A potent storm system moving from the Great Basin Region into the Desert Southwest resulted in very strong winds across portions of southeast California during the evening hours of the 21st and extending into the early morning hours of the 22nd. Wind gusts in excess of 60 mph were observed, with the highest gusts across portions of Imperial County.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PSR wrote it up.
A potent storm system moving from the Great Basin Region into the Desert Southwest resulted in very strong winds across portions of southeast California during the evening hours of the 21st and extending into the early morning hours of the 22nd. Wind gusts in excess of 60 mph were observed, with the highest gusts across portions of Imperial County.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Phoenix, AZ wrote its last area forecast discussion before the first event at Feb 21, 3:59 PM PST, 2 hours 56 minutes earlier.
Area Forecast Discussion
National Weather Service Phoenix AZ
459 PM MST Tue Feb 21 2023
.UPDATE...0Z Aviation Discussion (Below)...
&&
.SYNOPSIS...
A strong winter storm will sweep through the Southwest Wednesday
yielding a few showers and isolated thunderstorms along with
high terrain snow. Along with much cooler temperatures, winds will
be the most notable threat with this system. Windy to very windy
conditions will develop tonight and continue through Wednesday,
which will also cause blowing dust issues. Below normal
temperatures will continue through the remainder of the forecast
period, with the next broad chance for precipitation over the
weekend.
&&
.DISCUSSION...
A busy 24-36 hours lies ahead as the potent winter storm we've
been watching for days materializes and blasts through the
Southwest. From this morning into this afternoon, a band of
showers within a deformation zone has slowly eroded as the parent
upper level low shears-out while ejecting to the northeast. The
showers and ample cloud cover were keeping temperatures below
normal across out eastern CWA while the western CWA, under ample
sunshine and WAA ahead of the bigger system, was experiencing one
of the warmest days thus far of 2023.
Showers will remain possible generally along and west of a Gila
Bend - Phoenix - Payson line with the lifting upper level low
through this evening. Based on the 21.12Z HREF data, 90th
percentile CAPE is 100-300 J/kg in the warm sector of this first
low, thus we could see some lightning activity (in-line with the
SPC Day 1 outlook). Precipitation becomes confined late this
evening to upslope areas of central Arizona as the upstream storm
arrives.
Wind fields will begin responding to the incoming storm system
across our western CWA as early as this evening, with widespread
gusts of 30+ mph expected. Immediately downslope from the coastal
mountains, gusts of 70+ mph appear likely (80%+ chance) with 50+
mph likely (80%+ chance) into the rest of southeast California
including the Imperial Valley. The front will push into the CWA
overnight, getting into and through the Phoenix area roughly 4 AM
to 8 AM. Winds will further increase ahead of and with the frontal
passage. Gusts over 50 mph remain likely (80%+) for elevated
areas of our eastern CWA Wednesday morning. Doing a quick look at
KPHX METAR data, the highest peak wind gust on record (Nov-Mar) is
53 kt from 2011-11-04 and more recently a gust of 45 kt (5th highest)
on 2019-11-29. Of course with the winds comes dust potential - broad
lofting of dust seems like a given with pockets of denser dust
(dependent on local sources).
As the front enters central Arizona, there is a signal for
instability (~200 J/kg) to develop and combine with the strong
mechanical mixing to get some thunderstorms going. Should that
occur (10-20% chance), winds could locally be enhanced within the
convection. Any convection that forms will continue to push into
eastern Arizona with the front. Post frontal, windy/very windy
conditions will continue through the day (Wednesday). At this
moment, no adjustments were made to coverage or timing of any wind
products in effect.
Snow amounts will be tricky for our CWA owing to the quick
cessation of precipitation once the front passes and snow levels
remaining a bit high in the warm air ahead of the front (7000'
falling to 3500'). Current totals remain within existing
headlines thus no adjustments made to coverage/timing (end times
may be a bit generous as the heaviest precipitation should quickly
end with the FROPA).
Thursday into Friday, another closed low moves south along the
California coast. Precip chances continue in upslope areas of
central Arizona Thursday though reduce Friday as the pattern
becomes more amplified and ridging ahead of the system takes hold
over our CWA. Temperatures will warm a bit during this time but
still stay below normal (the forecast high of 58F at KPHX Thu is
approaching the record cool high of 55F). That closed system will
then move inland over the weekend, spreading precipitation chances
into the CWA. Ensemble uncertainty, unsurprisingly, is primarily
driven by latitudinal position with minor uncertainty to system
depth. Cluster analysis reveals the majority of members favoring a
moderate or slower forward progression with a minority of members
(~20%) falling into a quicker solution. Ultimately precipitation
chances increase Saturday across our western CWA, spreading east
Saturday night into Sunday. Current deterministic QPF is 0.1-0.3"
for lower elevations, upwards of an inch in JTNP, and 0.3-0.7" for
upslope/elevated area of the eastern CWA. Probability for 0.1"+ is
about 50-80% CWA-wide with notable chances for 0.5"+ confined to
typical upslope areas. Once this system roles through this
weekend, a brief respite looks likely early next week though
medium range data continue to support long wave troughing along
the West Coast well into next week.
