578
FXUS65 KBOI 020917
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
317 AM MDT SAT MAY 2 2026
KEY MESSAGES
- WELL ABOVE NORMAL TEMPERATURES THROUGH NEXT WEEK.
- CHANCE OF DAYTIME SHOWERS AND THUNDERSTORMS SUNDAY THROUGH
TUESDAY. GREATEST COVERAGE LIKELY MONDAY AFTERNOON/EVENING.
SHORT TERM /THROUGH MONDAY NIGHT/
AN ELONGATED CLOSED LOW OFF THE OREGON COAST WILL DIG FURTHER
OFF THE WEST COAST THROUGH MONDAY. WATER VAPOR SATELLITE
IMAGERY SHOWING PLENTY OF MOISTURE TRANSPORTED ON SOUTHERLY FLOW
WRAPPING AROUND THE EAST SIDE. FOR TODAY THIS WILL RESULT IN
MOSTLY MID-HIGH LEVEL CLOUD COVER. SHOWER AND THUNDERSTORM
DEVELOPMENT WILL INITIATE OVER CENTRAL OREGON THIS AFTERNOON,
WITH ISOLATED CELLS DRIFTING INTO WESTERN HARNEY COUNTY BY
EVENING, BRINGING LITTLE IF ANY RAIN AND A CHANCE OF GUSTY
OUTFLOW WINDS TO 35 MPH. THE CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL INCREASE TO 10-20% ALONG THE NORTHERN NV
BORDER ON SUNDAY. THE W-CENTRAL ID MTNS WILL SEE CUMULUS
BUILDUPS AS WELL, AND FOR NOW HOLD A 10% CHANCE FOR AREAS EAST
OF LOWMAN-YELLOWPINE, BUT WOULDN'T BE SURPRISED TO SEE A CELL OR
TWO POP-UP OVER HIGHER PEAKS. THE UPPER LOW CENTER IS STILL
MODELED TO TURN EAST AND TRACK INTO THE CENTRAL CA ON MONDAY.
THIS TRACK WILL PLACE SOUTHERN AREAS IN A MORE FAVORABLE
ENVIRONMENT FOR SHOWER/STORM DEVELOPMENT, AND EXPAND THE
POTENTIAL NORTHWARD INTO CENTRAL IDAHO. THE CHANCE OF
PRECIPITATION INCREASES TO 40-60% ALONG THE NV BORDER, WITH A
20-30% CHANCE INTO THE SNAKE PLAIN (EAST OF BOISE) AND W-CENTRAL
ID MTNS MAINLY EAST OF IDAHO CITY-WARM LAKE. THE MORE
WIDESPREAD THREAT WOULD CONTINUE TO BE GUSTY OUTFLOW WINDS, WITH
LOCALIZED HEAVY RAIN AND HAIL POTENTIAL FROM STRONGER STORMS
THAT DEVELOP. HIGH TEMPERATURES ARE 10-15 DEGREES ABOVE NORMAL
THROUGH MONDAY.
LONG TERM /TUESDAY THROUGH SATURDAY/
THE POSITIVELY-TILTED UPPER-LEVEL LOW/TROUGH WILL CONTINUE
MOVING EAST ACROSS THE GREAT BASIN ON TUESDAY. MOISTURE ON THE
NORTHERN FLANK OF THE LOW WILL CONTINUE SHOWER AND THUNDERSTORM
CHANCES FOR TUESDAY, PRIMARILY OVER SOUTHWEST IDAHO.
THUNDERSTORMS MAY PRODUCE BRIEF HEAVY RAIN, SMALL HAIL, AND
GUSTY WINDS. WIDESPREAD BREEZY TO GUSTY N/NW WINDS ARE ALSO
EXPECTED TUESDAY AS THE LOW PASSES. AS THE TROUGH MOVES OUT, AN
UPPER-LEVEL RIDGE QUICKLY BUILDS INTO THE PACIFIC NW, KEEPING
CONDITIONS WARM AND DRY WEDNESDAY THROUGH FRIDAY. ENSEMBLES ARE
HINTING AT A REX BLOCK PATTERN, WITH LOWER PRESSURE ALOFT IN
SOUTHERN CALIFORNIA. IF THIS WERE TO MATERIALIZE, WARM AND DRY
CONDITIONS COULD BE SEEN FOR AN EXTENDED TIME. TEMPERATURES WILL
REACH 10-15 DEGREES ABOVE NORMAL BY THURSDAY, WITH LOWER VALLEY
HIGHS IN THE LOW TO MID 80S. BY FRIDAY INTO SATURDAY, SOME
MODEL GUIDANCE INDICATES A WEAK SHORTWAVE TROUGH WILL PROVIDE
RIDGE BREAKDOWN OVER THE AREA. WHILE THIS SEEMS LIKE MORE OF AN
OUTLIER THAN THE PREDOMINANT SOLUTION, IT CREATES TWO SCENARIOS.
THIS UNCERTAINTY RESULTS IN A 10-20% CHANCE OF SHOWERS AND
THUNDERSTORMS WITH TEMPERATURES REMAINING WELL-ABOVE NORMAL.
AVIATION /06Z SATURDAY THROUGH SUNDAY/
ISSUED 1125 PM MDT FRI MAY 1 2026
VFR, WITH SCT-BKN HIGH CLOUDS. VIRGA SATURDAY PM, WITH A 10-20%
CHANCE OF SHOWERS/T-STORMS NEAR THE OR-NV BORDER SATURDAY
EVENING. POTENTIAL FOR 35 KT OUTFLOWS AND BLOWING DUST WITH
VIRGA/STORMS. SURFACE WINDS: VARIABLE UP TO 12 KT, THEN E-S 5-15
KT AFTER SAT/16Z. WINDS ALOFT AT 10KFT MSL: S-SW 5-15 KT.
KBOI...VFR, WITH SCT-BKN HIGH CLOUDS. AREAS OF REDUCED VISIBILITY
OVER BOISE MTNS DUE TO PRESCRIBED FIRES. SURFACE WINDS: SE-E
5-12 KT.
SUNDAY OUTLOOK...GENERALLY VFR WITH VIRGA. A 10-20% CHANCE OF
SHOWERS/T-STORMS SUNDAY AFTERNOON IN E OREGON, ID-NV BORDER, AND
CENTRAL ID MTNS. SURFACE WINDS: NW-NE 5-15 KT. VIRGA/STORMS
CAPABLE OF OUTFLOW WIND GUSTS TO 35 KT, CREATING POTENTIAL FOR
BLOWING DUST.
BOI WATCHES/WARNINGS/ADVISORIES
ID...NONE.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...DG
LONG TERM....CH
AVIATION.....CH
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