479
FXUS66 KMFR 081152
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
452 AM PDT WED APR 8 2026
UPDATED AVIATION DISCUSSION
AVIATION...08/12Z TAFS
VFR CONDITIONS WILL PREVAIL THROUGH THE
TAF PERIOD. THE MAIN AVIATION CONCERN TODAY WILL BE SHOWERS AND
THUNDERSTORMS FOCUSED ALONG THE I-5 CORRIDOR SOUTH OF THE ROGUE-
UMPQUA DIVIDE THIS AFTERNOON AND EVENING, INCLUDING THE ROGUE AND
SHASTA VALLEYS. BOTH MEDFORD AND KLAMATH FALLS TAF SITES HAVE AT
LEAST A 30% CHANCE OF A THUNDERSTORM IMPACTING THE TERMINAL TODAY.
EXPECT GUSTY AND ERRATIC OUTFLOW WINDS IN THE VICINITY OF ANY
THUNDERSTORMS TODAY. WHILE CONDITIONS SHOULD REMAIN VFR,
PRECIPITATION COULD TEMPORARILY LOWER CONDITIONS TO MVFR WITH ANY
HEFTIER CELLS.
PREV DISCUSSION
/ISSUED 305 AM PDT WED APR 8 2026/
DISCUSSION...THERE WILL BE TWO DISTINCT PATTERNS DURING THE
FORECAST PERIOD. THE FIRST BEGINS TODAY AS LOW PRESSURE
APPROACHES THE NORTHERN CALIFORNIA COAST AND LINGERS THERE THROUGH
FRIDAY. THIS IS A CLASSIC THUNDERSTORM PATTERN IN THE WARMER
MONTHS AND, WITH SPRING WELL UNDERWAY, THE FORECAST FEATURES DAILY
SHOWER/THUNDERSTORM CHANCES ACROSS THE AREA THROUGH FRIDAY,
MAINLY DURING THE AFTERNOONS AND EVENINGS. THE PATTERN TRANSITIONS
SATURDAY AS A STRONGER, AND COLDER, LOW PRESSURE DROPS SOUTHWARD
FROM THE GULF OF ALASKA. THIS PATTERN WILL LOWER THUNDERSTORM
CHANCES/ACTIVITY, BUT MAINTAIN SHOWERS (LIKELY WIDESPREAD) ACROSS
THE REGION THROUGH THE WEEKEND. SHOWER ACTIVITY TAPERS OFF EARLY
NEXT WEEK, BUT ENSEMBLES ARE CURRENTLY IN DECENT AGREEMENT ON MORE
ACTIVE WEATHER FOR THE LATTER HALF OF NEXT WEEK.
SATELLITE IMAGERY THIS MORNING SHOWS LOW PRESSURE SPINNING ALONG 40
N, CURRENTLY WEST OF 130 W. THIS LOW PRESSURE WILL GRADUALLY MOVE
EASTWARD THROUGH THE REMAINDER OF THE WEEK, MAINTAINING SOUTHERLY
FLOW OVER THE REGION. SHOWERS AND THUNDERSTORMS RETURN TO THE
FORECAST TODAY, PERSISTING THROUGH FRIDAY. MODELS ARE SHOWING AROUND
500-1000 J/KG OF SFC CAPE ALONG WITH LIS OF -2 TO -4 DURING THE
AFTERNOONS/EVENINGS, WITH SOME STRONGER INDICIES FOR THURSDAY
