642
FXUS66 KMFR 251738
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
1040 AM PDT FRI JUL 25 2025
DISCUSSION
THE AREA SAW PLENTY OF THUNDERSTORM ACTIVITY ON THURSDAY AFTERNOON
WITH THE NLDN DETECTING ABOUT 830 CLOUD TO GROUND FLASHES AND THE
ENI/ENLTN DETECTING UP TO 2500 CLOUD TO GROUND FLASHES. IF THERE
WAS ANY GOOD NEWS HERE, IT'S THAT THE STORMS WERE PRETTY SLOW
MOVING IN A RATHER MOIST ENVIRONMENT WITH PRECIPITABLE WATER(PWAT)
AROUND 1 INCH BASED OFF THE 0Z SOUNDING. IN ADDITION, WE SAW A FEW
SEVERE STORMS WITH RADAR AND SPOTTERS OBSERVING SOME SEVERE HAIL
AROUND 1" NEAR YREKA.
NOT A WHOLE LOT WILL CHANGE IN THE OVERALL ENVIRONMENT HEADING
INTO THIS AFTERNOON AND ONE CAN EXPECT MORE OF THE SAME FRIDAY
AFTERNOON. WE'LL HAVE VERY LITTLE STORM MOVEMENT AS 0-6KM SHEAR
HAS TO BE UNDER 10 KNOTS WITH SOME AREAS AROUND 20 KNOTS FARTHER
TO THE EAST AROUND HARNEY COUNTY. THE SPC HREF AGAIN IS
HIGHLIGHTING A 90-100 PERCENT CHANCE OF CLOUD TO GROUND LIGHTNING
AROUND MODOC COUNTY THIS AFTERNOON, WHICH IS PRETTY HIGH FOR OUR
AREA AND THE HIGHEST IN THE US TODAY. THOSE PROBABILITIES LOWER
THE FARTHER ONE MOVES NORTH AND WEST WITH 10% CHANCE AROUND THE
SISKIYOU MOUNTAINS NEAR JACKSON COUNTY AND NORTHERN LAKE COUNTY.
THE AMOUNT OF CONVECTIVE AVAILABLE POTENTIAL ENERGY(CAPE) IS AGAIN
ON THE HIGHER SIDE WITH POCKETS AROUND 1000 J/KG IN NORTHERN
CALIFORNIA. IN ADDITION, FORECAST SOUNDINGS HAVE A LARGE INVERTED
V WITH STORM BASES AROUND 8000 FEET, WHICH ISN'T SUPER HIGH, YET
HIGH ENOUGH TO BE CONCERNED WITH SOME STRONG OUTFLOWS FROM
STORMS. LASTLY, THE PWATS SEEM TO DIP A BIT TODAY, SO WE MIGHT SEE
STORM MODE TREND DRIER FOR PERIODS TODAY, ESPECIALLY IF THEY HAVE
A LITTLE MORE MOVEMENT.
HEADING INTO SATURDAY, STORM COVERAGE WILL BE FOCUSED ON EASTERN
LAKE AND MODOC COUNTIES. DEEPER WESTERLY FLOW WILL START TO PUSH
THINGS FARTHER EAST AND ONE COULD EVEN ANALYZE A COLD FRONT
BECOMING STATIONARY OVER OREGON ON SATURDAY AFTERNOON.
TEMPERATURES DO INDEED TREND LOWER WEST OF THE CASCADES BY ABOUT 2
OR 3 DEGREES.
MOVING TOWARDS SUNDAY AND MONDAY, WE'LL START TO SEE SOUTHERLY
FLOW WITH SOME TROUGHING OVER THE WESTERN PACIFIC. CURRENT
DETERMINISTIC MODELS SHOW A VIGOROUS SHORT WAVE HITTING
CALIFORNIA. THAT ENERGY WILL BRING THE NEXT ROUND OF THUNDERSTORMS
MID WEEK NEXT WEEK. AGAIN, AVAILABLE MOISTURE WILL BE HIGHER WITH
PWATS AROUND 1 TO 1.25 INCHES, WHICH IS ON THE HIGHER SIDE.
CONCERN WILL DEFINITELY BE WITH NEW FIRE IGNITIONS AS IT'S LOOKING
LIKE ANOTHER GOOD THUNDERSTORM EVENT.
-SMITH
AVIATION...25/18Z TAFS
AREAS OF IFR/LIFR STRATUS/FOG CONTINUE TO
IMPACT COASTAL AREAS LATE THIS MORNING WITH AN AREA OF CLEAR SKY
FROM AROUND CAPE BLANCO TO PORT ORFORD. EXPECT SOME VFR AREAS TO
DEVELOP ALONG THE COAST THIS AFTERNOON, BUT THE STRATUS PROBABLY
WON'T GO AWAY COMPLETELY. STRATUS AND/OR FOG FILLS BACK INTO COASTAL
AREAS THIS EVENING AND REMAINS THROUGH THE OVERNIGHT INTO SATURDAY
MORNING.
INLAND, VFR PREVAILS CURRENTLY, BUT SCATTERED THUNDERSTORMS ARE
EXPECTED TO DEVELOP AGAIN THIS AFTERNOON/EVENING, IMPACTING AREAS
SOUTH AND EAST OF THE MOUNTAINS (CASCADES/SISKIYOUS). THESE COULD
LOCALLY AND TEMPORARILY REDUCE VISIBILITY/CEILINGS TO IFR/MVFR. THE
MAIN FOCUS AREA SHOULD BE SLIGHTLY DISPLACED TO THE SOUTH AND EAST
OF WHERE STORMS OCCURRED YESTERDAY (GENERALLY SOUTH AND EAST OF A
LINE FROM HAPPY CAMP TO KLAMATH FALLS TO SUMMER LAKE). LOOKS LIKE
EASTERN PORTIONS OF SISKIYOU AND ALSO MUCH OF MODOC COUNTY WILL BE
THE AREA WITH THE HIGHEST PROBABILITY OF STORMS. ANY THUNDERSTORMS
WILL HAVE THE ABILITY TO PRODUCE CLOUD TO GROUND LIGHTNING, STRONG,
GUSTY OUTFLOW WIND GUSTS OF 40-60 MPH, BRIEF, HEAVY RAIN AND SMALL
HAIL. -SPILDE
MARINE...UPDATED 800 AM PDT FRIDAY, JULY 25, 2025
SUB-ADVISORY
NORTH WINDS AND LOW SEAS OF 5 FT OR LESS, WILL PERSIST THROUGH THE
WEEKEND INTO EARLY NEXT WEEK. OF NOTE, WINDS WILL BRIEFLY APPROACH
SMALL CRAFT ADVISORY LEVELS LATE THIS AFTERNOON AND EARLY EVENING,
BETWEEN PORT ORFORD AND GOLD BEACH, 2 TO 20 NM FROM SHORE. WINDS
THEN LOWER OVERNIGHT. AREAS OF FOG AND LOW STRATUS WILL ALSO PERSIST
THROUGH THIS TIME.
MFR WATCHES/WARNINGS/ADVISORIES
OR...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ624-625.
CA...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR CAZ280>282-284-285.
PACIFIC COASTAL WATERS...NONE.
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