000
FXUS65 KPIH 210939
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
339 AM MDT TUE MAY 21 2013
.SHORT TERM...TODAY THROUGH THU NIGHT. A BRIEF BREAK BEFORE
A RATHER STRONG SHORTWAVE ENTERS THE GEM STATE AND AFFECTS THE
WESTERN PART OF THE FORECAST AREA WED AFTERNOON. IN THE UNSTABLE
AIR LEFT BEHIND FROM THE SUNDAY TROUGH...SOME AFTERNOON AND EARLY
EVENING SHOWERS ARE POSSIBLE...BUT SHOULD BE MAINLY DRY
THUNDERSTORMS AND ONLY EXPECTED TO BE ISOLATED. AS THE NEXT TROUGH
MOVES IN LATE WED AFTERNOON...IT COULD BRING MODERATE TO STRONG
WIND...WHICH IS ENOUGH FOR A LAKE WIND ADVISORY. 90KT-PLUS JET...50KT-
60KT WINDS AT 500MB...AND ABOUT A 10MB PRESSURE GRADIENT ACROSS
SOUTHERN IDAHO WILL ALL WORK TO BOOST THE WIND. HOWEVER 700MB
WINDS ARE WEAK AND MAINLY FROM THE SOUTH...AND WINDS AT HIGHER
LEVELS ALSO FROM THE SOUTH AND SOUTHWEST...WHICH DO NOT SUPPORT
THE SURFACE WINDS. THE COLD AIR ADVECTION IS ALSO WEAK. THUS DO
NOT THINK A WHOLE SALE WIND ADVISORY IS NEEDED...JUST LAKE WIND.
WIND SHOULD BE SIMILAR ON THU. THE STRONG PRECIPITATION BAND
MOVES SLOWLY THROUGH THE FORECAST AREA...MAINLY AFFECTING THE
NORTHERN AND WESTERN ZONES FROM WED NIGHT THROUGH THU NIGHT. THE
CLOUD UP AND COLDER AIR MASS BEHIND THE FRONT WILL MEAN COOLER
TEMPERATURES AFTER TODAY. SOME SNOW IS POSSIBLE IN THE HIGH
ELEVATIONS...BUT TREND IS FOR LIGHTER PRECIPITATION AMOUNTS ON THE
NAM. GFS IS MUCH WETTER WITH AS MUCH AS 0.40 INCH LIQUID WATER
EQUIVALENT IN THE MOUNTAINS. HOWEVER THE SNOW LEVEL SHOULD RISE
DURING THE AFTERNOON EVEN IN THIS PATTERN AND SNOW BELOW 8000 FEET
ELEVATION SHOULD BE RARE. MESSICK
.LONG TERM...FRI THROUGH MON NIGHT. STORM DURING THE NEAR TERM
DEPARTS FRI MORNING...BUT AN ANCHOR LOW STILL SITS OVER THE
PACIFIC NORTHWEST WITH MORE SHORTWAVES EXPECTED TO ENTER THE BASE
OF THE UPPER LEVEL TROUGH AND EJECT NORTHEASTWARD. HOWEVER THE
TRAJECTORY IS NOT AS SOLID A STRIKE ON EASTERN IDAHO. THE CENTRAL
IDAHO MOUNTAINS BEAR THE BRUNT OF IT FOR THE FORECAST AREA...WITH
OTHER AREAS RECEIVING LITTLE PRECIPITATION. THE MAIN SHORTWAVE
DURING THIS PERIOD IS ON SUN/SUN NIGHT. THIS NEXT SHORTWAVE DOES
NOT PACK MUCH IN WIND...AND PRECIPITATION IS FAIRLY LIGHT.
