A winter storm brought light to moderate snow to much of eastern Iowa and northwest Illinois on March 9th, 2023. Precipitation began as a mix of rain and snow as it overspread the region during the morning hours.
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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 DVN wrote it up.
A winter storm brought light to moderate snow to much of eastern Iowa and northwest Illinois on March 9th, 2023. Precipitation began as a mix of rain and snow as it overspread the region during the morning hours. Snow was observed mainly north of Highway 34 to start, with more of a rain, snow, and sleet mix to the south. As the day progressed, precipitation began to change to all snow as temperatures dropped. This snow continued for most well into the early evening before tapering off by midnight. Snow totals were highest along and north of Interstate 80 with a range of around 4-6 inches. Pockets of higher amounts were observed in northwest Illinois in Stephenson County, with the highest total so far measured just west of Freeport at 6.5 inches. Further south, amounts were less with more rain and sleet mixing with the snow.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at Mar 9, 5:42 AM CST, 3 hours 18 minutes earlier.
Area Forecast Discussion
National Weather Service Quad Cities IA IL
542 AM CST Thu Mar 9 2023
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 303 AM CST Thu Mar 9 2023
Todays shortwave trough is evident on water vapor imagery
emerging into the Plains with developing precipitation on radar in
central and western Kansas/Nebraska. Skies were cloudy across
eastern Iowa, northwest Illinois and far northeast Missouri.
Temperatures at 2 AM ranged from 36 degrees at Dubuque and
Freeport to 43 degrees at Keokuk.
&&
.SHORT TERM...(Today and tonight)
Issued at 303 AM CST Thu Mar 9 2023
Key Messages:
1. There are no changes to the Winter Storm Warning and Winter
Weather Advisory with this issuance.
2. Warm ground temperatures and air temperatures above freezing
continue to lead to lower confidence with the snowfall amounts south
of Interstate 80.
Discussion:
Models are in good agreement with a 500 MB trough moving eastward
and into Iowa and Illinois by 00 UTC Friday. This trough is
forecast to exit the area between 6 and 12 UTC Friday. Models
show precipitation developing by mid morning west of a Cedar
Rapids to Burlington line and slowly spreading eastward to the
Mississippi by 18 UTC and then quickly overspread the rest of the
area by 20 UTC. Model time series show that precipitation will
have to overcome a dry layer at the surface that will likely cause
temperatures to cool to the wetbulb temperature. Precipitation
will being as all snow or a rain and snow mix north of Interstate
80 with all rain to the south. As temperatures cool, expect a rain
and snow mix to develop south of Interstate 80. All rain is
possible south of a line from Fairfield to Galesburg line. The
heaviest precipitation is expected to fall across the area from 21
to 03 UTC from southwest to northeast as a trowal moves across
the area. This trowal may result in periods of heavier convective
snow or rainfall. Equivalent potential temperature lines in the
mid levels indicate the potential for convective snow during this
period. HREF snowfall rates show 0.5 to 1.5 inches of snow are
possible during this period. Precipitation will come to an end
from southwest to northeast from 10 PM to 3 AM Friday as the
trough lifts northeastward and out of the area.
No changes were made to the Winter Storm Warning and
Winter Weather Advisory. In general, 4 to 7 inches of snow is
possible in the Winter Storm Warning with 1 to 3 inches possible
in the Winter Weather Advisory. Less than an inch is possible
south of Interstate 80. Warm ground temperatures and above
freezing temperatures and dewpoints is making the snowfall
amounts lower confidence along and south of Interstate 80 with
this event.
High temperatures today will occur before the precipitation begins
and be in the mid to upper 30s with temperatures slowly cooling as
precipitation begins. Low temperatures on Friday morning will
range from the upper 20s along and west of a line from Iowa City
to Freeport to the lower 30s east of that line.
.LONG TERM...(Friday through Wednesday)
Issued at 303 AM CST Thu Mar 9 2023
Key Messages:
1. Active weather continues through the long term period. Another
round of snow is possible this weekend.
2. Below normal temperatures are forecast into next week.
Discussion:
The 500 MB pattern will transition to more of a quasi zonal or
northwest flow aloft in the wake of the Thursday into Thursday
night storm system. Shortwave riding will quickly build into the
area at the surface and aloft bringing quiet weather to the region
through Saturday morning. The ECWMF is slightly faster with the
ridge moving eastward than the GFS and Canadian.
Models are trying to phase two systems that will impact the Upper
Midwest his weekend. There is one storm system moving from the
southern Plains into the lower Mississippi River Saturday while a
fast moving storm system dives southeastward from the northern
Plains into the Great Lakes. If these two storms systems phase
precipitation may spread northward during the day on Saturday.
