801
FXUS66 KMFR 170959
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
259 AM PDT THU SEP 17 2026
KEY MESSAGES
* SHOWERS AND THUNDERSTORMS AGAIN TODAY. MAIN RISK IS LIGHTNING,
BUT ALSO GUSTY ERRATIC OUTFLOW WINDS (40-45 MPH), ESPECIALLY
CASCADES EASTWARD THIS AFTERNOON/EVENING. DAYTIME TEMPERATURES
REMAINING BELOW NORMAL.
* SHOWERS AND THUNDERSTORMS DIMINISH TONIGHT WITH JUST ISOLATED
ACTIVITY LINGERING OVER FAR EAST SIDE FRIDAY MORNING.
* TEMPERATURES WARM FRIDAY THROUGH THE WEEKEND GETTING BACK ABOVE
NORMAL SATURDAY AND SUNDAY.
* SIGNAL FOR DRY WEATHER AND SEASONABLE TEMPERATURES CONTINUES
FOR NEXT WEEK.
DISCUSSION
THE CLOSED LOW THAT BROUGHT THE SHOWERS AND
THUNDERSTORMS TO THE AREA YESTERDAY IS CENTERED JUST SOUTH OF OUR
AREA IN NORCAL (AROUND 40N AND 122W) THIS MORNING, NOT TOO FAR
FROM REDDING. THE LOW WILL ELONGATE AND MOVE TOWARD THE NE ACROSS
NORTHEASTERN CALIFORNIA THIS AFTERNOON AND INTO EASTERN OREGON
AND NW NEVADA TONIGHT. THIS WILL MAINTAIN A HIGH PROBABILITY OF
SHOWERS AND ALSO SOME THUNDERSTORMS TODAY, WITH THE FOCUS FROM THE
CASCADES EASTWARD, BUT ALSO STILL SOME CHANCE ON THE WEST SIDE.
SINCE THE LOW WILL BE MOVING TODAY, THE ORIENTATION OF THE FLOW
WILL CHANGE, SO WE EXPECT THINGS TO BE A BIT DIFFERENT COMPARED
TO HOW THINGS EVOLVED YESTERDAY. EAST OF THE LOW, THE FLOW IS
SOUTHERLY CURRENTLY AND THIS WILL SEND ANOTHER SURGE OF MOISTURE
NORTHWARD EAST OF THE CASCADES THIS MORNING. ALREADY SOME SHOWERS
ARE DEVELOPING OVER OUR EASTERN COUNTIES. THESE ARE MOVING TOWARD
THE NW, BUT WILL PIVOT TOWARD THE WEST AND EVEN SW AS THEY HEAD
TOWARD THE CASCADES AND THINGS DESTABILIZE AGAIN LATER THIS
MORNING AND INTO EARLY THIS AFTERNOON. MOST OF THIS ACTIVITY IS
LIKELY TO BE SHOWERS WITH PERHAPS AN EMBEDDED LIGHTNING STRIKE OR
TWO THROUGH THE MORNING HOURS. BEST INSTABILITY, WITH STEEPER
LAPSE RATES AND CAPE DEVELOPS OVER NE CALIFORNIA AND OVER THE
EAST SIDE THIS AFTERNOON/EVENING. SO, THOSE AREAS STAND THE BEST
CHANCE AT LIGHTNING WITH LESS OF A RISK OVER WEST SIDE LOCATIONS
COMPARED TO YESTERDAY. AS THE LOW HEADS TOWARD THE NE, THE FLOW
ALOFT WILL BECOME MORE NORTHERLY ON THE BACK SIDE, SO SHOWER
ACTIVITY WILL REORIENT AND MOVE MOSTLY FROM NE TO SW THIS
AFTERNOON, THEN FROM N TO S BEFORE ENDING TONIGHT. PRECIPITATION
AMOUNTS ONCE AGAIN WILL BE HIGHLY VARIABLE, THOUGH GENERALLY
0.10-0.25 OF AN INCH WITH UP TO 0.50 OF AN INCH WHERE SHOWERS ARE
MOST PERSISTENT. AMOUNTS OF 0.10 OF AN INCH OR LESS ARE MOST
LIKELY WEST OF THE CASCADES, WITH SOME AREAS ALONG THE COAST NOT
LIKELY TO SEE ANY RAINFALL.
