Alert archive / California / Mesoscale Discussions in 2010
Mesoscale Discussion 1921
The Storm Prediction Center issued this mesoscale discussion at Oct 3, 2010, 11:45 PM PDT for 8 counties in California. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- Oct 3, 2010, 11:45 PM PDT (06:45 UTC)
- Expired
- Oct 4, 2010, 1:15 AM PDT
- In force
- 90 min
- Issued by
- the Storm Prediction Center
Counties Fresno County, CA, Kern County, CA, Kings County, CA, Madera County, CA, Mariposa County, CA, Merced County, CA, Stanislaus County, CA, Tulare County, CA
The radar
The San Joaquin Valley radar (KHNX), 40 km from the middle of the area, began a volume at 06:46 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 00:00Z, 6.8 hours before the alert went out and 252 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
- 761 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 94 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
253
ACUS11 KWNS 040646
SWOMCD
SPC MCD 040645
CAZ000-040815-
MESOSCALE DISCUSSION 1921
NWS STORM PREDICTION CENTER NORMAN OK
0145 AM CDT MON OCT 04 2010
AREAS AFFECTED...SAN JOAQUIN VALLEY
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 040645Z - 040815Z
ISOLATED STRONG TSTMS THROUGH TONIGHT/EARLY MONDAY WILL POSE A
THREAT FOR HAIL. MOST OF THE HAIL SHOULD REMAIN SUB-SEVERE...
THOUGH COOLING MIDLEVEL TEMPERATURES AND SUSTAINED UPDRAFTS MAY
SUPPORT A FEW HAIL EVENTS LOCALLY EXCEEDING 1 INCH. A SEVERE
WEATHER WATCH IS NOT WARRANTED AT THIS TIME...DUE TO THE OVERALL
LIMITED THREAT FOR LARGER HAIL.
LATE EVENING REGIONAL RADAR IMAGERY SHOWED TSTMS DEVELOPING FROM THE
NRN SIERRA SSWWD TO THE SAN JOAQUIN VALLEY...WITH THIS ACTIVITY
LOCATED ALONG A FRONT WHICH SHOULD MOVE SEWD OVERNIGHT AS A LONGWAVE
TROUGH DIGS SWD ALONG AND INTO THE W COAST. DEEP LAYER ASCENT AHEAD
OF THIS TROUGH ACROSS CA...ATTENDANT TO UPPER LEVEL DIFFLUENT FLOW
ATOP STRENGTHENING SWLY LOW-MIDLEVEL WINDS WILL SUPPORT ADDITIONAL
SHOWERS/TSTMS THROUGH 12Z. AN INFLUX OF MOISTURE INTO SRN CA PER
00Z SOUNDINGS IS MAINTAINING PW VALUES AOA 1 INCH. DESPITE THIS
MOISTURE AND COOLING MIDLEVEL TEMPERATURES WITH APPROACHING PACIFIC
TROUGH...TIME OF DAY IS LIMITING THE DEVELOPMENT OF STRONGER
INSTABILITY. NONETHELESS...MARGINAL INSTABILITY /MUCAPE AROUND 500
J PER KG/ AND STEEPENING MIDLEVEL LAPSE RATES SHOULD SUPPORT A FEW
MARGINAL TO LOCALLY SEVERE HAIL EVENTS OVER THE SAN JOAQUIN VALLEY
VICINITY WHERE LOW-MID LEVEL MOISTURE IS GREATER.
..PETERS.. 10/04/2010
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...HNX...STO...
LAT...LON 38292026 37111899 36241838 35211850 35091908 35661992
36572065 37582111 38292026SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 4, 10:52 AM PDT | Mesoscale Discussion | SPC | San Bernardino | 113 min |
| Oct 4, 12:01 PM PDT | Severe Thunderstorm Watch | SPC | San Bernardino | 7 hr |
| Oct 4, 2:34 PM PDT | Mesoscale Discussion | SPC | Imperial, Riverside | 116 min |
Nearby
Mesoscale Discussions in California, 2010Every mesoscale discussion in 2010
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.