Tornado Chaser's Winter Storm Grant Forecast

[Tornado_Chaser2005]

FINAL FORECAST FOR WINTER STORM GRANT
AREA FORECAST DISCUSSION
Sunday, Jan 2, 2005 9:00 AM

DISCUSSION ... FOR ALL OF SOUTHWESTERN CALIFORNIA INCLUDING ALL OF ORANGE COUNTY ... SOUTHERN LOS ANGELES COUNTY ... WESTERN RIVERSIDE COUNTY ... AND SOUTHWESTERN SAN BERNARDINO COUNTY ...

SYNOPSIS....WINTER STORM GRANT LOOKS VERY STRONG, AND WILL HIT US EARLIER TOMORROW MORNING, WITH HEAVY RAIN, AND THUNDERSTORMS POSSIBLE.

...SHORT RANGE DISCUSSION...
PRE-STORM FACTS: SCATTERED SHOWERS WILL INCREASE AHEAD OF THE MAIN COLD FRONT, AND THE WINDS WILL BE GETTING STRONGER FROM THE SOUTHWEST.

THE RAIN CHANCES WINTER STORM GRANT WILL HAVE LOTS OF RAIN ASSOCIATED WITH IT. THE RAIN SHOULD BEGIN FALLING IN THE EVENING HOURS TODAY, LIGHT AT FIRST, AND ONLY SCATTERED. THE RAIN SHOULD PICK UP THROUGHOUT THE NIGHT TONIGHT IN ADVANCE OF A STRONG COLD FRONT. THE COLD FRONT CENTER IS DUE IN THE WESTERN FORECAST AREAS BY SUNRISE TOMORROW, AND IN THE INLAND EMPIRE, AND ORANGE COUNTY AREAS BY ABOUT 10AM TOMORROW MORNING. 850MB RH WILL BE AT 100%, 850MB LOW LEVEL WINDS WILL BE BLOWING AT 30MPH, WITH GREAT UP-FORCING, THIS WILL BE A FLOODING EVENT, AND FLOOD WATCHES HAVE BEEN ISSUED.

THE THUNDERSTORM CHANCES WINTER STORM GRANT DYNAMICS LOOK RATHER GOOD RIGHT NOW. GRANT WILL HAVE MAIN THUNDERSTORM WAVES, BUT THUNDERSTORMS WILL BE POSSIBLE THROUGHOUT ITS PASSAGE OVER THE FORECAST AREA.
THE MAIN THUNDERSTORM WAVE WILL BE ALONG, AND AHEAD OF THE MAIN COLD FRONT. LOW LEVEL MOISTURE SATURATED, GOOD LOW LEVEL 850MB JET, A 500-750CAPE, 500MB TEMPS WILL FALL TO -20, 700MBVV VALUE AT 20, AND SLIGHT CONVERGENCE IN THE UPPER LEVEL JET OF 70MPH, WILL DEVELOP GOOD CHANCES OF THUNDERSTORMS. SUPERCELL CHANCES ARE SLIGHT AS OF RIGHT NOW, WITH LOW LEVEL WINDS ONLY BEING NEAR 30MPH, BUT WE WON'T RULE OUT THE POSSIBILITY THIS YET FOR AN ISOLATED SUPERCELL THUNDERSTORMS, MAINLY OUT AHEAD OF THE FRONT, AND MOVING FROM SOUTH TO NORTH. THIS MEANS AREAS ALONG THE COAST ARE IN THE DANGER ZONE. IN THE FRONT, EXPECT ISOLATED THUNDERSTORMS, AND SOME MAYBE SEVERE, WITH A BOW ECHO EFFECT. DAMAGING WINDS WILL BE POSSIBLE IN THIS FRONT. THE CONCERN FOR ISOLATED TORNADOES IN THE FORECAST AGAIN HAS BEEN REVIEWED, AND WE WILL ADD A TORNADO WATCH FOR THE ENTIRE FORECAST AREA, MAINLY ALONG THE COAST, BUT STILL POSSIBLE ANYWHERE AS HELICITY LEVELS IN THE LOWER 1KM REGION COUPLED WITH THE COLD AIR ALOFT CREATES POSSIBILITY OF TORNADOES AHEAD, AND ALONG THE FRONT. A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED AS WELL. DURING THE AFTERNOON HRS ON TUESDAY, THUNDERSTORMS COULD DEVELOP, AND TORNADOES CAN HAPPEN, HOWEVER COLD CORE FUNNEL CLOUDS, NOT REALLY ANY TOUCHDOWNS.
THE SECOND WAVE SHOULD COME IN AROUND 11PM ON TUESDAY NIGHT, AND LAST TILL AROUND 2AM WEDNESDAY MORNING, MAYBE A BIT LATER, DEPENDING ON NEXT RUNS. THIS WAVE WILL HAVE 700MBVV VALUES UP TO 15, WITH 100% RH AT 850MB,, CAPE NEARING 500, TEMPS AT 500MB WILL DROP TO -28C. THESE DYNAMICS ARE POSSIBLE FOR COLD CORE THUNDERSTORMS, BUT NOT TORNADIC IN ANY NATURE. THE TORNADO WATCH WILL BE EXPIRED IN THIS WAVE, BUT THE SEVERE THUNDERSTORM WATCH WILL STAY. THUNDERSTORMS WILL BE POSSIBLE TILL AROUND WEDNESDAY NIGHT INTO THURSDAY, BUT NOT ON THE LEVEL WE WILL SEE WITH THE FIRST 2 WAVES.

