Alert archive / Pennsylvania / Flash Flood Warnings in 2009

Flash Flood Warning 29, NWS Philadelphia/Mount Holly

August 2, 20095 counties in Pennsylvania; New Castle County, Delaware; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 2, 2009, 10:08 AM EDT for 5 counties in Pennsylvania; New Castle County, Delaware; Cecil County, Maryland. It was in force for 9 hr. 15 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 2, 2009, 10:08 AM EDT (14:08 UTC)
Expired: Aug 2, 2009, 7:00 PM EDT
In force: 9 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties New Castle County, DE, Cecil County, MD, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 93 km from the middle of the area, began a volume at 14:10 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.

What was reported inside it

Time	Report	Where	Remark
Aug 2, 10:35 AM EDT	FLASH FLOOD	Oxford, PA	ROADWAY FLOODING IN OXFORD.
Aug 2, 11:13 AM EDT	HEAVY RAIN 1.75	Elkton, MD	1.75 INCHES IN ONE HOUR.
Aug 2, 11:20 AM EDT	FLASH FLOOD	Drexel Hill, PA	WATER RESCUES WERE PREFORMED IN HAVERFORD AND UPPER DARBY.
Aug 2, 11:20 AM EDT	HEAVY RAIN 1	Drexel Hill, PA	1 INCH AND HOUR AND 1.65 IN 40 MINUTES.
Aug 2, 11:23 AM EDT	FLASH FLOOD	Ardmore, PA	INDIAN CREEK BROKE ITS BANK IN WYNNEWOOD.
Aug 2, 11:45 AM EDT	FLASH FLOOD	Quakertown, PA	ROUTE 313 FLOODED AND CLOSED.
Aug 2, 11:48 AM EDT	HEAVY RAIN 1.29	2 N Philadelphia Intern, PA	1.29 INCHES IN 28 MINUTES.
Aug 2, 11:50 AM EDT	FLASH FLOOD	Ambler, PA	BUTLER PIKE FLOODED WITH LANDSLIDE INTO THE ROAD.
Aug 2, 11:50 AM EDT	FLASH FLOOD	Conshohocken, PA	SCHUYLKILL EXPRESSWAY FLOODED AND CLOSED AT THE CONSHOHOCKEN CURVE.
Aug 2, 12:00 PM EDT	FLASH FLOOD	2 Wnw Morris Park, PA	FLOODING ALONG COBBS CREEK, HOMES FLOODED IN HAVERFORD.
Aug 2, 12:15 PM EDT	FLASH FLOOD	Langhorne, PA	NESHAMINY CREEK STARTING TO FLOOD.
Aug 2, 12:15 PM EDT	FLASH FLOOD	Newtown, PA	MAJOR STREET FLOODING IN NEWTOWN.
Aug 2, 1:05 PM EDT	FLASH FLOOD	Willow Grove, PA	EXIT RAMP AT ROUTE 611 OFF PA TURNPIKE CLOSED DUE TO WATER.
Aug 2, 1:19 PM EDT	FLASH FLOOD	Perkasie, PA	ROADWAYS FLOODED IN QUAKERTOWN BORO.
Aug 2, 1:23 PM EDT	FLASH FLOOD	Perkasie, PA	EAST BRANCH OF PERKIOMEN CREEK BREECHED ITS BANKS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 2.1 hours before the alert went out and 202 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 633 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 689 m above ground
0-6 km bulk shear: 0 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS51 KPHI 021408
FFWPHI
DEC003-MDC015-PAC017-029-045-091-101-021900-
/O.NEW.KPHI.FF.W.0029.090802T1408Z-090802T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1008 AM EDT SUN AUG 2 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF ELKTON...
  NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITIES OF...WILMINGTON...NEWARK...
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF WEST CHESTER...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...

* UNTIL 300 PM EDT

* AT 1002 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
THUNDERSTORMS WITH HEAVY RAIN MOVING INTO THE REGION. AN   
ADDITIONAL ONE TO TWO INCHES OF RAIN IS LIKELY BETWEEN NOW AND 2 PM. 
WITH HEAVY RAIN ALREADY FALLEN THIS MORNING, IT WILL NOT TAKE MUCH 
TO CAUSE STREAMS TO REACH OR EXCEED BANKFULL.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MORRIS
  PARK...CENTER CITY...WISSINOMING...VALLEY FORGE...TROUT LAKE...
  TINICUM...TEMPLE UNIVERSITY...TACONY...SPRINGTOWN...ROXBOROUGH...
  REVERE...PLEASANT VALLEY...PIPERSVILLE...OTTSVILLE...NORTHEAST
  PHILADELPHIA...NEWTOWN SQUARE...KENSINGTON...HOLMESBURG...
  GERYVILLE...GARDENVILLE...FRICKS...ERWINNA...CHESTER SPRINGS...
  CHESTNUT HILL...BENSALEM...BEDMINSTER...ANDALUSIA...ABINGTON...
  FERNDALE...GERMANTOWN...WOODSIDE...WILLOW GROVE...SPRING MOUNT...
  SOUDERTON...ROCKLEDGE...RICHBORO...RADNOR TOWNSHIP...QUAKERTOWN...
  POTTSTOWN...PLYMOUTH MEETING...PHOENIXVILLE...PERKASIE...PAOLI...
  NORRISTOWN...NEWTOWN...NEW HOPE...LIONVILLE...LEVITTOWN...
  LANSDALE...LANGHORNE...KING OF PRUSSIA...IVYLAND...GILBERTSVILLE...
  FEASTERVILLE...EAST GREENVILLE...DUBLIN...DOYLESTOWN...
  DOWNINGTOWN...COLLEGEVILLE...CHALFONT...BRYN MAWR...BRISTOL AND
  AMBLER