THE CORE OF THE LOW WILL MOVE EAST OF THE AREA BY FRIDAY MORNING
AND THINGS SHOULD DRY OUT FOR MOST FRIDAY AFTERNOON (NEAREST
ACTIVITY SHOULD BE IN HARNEY COUNTY TO THE EAST). EXPECT AN
INCREASE IN AFTERNOON TEMPERATURES, STILL SLIGHTLY BELOW NORMAL.
HIGH PRESSURE BUILDING IN THIS WEEKEND SHOULD BRING A COUPLE OF
WARM, DRY DAYS. SUNDAY APPEARS TO BE THE WARMEST DAY FOR WEST SIDE
VALLEYS WITH HIGHS IN THE LOW 90S HERE IN MEDFORD. WITH THE DRIER
AIR MASS, CHILLY MORNINGS CAN BE EXPECTED EAST OF THE CASCADES
THIS WEEKEND INTO EARLY NEXT WEEK.
WE DON'T SEE MUCH CHANCE FOR IMPACTFUL WEATHER THROUGH MID NEXT
WEEK. LOW PRESSURE WILL MOVE ONSHORE TO OUR SOUTH INTO
CENTRAL/SOUTHERN CALIFORNIA ON MONDAY, WITH ZONAL FLOW ALOFT TO
OUR NORTH. UPPER RIDGING COULD DEVELOP AGAIN BY WEDNESDAY. IT
WON'T BE UNTIL LATE NEXT WEEK THAT AN UPPER TROUGH OFFSHORE
COULD BRING A FRONT TOWARD THE COAST, BUT EVEN THAT IS A LONG SHOT
AT THIS POINT. -SPILDE
AVIATION...17/12Z TAFS
OVERALL, VFR PREVAILS EARLY THIS
MORNING WITH SCATTERED SHOWERS, MAINLY OVER OUR EASTERNMOST
COUNTIES. LOCAL IFR/LIFR FOG EXISTS ALONG THE COAST, BUT HASN'T
QUITE ESTABLISHED AT NORTH BEND JUST YET. THIS MORNING, MOST AREAS
WILL REMAIN VFR, THOUGH A FEW POCKETS OF FOG/LOWER CLOUDS ARE
POSSIBLE OVER INLAND AREAS WHERE IT RAINED YESTERDAY. THESE SHOULD
ALL CLEAR TO VFR DURING THE MORNING. EXPECT MORE WIDEPSREAD
SHOWERS LATER THIS MORNING/AFTERNOON WITH SCATTERED THUNDERSTORMS
DEVELOPING THIS AFTERNOON AND PERSISTING INTO THIS EVENING. WHILE
AN ISOLATED THUNDERSTORM IS POSSIBLE OVER THE WEST SIDE, BEST
INSTABILITY AND LIGHTNING RISK WILL BE FROM THE CASCADES EAST.
STRONGER CELLS COULD BRIEFLY REDUCE CONDITIONS TO MVFR, BUT VFR
SHOULD PREVAIL. -SPILDE
MARINE...UPDATED 200 AM PDT THURSDAY, SEPTEMBER 16, 2026
GUSTY
NORTH WINDS AND STEEP SEAS WILL CONTINUE THIS MORNING. CONDITIONS
EASE BELOW ADVISORY CRITERIA THIS AFTERNOON AND LIKELY PERSIST
THROUGH FRIDAY NIGHT. NORTH WINDS INCREASE AGAIN SATURDAY WITH
STEEP TO HAZARDOUS SEAS POSSIBLE AGAIN BY SATURDAY NIGHT,
ESPECIALLY SOUTH OF CAPE BLANCO. -SPILDE
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 AM PDT THIS
MORNING FOR PZZ350-356-370-376.
MAS
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