Area Forecast Discussion
Issued by NWS Pocatello, ID

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
000
FXUS65 KPIH 252003
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
203 PM MDT SAT APR 25 2015

.SHORT TERM...TONIGHT THROUGH TUESDAY.

A DEEP LOW PRESSURE SYSTEM CONTINUES TO MOVE THROUGH THE AREA THIS
AFTERNOON. SHOWERS HAVE BEGUN TO DEVELOP EARLY THIS AFTERNOON.
MODELS SHOW SHOWERS BECOMING MORE WIDESPREAD THROUGHOUT THE
AFTERNOON AND PERSISTING THROUGH THE EVENING. A FEW RUMBLES OF
THUNDER REMAIN POSSIBLE INTO THE EVENING AS MODELS SUGGEST SOME WEAK
INSTABILITY OVER THE REGION. SNOW LEVELS WILL FALL TO BETWEEN
5000 AND 5500 FEET OVERNIGHT. EXPECT SOME SNOW ACCUMULATIONS ABOVE
THESE LEVELS WITH 2 TO 5 INCHES POSSIBLE ACROSS THE CENTRAL
MOUNTAINS AND 1 TO 3 POSSIBLE ACROSS THE EASTERN HIGHLANDS. NOT
EXPECTING SIGNIFICANT IMPACT ISSUES WITH THESE SNOW AMOUNTS
THEREFORE WILL HOLD OFF ON ADVISORIES AT THIS TIME. THE SYSTEM
WILL BEGIN TO MOVE AWAY FROM THE REGION ON SUNDAY. SHOWERS WILL
GRADUALLY COME TO AN END ACROSS THE REGION...BUT WILL PROBABLY
HANG ON THE LONGEST ACROSS THE EASTERN HIGHLANDS BECAUSE OF
PROXIMITY TO THE LOW. HIGH PRESSURE WILL BUILD BACK INTO THE AREA
FOR MONDAY AND TUESDAY...WITH A RETURN OF PLEASANT CONDITIONS TO
THE REGION.

VALLE

.LONG TERM...TUE NIGHT THROUGH NEXT SAT NIGHT. IN THE LONGWAVE
PATTERN THERE IS A GRADUAL DE-AMPLIFYING OF THE WEST COAST
TROUGH...BUT IT IS SO SUBTLE THAT UPPER LEVEL SOUTHWESTERLY FLOW
CONTINUES FOR THE NORTHERN ROCKIES AND NORTHERN GREAT BASIN. THE
WEAKENING PATTERN MAKES THE EXTENDED FORECAST MORE SHORT-WAVE DRIVEN
AND THUS LESS AGREEMENT AMONG GUIDANCE PRODUCT SUITES AND LESS RUN
TO RUN CONSISTENCY. TUE NIGHT AND WED SHOULD BE DRY AS THE INTENSE
RIDGE OF THE NEAR TERM FORECAST CONTINUES...BUT AFTER THIS THE ECMWF
AND GFS DIFFER ON INTENSITY AND TIMING OF THE NEXT SHORTWAVE. BOTH
THE GFS AND ECMWF HAVE GOTTEN WETTER FOR WED NIGHT/THU MORNING...SO
HAVE TRENDED HIGHER FOR THAT PERIOD...BUT OTHERWISE IT IS A FAIRLY
DRY FORECAST IN SPITE OF THE WEST COAST TROUGHING.  LITTLE CHANGE TO
THE FORECAST FROM THIS MORNING. MESSICK

&&

.AVIATION...LOOKS LIKE SHOWERS AND THUNDERSTORMS WILL BE SPARSER
THIS AFTERNOON THAN PREVIOUSLY THOUGHT...WITH MARGINAL VFR HOLDING
OFF UNTIL THE OVERNIGHT HOURS. STILL A RISK OF -TSRA BUT NOT MUCH
MOISTURE TO WORK WITH. ALSO...THE INSTABILITY IS FIGHTING AGAINST
SYNOPTIC SUBSIDENCE. BY SUN MORNING...THE PROBLEMS SHOULD CONTINUE
ONLY AT KIDA AND KPIH WITH KSUN SCATTERED OUT AND KBYI ONLY HAVING
THE SLIGHTEST RISK OF MARGINAL VFR. THE ONE SURPRISE IT HE AMOUNT OF
WIND DURING THE OVERNIGHT HOURS. GUSTY WIND HAS ALREADY DEVELOPED IN
WESTERN ID AND EXPECT IT TO DEVELOP THIS AFTERNOON AND EVENING AT
ALL AIRPORTS...MAINLY FROM THE WEST AND NORTHWEST. MESSICK

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.