Alert archive / California / Flash Flood Warnings in 2018
Flash Flood Warning 12, NWS Hanford, CA
NWS Hanford, CA issued this flash flood warning at Oct 3, 2018, 1:21 PM PDT for Mariposa County, Tuolumne County, California. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Oct 3, 2018, 1:21 PM PDT (20:21 UTC)
- Expired
- Oct 3, 2018, 4:15 PM PDT
- In force
- 3 hr
- Issued by
- NWS Hanford, CA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Mariposa County, CA, Tuolumne County, CA
The radar
The San Joaquin Valley radar (KHNX), 168 km from the middle of the area, began a volume at 20:23 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
Oakland, CA (KOAK), launched 12:00Z, 8.4 hours before the alert went out and 200 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1131 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- -2 m²/s²
- 0-3 km storm-relative helicity
- 159 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Hanford, CA wrote its last area forecast discussion before this flash flood warning went out at Oct 3, 3:35 AM PDT, 9 hours 46 minutes earlier.
Area forecast discussion, Oct 3, 3:35 AM PDT, 9 hours 46 minutes before
Area Forecast Discussion National Weather Service San Joaquin Valley - Hanford CA 335 AM PDT Wed Oct 3 2018 .SYNOPSIS... A low pressure system will bring a threat of scattered showers through Wednesday night with isolated thunderstorms possible Wednesday afternoon. A weak disturbance may affect portions of Central California Thursday, before dry, northwest flow aloft returns to the area Thursday night. Cooler than normal conditions will continue through early next week. && .DISCUSSION... The upper low near 32N/125W is bringing a difluent southerly flow across central California early this morning. This is allowing showers to develop in the San Joaquin Valley as well as the Sierra Nevada and foothill areas. Expect showers to continue to develop through the morning hours and increase this afternoon as impulses rotate around the low as it moves closer to the coast. Thunderstorms will be possible across most of the CWA this afternoon and evening. The low is expected to be near the coast by late this afternoon then move inland overnight. Showers and thunderstorms will diminish late this evening. However, some shower activity will continue Thursday, mainly in the northeastern portion of the CWA as a trailing shortwave moves through. Friday through early next week, the region will be in a northerly flow aloft. Another shortwave will drop south from the Pacific Northwest and into the Great Basin on Saturday, bringing a slight chance of showers over the Sierra Nevada. Otherwise, the forecast will remain dry through next Tuesday. The shortwave moving through on Saturday may also bring gusty winds to parts of the San Joaquin Valley and the Kern County mountains and desert areas. Temperatures will remain near to slightly below normal through the period. && .AVIATION... A slight chance of afternoon thunderstorms across the Central California Interior between 18Z Today and 06Z Thursday. Afterward, VFR conditions will prevail for the rest of the period. && .AIR QUALITY ISSUES... None. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.php for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... NONE. && public...Bean avn/fw...Molina synopsis...Bean weather.gov/hanford
The office that day
Everything else NWS Hanford, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 3, 11:35 AM PDT | Flash Flood Watch | HNX | 12 hr | |
| Oct 3, 2:45 PM PDT | Flash Flood Warning | HNX | Mariposa | 3 hr |
| Oct 3, 3:02 PM PDT | Special Weather Statement | HNX | Kings | 43 min |
| Oct 3, 3:20 PM PDT | Severe Thunderstorm Warning | HNX | Fresno | 40 min |
| Oct 3, 3:46 PM PDT | Flash Flood Warning | HNX | Fresno | 3 hr |
| Oct 3, 4:11 PM PDT | Special Weather Statement | HNX | Kings | 49 min |
| Oct 3, 4:38 PM PDT | Areal Flood Advisory | HNX | Fresno, Kings | 3 hr |
Nearby
Flash Flood Warnings in California, 2018Every flash flood warning in 2018
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.