840  
FNUS86 KMTR 210842  
FWLMTR  
 
ECCDA DISCUSSIONS  
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA  
142 AM PDT TUE OCT 21 2025  
 
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## DISCUSSIONS FROM THE LATEST FWF BELOW ##  
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..DISCUSSION FROM SFOFWFMTR  
 
WEAK OFFSHORE FLOW CONTINUES THIS MORNING PROMOTING DRY CONDITIONS.  
ONSHORE FLOW AND DEEP MOISTURE RETURNS THIS EVENING ALONG WITH SOME  
MARGINAL INSTABILITY ASSOCIATED WITH AN UPPER LOW MOVING IN FROM THE  
SOUTH. THERE IS A SLIGHT CHANCE (15-20%) OF DRY LIGHTNING ACROSS THE  
INTERIOR CENTRAL COAST AND BAY AREA LATE TONIGHT INTO WEDNESDAY  
MORNING. A NEW STORM SYSTEM WILL BRING COOLER TEMPS AND WET WEATHER  
TO THE REGION BY FRIDAY EVENING THROUGH THE WEEKEND.  
 
   
..DISCUSSION FROM SFOFWFEKA  
 
DRIER AND WARMER WEATHER CONDITIONS TODAY. OFFSHORE FLOW INCREASING  
EARLY THIS MORNING, WITH GUSTS GENERALLY AROUND 20 TO 30 MPH OVER  
THE HIGHER TERRAIN. INTERIOR HIGHS BACK AROUND 80F AND MINIMUM RH  
BELOW 30 PERCENT. A SOUTHERLY REVERSAL STRATUS SURGE TONIGHT INTO  
WEDNESDAY, WITH A SHALLOW MARINE LAYER CHARGING UP AND LAPPING  
THE COASTAL AREAS. THIS WILL BRING A PUSH OF MARINE AIR TO THE  
INTERIOR ON WEDNESDAY, PROMOTING INCREASING OVERNIGHT RH  
RECOVERIES AND DAYTIME HUMIDITY BACK TO ABOVE 30%. CONFIDENCES  
REMAIN HIGH WITH A MODERATE ATMOSPHERIC RIVER (AR) IMPACTING THE  
REGION FRIDAY THROUGH THE WEEKEND, BRINGING HEAVY RAINFALL, HIGH-  
ELEVATION SNOW AND STRONG SOUTHERLY WINDS.  
 
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## COMPLETE A DISCUSSION FOR EACH ECCDA SEGMENT BELOW ##  
## WHEN DONE CLICK TRANSMIT, PRODUCT SENT AS KMTRFWLMTR ##  
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ECC010-212045-  
ST HELENA ECC DISPATCH-  
DISCUSSION FOR MARIN AND SONOMA AND NAPA COUNTIES  
142 AM PDT TUE OCT 21 2025  
 
WEAK OFFSHORE FLOW CONTINUES THIS MORNING PROMOTING DRY CONDITIONS.  
ONSHORE FLOW AND DEEP MOISTURE RETURNS THIS EVENING ALONG WITH SOME  
MARGINAL INSTABILITY ASSOCIATED WITH AN UPPER LOW MOVING IN FROM THE  
SOUTH. THERE IS A SLIGHT CHANCE (15-20%) OF DRY LIGHTNING ACROSS THE  
INTERIOR CENTRAL COAST AND BAY AREA LATE TONIGHT INTO WEDNESDAY  
MORNING. A NEW STORM SYSTEM WILL BRING COOLER TEMPS AND WET WEATHER  
TO THE REGION BY FRIDAY EVENING THROUGH THE WEEKEND.  
 
 
 
ECC014-212045-  
MORGAN HILL ECC DISPATCH-  
DISCUSSION FOR ALAMEDA AND CONTRA COSTA AND SANTA CLARA COUNTIES  
142 AM PDT TUE OCT 21 2025  
 
WEAK OFFSHORE FLOW CONTINUES THIS MORNING PROMOTING DRY CONDITIONS.  
ONSHORE FLOW AND DEEP MOISTURE RETURNS THIS EVENING ALONG WITH SOME  
MARGINAL INSTABILITY ASSOCIATED WITH AN UPPER LOW MOVING IN FROM THE  
SOUTH. THERE IS A SLIGHT CHANCE (15-20%) OF DRY LIGHTNING ACROSS THE  
INTERIOR CENTRAL COAST AND BAY AREA LATE TONIGHT INTO WEDNESDAY  
MORNING. A NEW STORM SYSTEM WILL BRING COOLER TEMPS AND WET WEATHER  
TO THE REGION BY FRIDAY EVENING THROUGH THE WEEKEND.  
 
 
 
ECC013-212045-  
FELTON ECC DISPATCH-  
DISCUSSION FOR SANTA CRUZ AND SAN MATEO COUNTIES  
142 AM PDT TUE OCT 21 2025  
 
WEAK OFFSHORE FLOW CONTINUES THIS MORNING PROMOTING DRY CONDITIONS.  
ONSHORE FLOW AND DEEP MOISTURE RETURNS THIS EVENING ALONG WITH SOME  
MARGINAL INSTABILITY ASSOCIATED WITH AN UPPER LOW MOVING IN FROM THE  
SOUTH. THERE IS A SLIGHT CHANCE (15-20%) OF DRY LIGHTNING ACROSS THE  
INTERIOR CENTRAL COAST AND BAY AREA LATE TONIGHT INTO WEDNESDAY  
MORNING. A NEW STORM SYSTEM WILL BRING COOLER TEMPS AND WET WEATHER  
TO THE REGION BY FRIDAY EVENING THROUGH THE WEEKEND.  
 
 
 
ECC018-212045-  
MONTEREY ECC DISPATCH-  
DISCUSSION FOR MONTEREY AND SAN BENITO COUNTY  
142 AM PDT TUE OCT 21 2025  
 
WEAK OFFSHORE FLOW CONTINUES THIS MORNING PROMOTING DRY CONDITIONS.  
ONSHORE FLOW AND DEEP MOISTURE RETURNS THIS EVENING ALONG WITH SOME  
MARGINAL INSTABILITY ASSOCIATED WITH AN UPPER LOW MOVING IN FROM THE  
SOUTH. THERE IS A SLIGHT CHANCE (15-20%) OF DRY LIGHTNING ACROSS THE  
INTERIOR CENTRAL COAST AND BAY AREA LATE TONIGHT INTO WEDNESDAY  
MORNING. A NEW STORM SYSTEM WILL BRING COOLER TEMPS AND WET WEATHER  
TO THE REGION BY FRIDAY EVENING THROUGH THE WEEKEND.  
 
 
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