Severe Thunderstorm Warning 17, NWS Eureka, CA

000 
WWUS56 KEKA 022337
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE
437 PM PDT SUN AUG 2 2009

CAC015-022345-
/O.CON.KEKA.SV.W.0017.000000T0000Z-090802T2345Z/
DEL NORTE CA-
437 PM PDT SUN AUG 2 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM PDT
FOR DEL NORTE COUNTY...

AT 435 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS
LOCATED OVER SISKIYOU COUNTY...OR 13 MILES WEST OF HAPPY CAMP...
MOVING NORTHWEST AT 15 MPH.

LAT...LON 4193 12353 4191 12354 4188 12360 4188 12363
      4184 12365 4182 12368 4179 12366 4174 12367
      4172 12365 4165 12367 4197 12412 4198 12356
TIME...MOT...LOC 2336Z 139DEG 14KT 4176 12362

$$

MS

000 
WWUS56 KEKA 022342
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE
442 PM PDT SUN AUG 2 2009

CAC015-022352-
/O.EXP.KEKA.SV.W.0017.000000T0000Z-090802T2345Z/
DEL NORTE CA-
442 PM PDT SUN AUG 2 2009

...THE SEVERE THUNDERSTORM WARNING FOR DEL NORTE COUNTY WILL EXPIRE
AT 445 PM PDT...

LAT...LON 4193 12353 4191 12354 4188 12360 4188 12363
      4184 12365 4182 12368 4179 12366 4174 12367
      4172 12365 4165 12367 4197 12412 4198 12356
TIME...MOT...LOC 2342Z 139DEG 14KT 4178 12364

$$

MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
330 PM PDT SUN AUG 2 2009

.SYNOPSIS...A BROAD UPPER LOW WILL MEANDER WELL OFF THE CALIFORNIA
COAST THROUGH THE MIDDLE OF THE UPCOMING WEEK. THIS LOW WILL PRODUCE
THE THREAT FOR THUNDERSTORMS EACH AFTERNOON OVER THE HIGHER
ELEVATIONS OF TRINITY COUNTY. OVERALL...TEMPERATURES WILL SLOWLY
TREND DOWNWARD FOR INLAND AREAS. COASTAL LOCATIONS WILL REMAIN
SOCKED IN WITH CLOUDS AND VERY LITTLE FLUCTUATION IN TEMPERATURES
FROM DAY TO DAY.

&&

.DISCUSSION...LARGE AND SEVERE THUNDERSTORMS ARE DEVELOPING ACROSS
SOUTHERN OREGON AND NORTHEAST CALIFORNIA AT THIS TIME.  SPC HAS
ISSUED A SEVERE THUNDERSTORM WATCH FOR THE ABOVE AREAS THAT WOULD
PLACE THE EKA CWA ON THE SOUTHERN EDGE OF THAT WATCH.  CURRENTLY ALL
STORMS ARE NORTH OR NORTEAST OF THE CWA HOWEVER RAPID SCAN SATELLITE
IMAGERY DEPICTS TOWERING CU DEVELOPMENT ALONG THE SOUTHFORK RIDGE
LINE AS WELL AS THE YOLLA BOLLYS AS WELL AS PORTIONS OF THE TRINITY
ALPS.  THIS IS SIGNIFICANT SINCE THE CURRENT STEARING FLOW ALOFT
WOULD TRACK ANY STORMS DEVELOPING IN THOSE AREAS BACK ACROSS THE CWA
TO THE NORTHWEST...POTENTIALLY REACHING THE REDWOOD COAST.  ALSO
GIVEN THE DRY LOW AND MID LEVELS OF THE CURRENT AIRMASS ANY LIGHTING
STRIKES WOULD LIKELY NOT BE ACCOMPANIED BY MUCH RAINFALL...POSING A
THREAT FOR FIRE STARTS.  AT THIS TIME CONFIDENCE IS STILL LOW ON THE
CONTINUED DEVELOPMENT AS THE MAIN AXIS OF IN-STABILITY REMAINS TO
THE NORTH AND NORTHEAST THUS HAVE HELD OFF ON ANY FIRE WEATHER
WATCHES BUT DID HEADLINE THE POSSIBILITY OF ISOLATED DRY STRIKES.
TOMORROW CONVECTIVE ACTIVITY SHOULD DIMINISH AS THE AIRMASS BEGINS
TO STABLEIZE SLIGHTLY AND UPPER LEVEL DYNAMICS WEAKEN. NONETHELESS
CANNOT DISCOUNT THE POSSIBILITY OF MORE STORMS TOMORROW AFTERNOON.

