EXACTLY WHERE AND HOW MUCH
PRECIPITATION THERE WILL BE. BUT, AMOUNTS OF 0.25-0.75 OF AN INCH
APPEAR TO BE MOST LIKELY WITH THIS EVENT, SOME PLACES (MOUNTAINS)
RECEIVING A LITTLE MORE AND SOME (VALLEYS) A LITTLE LESS.
HEIGHTS BEGIN TO RISE SUNDAY, THOUGH THERE IS STILL A CHANCE OF
SHOWERS OVER THE MOUNTAINS AND SE PORTIONS OF THE CWA. IT'LL
REMAIN ON THE COOL SIDE, BUT SHOULD BE MOSTLY NICE FOR OUTDOOR
ACTIVITIES. MODELS THEN SHOW MORE PRONOUNCED UPPER RIDGING
ARRIVING ON MONDAY WITH TEMPS REBOUNDING TO ABOVE NORMAL LEVELS.
ASIDE FROM A WEAK TROUGH SWINGING BY TO THE NORTH ON TUESDAY, THE
RIDGE SHOULD AMPLIFY INTO MID NEXT WITH TEMPERATURES GETTING BACK
CLOSE TO 80F HERE IN MEDFORD BY WEDNESDAY. -SPILDE
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 AM PDT
THURSDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ356-
376.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page