Delaware, 2001

Sleet in Delaware, January 20 to 21, 2001

January 20 to 21, 2001 · NWS PHI · 4 events in 4 counties and zones

A vigorous upper air disturbance coupled with a low pressure system that was intensifying east of the New Jersey coast produced a wintry mix across the state of Delaware. Precipitation began as rain across the state during the afternoon of the 20th.

Where it happened

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.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
4

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.

What happened

The episode as NWS PHI wrote it up.

A vigorous upper air disturbance coupled with a low pressure system that was intensifying east of the New Jersey coast produced a wintry mix across the state of Delaware. Precipitation began as rain across the state during the afternoon of the 20th. During the evening, precipitation changed to sleet and then snow, first in New Castle County. It took until about midnight for the changeover to occur across Sussex County. The heaviest precipitation, thus the largest accumulation of sleet and snow, occurred across New Castle County. Accumulations ranged from less than one inch at the shore to four inches in New Castle County. The snow ended around daybreak on the 21st.Because this event occurred on a Saturday night (the 20th) and a Sunday morning (the 21st), the number of traffic accidents was relatively lower. But, about 40 accidents were still reported in New Castle County between 11 p.m. EST on the 20th and 11 a.m. EST on the 21st. Specific accumulations included 4 inches in Wilmington (New Castle County), 3.6 inches in Bear (New Castle County), 3 inches in Newark (New Castle County) and at the New Castle County Airport, 1 inch in Milford (Kent County) and Greenwood (Sussex County) and less than one inch in Rehoboth Beach.

What forecasters said that day

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 Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Jan 20, 3:29 PM EST, 5 hours 31 minutes earlier.

Area forecast discussion, Jan 20, 3:29 PM EST, 5 hours 31 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
329 PM EST SAT JAN 20 2001

THIS FCST HOLDS A FAIR AMOUNT OF CONTINUITY FROM PREVIOUS ONE. SOME
MINOR MODIFICATIONS TO SNOWFALL PREDICITIONS BASED ON COORD WITH
SURROUNDING OFFICES AND HPC AND A MILD DELAY IN PRECIPITATION
CHANGEOVER.

AVN AND ETA ARE IN GOOD AGREEMENT NOW ON THE PATH OF THE MID LEVEL
LOW...WHICH IS NOW GENERATING SNOW OVER THE CENTRAL OH RVR VALLEY.
THEY ARE ALSO IS FAIRLY GOOD AGREEMENT ON FAIRLY STRONG VERTICAL
VELOCITIES AS THIS FEATURE MOVES ACROSS FA. MOISTURE PLUME FROM THE
SSW HAS BEEN HANGING JUST OFF THE COAST ALL DAY BUT SOME OF THIS MAY
WELL GET SUCKED INTO THE APCHG SYSTEM. GVN MODELS HAVE A TENDENCY TO
UNDERPLAY SNOW DUE TO AN UPPER SYSTEM WAS FEELING GOOD ABOUT RAISING
SOME AMOUNTS OVER NRN AND CNTRL FA...BUT MODELS ALSO VERY CONSISTENT
IN DRYING US OUT FROM TIME TO TIME AOA H6 OVERNIGHT. THIS COULD
ACTUALLY MEAN OSCILLATING BETWEEN SN AND -FZDZ WHENEVER SNOW DEVELOPS...
BUT DIDNT FEEL CONFIDENT ENOUGH TO WORD FCST AS SUCH. JUST WENT
OCCASIONAL SNOW AND BASICALLY DID NOT INCREASE AMOUNTS.
IN FACT...DWN SRN AND ERN FA...THE TIMING OF A CHANGEOVER GETS
BACKED UP A LTL. DYNAMIC COOLG CERTAINLY WILL ENSURE THAT CHANGEOVER
EVERYWHERE...BUT THE DELAY S AND E MADE FOR SOME MODEST DECREASES IN
AMOUNTS THERE.

GUIDANCE TEMPS NOT TOO DIFFERENT FROM EACH OTHER OR FROM PREV FCST
AND BASICALLY ACCEPTED THEM. DID RADIATE US SOME TMRW NITE IN ALL
BUT FAR SRN AND SERN ZONES IN ANTICIPITATION OF LGT WINDS AND SNOW
COVER AS SFC HIGH MOVES IN. MAY NOT HAVE DONE IT ENOUGH. STAYED A
LTL UNDER GUIDANCE FOURTH PD...AGAIN IN ANTICIPATION OF SOME SNOW
COVER THAT DOESNT EXIST MOST LOCATIONS NOW.

ON THE MARINE...CONTINUE GALES FOR THE NJ/DE COASTS AND LWR DEL BAY
AND SCA FOR THE UPPER BAY. FEEL IT IS A MARGINAL GALE BUT DO NOT
FEEL IT IS PRUDENT TO DROP IT NOW.

.PHI...WINTER STORM WARNING PAZ054/055/060>062/067>071/NJZ001/007/
       008/009/010/012>020/026/MDZ008/DEZ001

       WINTER WEATHER ADVISORY MDZ012/015/019/020/DEZ002>004/
       NJZ021>025

       GALE WARNING COAST AND LOWER DE BAY.

       SCA UPPER DEL BAY.

MPD

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 sleet. Local standard time, as filed.

Sleet, New Castle

When
January 20, 9:00 PM EST to January 21, 8:00 AM EST
Where
New Castle forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
39.578, -75.639 (the zone’s center; the record gives no point)

Sleet, Kent

When
January 20, 10:00 PM EST to January 21, 7:30 AM EST
Where
Kent forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
39.096, -75.505 (the zone’s center; the record gives no point)

Sleet, Inland Sussex

When
January 20, 11:00 PM EST to January 21, 7:00 AM EST
Where
Inland Sussex forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
38.683, -75.339 (the zone’s center; the record gives no point)

Sleet, Delaware Beaches

When
January 20, 11:30 PM EST to January 21, 7:00 AM EST
Where
Delaware Beaches forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
38.683, -75.339 (the zone’s center; the record gives no point)

What these are

Sleet
Sleet accumulating half an inch or more.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Delaware in 2001Every state in 2001This day in weather historyWarnings in Delaware, January 2001

Sources

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: 5227849, 5227848, 5227847, 5227846.