FORECAST CONFIDENCE IS LOW...AS THE ECMWF DOESNT REALLY EVEN HAVE
THIS TROUGH. IT BRINGS IN A WEAKER TROUGH ON TUE. SO HAVE REALLY
BROAD-BRUSHED TOWARDS THE END OF THE EXTENDED FORECAST. MESSICK
&&
.AVIATION...TRANSITORY RIDGE PUSHES ACROSS EASTERN IDAHO TODAY. DEEP
PACIFIC LOW ALREADY ENCROACHING ON PACNW COAST WITH MOISTURE
PUNCHING THROUGH SOUTHERN OREGON THIS MORNING...EXPECTED TO REACH
EASTERN IDAHO THIS AFTERNOON. CONVECTION POSSIBLE AGAIN MAINLY OVER
CENTRAL MOUNTAINS AND FAR NORTHEAST CORNER THIS AFTERNOON AND
EVENING WITH MVFR CONDITIONS. DMH
&&
.FIRE WEATHER...A WEAK RIDGE WILL PASS BY THE FIRE DISTRICT THIS
MORNING. THE NEXT PACIFIC TROUGH ALREADY ALONG THE PACNW COAST WILL
PUSH MOISTURE BACK INTO EASTERN IDAHO TODAY WITH ANOTHER THREAT OF
AFTERNOON AND EVENING CONVECTION MAINLY IN THE CENTRAL MOUNTAINS AND
ALONG THE NORTHEAST PORTIONS OF THE DISTRICT. A COLD FRONT TO PASS
THROUGH THE REGION EARLY WEDNESDAY MORNING WITH GUSTY WINDS THROUGH
THE DAY AND ANOTHER ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS65 KPIH 201955
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
155 PM MDT MON MAY 20 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY. AN UPPER LOW OVER THE
NORTHERN PLAINS TODAY STILL HAS MOISTURE CIRCULATING INTO EASTERN
IDAHO. THIS WILL ALLOW FOR SHOWERS AND A FEW TSTMS OVER MAINLY THE
EASTERN HIGHLANDS AND CENTRAL MTNS INTO THIS EVENING. A FEW MAY
SPILL INTO THE UPPER SNAKE PLAIN AS WELL. UPPER RIDGING BUIIDS
INTO THE NORTHERN ROCKIES ON TUE...AHEAD OF A DEEP UPPER LOW
MOVING INTO THE PAC NW. SHOWERS WILL SPREAD INTO THE CENTRAL MTNS
TUE AFTN AND EVE. THE UPPER LOW IS EXPECTED TO ANCHOR ITSELF OVER
OREGON FOR WED AND THU. SHOWERS AND A FEW AFTN/EVE TSTMS CAN BE
EXPECTED WED AND THU MAINLY OVER THE NORTHERN PARTS OF THE FCST
AREA...ALONG WITH COOLER TEMPS. MODELS HAVE BEEN INCONSISTENT ON
THE POSITION OF THIS UPPER LOW. IF IT TRACKS MORE TO THE SE...
PRECIP WILL SPREAD TO MUCH OF THE FCST AREA. AS IT STANDS
NOW...STRONG SOUTHERLY FLOW AHEAD OF THE UPPER LOW WILL RESULT IN
DOWNSLOPE OVER THE SOUTHERN HIGHLANDS AND SNAKE RIVER PLAIN. THIS
WILL KEEP THE SOUTHERN PARTS OF THE FCST AREA DRY. HEDGES
.LONG TERM...THURSDAY EVENING THROUGH MONDAY. MODELS CONTINUE TO
SHOW AN UPPER LEVEL LOW OVER WESTERN WASHINGTON AND OREGON EARLY
IN THE PERIOD BRINGING AN RELATIVELY DRY SOUTHWEST FLOW OVER AREA.
EXPECT ANY SHOWERS AND THUNDERSTORMS MAINLY OVER OUR NORTHERN
AREAS EARLY IN THE PERIOD. MODELS SHOW THIS UPPER LEVEL LOW MOVING
NORTH OVER CANADA AND WEAKENING OVER THE WEEKEND. BY LATE SUNDAY
INTO MONDAY MODELS SHOW AN UPPER LEVEL OPEN TROUGH MOVING OVER OUR
AREA ALLOWING FOR A SLIGHTLY BETTER CHANCE OF PRECIPITATION OVER
OUR AREA. LOOK FOR NEAR NORMAL TEMPERATURES THROUGH THE PERIOD. A
SLIGHT EASTERN AND/OR SOUTHERN SHIFT IN THE UPPER LEVEL LOW WILL
BRING US A MUCH COOLER AND WETTER HOLIDAY WEEKEND THAN OUR CURRENT
FORECAST. PARTICULARLY THOSE WITH HOLIDAY OUTDOOR PLANS...PLEASE
MONITOR THE FORECAST FOR ANY POSSIBLE CHANGES IN THE FORECAST.
WYATT
&&
.AVIATION...LOOK FOR VICINITY SHOWERS AND THUNDERSTORMS ACROSS OUR
CENTRAL AND EASTERN AREAS MAINLY IMPACTING KIDA THIS AFTERNOON...
THOUGH KPIH AND KSUN HAVE A SLIGHT CHANCE TO BE IMPACTED AS WELL.
