Mastodawn

#MTR #CAwx 620
FXUS66 KMTR 211436
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
736 AM PDT Tue Apr 21 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 725 AM PDT Tue Apr 21 2026

- Scattered showers this morning with a good chance for
thunderstorms midday

- Lightning strikes, heavy downpours, small hail, and gusty
erratic winds are the primary hazards

- Dry weather Wed afternoon through Friday before disturbed
https://mesonet.agron.iastate.edu/p.php?pid=202604211436-KMTR-FXUS66-AFDMTR

IEM :: AFD from NWS MTR

AFD issued by NWS MTR at 21 Apr 2026 14:36 UTC

IEMbot MTR 25m ago

#MTR #CAwx 621
NOUS46 KMTR 211413
PNSMTR
CAZ006-502>506-508>510-512>518-528>530-220213-

Public Information Statement
National Weather Service San Francisco CA
713 AM PDT Tue Apr 21 2026

...36 HOUR PRECIPITATION REPORTS ENDING 7 AM...

Location Amount Time/Date Lat/Lon
4.1 W Boulder Creek 3.78 in 0700 AM 04/21 37.14N/122.20W
Anderson Peak 3.24 in 0700 AM 04/21 36.18N/121.65W
Ben L https://mesonet.agron.iastate.edu/p.php?pid=202604211413-KMTR-NOUS46-PNSMTR

IEM :: PNS from NWS MTR

PNS issued by NWS MTR at 21 Apr 2026 14:13 UTC

IEMbot MTR 3h ago

#MTR #CAwx 521
FXUS66 KMTR 211137
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
437 AM PDT Tue Apr 21 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1214 AM PDT Tue Apr 21 2026

- Steady rain this morning gives way to isolated to scattered
thunderstorms in the afternoon and evening, lingering showers
through Wednesday

- Seasonal temperatures and dry conditions for the later part of
the week

- Monitoring a pass https://mesonet.agron.iastate.edu/p.php?pid=202604211137-KMTR-FXUS66-AFDMTR

IEM :: AFD from NWS MTR

AFD issued by NWS MTR at 21 Apr 2026 11:37 UTC

NWS Bay Area (bot)5h ago

#CAwx #MTR #graphicast
Isolated to scattered thunderstorms are possible across the Bay Area and Central Coast today with lightning, locally heavy rainfall, and small hail being the primary threats. Localized flooding may occur within heavier showers and/or thunderstorms. When thunder roars, go indoors! See a flash, dash inside!

IEMbot MTR 6h ago

#MTR #CAwx 802
CDUS46 KMTR 210838
CLIOAK

CLIMATE REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
138 AM PDT TUE APR 21 2026

...................................

...THE OAKLAND AIRPORT CLIMATE SUMMARY FOR APRIL 20 2026...

CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1948 TO 2026

WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
https://mesonet.agron.iastate.edu/p.php?pid=202604210838-KMTR-CDUS46-CLIOAK