Alert archive / Pennsylvania / Flash Flood Warnings in 2025

Flash Flood Warning 8, NWS State College, PA

May 15, 2025Adams County, Cumberland County, York County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 15, 2025, 6:39 AM EDT for Adams County, Cumberland County, York County, Pennsylvania. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 15, 2025, 6:39 AM EDT (10:39 UTC)
Expired
May 15, 2025, 8:55 AM EDT
In force
2 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Adams County, PA, Cumberland County, PA, York County, PA

The radar

The Sterling radar (KLWX), 118 km from the middle of the area, began a volume at 10:42 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 flash flood 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 10.7 hours before the alert went out and 119 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2025-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 366 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2025-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
366 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
577 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

652 
WGUS51 KCTP 151039
FFWCTP
PAC001-041-133-151345-
/O.NEW.KCTP.FF.W.0008.250515T1039Z-250515T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
Issued by National Weather Service Binghamton NY
639 AM EDT Thu May 15 2025

The National Weather Service in State College has issued a

* Flash Flood Warning for...
  Northeastern Adams County in south central Pennsylvania...
  South Central Cumberland County in south central Pennsylvania...
  West Central York County in south central Pennsylvania...

* Until 945 AM EDT.

* At 639 AM EDT, Local law enforcement reported heavy rain and flash 
  flooding across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts of 0.5 to 1 inch are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Law enforcement reported.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Hampton, Lake Meade, New Oxford, York Springs, Heidlersburg, 
  Hunterstown, Franklintown, Idaville and Gardners.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4011 7716 4011 7706 4009 7703 3991 7705
      3983 7706 3982 7718 3993 7721 4000 7722
      4006 7721

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

JRB/MLJ
1 follow-up statement
758 
WGUS71 KCTP 151255
FFSCTP

Flash Flood Statement
National Weather Service State College PA
Issued by National Weather Service Binghamton NY
855 AM EDT Thu May 15 2025

PAC001-041-133-151305-
/O.CAN.KCTP.FF.W.0008.000000T0000Z-250515T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams PA-Cumberland PA-York PA-
855 AM EDT Thu May 15 2025

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHEASTERN ADAMS, SOUTH 
CENTRAL CUMBERLAND AND WEST CENTRAL YORK COUNTIES...

Flood waters are receding. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

&&

LAT...LON 4011 7716 4011 7706 4009 7703 3991 7705
      3983 7706 3982 7718 3993 7721 4000 7722
      4006 7721

$$

MLJ

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS State College, PA wrote its last area forecast discussion before this flash flood warning went out at May 15, 5:58 AM EDT, 41 minutes earlier.

Area forecast discussion, May 15, 5:58 AM EDT, 41 minutes before
Area Forecast Discussion
National Weather Service State College PA
Issued by National Weather Service Binghamton NY
558 AM EDT Thu May 15 2025

.SYNOPSIS...
* Daily chances for thunderstorms continue through Saturday
  with potential for damaging winds and localized flooding.
* Temperatures trend warmer Friday and Saturday with a notable
  uptick in humid/sticky weather.
* A cold front will bring much colder temperatures and less
  rainy/more sunny weather later this weekend and early next
  week with breezy conditions.

&&

.NEAR TERM /THROUGH TONIGHT/...
Low ceilings, reduced visibility and some drizzle evident all
across Central PA this morning as persisent southeast flow
continues to keep moisture locked into place. Weak ridging aloft
has contributed to a decrease in shower activity overnight and
daybreak temperatures are generally in the 50s.

Later today, the upper low that has enveloped the region over
the past couple days will continue to lift northeast, but will
be replaced by an approaching and rather vigorous northern
stream upper- level wave. Lingering energy aloft from the
opening up and former cutoff low could still well produce
diurnally favored showers and thunderstorms this afternoon, with
most of the coverage probably occurring near and east of US-15.
Although precipitable water values look a little lower today
than previous days, any sustained convection over
hydrologically sensitive areas will have to be watched.
Fortunately, most of the rain/storms today should fire up east
of the areas that got hit hard by rainfall the last couple days.
A Marginal Risk of excessive rainfall is in place for all of PA,
but the most vulnerable locations are in Somerset and Bedford
County.

