In reviewing the weather report, I noted a 20% chance of rain and/ or thunderstorms throughout the weekend. The NOAA red flag warnings are going out to all areas from Big Sur north and east, just the various times it is expected to hit are changing. If you live anywhere in Northern California, you can see a listing of all the red flag warnings listed for the various areas at this link:
NOAA update. The LAL for this event is listed as 6 for this approaching storm which is scheduled to arrive about midnight. NOAA explains LALs like this: “Lightning Activity Level (LAL) is a numerical rating ranging from 1 to 6 that represents observed or forecast frequency and characteristics of cloud-to-ground (CG) lightning for a fire zone. The scale that determines the amount of activity is exponential and based upon a power of 2. For example, a LAL of 3 indicates twice the lightning as LAL 2. LAL of 4 is twice that of 3 and so forth. LAL 6 is special and rare – and only used for dry thunderstorms that create severe fire problems.”
.FIRE WEATHER…AS OF 8:55 PM FRIDAY…A RED FLAG WARNING IS IN
EFFECT. NO LIGHTING HAS BEEN REPORTED YET HOWEVER… THE UPPER
LEVEL LOW IS APPROACHING THE COAST AND IR IMAGERY SHOWS CLOUD TOP
ENHANCEMENT. A LINE OF COLD CLOUD TOPS…BETWEEN -35 AND -40C IS
APPROXIMATELY 80 MILES OFF OF THE MONTEREY COAST AND SHOULD REACH
THE COAST LINE BY 1200 UTC. THE LATEST MODEL RUNS ARE STILL
INDICATING ELEVATED INSTABILITY TONIGHT INTO TOMORROW MORNING FOR THE
CENTRAL COAST WITH THE GREATEST THREAT OVERNIGHT FROM SANTA CRUZ
NORTH TO THE GOLDEN GATE. TOMORROW AFTERNOON THE GREATEST THREAT
MOVES INTO THE NORTH BAY AREA. THE LIGHTNING EFFICIENCY IS VERY HIGH
AND EVEN A FEW STRIKES COULD QUICKLY BECOME PROBLEMATIC. ONE POSITIVE
IS THAT A COOLING TREND IS FORECAST FOR THE REST OF THE WEEKEND WITH
WETTING RAIN POSSIBLE IN THE NORTH BAY BY SUNDAY NIGHT INTO MONDAY.
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NOAA forecast discussion posted this for our area:
FIRE WEATHER…AS OF 2:30 PM FRIDAY…FIRE WEATHER WATCH WILL BE
UPGRADED TO A RED FLAG WARNING. NO STRIKES NOTED YET OVER THE OCEAN
BUT MOISTURE AND INSTABILITY CONTINUE TO INCREASE AND 18Z MODELS
RUNS CONTINUE TO SHOW HIGH POTENTIAL FOR SCENARIO UNFOLDING.
MODEL SOLUTIONS CONTINUE TO INDICATE INSTABILITY WILL BE MAXIMIZED
AROUND SUNSET WEST OF BIG SUR AND THE SAN MATEO COAST…SO BEST BET
IS THAT FIRST STRIKES WILL OCCUR OVER THE OCEAN AND THEN PROPAGATE
NORTHWARD. THERE IS STILL THE POSSIBILITY THAT ALL PARAMETERS WONT
LINE UP AND WE SEE NO STRIKES. ANOTHER SCENARIO WOULD BE THAT ALL
THE LIGHTNING STAYS OFFSHORE. HOWEVER THREAT IS HIGH THAT STRIKES
WILL OCCUR AND PASS OVER THE REGION. RIGHT NOW THE BEST CHANCES
APPEAR TO BE OVER THE SF PENINSULA INCLUDING THE SANTA CRUZ
MOUNTAINS AND THEN THE ENTIRE NORTH BAY WHERE THE BEST CHANCES WILL
BE AFTER MIDNIGHT. HAVE INCLUDED THE MONTEREY RANGER DISTRICT OF
THE LOS PADRES NATIONAL FOREST AS WELL AS THE EAST BAY HILLS AND
DIABLO RANGE OF SANTA CLARA COUNTY BECAUSE ANY STRAY STRIKES IN
THESE AREAS WOULD HAVE HIGH POTENTIAL FOR NEW STARTS. LATEST FUELS
DATA INDICATES REGIONS LIGHT AND HEAVY FUELS AS WELL AS THE LIVE
FUEL MOISTURES ARE AT OR NEAR ALL TIME RECORD DRY LEVELS. BASICALLY
THE LIGHTNING EFFICIENCY IS VERY HIGH AND EVEN A FEW STRIKES COULD
QUICKLY BECOME PROBLEMATIC. ONE POSITIVE IS THAT COOLING TREND IS
FORECAST FOR THE REST OF THE WEEKEND WITH WETTING RAIN POSSIBLE IN
THE NORTH BAY BY SUNDAY NIGHT INTO MONDAY.