EXPECT SLIGHTLY BREEZY WINDS THIS AFTERNOON. LOOK FOR GRADUALLY
CLEARING AND LIGHTER WINDS OVERNIGHT INTO TOMORROW MORNING WITH HIGH
PRESSURE RIDGING BUILDING INTO THE AREA. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS65 KPIH 200859
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
259 AM MDT MON MAY 20 2013
.SHORT TERM...TODAY THROUGH WED. SHOWERS AND AFTERNOON
THUNDERSTORMS WILL CONTINUE WITH A COLD CORE ALOFT GENERATING
ENOUGH INSTABILITY WITH PLENTY OF AVAILABLE MOISTURE FOR SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS. UPPER LEVEL CLOSED LOW IS SLOW TO
MOVE...BUT BY TUE MORNING SHOULD HAVE MOST OF THE PRECIPITATION
END WITH ONLY A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ALONG
THE ID-WY BORDER BY TUE AFTERNOON AND EVENING. THE KICKER FOR THIS
FIRST LOW THEN MOVES ONSHORE BY TUE NIGHT.THIS IS AN INTENSE LOW
THAT WILL BRING PRECIPITATION AS EARLY AS TUE NIGHT IN THE
SAWTOOTHS AND TETONS. GUIDANCE CONTINUES TO INDICATE THAT THE
PRECIPITATION WILL MAINLY BE IN MONTANA...WITH ONLY THE MONTANA
BORDER REGION OF THE FORECAST AREA HAVING SIGNIFICANT POPS ON TUE
NIGHT/WED. STRONG UPPER LEVEL WINDS COULD POSSIBLY AFFECT EASTERN
IDAHO WITH MODERATE TO STRONG WIND BY WED AFTERNOON...BUT UNTIL
THEN WIND SHOULD CONTINUE LIGHT TO MODERATE. WITH THE CLEARER
SKIES TUE...THIS SHOULD BE THE WARMEST DAY OF THE NEAR TERM.
TEMPERATURES HAVE A CHANCE TO GET ABOVE NORMAL AFTER THE PREVIOUS
THREE DAYS OF CLOUDS AND RAIN...BUT WILL BE COOL AGAIN WED.
OVERNIGHT LOWS WITH WITH THE CLOSED LOW COULD MEAN SNOW ABOVE 8500
FEET ELEVATION...BUT SHOULD NOT ACCUMULATE TO ANY SIGNIFICANT
AMOUNT. MESSICK
.LONG TERM...WED NIGHT THROUGH SUN NIGHT. THE INTENSE PACIFIC
NORTHWEST UPPER LEVEL LOW WILL SLOWLY SPIN IN PLACE THROUGH THU
NIGHT. EXPECT CONTINUED SHOWERY WEATHER...MAINLY FOR THE NORTHERN
HALF OF THE FORECAST AREA...WITH AFTERNOON THUNDERSTORMS POSSIBLE
IN THE UNSTABLE AIR. THU HAS THE MOST SIGNIFICANT SHORTWAVE ENTER
THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD ACROSS THE GEM
STATE. THIS SHORTWAVE IS ENOUGH TO LIFT THE ENTIRE UPPER LEVEL LOW
TO THE NORTH-NORTHEAST FOR THE SECOND HALF OF THIS EXTENDED
PERIOD. THIS WILL MEAN CLEARER SKIES ONCE AGAIN WITH A LOWERED
THREAT OF SHOWERS AND THUNDERSTORMS AFTER THU NIGHT. THE NEXT
UPSTREAM LOW COULD ARRIVE AS EARLY AS SUN AFTERNOON...SO IT IS
MAINLY A THREAT IN THE CENTRAL IDAHO MOUNTAINS. MESSICK
&&
.AVIATION...REMNANTS OF DEPARTING UPPER LOW WILL LINGER ACROSS
EASTERN IDAHO TODAY. SHOWERS CONTINUE THIS MORNING UNDER VFR
CONDITIONS BUT EXPECT AFTERNOON INSTABILITY TO PRODUCE A FEW
THUNDERSTORMS AS WELL. CONDITIONS WILL REMAIN MAINLY VFR WITH
OCCASIONAL MVFR IN SLIGHTLY LOWER CEILINGS AND VISIBILITIES UNDER
THE STRONGER CELLS. DMH
&&
.FIRE WEATHER...SHOWERS AND ISOLATED THUNDERSTORMS WILL REMAIN
ACROSS EASTERN IDAHO THROUGH THIS EVENING AS AN UPPER LOW CONTINUES
TO SHIFT EAST. AN UPPER RIDGE WILL BE IN PLACE FOR TUESDAY...BUT
LINGERING MOISTURE MAY ALLOW SHOWERS TO DEVELOP OVER HIGHER TERRAIN
AREAS. THE CENTRAL MOUNTAINS...CLOSEST TO NEXT UPPER LOW DEEPENING
OVER THE PAC NW COAST...MAY BE MOST VULNERABLE TO AFTERNOON
CONVECTION TUESDAY. THE PAC NW LOW REMAINS IN PLACE THROUGH FRIDAY
WITH THE THREAT OF UNSETTLED CONDITIONS...THEN THE CENTER FILLS AND
LIFTS NORTHEAST ON SATURDAY. EASTERN IDAHO REMAINS UNDER SOUTHWEST
FLOW WITH CONTINUED TROUGH CONDITIONS OVER THE WESTERN STATES. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS65 KPIH 191948
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
148 PM MDT SUN MAY 19 2013
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
SHOWERS AND A FEW THUNDERSTORMS CONTINUE ACROSS THE REGION. THE
LOW PRESSURE SYSTEM RESPONSIBLE FOR THE UNSETTLED CONTINUE TO MOVE
EASTWARD INTO THE MIDWEST. THIS IS A RATHER LARGE SYSTEM AND
MODELS CONTINUE TO SHOW ISOLATED SHOWERS AND THUNDERSTORMS
PERSISTING OVER THE MOUNTAINS AND HIGHLANDS INTO MONDAY. BY
TUESDAY...A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE AREA AND
PRODUCE MAINLY DRY CONDITIONS.