Good news is we should see more sunshine by this afternoon as
winds turn more southerly and ridging builds in. Highs today
will moderate nicely compared to yesterday, generally in the 70s
across the region (+10F day over day). By this evening, a warm
front will lift through the Commonwealth and bring the potential
for more showers and storms overnight. The best
shear/instability is not expected to make it into central PA,
but decaying storms will roll through during the predawn hours
and linger into Friday morning. SPC has hoisted a MRGL risk for
the western half of PA where a few storms could produce some
gusty winds or small hail. Daybreak temperatures on Friday will
be around 60F areawide.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Latest guidance indicates a lull in the precipitation during the
late morning and afternoon on Friday following the passage of
the warm front. Southwest flow will continue to funnel moisture
up into the northeast US as dewpoints reach their highest values
so far this year (in the mid to upper 60s). It will feel
noticeably humid as well. Highs in the 80s across the area
appear likely with the only exception being if thunderstorms can
fire up in the afternoon.

Another round of convection appears likely Friday night into
Saturday morning (yet again decaying as it moves across
Pennsylvania from the Midwest). Severe weather appears a bit
more likely with this round as 2500J/kg of MLCAPE overlaps with
sufficient shear in the evening. The SPC Slight Risk gets into
southwest PA, but would not be surprised to see an eastward
expansion across southern PA with subsequent updates.

By Saturday, a cold front will approach the Commonwealth with a
convective outflow boundary likely surging out ahead of it from
the previous night's convection. The outflow boundary will
encounter a warm and moist airmass that could lead to
development of sustained strong thunderstorms on Saturday
afternoon. Still some uncertainty with how quickly a line of
thunderstorms will congeal Saturday afternoon, but southeast PA
would be favored for a primarily damaging wind threat, as
outlined by SPC's Slight Risk (level 2 out of 5) that covers
York and Lancaster County. With all 3 rounds of storms,
progressive storm motions should limit the risk of signficant
flooding, but cannot rule out some isolated issues for locations
who's soil moistures/creeks are already running high.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The latest model timing now brings a surface cold front through
PA a little faster than earlier model runs (by later Saturday
night). Although some upper-level energy could still produce
isolated showers on Sunday, an overall drier trend should be
underway.

Early next week (Monday and Tuesday), a confluent NW flow
pattern aloft over the Commonwealth will encourage the approach
of expansive surface high pressure and a dry, cooler air mass.

By the middle of next week, once the upper ridge line passes off
the coast, the approach of the next disturbance aloft and
surface warm front should bring a renewed threat of showers.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
Reduced ceilings and visibility evident across the entire area
this morning as southeast flow continues to keep low
clouds/moisture locked in. Conditions should gradually improve
into this afternoon as winds turn to come out of the south. VFR
conditions should prevail by this evening everywhere. A few
scattered showers and thunderstorms are possible this afternoon,
but predicability remains too low to prevail any thunder.

Conditions will deteriorate again tonight. A decaying line of
thunderstorms could bring some restrictions to western airfields
before daybreak Friday with gusty winds possible.

Outlook...

Fri...Morning storms (some could be strong), improving
conditions in the afternoon.

Sat...Mainly VFR, isolated PM showers/storms.

Sun...Some improvement, as a series of cold fronts move
southeast of the area.

Mon...Mainly dry with VFR conditions. Perhaps a shower
early at BFD and JST, with MVFR CIGS early at these sites.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

SYNOPSIS...Jurewicz/Banghoff
NEAR TERM...Jurewicz/Banghoff
SHORT TERM...Jurewicz/Banghoff
LONG TERM...Jurewicz/Banghoff
AVIATION...Banghoff/Martin
Hazardous weather outlook, May 15, 4:47 AM EDT, 1 hour 52 minutes before
Hazardous Weather Outlook
National Weather Service State College PA
Issued by National Weather Service Binghamton NY
447 AM EDT Thu May 15 2025

PAZ028-037-041-042-046-049>053-056>059-063>066-160900-
Juniata-Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Union-
Snyder-Montour-Northumberland-Columbia-Perry-Dauphin-Schuylkill-
Lebanon-Cumberland-Adams-York-Lancaster-
447 AM EDT Thu May 15 2025

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Strong to severe thunderstorms with gusty winds are possible
Friday and Saturday. Isolated flooding may also occur. In addition
to typical afternoon thunderstorms, a few strong storms may occur
overnight.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ004>006-010>012-017>019-024>027-033>036-045-160900-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin-
Somerset-Bedford-Fulton-Franklin-Southern Clinton-
447 AM EDT Thu May 15 2025

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

Strong to severe thunderstorms with gusty winds are possible
late tonight into early Friday morning. Locally heavy rainfall from
thunderstorms could produce flash flooding.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Strong to severe thunderstorms with gusty winds are possible again
Friday afternoon and overnight. Flooding is possible in locations
that have had significant rainfall recently.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

The office that day

Everything else NWS State College, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 6:10 AM EDTRiver Flood WarningCTPCumberland23 hr
May 15, 3:50 PM EDTFlood WatchCTPBedford, Somerset17 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2025Every flash flood warning in 2025

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.