Alert archive / Maryland / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 318, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 20, 2026, 6:21 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Queen Anne's County, Talbot County, Maryland. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 20, 2026, 6:21 PM EDT (22:21 UTC)
- Expired
- Aug 20, 2026, 7:00 PM EDT
- In force
- 39 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Queen Anne's County, MD, Talbot County, MD
The radar
The Dover AFB radar (KDOX), 53 km from the middle of the area, began a volume at 22:25 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.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 20, 2:31 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 20, 2:58 PM EDT | Tornado Watch | SPC | 7 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.4 hours before the alert went out and 118 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
- 97 J/kg
- Mixed-layer CIN
- -72 J/kg
- Mixed-layer LCL
- 1192 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 115 m²/s²
- 0-3 km storm-relative helicity
- 230 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.0
The text
As transmitted.
773
WUUS51 KPHI 202221
SVRPHI
DEC001-005-MDC011-035-041-202300-
/O.NEW.KPHI.SV.W.0318.260820T2221Z-260820T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
621 PM EDT Thu Aug 20 2026
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northwestern Sussex County in southern Delaware...
Southern Kent County in central Delaware...
Talbot County in eastern Maryland...
Southern Queen Anne's County in northeastern Maryland...
Caroline County in eastern Maryland...
* Until 700 PM EDT.
* At 620 PM EDT, severe thunderstorms were located along a line
extending from near Starkey Corner to Flag Harbor, moving east at
35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to trees and power lines.
* Locations impacted include...
Dover, Easton, Centerville, Talbot, Milford, Denton, Centreville,
Harrington, Camden, Federalsburg, Milton, Bridgeville, Greensboro,
Oakland, and Ridgely.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern and northeastern Maryland.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.
For your protection move to an interior room on the lowest floor of a
building.
A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern and northeastern Maryland.
&&
LAT...LON 3877 7627 3875 7632 3886 7626 3885 7626
3878 7622 3879 7619 3880 7619 3894 7622
3894 7623 3892 7626 3894 7624 3906 7603
3912 7538 3881 7522 3881 7524 3866 7571
3870 7589 3857 7604 3877 7623 3869 7634
TIME...MOT...LOC 2220Z 273DEG 32KT 3911 7606 3848 7644
TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
DeSilva1 follow-up statement
814
WWUS51 KPHI 202244
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
644 PM EDT Thu Aug 20 2026
DEC001-005-MDC011-035-041-202300-
/O.CON.KPHI.SV.W.0318.000000T0000Z-260820T2300Z/
Sussex DE-Kent DE-Talbot MD-Queen Anne's MD-Caroline MD-
644 PM EDT Thu Aug 20 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHWESTERN SUSSEX...SOUTHERN KENT...TALBOT...SOUTHEASTERN QUEEN
ANNE'S AND CAROLINE COUNTIES...
At 643 PM EDT, severe thunderstorms were located along a line
extending from near Goldsboro to near Taylors Island, moving east at
35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to trees and power lines.
Locations impacted include...
Dover, Easton, Milford, Denton, Harrington, Camden, Federalsburg,
Milton, Bridgeville, Greensboro, Oakland, Ridgely, Trappe, Preston,
and Ellendale.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern and northeastern Maryland.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3858 7605 3860 7605 3862 7608 3875 7621
3907 7590 3912 7539 3907 7538 3898 7531
3881 7522 3866 7571 3869 7576 3868 7580
3870 7580 3870 7590 3867 7595
TIME...MOT...LOC 2243Z 273DEG 32KT 3910 7582 3847 7620
TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
DeSilvaWhat forecasters said that day
The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Aug 20, 4:23 PM EDT, 1 hour 58 minutes earlier. Its key messages:
- 1. A cold front will cross the region this evening, resulting in widespread showers and thunderstorms. Flash flooding, damaging wind gusts and tornadoes are possible later today. 2. Conditions look to remain unsettled through the weekend, with daily chances of showers and storms each day. 3. Fair weather is expected to return for early next week.
Area forecast discussion, Aug 20, 4:23 PM EDT, 1 hour 58 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
423 PM EDT Thu Aug 20 2026
.WHAT HAS CHANGED...
Severe thunderstorm and tornado watches now in effect for most
of the forecast area.