VALLE
.LONG TERM...WEDNESDAY MORNING THROUGH SUNDAY. BOTH MODELS ARE IN
FAIRLY GOOD AGREEMENT SHOWING AN UPPER LEVEL LOW DROP OVER OREGON
AND WASHINGTON BRINGING LIGHT SHOWERS OVER OUR AREA EARLY IN THE
PERIOD. NEAR THE END OF THE PERIOD THE MODELS SHOW THE UPPER LEVEL
LOW MOVING BACK NORTH OVER CANADA AND SENDING A WEAK WAVE OVER OUR
AREA. LOOK FOR NEAR AVERAGE TO SLIGHTLY ABOVE AVERAGE TEMPERATURES
THROUGH THE PERIOD. WYATT
&&
.AVIATION...LOOK FOR VICINITY SHOWERS AND THUNDERSTORMS FOR ALL TAF
SITES THIS AFTERNOON INTO EARLY EVENING. EXPECT LINGERING MVFR CIGS
FOR KIDA EARLY THIS AFTERNOON DURING PERIODS OF SHOWERS. TOMORROW
MORNING VICINITY SHOWERS ARE POSSIBLE FOR KIDA AND KPIH. LOOK FOR
MVFR CIGS/VIS FOR KIDA AND KPIH TOMORROW MORNING DURING ANY PERIODS
OF SHOWERS ON STATION. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS65 KPIH 191811
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
1211 PM MDT SUN MAY 19 2013
.UPDATE...
UPDATING FORECAST TO INCREASE RAIN CHANCES ACROSS THE UPPER SNAKE
PLAIN. MORNING SHOWERS ARE NOT DISSIPATING AND SHOWERS LOOK VERY
LIKELY FOR THAT REGION.
VALLE
&&
.PREV DISCUSSION... /ISSUED 300 AM MDT SUN MAY 19 2013/
DISCUSSION...ACTIVE TROUGH CONTINUES OVER THE NORTHERN ROCKIES
AND PACNW. WV SAT IMAGERY SHOWS A WEAK CIRCULATION OVER EASTERN
IDAHO WITH WEAK CONVECTION OCCURRING THIS MORNING IN THE UPPER
SNAKE PLAIN AND EASTERN HIGHLANDS. A SECOND STRONGER SHORTWAVE
SLIDING INTO WESTERN IDAHO THIS MORNING PROGGED TO REACH THE
REGION LATER TODAY. AIR MASS AGAIN WEAKLY UNSTABLE SO CONTINUED
HIGH CHANCE SHOWERS MOST LOCATIONS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON. SHORTWAVE EXITS THE REGION TONIGHT WITH FLOW ALOFT
TURNING NORTHERLY AHEAD OF BUILDING RIDGE. BOTH GFS AND NAM LINGER
SOME WEAK CONVECTION ALONG THE EASTERN HIGHLANDS INTO MONDAY BUT
OVERALL TREND IS DRIER. RIDGE AXIS IN PLACE FOR TUESDAY BUT GFS
HOLDING ON TO POTENTIAL FOR WEAK CONVECTION ALONG NORTHERN
FORECAST AREA BORDER. THUS KEPT WEAK COLLABORATION POPS ALONG THE
FRINGES OF THE REGION.
MUCH DEEPER UPPER LOW SETTLES INTO THE PACNW FOR MUCH OF THE
REMAINDER OF THE FORECAST PERIOD. MODELS IN GENERAL AGREEMENT WITH
CENTER OF THE LOW CIRCULATING OVER OREGON/WASHINGTON WITH MULTIPLE
SHORTWAVES ROTATING AROUND THE LOW ACROSS EASTERN IDAHO. THAT
SAID...BOTH GFS AND ECMWF REMAIN SOMEWHAT SKIMPY WITH QPF FIELDS
OVER EASTERN IDAHO AS LOW REMAINS WEST OF THE REGION THROUGH THURSDAY.
