Severe Thunderstorm Warning 36, NWS Pocatello, ID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
150 PM MDT THU AUG 14 2014

.DISCUSSION...THE PERSISTENT UPPER LOW WAS LOCATED OVER THE
COLUMBIA GORGE THIS AFTN...AND EXPECTED TO FILL AND MOVE TO NC MT
ON SATURDAY. MOST OF THE MONSOON MOISTURE HAS MOVED OFF TO THE
NORTH AND EAST...BUT ENOUGH MOISTURE LINGERS TO FUEL SHOWERS/TSTMS
OVER THE FCST AREA. GREATEST COVERAGE WILL BE IN THE EAST AND
NORTH PARTS OF THE FCST AREA. SOME TSTMS MAY PRODUCE GUSTY WINDS
AND SMALL HAIL...ESPECIALLY LATE THIS AFTN. ACTIVITY WILL DIMINISH
THIS EVENING OVER THE WESTERN PARTS AND THE SNAKE RIVER PLAIN...
BUT CONTINUE NEAR THE WY AND MT BORDERS. ON FRIDAY...DRIER AIR
BECOMES MORE DOMINANT. THIS WILL LIMIT ACTIVITY TO ONLY ISOLD
TSTMS IN THE CENTRAL MTNS AND EASTERN HIGHLANDS. BY SATURDAY...THE
UPPER LOW MOVES FAR ENOUGH AWAY TO LIMIT ACTIVITY TO ALONG THE
DIVIDE. WEAK UPPER RIDGING SETS UP FOR THE REST OF THE WEEKEND AND
PERSISTS THRU TUE. THIS WILL RESULT IN DRY CONDITIONS AND WARMER
TEMPS THRU TUE.

BY WED...THE PATTERN SHOWS SIGNS OF CHANGE. THE NORTHERN STREAM
BEGINS TO SAG SOUTHWARD INTO THE PAC NW...AND SUGGEST COOLER TEMPS
FOR WED AND THU. ALSO...THE POSSIBILITY OF SHOWERS NEAR THE
DIVIDE. HEDGES

&&

.AVIATION...UPPER LEVEL LOW IN THE PACIFIC NORTHWEST CONTINUES TO
BRING MOIST UNSTABLE AIR INTO SOUTHERN/CENTRAL IDAHO. NOT MUCH IN
THE WAY OF WIND UNLESS THUNDERSTORM OUTFLOW REACHES AIRDROME. GFS
HAD THE BETTER INSTABILITY FORECAST...AND KSUN SHOULD BE OUT OF ANY
SERIOUS THUNDERSTORM ACTIVITY. BUT KIDA AND KPIH HAVE NEGATIVE
LIFTED INDICES AND CAPE GREATER THAN 300J/KG THROUGH NEARLY 15/06Z.
SO HAVE EXTENDED VCTS FORECAST FOR THOSE TWO AIRPORTS AND INTRODUCED
ONE UNTIL 15/00Z AT KBYI...WHEN LIFTED INDEX AND CAPE ARE
NEGATIVE/ABOVE 300J/KG. SPC IS CONSIDERING A SEVERE THUNDERSTORM
WATCH WITH GOOD INVERTED-V SOUNDINGS...SO HAVE PUT IN TEMPO GROUP OF
TSRA ACTIVITY FOR MID- TO LATE AFTERNOON PERIOD AT THESE TWO
LOCATIONS. BOTH HAVE MORE THAN 40 PERCENT CHANCE OF THUNDERSTORMS IN
MOS GUIDANCE...GOOD UPPER LEVEL DIFFLUENCE...AND STABILITY
PARAMETERS ALL POINT TO INTENSE AND WIDESPREAD TSRA ACTIVITY.
CLEARING SHOULD TAKE PLACE TONIGHT AS THIS UPPER LEVEL LOW FINALLY
GETS IN PHASE WITH A MORE NORTHERN SHORTWAVE WHICH ACTS AS A KICKER
TO THE PACIFIC NORTHWEST LOW. THERE IS ALSO A POTENTIAL ROUND OF
SHRA LATE TONIGHT. ONLY IMPACT TO CIG OR VSBY WOULD BE REDUCED VSBY
IN TSRA. WINDS OUTSIDE OF TSRA CONTINUE LIGHT. MESSICK

&&

.FIRE WEATHER...CLOSED UPPER LEVEL LOW LINGERING OVER THE PACIFIC
NORTHWEST FOR ANOTHER 24 HOURS OR SO...THUS EXPECT MORE THUNDERSTORM
ACTIVITY WITH LESS INTENSE SHOWERS. STILL...A GOOD PORTION OF THE
THUNDERSTORMS WILL BRING WETTING RAINS. THE LOW...AFTER LINGERING
FOR NEARLY 9 DAYS...WILL BEGIN TO MOVE OUT AS IT GETS ABSORBED BY A
STRONG TROUGH MOVING THROUGH NORTHERN CANADA. AS IT CLEARS OUT
FRI...DRYING DEVELOPS...ALBEIT SLOW. THE UPPER LEVEL HAS A STRONGER
WESTERLY FLOW THAT WILL MEAN STRONGER WINDS THAN WE HAVE BEEN HAVING
LATELY WITH WED AND THU LOOKING MUCH STRONGER FOR WIND. SLOW DRYING
OF HUMIDITY AS TEMPERATURES WILL NOT SEE MUCH OF A WARM UP DESPITE
MAINLY CLEAR SKIES. MESSICK

&&

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
230 PM MDT THU AUG 14 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0228 PM     HAIL             20 SE POCATELLO         42.67N 112.19W
08/14/2014  E0.25 INCH       BANNOCK            ID   DEPT OF HIGHWAYS

&&

ADESMET

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
231 PM MDT THU AUG 14 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0230 PM     HAIL             5 N PORTNEUF GAP        42.87N 112.34W
08/14/2014  E0.25 INCH       BANNOCK            ID   TRAINED SPOTTER

&&

ADESMET

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
246 PM MDT THU AUG 14 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0245 PM     HAIL             2 SSE INKOM             42.77N 112.23W
08/14/2014  E0.25 INCH       BANNOCK            ID   TRAINED SPOTTER

&&

ADESMET

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
339 PM MDT THU AUG 14 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0335 PM     FLASH FLOOD      POCATELLO               42.88N 112.47W
08/14/2014                   BANNOCK            ID   COUNTY OFFICIAL

            ON I-15 BETWEEN MILE MARKER 63 AND 65 1.5 INCHES OF
            WARTER ON ROAD.

&&

ADESMET

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
341 PM MDT THU AUG 14 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0339 PM     FLASH FLOOD      INKOM                   42.80N 112.25W
08/14/2014                   BANNOCK            ID   TRAINED SPOTTER

            STANDING WATER ON ROAD

&&

ADESMET

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
351 PM MDT THU AUG 14 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0351 PM     HAIL             10 SSW AMERICAN FALLS   42.65N 112.93W
08/14/2014  E0.25 INCH       POWER              ID   TRAINED SPOTTER

            PEA SIZE HAIL

&&

ADESMET