&&
.KEY MESSAGES...
1. A cold front will cross the region this evening, resulting
in widespread showers and thunderstorms. Flash flooding,
damaging wind gusts and tornadoes are possible later today.
2. Conditions look to remain unsettled through the
weekend, with daily chances of showers and storms each day.
3. Fair weather is expected to return for early next week.
&&
.DISCUSSION...
KEY MESSAGE 1...Broad troughing will be the main driving force
in the sensible weather into the early to middle part of next
week across much of the Eastern Seaboard. A shortwave will round
the base of the trough today into this evening providing some
mid level synoptic forcing. At the surface a warm front has
lifted north into the Philadelphia metro area with a cold front
approaching from the west.
The trend for increasing QPF and increasing severe weather
potential is being realized this afternoon. Severe thunderstorm,
tornado, and flood watches are in effect for most of the
forecast area.
Mesoanalysis fields this afternoon show moderate to strong
instability centered roughly around the Delmarva peninsula, but
extending north into southern NJ and southeast PA. Deep layer
shear of 40-60kt along with backed low level flow and strongly
curved hodographs will support a tornado risk, most notably from
the Philadelphia metro area and points south. Primary mode at
the moment is supercellular with all attendant risks, but more
multicell clusters may become the primary mode along the cold
front.
The other threat this evening is the potential for flash
flooding. Guidance shows very moisture rich airmass surging into
the region with PWAT values raching 2-2.5 inches. Warm cloud
depths suggest warm rain processes and high precipitation
efficiency into this evening and WPC has introduced a moderate
risk of execessive reainfall from Philadelphia north and east.
In general, expecting anywhere between 1 to 2 inches of rain to
fall, with localized higher amounts up to 3 to 5 inches.
The severe and flooding rain threat will diminish by the late
evening and overnight hours.
KEY MESSAGE 2...Conditions look to remain unsettled through the
weekend, with daily chances of showers and storms each day.
Mid to long range NWP and AI guidance suggests that the pattern
could become unsettled Friday night and into the weekend.
The cold front crossing the area tonight will stall in the
offshore waters. waves of low pressure will ride along the
stalled front resulting in unsettled weather through the
weekend. The main periods to watch are early Saturday through
Saturday evening, with periods of rain increasingly likely, and
again on Sunday. The severe threat appears low at this time but
there could be additional flooding concerns, although no day
has more than a Marginal (1/5) Risk for excessive rainfall.
Temperatures will be seasonable, but humidity will be
uncomfortable.
KEY MESSAGE 3...Fair weather is expected to return for early
next week.
Weak high pressure looks to bring quieter and drier weather in
the early part of the week, with more unsettled conditions
expected later in the week with seasonable temperatures.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Today...Widespread showers and thunderstorms are likely at all
locations this afternoon and evening. Any storms will be
capable of producing very heavy rainfall and LIFR conditions.
Winds will vary depending on location, with northern terminals
experiencing northeast winds 5 to 10 kt where southern
terminals will encounter southeasterly winds around 10 kt. Winds
will be gusty and erratic near any storm. Bulk of the shower and
storm activity ending around 01-02z. Moderate confidence
overall, but low confidence on exact timing details.
Tonight...Sub-VFR conditions probable at times with showers and
thunderstorms continuing into the evening hours. Fog and/or low
stratus possible at night after the precipitation moves out.
Conditions should lift back to VFR near or not long after
daybreak. North/northeast winds around 5 to 10 kt. Moderate
confidence.
Outlook...
Friday through Friday night...Primarily VFR.
Saturday through Sunday...Periods of VFR and sub-VFR at times.
Restrictions expected with daily chances for showers and
thunderstorms.
Monday...VFR. No significant weather expected.
&&
.MARINE...
A cold front will move through tonight, with winds becoming
more north/northeasterly around 10-15 kt. Seas of 2 to 3 feet.
Showers and thunderstorms expected on the waters this evening
into tonight.
Outlook...
Friday through Monday...No marine headlines expected. Showers
and thunderstorms possible during the day Friday through
Sunday.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch until 2 AM EDT Friday for PAZ054-055-060>062-070-
071-101>106.
NJ...Flood Watch until 2 AM EDT Friday for NJZ001-007>010-012>022-
025>027.
