Flash Flood Warning 4, NWS Boise, ID

000 
WGUS75 KBOI 051758
FFSBOI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BOISE ID
1154 AM MDT WED SEP 5 2007

IDC025-039-051804-
ELMORE ID-CAMAS ID-
1154 AM MDT WED SEP 5 2007

...THE FLASH FLOOD WARNING WILL EXPIRE AT NOON MDT FOR SOUTHWESTERN 
CAMAS AND SOUTHEASTERN ELMORE COUNTIES...

RAIN HAS TAPERED OFF OVER THE WARNED AREA AND THE THREAT OF FLASH 
FLOODING HAS DIMINISHED.  CAUTION IS STILL URGED WHEN TRAVELING IN 
THE MOUNTAINS NORTH OF HILL CITY AND ANDERSON RANCH RESERVOIR AS 
SOME FOREST SERVICE ROADS MAY HAVE SECTIONS THAT HAVE BEEN 
UNDERMINED OR WASHED OUT FROM THE HEAVY RAIN WHICH FELL THIS MORNING.


LAT...LON 4284 11536 4336 11522 4360 11492 4345 11479
      4335 11492 4319 11507 4285 11511
TIME...MOT...LOC 1754Z 180DEG 0KT 4332 11510

$$

JPB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
930 AM MDT WED SEP 5 2007

.DISCUSSION...WE ISSUED A FLASH FLOOD WATCH JUST BEFORE
15Z ...VALID THROUGH 03Z...FOR CAMAS PRAIRIE AND THE BOISE
MOUNTAINS AS THUNDERSTORMS WITH HEAVY RAINS HAVE OCCURRED
IN THOSE AREAS AND WERE CIRCLING AROUND UPPER LOW WHICH
WAS RIGHT OVER THAT AREA AND MOVING VERY SLOWLY EAST.
LATE TODAY WHEN THE UPPER LOW SHIFTS TO EASTERN IDAHO
RAINFALL WILL DECREASE BUT NOT END AS WRAP-AROUND MOIST
BAND COMES IN BEHIND THE DEPARTING LOW. TWO DAYS AGO THIS
LOW WAS PROGGED BY GFS TO TRACK ACROSS THE OWYHEES WITH
HEAVY RAIN EXPECTED THERE. RELATIVELY LITTLE RAIN ACTUALLY
FELL.  OTHER MODELS CARRIED THE LOW ACROSS NORTHERN NEVADA.
THE LOW AND THE HEAVY RAINS ENDED UP FURTHER NORTH THAN ANY
PROG.  FORECAST UPDATES HAVE ALREADY BEEN ISSUED FOR TODAY
AND THIS EVENING.  THE FIRE WEATHER WATCH WAS ALSO CANCELLED.
REST OF EARLY MORNING PACKAGE REMAINS IN EFFECT.

&&

.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH THURSDAY...AN UPPER LOW OVER SW IDAHO
WILL SLOWLY MOVE EAST TONIGHT. A PAIR OF MOISTURE SPOKES AROUND THE
UPPER LOW AT 345 AM EXTENDED FROM HELLS CANYON ALONG THE HARNEY-
MALHEUR COUNTY LINE /GENERALLY PIVOTING SSW/ AND OVER S CENTRAL
IDAHO /GENERALLY LIFTING NNE. BOTH MODELS SHOW DESTABILIZATION IN
THE DRY SLOT THIS AFTERNOON FOR PRECIPITATION OVER SW IDAHO WITH THE
LOW. EARLY THIS MORNING FOG IS POSSIBLE IN SHELTERED AREAS IN THE
DRY SLOT...MAINLY THE LONG VALLEY. LATEST RUNS AND SATELLITE TRENDS
ARE SLOWER WITH THE EXIT OF THE MOIST UPPER LOW AND NO STRONG KICKER
IS EVIDENT UPSTREAM SO HAVE GONE WITH THE NEW TIMING. THUNDERSTORMS
ARE ANTICIPATED IN SPITE OF COOLER THAN NORMAL TEMPERATURES
TODAY...THE CONVECTIVE TEMP AT BOISE IS ONLY 71 THIS AFTERNOON.
CLEARING TONIGHT WITH ONLY 3 MBS GRADIENT ACROSS BURNS TO TWIN FALLS
WILL ALLOW PATCHY FOG TO DEVELOP DUE TO ABUNDANT LOW LEVEL MOISTURE
FROM RECENT RAINS. HAVE EXPANDED THE AREA OF FOG THURSDAY MORNING
SLIGHTLY. FORECAST TEMPERATURES WILL BE SLIGHTLY WARMER IN HARNEY
COUNTY TODAY BUT COOLER WITH PRECIP AND UNDER THE COLD CORE UPPER
LOW OVER SW IDAHO TODAY. CLEARING SKIES WILL ALLOW LOWS TO AGAIN
DROP TO AROUND NORMAL TONIGHT. ALL AREAS WILL SEE WARMING WITH
MOSTLY SUNNY SKIES INTO THURSDAY.

LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY...THE UPPER LEVEL
LONGWAVE RIDGE CENTERED 40-50N 140-150W AND THE LONGWAVE TROUGH OVER
THE MID CONTINENT WILL KEEP US IN A DRY WEAKLY CYCLONIC NORTHWEST
FLOW ALOFT. TEMPERATURES WILL COOL TO A LITTLE BELOW NORMAL THIS
WEEKEND AS THE FLOW VEERS TO MORE NORTHERLY AND HEIGHTS LOWER. USING
ANALOGS BASED ON A GFS40/ADJMEX BLEND GAVE A SLIGHTLY COOLER
FORECAST FOR SATURDAY AND SUNDAY COMPARED TO THE PREVIOUS FORECAST.
MODELS ARE STILL IN REASONABLY GOOD AGREEMENT UNTIL MONDAY...WHEN
THE DGEX AND GFSLR WANT TO BRING A MUCH DEEPER UPPER LOW SOUTH OUT
OF B.C. THAN PREVIOUS RUNS. OUR FORECAST FOR MONDAY AND TUESDAY IS
COMPATIBLE WITH THE WARMER CANADIAN AND EUROPEAN MODELS...BUT
RAPIDLY INCREASING GFS ENSEMBLE SPREAD SHOWS HIGH UNCERTAINTY.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...FLASH FLOOD WATCH TIL 03Z TONIGHT ZONES 13 28.
OR...NONE.

&&

WEATHER.GOV/BOISE

DISCUSSION...LC
AVIATION.....JA
PREV SHORT TERM....VM
PREV LONG TERM.....JT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BOISE ID
916 AM MDT WED SEP 5 2007

IDZ011-012-014>016-029-030-ORZ061>064-061530-
WEST CENTRAL MOUNTAINS-LOWER TREASURE VALLEY ID-
UPPER TREASURE VALLEY-SOUTHWEST HIGHLANDS-WESTERN MAGIC VALLEY-
OWYHEE MOUNTAINS-SOUTHERN TWIN FALLS COUNTY-HARNEY COUNTY-
BAKER COUNTY-MALHEUR COUNTY-LOWER TREASURE VALLEY OR-
916 AM MDT WED SEP 5 2007 /816 AM PDT WED SEP 5 2007/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
IDAHO...SOUTHWEST IDAHO...WEST CENTRAL IDAHO...NORTHEAST OREGON
AND SOUTHEAST OREGON.

.DAY ONE...TODAY AND TONIGHT

THE FIRE WEATHER WATCH HAS BEEN CANCELED FOR TODAY.  NO HAZARDOUS
WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

IDZ013-028-061530-
BOISE MOUNTAINS-CAMAS PRAIRIE-
916 AM MDT WED SEP 5 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST IDAHO
AND WEST CENTRAL IDAHO.

.DAY ONE...TODAY AND TONIGHT

A FLASH FOOLD WATCH IN IN EFFECT FOR THE BOISE MOJNTAINS AND THE
CAMAS PRAIRIE FOR CONTINUING THUNDERSTORMS AND HEAVY RAIN THROUGH
THIS EVENING.

A FLASH FLOOD WARNING IS IN EFFECT FOR SOUTHWEST CAMAS COUNTY AND
EAST CENTRAL ELMORE COUNTY UNTIL 1030 AM MDT BECASUE OF VERY HEAVY
RAIN OCCURRING IN THAT AREA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS SHOULD REPORT SIGNIFICANT WEATHER CONDITIONS THROUGH
ESTABLISHED PROCEDURES.