AFTERNOON/EVENING. THE FOCUS OF THUNDERSTORMS WILL VARY EACH DAY AND
OF THE THREE DAYS, TODAY LOOKS LIKE THE LEAST AMOUNT OF THUNDERSTORM
COVERAGE WITH THE GREATEST EXPECTED ON THURSDAY. FRIDAY COULD BE
EQUALLY AS ACTIVE AS THURSDAY, BUT LINGERING CLOUD COVER COULD LIMIT
INSTABILITY BY THE TIME WE GET TO FRIDAY. THE FOCUS FOR
SHOWER/THUNDERSTORM ACTIVITY TODAY LOOKS TO BE RIGHT ALONG AND JUST
WEST OF THE I-5 CORRIDOR IN SISKIYOU/JACKSON/JOSEPHINE COUNTIES,
WITH SOME ISOLATED ACTIVITY POSSIBLE EAST OF THE CASCADES. THE
HIGHEST CHANCES FOR LIGHTNING TODAY (50-70%) ARE FOCUSED OVER
WESTERN SISKIYOU COUNTY/SHASTA VALLEY REGION, WITH LOWER CHANCES (20-
40%) TO THE NORTH IN JACKSON/JOSEPHINE COUNTIES. LOOKING THURSDAY,
THE BULLSEYE EXTENDS NORTHWARD, COVERING MUCH OF THE AREA FROM THE
WESTERN CASCADE FOOTHILLS AND AREAS WESTWARD, INCLUDING MUCH OF
JACKSON/JOSEPHINE/DOUGLAS COUNTIES. IN THESE AREAS, THERE IS ABOUT A
60-80% CHANCE OF THUNDERSTORMS THURSDAY AFTERNOON/EVENING, WITH
AROUND 30-50% CHANCE OF THUNDERSTORMS FOR THE REST OF THE FORECAST
AREA. CHANCES ARE LOWER ALONG THE COAST, AROUND 15-25%, HIGHER FOR
AREAS SOUTH OF CAPE BLANCO. WE AREN'T EXPECTING SEVERE WEATHER AT
THIS TIME, BUT ANY LIGHTNING IS ALWAYS DANGEROUS AND OUTFLOW WINDS
WILL BE GUSTY, POSSIBLY REACHING UP 30 TO 40 MPH IN STRONGER CELLS.
WHILE ANY PRECIPITATION IS BENEFICIAL AT THIS POINT, THERE COULD BE
SOME BRIEF HEAVY DOWNPOURS RIGHT UNDER STORM CORES.
BY FRIDAY, LOW PRESSURE OFFSHORE WILL BE WEAKER, AND INSTABILITY
WON'T BE AS POTENT AS WHAT'S EXPECTED THURSDAY. THERE STILL WILL BE
WIDESPREAD SHOWER/THUNDERSTORM CHANCES, BUT THOSE CHANCES FOR
LIGHTNING LOWER TO 20 TO 30% AND THEN THERE'S THE QUESTION OF HOW
MUCH LINGERING CLOUD COVER WILL LIMIT DAYTIME INSTABILITY. AMPLE
CLOUD COVER WILL KEEP TEMPERATURES LOWER BY AROUND 5 TO 10 DEGREES
COMPARED TO RECENT DAYS. THIS COOLING TREND WILL CONTINUE INTO THE
WEEKEND AS THE UPPER LEVEL PATTERN TRANSITIONS.
LOW PRESSURE RESPONSIBLE THE LATE WEEK THUNDERSTORM ACTIVITY SHIFTS
SOUTHWARD ON SATURDAY AS LOW PRESSURE FROM THE NORTH DIGS SOUTHWARD.