DE...Flood Watch until 2 AM EDT Friday for DEZ001.
MD...None.
MARINE...None.
&&
DISCUSSION...Manning
AVIATION...Manning
MARINE...ManningHazardous weather outlook, Aug 20, 5:12 AM EDT, 13 hours 9 minutes before
Hazardous Weather Outlook National Weather Service Mount Holly NJ 512 AM EDT Thu Aug 20 2026 MDZ012-015-019-020-210915- Kent MD-Queen Annes-Talbot-Caroline- 512 AM EDT Thu Aug 20 2026 This Hazardous Weather Outlook is for northeast Maryland. .DAY ONE...Today and tonight. Numerous thunderstorms are expected between about 2 PM and 8 PM. These storms may contain damaging wind gusts and potentially a couple of tornadoes over the Eastern Shore. Storms will be capable of producing heavy rainfall, with rainfall rates of 2 to 4" per hour possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. Hoeflich
In the hours before
Local storm report, Aug 20, 5:42 PM EDT, 39 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
542 PM EDT Thu Aug 20 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0541 PM Tstm Wnd Dmg West Grove 39.82N 75.83W
08/20/2026 Chester PA Public
Trees down. some trees on wires.
&&
PFLocal storm report, Aug 20, 5:45 PM EDT, 36 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
545 PM EDT Thu Aug 20 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0520 PM Tstm Wnd Dmg Honey Brook 40.10N 75.91W
08/20/2026 Chester PA Public
Trees down and blocking route 322.
&&
PFLocal storm report, Aug 20, 5:48 PM EDT, 33 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
548 PM EDT Thu Aug 20 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0525 PM Tstm Wnd Dmg Glenmoore 40.09N 75.77W
08/20/2026 Chester PA Public
Trees and wires down across Creek Road with
wires arcing. Time estimated from radar.
&&
PFLocal storm report, Aug 20, 6:04 PM EDT, 17 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
604 PM EDT Thu Aug 20 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0550 PM Rain 1 SE Atlantic City Inte 39.44N 74.55W
08/20/2026 M1.98 Inch Atlantic NJ Trained Spotter
CoCoRaHS station reported 1.98 inches of
rain over 2 hours.
&&
MJLLocal storm report, Aug 20, 6:18 PM EDT, 3 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
618 PM EDT Thu Aug 20 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0550 PM Rain 3 SW Milmay 39.40N 74.89W
08/20/2026 M3.51 Inch Cumberland NJ Trained Spotter
CoCoRaHS station Estell Manor 4.0 WNW
reported 3.51 inches of rainfall over 3
hours.
&&
MJLLocal storm report, Aug 20, 6:20 PM EDT, 1 minute before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
620 PM EDT Thu Aug 20 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0618 PM Tornado Dover 39.16N 75.54W
08/20/2026 Kent DE Trained Spotter
Trained spotter reported a rain wrapped
tornado on the ground, flying debris.
&&
MJLThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 4:16 PM EDT | Tornado Warning | PHI | Kent | 29 min |
| Aug 20, 4:50 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 40 min |
| Aug 20, 5:27 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 48 min |
| Aug 20, 5:39 PM EDT | Flash Flood Warning | PHI | New Castle | 4 hr |
| Aug 20, 5:39 PM EDT | Tornado Warning | PHI | Kent | 36 min |
| Aug 20, 5:40 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 50 min |
| Aug 20, 6:03 PM EDT | Tornado Warning | PHI | Kent | 42 min |
| Aug 20, 6:09 PM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 51 min |
| Aug 20, 6:13 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 47 min |
| Aug 20, 6:53 PM EDT | Flash Flood Warning | PHI | Kent | 105 min |
| Aug 20, 6:57 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 48 min |
| Aug 20, 2:43 PM EDT | Tornado Warning | PHI | Kent, Queen Anne's | 32 min |
| Aug 20, 5:05 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 40 min |
| Aug 20, 5:30 PM EDT | Tornado Warning | PHI | Kent, Queen Anne's | 30 min |
Nearby
Severe Thunderstorm Warnings in Maryland, 2026Severe Thunderstorm Warnings in Delaware, 2026Every severe thunderstorm warning in 2026
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.