&&
.AVIATION...Updated at 00Z.
South-Central Arizona including KPHX, KIWA, KSDL, KDVT:
IMPACTS:
-Southerly crosswinds at PHX this evening and overnight with winds
increasing to 15-25KT gusts.
-Band(s) of windy showers with 5-10% chance of lightning between
12-15Z (gusts may exceed 40 KT). Potential MVFR CIGs 12-15Z.
-Continued windy Wednesday with dust/slantwise VIS restrictions.
CONFIDENCE: Moderate to High
A challenging aviation period the next 24HR. An approaching
strong disturbance will cause winds to increase through the depth
of the atmosphere tonight into tomorrow. Overnight, S/SW winds
gust 15-25KT around the metro. If surface winds relax, LLWS could
be noticeable (20+KT in lowest 2KFT) but believe surface speeds
stay up just enough to omit from TAF overnight.
From 12-15Z, a strong cold front pushes across the metro with
developing showers, 5-10% lightning chance, and even stronger W/SW
winds. Peak gusts will be on the order of 35-45KT with an outside
(<10%) chance of a 50KT gust. Risk for MVFR ceilings is around
30-60%, greatest SDL/IWA/DVT. Showers will exit quickly by 15Z
with VFR CIGs for all sites.
Mid-morning through the afternoon, WSW winds will continue to howl
from 20-30KT gusts 35-40KT beneath SCT/BKN 070-090 bases.
Slantwise VIS reductions are expected from a long fetch of
dust/haze. Winds to really diminish near and after sunset
tomorrow evening.
Southeast California/Southwest Arizona including KIPL and KBLH:
IMPACTS:
-Gusty to locally damaging SW/W winds develop overnight.
-Periods of blowing dust with significant VIS restrictions
possible.
-Continued windy Wednesday with dust/slantwise VIS restrictions.
CONFIDENCE: Moderate to High
Winds are already increasing over 30KT in some cases. Stronger
winds will develop ahead of and following a cold front, which
will push through both terminals between 7-10Z tonight. A
prolonged period of westerly wind gusts up to 45-55 kts is likely.
An occasional gust up to 60-65 kts cannot be ruled out (20%
chance) at KIPL. Small planes could be flipped if not tied down
properly outside. BLDU is likely across the region, with greater
coverage after sunrise Wednesday, which will be capable of
reducing visibility down to IFR/LIFR at times. FEW to SCT clouds,
down to 060-070 are likely at times, including with the front at
KBLH. There is also a low chance (10%) for a shower at KBLH with
the front.
&&
.FIRE WEATHER...
Light showers and a few isolated thunderstorms will be possible
today primarily across Pinal and southern Gila Counties. A strong
weather system will bring widespread strong, gusty winds,
precipitation chances, and cooler weather later today through
Wednesday. Strong winds will begin to increase across southeast
California this afternoon/evening before spreading into south-
central Arizona Wednesday with a frontal passage. Winds in excess
of 40 mph are likely (>90%) for much of the area, with gusts in
excess of 58 mph likely (>90%) across the southern Gila County
high terrain and Imperial County. Precipitation with this system
is expected to remain on the light side with the highest amounts
across southern Gila County.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Wind Advisory until 5 PM MST Wednesday for AZZ530>533-535-536.
Wind Advisory from 8 PM this evening to 8 PM MST Wednesday for
AZZ534-538-539-559.
High Wind Warning from 11 PM this evening to 8 PM MST Wednesday
for AZZ541-545-547-552-557-558-561.
Wind Advisory from 11 PM this evening to 8 PM MST Wednesday for
AZZ556-560-562-563.
Winter Storm Warning from 2 AM to 11 PM MST Wednesday for AZZ557-
558-563.
Winter Weather Advisory from 2 AM to 11 PM MST Wednesday for
AZZ557-558-563.
Wind Advisory from 2 AM to 8 PM MST Wednesday for AZZ537-540-
542>544-546-548>551-553>555.
CA...Wind Advisory until 1 PM PST Wednesday for CAZ560-561-568>570.
High Wind Warning until 4 PM PST Wednesday for CAZ562>567.
&&
DISCUSSION...Iniguez
AVIATION...Heil/Benedict
FIRE WEATHER...SmithThe national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
A 60 mph wind gust was measured at the El Centro Naval Air Facility.
A 62 mph wind gust was measured at the Imperial County Airport.
A 66 mph wind gust was measured at the El Centro Naval Air Facility.
Seventy-six power poles were knocked down, cutting power to about 2500 customers. Thirty-five poles went down north of Salton City and forty-one poles went down south of Salton City.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2023Every state in 2023This day in weather historyWarnings in California, February 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1082438, 1082437, 1082436, 1082435.