Alert archive / California / Frost Advisories in 2025

Frost Advisory 29, NWS San Francisco Bay Area, CA

March 13, 2025Monterey County, San Benito County, California

NWS San Francisco Bay Area, CA issued this frost advisory at Mar 13, 2025, 12:48 AM PDT for Monterey County, San Benito County, California. It took effect at Mar 13, 2025, 11:00 PM PDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued: Mar 13, 2025, 12:48 AM PDT (07:48 UTC)
In effect from: Mar 13, 2025, 11:00 PM PDT
Expired: Mar 14, 2025, 8:15 AM PDT
In force: 9 hr
Issued by: NWS San Francisco Bay Area, CA

Counties Monterey County, CA, San Benito County, CA

The radar

The San Francisco radar (KMUX), 103 km from the middle of the area, began a volume at 07:49 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Vandenberg AFB, CA (KVBG), launched 00:00Z, 7.8 hours before the alert went out and 198 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 781 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this frost advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Francisco Bay Area, CA wrote its last area forecast discussion before this frost advisory went out at Mar 12, 10:27 PM PDT, 2 hours 21 minutes earlier.

Area forecast discussion, Mar 12, 10:27 PM PDT, 2 hours 21 minutes before

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In the hours before

Local storm report, Mar 12, 7:14 PM PDT, 5 hours 34 minutes before

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Special weather statement, Mar 12, 7:39 PM PDT, 5 hours 9 minutes before

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Special weather statement, Mar 12, 7:44 PM PDT, 5 hours 4 minutes before

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Special weather statement, Mar 12, 8:09 PM PDT, 4 hours 39 minutes before

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Local storm report, Mar 12, 8:33 PM PDT, 4 hours 15 minutes before

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Local storm report, Mar 12, 8:54 PM PDT, 3 hours 54 minutes before

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The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 12, 7:39 PM PDT	Special Weather Statement	MTR	Santa Cruz	36 min
Mar 12, 7:44 PM PDT	Special Weather Statement	MTR		31 min
Mar 12, 8:09 PM PDT	Special Weather Statement	MTR	San Mateo	36 min
Mar 12, 8:37 PM PDT	Small Craft Advisory	MTR		30 hr
Mar 13, 8:19 AM PDT	Small Craft Advisory	MTR		37 hr
Mar 13, 2:33 PM PDT	Small Craft Advisory	MTR		12 hr

Nearby

Frost Advisories in California, 2025 Every frost advisory in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.