ECMWF SLIGHTLY WETTER THAN THE GFS...AND ENOUGH TO KEEP POPS
AROUND OR SLIGHTLY HIGHER THAN CLIMO THROUGH THAT TIME. BY
FRIDAY...BOTH MODELS BEGIN TO OPEN THE LOW AND LIFT IT NORTHEAST
ENDING IN SOUTHERN ALBERTA BY SATURDAY MORNING. GFS DROPS A
SECONDARY TROUGH ALONG THE COAST WITH DRY CONDITIONS OVER IDAHO
SATURDAY INTO SUNDAY WHILE THE ECMWF MAINTAINS A FLATTER AND
SLIGHTLY WETTER FLOW. MADE LITTLE CHANGE FROM PERSISTENCE FOR DAYS
7 TO 8. DMH
AVIATION...NORTHERLY FLOW ALOFT ON THE BACK SIDE AND EXISTING STORM
SYSTEM WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS
THE REGION TODAY. MVFR CEILINGS ARE POSSIBLE THIS MORNING AT KIDA
AND KPIH. THIS AFTERNOON ISOLATED THUNDERSTORMS MAY PRODUCE GUSTY
WINDS AND MVFR CEILINGS. WINDS MAY GUST A LITTLE THIS AFTERNOON AS
WELL AS NEAR ANY THUNDERSTORMS. PRESTON
FIRE WEATHER...ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE TODAY
ACROSS ALL DISTRICTS. MONDAY AND TUESDAY A RIDGE OF HIGH PRESSURE
BUILDS WITH LIGHTER WINDS, WARMING TEMPERATURES AND LOWER RELATIVE
HUMIDITIES. A LOW PRESSURE SYSTEM DEVELOPS IN THE PACIFIC NORTHWEST
BUT OUR AREA WILL REMAIN IN THE WARM AND DRY SECTOR EXPECT THE
CENTRAL IDAHO MOUNTAINS MAY SEE ISOLATED AFTERNOON THUNDERSTORM
POTENTIAL THROUGH FRIDAY. PRESTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS65 KPIH 190900
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
300 AM MDT SUN MAY 19 2013
.DISCUSSION...ACTIVE TROUGH CONTINUES OVER THE NORTHERN ROCKIES
AND PACNW. WV SAT IMAGERY SHOWS A WEAK CIRCULATION OVER EASTERN
IDAHO WITH WEAK CONVECTION OCCURRING THIS MORNING IN THE UPPER
SNAKE PLAIN AND EASTERN HIGHLANDS. A SECOND STRONGER SHORTWAVE
SLIDING INTO WESTERN IDAHO THIS MORNING PROGGED TO REACH THE
REGION LATER TODAY. AIR MASS AGAIN WEAKLY UNSTABLE SO CONTINUED
HIGH CHANCE SHOWERS MOST LOCATIONS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON. SHORTWAVE EXITS THE REGION TONIGHT WITH FLOW ALOFT
TURNING NORTHERLY AHEAD OF BUILDING RIDGE. BOTH GFS AND NAM LINGER
SOME WEAK CONVECTION ALONG THE EASTERN HIGHLANDS INTO MONDAY BUT
OVERALL TREND IS DRIER. RIDGE AXIS IN PLACE FOR TUESDAY BUT GFS
HOLDING ON TO POTENTIAL FOR WEAK CONVECTION ALONG NORTHERN
FORECAST AREA BORDER. THUS KEPT WEAK COLLABORATION POPS ALONG THE
FRINGES OF THE REGION.
MUCH DEEPER UPPER LOW SETTLES INTO THE PACNW FOR MUCH OF THE
REMAINDER OF THE FORECAST PERIOD. MODELS IN GENERAL AGREEMENT WITH
CENTER OF THE LOW CIRCULATING OVER OREGON/WASHINGTON WITH MULTIPLE
SHORTWAVES ROTATING AROUND THE LOW ACROSS EASTERN IDAHO. THAT
SAID...BOTH GFS AND ECMWF REMAIN SOMEWHAT SKIMPY WITH QPF FIELDS
OVER EASTERN IDAHO AS LOW REMAINS WEST OF THE REGION THROUGH THURSDAY.