WIND CHANCES WINTER STORM GRANT'S WINDS WILL BE PRETTY MODERATE, SO A HIGH WIND WARNING HAS BEEN ISSUED FOR THE ENTIRE FORECAST AREA AS THE FRONT PASSES. WINDS ALONG THE FRONT COULD REACH 40-50MPH GUSTS, THEN DIE DOWN RATHER QUICKLY AFTER.

MEDIUM RANGE DISCUSSION...STILL UNDER A HUGE TROUGH IN THE PACIFIC OCEAN, SO WE WILL BE OPEN FOR NEW STORMS.
----------------------------------------------------------------------------------------------------------------------------------
SPECIAL WEATHER STATEMENT

Sunday, Jan 2, 2005 9:00 AM

WINTER STORM GRANT WILL BRUSH THE FORECAST AREA BRINGING A STRONG COLD FRONT THROUGH WITH RAIN, HEAVY AT TIMES, AND A FEW THUNDERSTORMS, SOME OF WHICH COULD BE SEVERE, AND SPIN TORNADOES.
-----------------------------------------------------------------------------------------------------------------------------------
FLOOD WATCH

Sunday, Jan 2, 2005 9:00 AM

A FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE FORECAST AREA, MAINLY FOR AHEAD, AND ALONG THE COLD FRONT. FROM ALREADY SATURATED GROUND TO THIS, WE COULD SEE ALOT OF FLOODING ROADS, AND SURFACES. DO NOT BE CARELESS, AND DRIVE FAST, OR THINK ITS FUN TO SKID AROUND IN THE WATER IN YOUR VEHICLE, UNLESS ITS A BOAT.
-----------------------------------------------------------------------------------------------------------------------------------
HIGH WIND WARNING

Sunday, Jan 2, 2005 9:00 AM

A HIGH WIND WATCH HAS BEEN ISSUED. WINDS ALONG THE FRONT COULD REACH 40-50MPH GUSTS, WITH SUSTAINED WINDS TO NEAR 30MPH. POWER OUTAGES WILL HAPPEN, AND BRANCHES WILL BE KNOCKED DOWN, SO BE AWARE OF THIS WARNING.
-----------------------------------------------------------------------------------------------------------------------------------
SEVERE THUNDERSTORM WATCH

Sunday, Jan 2, 2005 9:00 AM

A SEVERE THUNDERSTORMS WATCH HAS BEEN ISSUED, AND THIS MEANS THAT DAMAGING WINDS IN EXCESS OF 58MPH, AND ISOLATED TORNADOES ARE POSSIBLE ALONG, AND WITHIN THE MAIN COLD FRONT. ADDITIONAL THUNDERSTORMS BEHIND THE FRONT IN THE COLD AIR ALOFT COULD REACH SEVERE LEVELS, SO WE WILL LET THE WATCH STICK TILL 12AM THURSDAY MORNING.
-----------------------------------------------------------------------------------------------------------------------------------
TORNADO WATCH

Sunday, Jan 2, 2005 9:00 AM

A TORNADO WATCH HAS BEEN ISSUED. TORNADOES ARE POSSIBLE IN THE 250-300 HELICITY LEVELS AHEAD OF THE FRONT. HELICITY LEVELS WILL BE NEARING 200 INSIDE THE FRONT, SO WE WILL MAKE IT STICK. TORNADOES ON THE MAGNITUDE WE SAW LAST WEEK COULD HAPPEN ONCE MORE IN THE SAME AREAS, SO BE ON THE LOOK OUT, AND WATCH YOUR LOCAL NEWS STATIONS FOR WARNINGS. THIS WATCH BEGIN THIS EVENING AT 10PM, AND LASTS TILL 6PM TUESDAY EVENING.
-----------------------------------------------------------------------------------------------------------------------------------

Tornado Chaser