HAVE ADJUSTED POPS FOR THE TUE WED PERIOD TO REFLECT THE LOW PASSAGE
AND THE HIGHER LIKLIHOOD OF SHOWER ACTIVITY. MODELS HAVE CHANGED YET
AGAIN WHEN IT COMES TO THE EVENTUAL EASTWARD ADVANCEMENT OF THE LOW.
AT LEAST (FOR NOW) ALL GLOBAL MODELS AGREE WITH PUSHING THE LOW
ASHORE ACROSS NORCAL ON THURSDAY. LONG TERM FORECAST MODELS THEN SHOW
ANOTHER DECENT TROUGH ON THE HEELS OF THE CUTOFF LOW EXITING THE REGION
THUS THE CHANCES OF ADDITIONAL CONVECTION RETURN.

&&

.AVIATION...LOW MARINE CLOUDS AND PATCHY FOG WITH IFR FLIGHT
CONDITIONS WILL RETURN TO THE COAST THIS EVENING.  VFR CONDITIONS
WILL PREVAIL INLAND WITH ISOLATED THUNDERSTORMS POSSIBLE ACROSS
HIGHER ELEVATIONS IN THE EARLY EVENING. TH

&&

.MARINE...FROM PREVIOUS DISCUSSION...QUIET CONDITIONS WILL PERSIST
OVER THE COASTAL WATERS AS A VERY LIGHT PRESSURE GRADIENT REMAINS
OVER THE REGION. A LARGE AREA OF LOW PRESSURE SITS OFFSHORE TO THE
SOUTHWEST OF THE NORTHERN CALIFORNIA COASTAL WATERS...AND WILL
REMAIN NEARLY STATIONARY THROUGH EARLY NEXT WEEK. WHILE THIS
PERSISTS...WINDS WILL REMAIN LIGHT AND MOSTLY SOUTHERLY. AS THE LOW
EDGES CLOSER TO THE COAST ON WEDNESDAY...WINDS WILL INCREASE
SLIGHTLY FROM THE SOUTH. THE LOW IS FORECAST TO MOVE ONSHORE
THURSDAY...AND INLAND ON FRIDAY. MEANWHILE THE SEA STATE WILL
CONTINUE WITH A MIX OF SHORTER PERIOD NW SWELL AND LONGER PERIOD SW
SWELL...BOTH ON THE SMALL SIDE. THE COMBINED SEA HEIGHT WILL REMAIN
AROUND 3 TO 5 FT THROUGH THE WEEKEND AND MOST OF NEXT WEEK. CC

&&

.EKA WATCHES/WARNINGS/ADVISORIES...NONE.

&&

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EUREKA CA
354 PM PDT SUN AUG 2 2009

CAZ003-004-031200-
NORTH COAST INTERIOR-UPPER TRINITY RIVER-
354 PM PDT SUN AUG 2 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST
CALIFORNIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A BROAD UPPER LOW WILL MEANDER WELL OFF THE CALIFORNIA
COAST THROUGH THE MIDDLE OF THE UPCOMING WEEK. THIS LOW WILL PRODUCE
THE THREAT FOR THUNDERSTORMS...POSSIBLY SEVERE IN NATURE...THIS AFTERNOON
INTO THIS EVENING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS WILL REMAIN POSSIBLE DURING THE AFTERNOON AND EARLY
EVENING THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER TO THE
NATIONAL WEATHER SERVICE IN EUREKA.