ECMWF SLIGHTLY WETTER THAN THE GFS...AND ENOUGH TO KEEP POPS
AROUND OR SLIGHTLY HIGHER THAN CLIMO THROUGH THAT TIME. BY
FRIDAY...BOTH MODELS BEGIN TO OPEN THE LOW AND LIFT IT NORTHEAST
ENDING IN SOUTHERN ALBERTA BY SATURDAY MORNING. GFS DROPS A
SECONDARY TROUGH ALONG THE COAST WITH DRY CONDITIONS OVER IDAHO
SATURDAY INTO SUNDAY WHILE THE ECMWF MAINTAINS A FLATTER AND
SLIGHTLY WETTER FLOW. MADE LITTLE CHANGE FROM PERSISTENCE FOR DAYS
7 TO 8. DMH
&&
.AVIATION...NORTHERLY FLOW ALOFT ON THE BACK SIDE AND EXISTING STORM
SYSTEM WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS
THE REGION TODAY. MVFR CEILINGS ARE POSSIBLE THIS MORNING AT KIDA
AND KPIH. THIS AFTERNOON ISOLATED THUNDERSTORMS MAY PRODUCE GUSTY
WINDS AND MVFR CEILINGS. WINDS MAY GUST A LITTLE THIS AFTERNOON AS
WELL AS NEAR ANY THUNDERSTORMS. PRESTON
&&
.FIRE WEATHER...ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE TODAY
ACROSS ALL DISTRICTS. MONDAY AND TUESDAY A RIDGE OF HIGH PRESSURE
BUILDS WITH LIGHTER WINDS, WARMING TEMPERATURES AND LOWER RELATIVE
HUMIDITIES. A LOW PRESSURE SYSTEM DEVELOPS IN THE PACIFIC NORTHWEST
BUT OUR AREA WILL REMAIN IN THE WARM AND DRY SECTOR EXPECT THE
CENTRAL IDAHO MOUNTAINS MAY SEE ISOLATED AFTERNOON THUNDERSTORM
POTENTIAL THROUGH FRIDAY. PRESTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS65 KPIH 190303
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
905 PM MDT SAT MAY 18 2013
.SHORT TERM...TONIGHT THROUGH MONDAY EVENING. A QUICK UPDATE THIS
EVENING TO EXPIRE THE LAKE WIND ADVISORY WITH SOME MINOR TWEEKS TO
PRECIPITATION COVERAGE TONIGHT GIVEN CLEARING SKIES TO WEST. SEE
PREVIOUS DISCUSSION BELOW. HUSTON
A LOW PRESSURE SYSTEM MOVING INTO SOUTHWEST WYOMING BROUGHT WET
WEATHER TO PORTIONS OF THE CENTRAL MOUNTAINS...UPPER SNAKE PLAIN AND
EASTERN HIGHLANDS TODAY. GUSTY WINDS ARE OCCURRING BEHIND THE LOW. A
LAKE WIND ADVISORY REMAINS IN EFFECT FOR THE AMERICAN FALLS
RESERVOIR INTO THE EVENING HOURS BECAUSE OF THE WINDS. EXPECT
SHOWERS TO DIMINISH LATER THIS EVENING. ANOTHER WEAK LOW PRESSURE
SYSTEM WILL MOVE THROUGH THE REGION ON SUNDAY. THIS WILL PRODUCE
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA FOR SUNDAY
AFTERNOON AND EVENING. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE
REGION ON MONDAY. THIS WILL PRODUCE DRY CONDITIONS OVER MUCH OF THE
AREA...HOWEVER ENOUGH MOISTURE WILL BE AROUND TO TRIGGER ISOLATED TO
SCATTERED SHOWERS OVER THE MOUNTAINS AND EASTERN HIGHLANDS ON
MONDAY. TEMPS WILL REMAIN COOL ON SUNDAY...BUT SHOULD REBOUND INTO
THE 70S ON MONDAY WITH ADDITIONAL SUNSHINE IN THE FORECAST. VALLE
.LONG TERM...TUESDAY MORNING THROUGH SATURDAY. MODELS CONTINUE TO
SHOW HIGH PRESSURE RIDGING OVER THE AREA EARLY IN THE PERIOD WITH
GRADUAL WARMING TEMPERATURES THROUGH THE PERIOD. ALSO THE MODELS ARE
CONTINUING THEIR TREND OF BRINGING AN UPPER LEVEL LOW OVER THE
NORTHWEST BY THE END OF THE WEEK INTO THE WEEKEND. THE ECMWF BRINGS
THE LOW A LITTLE FARTHER EAST OVER THE WASHINGTON AND OREGON
BRINGING MORE PRECIPITATION OVER OUR AREA. THE GFS MODEL CONTINUES
TO DROP THE LOW DOWN JUST OFF THE PACIFIC COAST BRINGING DRIER
CONDITIONS OVER SOUTHEAST LATE IN THE WEEKEND INTO THE WEEKEND.