Warmer temperatures may bring more of a rain and snow mix during
the day on Saturday with all rain south of Interstate 80.
Precipitation would transition to all snow Saturday night north of
Interstate 80 with a mix to the south. Precipitation types
appear similar to the current system with all rain falling south
of a Fairfield to Galesburg line. Precipitation quickly comes to
an end on Sunday morning as a cold front sweeps across the area.
Sunday will be breezy as the pressure gradient increase with the
storm system to our north and high pressure in the northern
Plains. As the surface low passes to our north on Sunday night,
light snow is possible over the far northwest Illinois and far
eastern Iowa.
High pressure will prevail with dry weather Monday through Tuesday
night. Colder low temperatures are forecast on Tuesday morning
with high pressure directly overhead and clear skies. The current
forecast has temperatures in the teen above zero along and north
of a Fairfield to Galesburg line with lower 20s south of the line.
Models agree on warmer weather across the area on Wednesday as
southerly winds behind the departing surface high draw warmer
weather northward. High temperatures next Wednesday are in the 40s.
Models disagree on the progression of a trough across the western US
with the GFS and Canadian move the ridge quickly eastward while the
ECWMF keeps the trough across western US with broad ridging
across the Plains.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 530 AM CST Thu Mar 9 2023
Clouds are thickening and lowering this morning ahead of a storm
system that will spread precipitation across the area from west
to east this morning. Conditions are currently VFR at all TAF
sites with ceilings between 4 to 8kft from west to east across
the area. Precipitation will move into KCID by 15 UTC and slowly
spread eastward to KBRL, KDBQ, and KMLI around 18 UTC. Precipitation
will remain all snow at KCID and KDBQ. Periods of -rasn and -sn
are possible at KMLI this afternoon before changing over to all
snow and -ra and -rasn are possible at KBRL. Ceilings and
visibilities will quickly deteriorate as precipitation spreads
across the area with IFR to LIFR and VLIFR possible in heavy
precipitation. Precipitation will come to an end from west to east
from 00 to 06 UTC. East winds around 10 knots this morning will
slowly turn to the north from 3 to 9 UTC.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Storm Warning from 9 AM this morning to 3 AM CST Friday
for Benton-Buchanan-Delaware-Linn.
Winter Storm Warning from noon today to 6 AM CST Friday for
Dubuque-Jackson-Jones.
Winter Weather Advisory from 9 AM this morning to 3 AM CST
Friday for Iowa-Johnson.
Winter Weather Advisory from noon today to 6 AM CST Friday for
Cedar-Clinton-Scott.
IL...Winter Storm Warning from noon today to 6 AM CST Friday for
Carroll-Jo Daviess-Stephenson.
Winter Weather Advisory from noon today to 6 AM CST Friday for
Whiteside.
MO...NONE.
&&
SYNOPSIS...Cousins
SHORT TERM...Cousins
LONG TERM...Cousins
AVIATION...CousinsHazardous Weather Outlook...CORRECTED National Weather Service Quad Cities IA IL 802 AM CST Thu Mar 9 2023 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-100915- Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson- Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson- Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll- Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson- Warren-Hancock-McDonough-Scotland-Clark- 802 AM CST Thu Mar 9 2023 This Hazardous Weather Outlook is for portions of north central Illinois...northwest Illinois...west central Illinois...east central Iowa...northeast Iowa...southeast Iowa and northeast Missouri. .DAY ONE...TODAY AND TONIGHT A winter storm will bring accumulating snow to portions of eastern Iowa and northern Illinois. Please refer to the Winter Storm Warning and Winter Weather Advisory products for more details. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Another round of snow is expected Saturday and Saturday night, but exact snowfall totals remain uncertain at this time. .SPOTTER INFORMATION STATEMENT... Reports of snow amounts over an inch would be appreciated.
The national radar mosaic for the moment the first event began.
3 winter storm. Local standard time, as filed.
Trained spotters and public reported snowfall of 4 to 6 inches falling over Jo Daviess County from the morning of March 9 and into the early morning hours of March 10. This snow contributed to travel issues through the day and into the nighttime hours.
Trained spotters and public reported snowfall of 4 to 7 inches falling over Stephenson County from the morning of March 9 and into the early morning hours of March 10. This snow contributed to travel issues through the day and into the nighttime hours.
Trained spotters and public reported snowfall of 4 to 7 inches falling over Carroll County from the morning of March 9 and into the early morning hours of March 10. This snow contributed to travel issues through the day and into the nighttime hours.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2023Every state in 2023This day in weather historyWarnings in Illinois, March 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: 1083412, 1083419, 1083420.