THERE ARE SOME DIFFERENCES BETWEEN MODELS ON JUST HOW FAR SOUTH THIS
LOW DIGS, WITH THE GEFS BRINGING MORE INTO THE BAY AREA IN
CALIFORNIA AND OTHER SOLUTIONS BRINGING IT MORE ACROSS THE CA/OR
BORDER. THE MORE NORTHERN SOLUTION WOULD FAVOR MORE WIDESPREAD
SHOWER CHANCES ACROSS MORE OF SOUTHERN OREGON WHEREAS THE SOUTHERN
SOLUTION WOULD FOCUS SHOWER ACTIVITY ALONG AND SOUTH OF THE OR/CA
BORDER. IT STILL LOOKS LIKE THE ATMOSPHERE WILL STABILIZE SATURDAY
COMPARED TO THURSDAY AND FRIDAY, WITH MORE OF A WIDESPREAD
SHOWERS/EMBEDDED THUNDERSTORMS PATTERN VS A SOUTHERLY FLOW
THUNDERSTORM PATTERN. PRECIP CHANCES REMAIN FAIRLY HIGH (60-90%) FOR
THE WHOLE FORECAST AREA FOR SATURDAY INTO EARLY SUNDAY, THEN
DIMINISH LATER SUNDAY AS THE TROUGH MOVES EASTWARD. THE SNOW LEVEL
FORECAST HAS TRENDED LOWER, NOW EXPECTED TO LOWER TO AROUND 4000 FT
SATURDAY NIGHT INTO SUNDAY, AND SNOW AMOUNTS HAVE TRENDED UPWARD A
BIT. CURRENT FORECAST NOW BRINGS AROUND 4-6 INCHES OF SNOW IN THE
MOUNTAINS, BUT WITH THE RECENT WARM WEATHER AND THE APRIL SUN ANGLE,
WE DON'T ANTICIPATE MUCH IN THE WAY OF ROAD ACCUMULATIONS.
TEMPERATURES WILL TREND SIGNIFICANTLY COOLER OVER THE WEEKEND, AND
IT WILL FEEL PRETTY COOL DUE TO HOW WARM IT HAS BEEN. IN FACT,
AFTERNOON HIGHS ARE NOW FORECAST TO BE AROUND 5 TO 10 DEGREES BELOW
NORMAL THROUGH MONDAY (MID/UPPER 50S/LOW 60S WEST, LOW 50S/UPPER 40S
EAST).
A REINFORCING SHORTWAVE MOVES INTO THE REGION SUNDAY NIGHT INTO
MONDAY, MAINTAINING SHOWER ACTIVITY INTO EARLY MONDAY. CONDITIONS
DRY OUT LATE MONDAY AND A BREAK IN THE WEATHER IS EXPECTED THROUGH
AROUND MID-WEEK NEXT WEEK. TEMPERATURES TREND WARMER DURING THIS
TIME, BUT REMAIN MORE NEAR SEASONAL VALUES INSTEAD OF A DRASTIC WARM
UP LIKE IN RECENT DAYS. WHILE DETAILS ARE HIGHLY VARIABLE AT THIS
POINT IN TIME, BOTH GFS AND EC ENSEMBLES INDICATE THIS BREAK WILL BE
SHORTLIVED AND BRING THE RETURN OF ACTIVE WEATHER FOR THE LATTER
HALF OF NEXT WEEK.
MARINE...UPDATED 100 AM PDT WEDNESDAY, APRIL 8, 2026...FOR THE
REMAINDER OF THE WEEK, BREEZY NORTH WINDS WILL PERSIST, GENERALLY
REMAINING BELOW ADVISORY CRITERIA. BORDERLINE STEEP SEAS WILL
LINGER THROUGH AROUND SUNRISE THIS MORNING, TRANSITIONING TO FRESH
SWELL THIS MORNING AND BECOMING LESS STEEP. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER THE WATERS DURING THE
AFTERNOONS AND EVENINGS TODAY THROUGH FRIDAY. THE UPPER LEVEL
PATTERN TRANSITIONS OVER THE WEEKEND, BRINGING LESS THUNDERSTORMS
AND MORE WIDESPREAD SHOWER ACTIVITY INTO EARLY NEXT WEEK. OVERALL,
CONDITIONS LOOK TO REMAIN BELOW ADVISORY CRITERIA THROUGH THE
WEEKEND WITH WINDS BECOMING WESTERLY AND SEAS BECOMING NORTHWEST
SWELL DOMINATED.
MFR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT EARLY
THIS MORNING FOR PZZ350-356-370-376.
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