WYATT
&&
.AVIATION...SHOWERS ARE JUST ENDING FOR KIDA. LOOK FOR LINGERING
IFR/MVFR CIGS UNTIL LATE THIS AFTERNOON INTO EARLY EVENING. EXPECT
VICINITY SHOWERS FOR KPIH AND KIDA THROUGH EARLY EVENING. LOOK FOR
VICINITY THUNDERSTORMS FOR KSUN THIS AFTERNOON INTO EARLY EVENING.
TOMORROW LOOK FOR VICINITY THUNDERSTORMS BY LATE MORNING FOR ALL TAF
SITES AS AN ADDITIONALLY DISTURBANCE MOVES THROUGH THE AREA. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
000
FXUS65 KPIH 181956
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
156 PM MDT SAT MAY 18 2013
.SHORT TERM...A LOW PRESSURE SYSTEM MOVING INTO SOUTHWEST WYOMING
BROUGHT WET WEATHER TO PORTIONS OF THE CENTRAL MOUNTAINS...UPPER
SNAKE PLAIN AND EASTERN HIGHLANDS TODAY. GUSTY WINDS ARE OCCURRING
BEHIND THE LOW. A LAKE WIND ADVISORY REMAINS IN EFFECT FOR THE
AMERICAN FALLS RESERVOIR INTO THE EVENING HOURS BECAUSE OF THE
WINDS. EXPECT SHOWERS TO DIMINISH LATER THIS EVENING. ANOTHER WEAK
LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION ON SUNDAY. THIS
WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA
FOR SUNDAY AFTERNOON AND EVENING. A RIDGE OF HIGH PRESSURE WILL
BUILD INTO THE REGION ON MONDAY. THIS WILL PRODUCE DRY CONDITIONS
OVER MUCH OF THE AREA...HOWEVER ENOUGH MOISTURE WILL BE AROUND TO
TRIGGER ISOLATED TO SCATTERED SHOWERS OVER THE MOUNTAINS AND
EASTERN HIGHLANDS ON MONDAY. TEMPS WILL REMAIN COOL ON
SUNDAY...BUT SHOULD REBOUND INTO THE 70S ON MONDAY WITH ADDITIONAL
SUNSHINE IN THE FORECAST.
VALLE
.LONG TERM...TUESDAY MORNING THROUGH SATURDAY. MODELS CONTINUE TO
SHOW HIGH PRESSURE RIDGING OVER THE AREA EARLY IN THE PERIOD WITH
GRADUAL WARMING TEMPERATURES THROUGH THE PERIOD. ALSO THE MODELS ARE
CONTINUING THEIR TREND OF BRINGING AN UPPER LEVEL LOW OVER THE
NORTHWEST BY THE END OF THE WEEK INTO THE WEEKEND. THE ECMWF BRINGS
THE LOW A LITTLE FARTHER EAST OVER THE WASHINGTON AND OREGON
BRINGING MORE PRECIPITATION OVER OUR AREA. THE GFS MODEL CONTINUES
TO DROP THE LOW DOWN JUST OFF THE PACIFIC COAST BRINGING DRIER
CONDITIONS OVER SOUTHEAST LATE IN THE WEEKEND INTO THE WEEKEND.
WYATT
&&
.AVIATION...SHOWERS ARE JUST ENDING FOR KIDA. LOOK FOR LINGERING
IFR/MVFR CIGS UNTIL LATE THIS AFTERNOON INTO EARLY EVENING. EXPECT
VICINITY SHOWERS FOR KPIH AND KIDA THROUGH EARLY EVENING. LOOK FOR
VICINITY THUNDERSTORMS FOR KSUN THIS AFTERNOON INTO EARLY EVENING.
TOMORROW LOOK FOR VICINITY THUNDERSTORMS BY LATE MORNING FOR ALL TAF
SITES AS AN ADDITIONALLY DISTURBANCE MOVES THROUGH THE AREA. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING IDZ021.
&&
$$
000
FXUS65 KPIH 181536
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
936 AM MDT SAT MAY 18 2013
.UPDATE...
UPDATED FORECAST TO ISSUE A LAKE WIND ADVISORY FOR THE AMERICAN
FALLS RESERVOIR. OBSERVATIONS THE PAST COUPLE OF HOURS HAVE SHOWN
WIND SPEEDS NEAR 20 MPH. EXPECT WINDS TO REMAIN NEAR THIS SPEED
THROUGH THE AFTERNOON AND EARLY EVENING. MADE SOME MINOR
ADJUSTMENTS TO SKY AND PRECIPITATION CHANCES FOR THE AFTERNOON AND
TONIGHT AS WELL. STILL LOOKS RATHER UNSETTLED ACROSS THE REGION
TODAY...ESPECIALLY OVER THE EASTERN HIGHLANDS.