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 3970 7623 4014 7557 4026 7569 4044 7553
      4042 7549 4062 7520 4056 7519 4053 7507
      4042 7506 4040 7497 4014 7473 3998 7511
      3988 7515 3984 7537 3962 7560 3960 7555
      3950 7558 3938 7603 3955 7598 3954 7607

$$

RPW

3 follow-up statements

000 
WGUS71 KPHI 021844
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
244 PM EDT SUN AUG 2 2009

DEC003-MDC015-021852-
/O.CAN.KPHI.FF.W.0029.000000T0000Z-090802T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CECIL MD-NEW CASTLE DE-
244 PM EDT SUN AUG 2 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NEW CASTLE AND
CECIL COUNTIES...

THE HEAVY RAIN AND REPORTED SERIOUS FLOODING HAS ENDED ACROSS 
THE AREA. NO ADDITIONAL HEAVY RAIN IS EXPECTED AT THIS TIME.

LAT...LON 4014 7557 4026 7569 4044 7553 4042 7549
      4062 7520 4056 7519 4053 7507 4042 7506
      4040 7497 4034 7495 4014 7473 3998 7511
      3988 7516 3985 7535 3980 7542 3984 7552
      3984 7566 3973 7578 3972 7615 3973 7615

$$

PAC017-029-045-091-101-021900-
/O.CON.KPHI.FF.W.0029.000000T0000Z-090802T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA-BUCKS PA-
244 PM EDT SUN AUG 2 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 PM EDT FOR
BUCKS...MONTGOMERY...CHESTER...PHILADELPHIA AND DELAWARE COUNTIES...

AT 240 PM EDT...THE ORGANIZED HEAVY RAIN HAS ENDED, BUT FLOODING
WAS STILL REPORTED AROUND THE REGION. THE FLASH FLOOD WARNING
WILL BE EXTENDED SHORTLY.
 
LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO VALLEY
FORGE...TINICUM...TACONY...SPRINGTOWN...REVERE...PLEASANT VALLEY...
PIPERSVILLE...OTTSVILLE...NORTHEAST PHILADELPHIA...HOLMESBURG...
GERYVILLE...GARDENVILLE...FRICKS...ERWINNA...CHESTER SPRINGS...
CHESTNUT HILL...BENSALEM...BEDMINSTER...ANDALUSIA...ABINGTON...
FERNDALE...GERMANTOWN...WOODSIDE...WILLOW GROVE...SPRING MOUNT...
SOUDERTON...ROCKLEDGE...RICHBORO...RADNOR TOWNSHIP...QUAKERTOWN...
POTTSTOWN...PLYMOUTH MEETING...PHOENIXVILLE...PERKASIE...PAOLI...
NORRISTOWN...NEWTOWN...NEW HOPE...LIONVILLE...LEVITTOWN...LANSDALE...
LANGHORNE...KING OF PRUSSIA...IVYLAND...GILBERTSVILLE...
FEASTERVILLE...EAST GREENVILLE...DUBLIN...DOYLESTOWN...
COLLEGEVILLE...CHALFONT...BRISTOL AND AMBLER

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

FLOODING IS OCCURRING. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER
GROUND.

&&

LAT...LON 4014 7557 4026 7569 4044 7553 4042 7549
      4062 7520 4056 7519 4053 7507 4042 7506
      4040 7497 4034 7495 4014 7473 3998 7511
      3988 7516 3985 7535 3980 7542 3984 7552
      3984 7566 3973 7578 3972 7615 3973 7615

$$
 
TFG

000 
WGUS51 KPHI 021847
FFWPHI
PAC017-029-045-091-101-022300-
/O.EXT.KPHI.FF.W.0029.000000T0000Z-090802T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
247 PM EDT SUN AUG 2 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF WEST CHESTER...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...

