Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 071600
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1000 AM MDT TUE JUL 7 2015

.DISCUSSION...ISOLATED SHOWERS NORTH OF ONTARIO...STRETCHING TO
BAKER CITY AND MCCALL...WILL CONTINUE TO MOVE EASTWARD INTO THE
WEST CENTRAL IDAHO MOUNTAINS BY THIS AFTERNOON. NEWER MODELS
/ESPECIALLY THE NAM/ SUPPORT EXPANDING THE ISOLATED SHOWER AND
THUNDERSTORM COVERAGE THIS AFTERNOON INTO MORE OF SE OREGON AND SW
IDAHO...WHICH WILL BE INCLUDED IN THIS MORNING/S UPDATE. MOST OF
TREASURE VALLEY LOOKS TO REMAIN DRY. THE THUNDERSTORMS WILL BE
SLOW-MOVING ONCE AGAIN...RESULTING IN HEAVY RAIN.

&&

.AVIATION...VFR. ISOLATED SHOWERS THIS MORNING MAINLY NORTH OF A
KBNO-KBOI-KSNT LINE. ISOLATED SHOWERS AND THUNDERSTORMS EXPAND
THIS AFTERNOON TO SOUTHEAST OREGON AND CENTRAL IDAHO MOUNTAINS.
SURFACE WINDS 12KT OR LESS EXCEPT ERRATIC GUSTS UP TO 40KT NEAR
THUNDERSTORMS. WINDS ALOFT UP THROUGH 10K FT MSL...NORTHWEST
10-20KT.

&&

.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH WEDNESDAY...AS OF 310 AM RADAR SHOWED
WEAK ECHOES OVER JORDAN VALLEY...NW OWYHEE COUNTY...TO WEST OF
MELBA...AS WELL AS ALONG THE OREGON-NV BORDER. STORMS WERE DRIFTING
TO THE SE AT 5-10 MPH. PATCHY DENSE CLOUDS COVERED THE AREA ALONG
AND SOUTH OF A LINE FROM BAKER CITY TO IDAHO CITY. SHOWERS AND
POSSIBLY A THUNDERSTORM ARE EXPECTED THIS MORNING MAINLY FROM
JORDAN VALLEY SOUTH THROUGH THE NV-OREGON BORDER BEFORE INCREASING
FOR THE AFTERNOON.

A WARMER UPPER LEVEL RIDGE AXIS WILL BE OVER THE REGION TODAY -
GENERALLY KRDM-KBNO-KEKO...SO HIGHS WILL GENERALLY BE 4-9F WARMER
THAN YESTERDAY. BY AFTERNOON AN UPPER TROUGH WILL SHIFT TOWARDS
BAKER COUNTY WHICH BRINGS IN A LITTLE COOLING VS. MONDAY BUT TEMPS
WILL STILL BE ABOVE NORMAL THERE. AFTERNOON CONVECTION WITH BRIEF
HEAVY RAIN UP TO AN INCH PER HOUR AND OUTFLOW WIND GUSTS AROUND 45
MPH WILL BE FOCUSED ALONG AND WEST OF THE RIDGE AXIS...SO MAINLY
OVER SE OREGON. APPROACHING TROUGH...AND W/NW FLOW INTO HIGHER
TERRAIN OF CENTRAL ID WILL ALSO HELP FOCUS STORMS. LIGHTNING
ACTIVITY SHOULD REMAIN ISOLATED TODAY. THE NORTHERN STREAM TROUGH
WILL SHIFT ACROSS E OREGON AND CENTRAL ID THROUGH WED...AND THE
RIDGE AXIS WILL ERODE IN RESPONSE TO AN UPPER LOW EXPANDING INLAND
MAINLY OVER CA-NV ON WEDNESDAY. THIS LOOKS TO ENHANCE CONVECTIVE
ACTIVITY WEDNESDAY ESPECIALLY NEAR THE NV BORDER...AND DROP HIGH
TEMPERATURES ABOUT 5F DEGREES FROM TODAY. SURFACE LOW PRESSURE
TROUGH WEDNESDAY AFTERNOON OVER SW IDAHO MAY ALSO AID SFC
CONVERGENCE FOR LIFT AND VALLEY THUNDERSTORMS AS WELL. MILD LOWS
ARE EXPECTED STILL DUE TO CLOUDS. VERY LOW PRESSURE FOR THIS TIME
OF YEAR...1000 MBS ACROSS SW IDAHO LATE WED. BUT GRADIENT IS LIGHT
TOO...SO LIGHT 5-15 MPH SURFACE WINDS OUTSIDE OF STRONGER WINDS
WITH OUTFLOW BOUNDARIES.

LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...UPPER LEVEL TROUGH OFF
THE CALIFORNIA COAST WILL MOVE INLAND WEDNESDAY NIGHT. MODELS ARE
TRENDING DEEPER /COOLER ALOFT/ WITH THIS TROUGH THUS HAVE INCREASED
CHANCES OF PRECIPITATION ACROSS THE FORECAST AREA. UPPER LEVEL
DYNAMICS COMBINED WITH SUFFICIENT MONSOONAL MOISTURE WILL ALLOW
SHOWERS AND THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON AND
EVENINGS EACH DAY. THIS TROUGH WILL SLOWLY MOVE ACROSS THE GREAT
BASIN AND OVER SOUTHEAST OREGON AND SOUTHWEST IDAHO LATE FRIDAY INTO
SATURDAY. AS THIS TROUGH MOVES ACROSS THE AREA A DEEPER TROUGH WILL
DEVELOP OFF THE WEST COAST AND SOUTHWESTERLY FLOW ALOFT WILL SET UP.
A WEAK SHORTWAVE WILL MOVE ACROSS THE AREA SUNDAY KEEPING ELEVATED
CHANCES OF PRECIPITATION. MODELS DIFFER AFTER SUNDAY WITH HOW IT
WANTS TO HANDLE THIS TROUGH OFF THE WEST COAST. NONETHELESS
TEMPERATURES WILL BE BELOW NORMAL THROUGH THE EXTENDED PERIOD AND
PRECIPITATION CHANCES WILL BE ELEVATED WITH THIS UPPER LEVEL TROUGH
JUST OFF THE PACIFIC NORTHWEST COAST AND POSSIBLY OVER CENTRAL
OR/WA.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.

&&

$$

WEATHER.GOV/BOISE

DISCUSSION...BW
AVIATION.....JS
PREV SHORT TERM...VM
PREV LONG TERM....KA



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