045
FXUS65 KPIH 181857
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
1257 PM MDT THU SEP 18 2025
KEY MESSAGES
- AVERAGE TO ABOVE AVERAGE TEMPERATURES RETURN
- VIRGA LIKELY ON FRIDAY, ALTHOUGH A FEW SPRINKLES POSSIBLE
- SHOWERS AND STORMS OVER THE WEEKEND, ESPECIALLY SUNDAY
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 1219 PM MDT THU SEP 18 2025
THE RIDGE BEGINS TO WEAKEN ACROSS THE AREA STARTING TOMORROW. WE
WILL CONTINUE TO SEE MONSOON MOISTURE INCREASING. HIGHER
RESOLUTION MODELS WANT TO PRODUCE A FEW SHOWERS OR STORMS ACROSS
OUR AREA TOMORROW AFTERNOON. THIS POTENTIALLY IS THE MODELS
GETTING A BIT ANTSY, SO TO SPEAK, AND INITIALLY WE USUALLY ONLY
SEE SOME VIRGA OR SPRINKLES WITH THIS PATTERN. WE COULD A FEW
SHOWERS AND STORMS TOMORROW NIGHT ALONG AND SOUTH OF THE SNAKE
PLAIN BASED ON CURRENT TRENDS. OUR BLEND OF MODELS LITTLE TO NO
CHANCE OF SHOWERS OR STORMS IN THE AFTERNOON AND LESS THAN 15%
CHANCE OF RAIN TOMORROW NIGHT WITH WHAT TRIES TO MOVE IN FROM
THE SOUTHWEST. THE HREF DOESN'T WANT TO PRODUCE ANY
THUNDERSTORMS OR GUSTS OVER 35 MPH, WHICH ALSO BACKS UP THE IDEA
THAT NOTHING OF NOTE IS EXPECTED FOR NOW. TEMPERATURES WILL BE
VERY SIMILAR TO TODAY, WITHIN 1-3 DEGREES AT LEAST...MEANING AT
OR JUST ABOVE AVERAGE FOR MID-SEPTEMBER.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 1219 PM MDT THU SEP 18 2025
WE SHOULD SEE SOME ACTUAL RAIN PRODUCING STORMS OVER THE
WEEKEND. OUR BLEND OF MODELS FOLLOWS THIS PATTERN, WITH A BETTER
CHANCE OF MODERATE TO LOCALLY HEAVY RAINFALL SUNDAY. ANY POCKETS
OF MODERATE/BRIEF HEAVY RAIN WILL BE HEAVILY DEPENDENT ON WHERE
STRONGER SHOWERS OR STORMS DEVELOP, IN OTHER WORDS...MAXING OUT
ON THE POTENTIAL FOR SUNSHINE AND INSTABILITY. THE BLEND MIGHT
BE A BIT SLOW IN RECOGNIZING THE POSSIBILITY OF STORMS SATURDAY
AFTERNOON AND EVENING ACROSS THE MAGIC VALLEY AND CENTRAL
MOUNTAINS. IT HAS LESS THAN 10% THERE, BUT HIGHER RESOLUTION
MODELS ARE TRENDING TOWARD AT LEAST ISOLATED COVERAGE IN THOSE
AREAS. WE WILL LEAVE THINGS AS THEY ARE FOR NOW, AND WHAT TO SEE
WHERE THINGS ARE HEADED. AFTER THAT, THE FORECAST BECOMES QUITE
A BIT MURKY. THE BLEND OF MODELS AND ECMWF WANT TO POPPED THE
RIDGE RIGHT OVER THE TOP OF US EARLY NEXT WEEK, AND DRY THINGS
OUT. IT ACTUALLY FOLLOWS THE PRIOR IDEA OF A BLOCKING PATTERN
OVER THE LOWER 48. THE GFS HAS DECIDED TO DROP A CLOSED LOW
RIGHT OVER IDAHO EARLY NEXT WEEK FOR CONTINUED SHOWERS AND
STORMS. THAT ONLY FITS ABOUT OF THE 30% OF THE CLUSTERS, OR
CLOSE ENOUGH TO POTENTIALLY FIT INTO THAT TYPE OF PATTERN. IT IS
A NEW WRINKLE OBVIOUSLY. SINCE WE ARE HEADED INTO FALL, EXPECT
TO SEE MORE CHAOS IN THE EXTENDED LIKE THIS. TEMPERATURES DO EBB
AND FLOW A BIT BASED ON CLOUD COVER AND/OR INFLUENCE OF A RIDGE
OR LOW. WE ARE STILL LOOKING AT TEMPERATURES AT/JUST ABOVE
AVERAGE EITHER WAY.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1126 AM MDT THU SEP 18 2025
VERY LITTLE IMPACT EXPECTED FOR EAST IDAHO TERMINALS THROUGH
FRIDAY MORNING. SATELLITE IMAGERY SHOWS A BROAD AREA OF MID/HIGH
CLOUDS STREAMING NORTH THROUGH NEVADA LATE THIS MORNING. EXPECT
CLOUD COVERAGE TO INCREASE ACROSS THE REGION THROUGH THE
EVENING, BUT BASES GENERALLY AROUND OR ABOVE 10KFT AGL THUS VFR.
WINDS STAY LIGHT THROUGH TONIGHT.
FIRE WEATHER
ISSUED AT 1219 PM MDT THU SEP 18 2025
RIDGE OF HIGH PRESSURE WEAKENS INTO THE WEEKEND, ALLOWING FOR SOME
MOISTURE TO SHIFT INTO IDAHO. THERE MAY BE ENOUGH INSTABILITY TO
GENERATE A FEW SHOWERS AND THUNDERSTORMS LATE FRIDAY AFTERNOON AND
EVENING, MAINLY IMPACTING 427 AND 413, THOUGH SOME MAY CREEP INTO
425 AND 410 AS WELL. MOISTURE IS VERY LIMITED, SO THE CONFIDENCE IS
LOW, AND WHATEVER CAN DEVELOP WILL LIKELY BE EXTREMELY LIMITED IN
PRECIPITATION POTENTIAL. VIRGA OR A SPRINKLE AT BEST IS THE FAR MORE
LIKELY SCENARIO FOR FRIDAY. PRECIPITATION CHANCES LOOK SLIGHTLY
BETTER FOR SATURDAY ACROSS THE SOUTHERN ZONES, THEN INCREASE TO
ISOLATED TO SCATTERED COVERAGE FOR MOST AREAS SUNDAY. PRECIPITATION
POTENTIAL PEAKS ON SUNDAY, AS MOST STORMS SHOULD BE ABLE TO APPROACH
OR EXCEED A WETTING RAIN, ALBEIT BRIEFLY. MOVING INTO THE WEEK,
MONDAY AND TUESDAY TREND DRIER UNDER A DEVELOPING BLOCKING PATTERN
ACROSS THE SOUTHWEST US. THERE ARE SOME DIFFERENCES IN THE MODELS
REGARDING HOW THE DEVELOPING RIDGE WANTS TO EVOLVE, AND THUS SOME
DOWNSTREAM DIFFERENCES IN POTENTIAL BREAKDOWN OF THAT PATTERN LATE
IN THE WEEK.
PIH WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...KEYES
LONG TERM...KEYES
AVIATION...DMH/MCKAUGHAN
FIRE WEATHER...DMH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page