* UNTIL 700 PM EDT

* AT 245 PM EDT...ONGOING FLOODING WAS STILL OCCURRING ACROSS
  THE WARNED AREA. WHILE THE ORGANIZED TORRENTIAL RAIN IS OVER, IT
  WILL TAKE TIME FOR FLOODING TO END. PLEASE FOLLOW THE DIRECTION
  OF EMERGENCY RESPONDERS AND MANAGERS IN YOUR AREA. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO TINICUM...
  SPRINGTOWN...REVERE...PLEASANT VALLEY...PIPERSVILLE...OTTSVILLE...
  GERYVILLE...GARDENVILLE...FRICKS...ERWINNA...BEDMINSTER...
  FERNDALE...WOODSIDE...WILLOW GROVE...SPRING MOUNT...SOUDERTON...
  RICHBORO...QUAKERTOWN...POTTSTOWN...PHOENIXVILLE...PERKASIE...
  NEWTOWN...NEW HOPE...LEVITTOWN...LANSDALE...LANGHORNE...IVYLAND...
  GILBERTSVILLE...FEASTERVILLE...EAST GREENVILLE...DUBLIN...
  DOYLESTOWN...COLLEGEVILLE...CHALFONT AND AMBLER

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER
GROUND.

&&

LAT...LON 4014 7557 4026 7569 4044 7553 4042 7549
      4062 7520 4056 7519 4053 7507 4042 7506
      4040 7497 4034 7495 4014 7473 3998 7511
      3988 7516 3985 7535 3980 7542 3984 7552
      3984 7566 3973 7578 3972 7615 3973 7615

$$
 
TFG

000 
WGUS71 KPHI 022241
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
641 PM EDT SUN AUG 2 2009

PAC017-029-045-091-101-022300-
/O.CON.KPHI.FF.W.0029.000000T0000Z-090802T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA-BUCKS PA-
641 PM EDT SUN AUG 2 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM EDT FOR
BUCKS...MONTGOMERY...CHESTER...PHILADELPHIA AND DELAWARE COUNTIES...

THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE AT 700 PM EDT.
NO ADDITIONAL HEAVY RAIN IS EXPECTED. SEVERAL GAGED LARGER CREEKS 
ARE STILL FLOODING IN THE AREA INCLUDING THE NESHAMINY AND PENNYPACK. 
PLEASE REFER TO INDIVIDUAL FLOOD WARNING BULLETINS FOR FURTHER
DETAILS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 4014 7557 4026 7569 4044 7553 4042 7549
      4062 7520 4056 7519 4053 7507 4042 7506
      4040 7497 4034 7495 4014 7473 3998 7511
      3988 7516 3985 7535 3980 7542 3984 7552
      3984 7566 3973 7578 3972 7615 3973 7615

$$
 
TFG

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 2, 2:19 AM EDT	Flash Flood Watch	PHI	Berks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more	13 hr
Aug 2, 3:29 AM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Aug 2, 5:54 AM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Aug 2, 7:34 AM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	3 hr
Aug 2, 7:51 AM EDT	Areal Flood Warning	PHI	Chester	4 hr
Aug 2, 9:04 AM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	4 hr
Aug 2, 9:06 AM EDT	Flash Flood Warning	PHI	Berks, Carbon, Chester, Lehigh, Monroe, Northampton	4 hr
Aug 2, 10:08 AM EDT	Severe Thunderstorm Warning	PHI	Chester	67 min
Aug 2, 10:24 AM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery	66 min
Aug 2, 10:53 AM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	67 min
Aug 2, 11:14 AM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Montgomery, Northampton	61 min
Aug 2, 11:25 AM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	65 min
Aug 2, 11:48 AM EDT	Severe Thunderstorm Warning	PHI	Bucks	57 min
Aug 2, 11:51 AM EDT	Tornado Warning	PHI	Bucks	24 min
Aug 2, 12:33 PM EDT	River Flood Warning	PHI	Bucks	28 hr
Aug 2, 1:25 PM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	6 hr
Aug 2, 4:06 PM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	4 hr
Aug 2, 4:21 PM EDT	River Flood Warning	PHI	Chester	56 min
Aug 2, 4:22 PM EDT	Flash Flood Warning	PHI	Berks	2 hr
Aug 2, 6:15 PM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	4 hr
Aug 2, 6:25 PM EDT	Areal Flood Warning	PHI	Philadelphia	4 hr
Aug 2, 10:32 AM EDT	Tornado Warning	PHI	New Castle	28 min
Aug 2, 10:39 AM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	96 min
Aug 2, 12:13 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	3 hr
Aug 2, 12:53 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	67 min
Aug 2, 12:10 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Talbot	65 min

Nearby

Flash Flood Warnings in Pennsylvania, 2009 Flash Flood Warnings in Delaware, 2009 Flash Flood Warnings in Maryland, 2009 Every flash flood warning in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.