VALLE
&&
.PREV DISCUSSION... /ISSUED 311 AM MDT SAT MAY 18 2013/
DISCUSSION...SAT IMAGERY SHOWS COMPLEX UPPER TROUGH SWINGING
THROUGH THE REGION THIS MORNING. MAIN CIRCULATION CENTER OVER
NORTHWEST UTAH THIS MORNING...WITH LARGE SWATH OF PRECIPITATION
EXTENDING NORTH INTO SOUTHEAST CORNER OF EASTERN IDAHO PER RADAR
IMAGERY. NEXT CIRCULATION OF INTEREST IN NORTHEAST OREGON WITH
SMALLER AND WEAKER AREA OF PRECIPITATION ASSOCIATED WITH IT.
MODELS SWING TROUGH NORTHEAST THIS MORNING WITH NEGATIVE TILT.
AIRMASS BECOMES WEAKLY UNSTABLE BY 18Z OVER MOST OF THE REGION SO
HAVE MAINTAINED HIGH POP GRIDS THROUGH THE DAY WITH ISOLATED
THUNDER INTO THE AFTERNOON. EASTERN IDAHO REMAINS UNDER THE
INFLUENCE OF CYCLONIC FLOW WITH NEXT STRONGER SHORTWAVE ALREADY
ALONG THE OREGON COAST THIS MORNING PROGGED TO REACH THE REGION
OVERNIGHT TONIGHT. MODELS NOT QUITE IN AGREEMENT ON BEST LOCATION
FOR DEVELOPMENT THIS EVENING INTO SUNDAY THUS BROADBRUSHED LIGHT
CHANCE POPS WITH SLIGHT SNAKE PLAIN. TROUGH DEEPENS INTO CLOSED
LOW OVER THE GREAT PLAINS BY MONDAY WITH ONLY LINGERING LIGHT
SHOWERS ALONG THE EASTERN HIGHLANDS AS RIDGE BEGINS TO BUILD INTO
THE PACNW.
RIDGE SHORTLIVED IN THE AMPLIFIED BUT PROGRESSIVE FLOW WITH NEXT
PACIFIC TROUGH REACHING THE COAST DURING THE DAY TUESDAY. BOTH GFS
AND ECMWF AGREE ON DEVELOPMENT OF THIS NEXT LARGE LOW OVER THE
REGION THROUGH THE LATTER HALF OF THE WEEK THOUGH GFS KEEPS THE
CENTER OF THE LOW SLIGHTLY FURTHER NORTH THAN THE ECMWF. INTERESTINGLY
BOTH MODELS ALSO MAINTAIN A LARGE DRY SLOT CENTERED OVER EASTERN
IDAHO WITH PRECIP PUSHED MAINLY NORTH OF THE AREA. GIVEN THE DEPTH
OF THE LOW...OPTED TO MAINTAIN WEAK POPS MOST AREAS THROUGH THE
WEEK. DMH
AVIATION...RAIN AND CONVECTIVE SHOWERS EXPECTED FROM PIH TO IDA AND
AREAS EASTWARD TODAY. MVFR POSSIBLE NEAR CONVECTIVE SHOWERS THIS
AFTERNOON WHILE VFR FOR REST OF THE AREA. GUSTY SOUTHWEST WINDS ARE
EXPECTED BY THIS AFTERNOON FROM THE SOUTHWEST IN THE SNAKE RIVER
PLAIN. PRESTON
FIRE WEATHER...NUMEROUS RAIN SHOWERS ARE POSSIBLE IN THE SOUTHEAST
CORNER TODAY WITH WETTING RAINS AS AS AN UPPER TROUGH MOVES THROUGH
THE AREA. ISOLATED AFTERNOON CONVECTIVE SHOWERS ARE POSSIBLE IN
UNSTABLE AIR OVER ALL THE AREA THIS AFTERNOON. BEHIND THIS EXITING
SYSTEM GUSTY SOUTHWEST WINDS WILL DEVELOP IN THE SNAKE RIVER PLAIN
BY THIS AFTERNOON. A SECOND SHOT OF ENERGY WILL DEVELOP ON SUNDAY
WITH MORE SHOWERS POSSIBLE. DRY CONDITIONS AND WARMER TEMPS ARE
EXPECTED ON MON AND TUE AS UPPER RIDGING MOVES INTO THE NW. A DEEP
UPPER LOW IS EXPECTED TO MOVE INTO THE PAC NW BY WEDNESDAY...HOWEVER
CURRENT MODEL TRENDS KEEP OUR AREA IN THE WARM SECTOR WITH A FEW
AFTERNOON THUNDERSTORMS POSSIBLE ESPECIALLY IN THE CENTRAL IDAHO
MOUNTAINS THROUGH THE LATER PART OF THE WEEK. PRESTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING IDZ021.
&&
$$
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