High moisture content and relatively light winds created prime conditions for flash flooding to occur with rain and thunderstorms on the evening of April 22. There were several reports of flooding and flash flooding due to the heavy rainfall across portions of the region.
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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 LWX wrote it up.
High moisture content and relatively light winds created prime conditions for flash flooding to occur with rain and thunderstorms on the evening of April 22. There were several reports of flooding and flash flooding due to the heavy rainfall across portions of the region.
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 Baltimore/Washington wrote its last area forecast discussion before the first event at Apr 22, 5:02 PM EST, 13 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 602 PM EDT SAT APR 22 2006 .EVENING UPDATE... LINEAR FORCING PRODUCING LARGE AREA OF RAIN WITH SOME EMBEDDED THUNDER...CONTINUING ACROSS THE MIDDLE OF OUR CWA. FLASH FLOOD THREAT IS BECOMING A SERIOUS CONCERN IN THE SHEN VLY AND NORTHERN PIEDMONT ATTM...WITH LARGE AREA OF RAIN MOVING VERY LITTLE AND 1 HR PRECIP RATES BEGINNING TO APPROACH 2 PER HR. HAVE ISSUED A QUICK UPDATE JUST TO INCRS POPS ACROSS THE CWA MAINLY E OF THE BLUE RIDGE. STILL EXPECT PRECIP TO TAPER OFF MOST AREAS BY MIDNIGHT. DRY SLOTTING MOVING THROUGH SE VA ATTM AND SHOULD MOVE INTO NRN VA AND SRN MD BY LATE EVNG. NO OTHER CHANGES ATTM. JB && .SHORT TERM /TONIGHT THROUGH SUNDAY/... WATER VAPOR LOOP SHOWS A NEARLY STATIONARY UPPER LOW ACROSS THE GREAT LAKES...AS A VIGOROUS WAVE SHEARS NORTHEAST ALONG THE APPALACHIANS. ACARS 400-250MB WIND OBSERVATIONS INDICATES THE UPPER LEVEL FLOW PHASES MACROS THE EASTERN GREAT LAKES...WHERE SOUTHWESTERLY WINDS OF 100KT WAS OBSERVED. 11Z MESOANALYSIS PLACES AN OCCLUDED BOUNDARY SOUTHEAST THROUGH THE GREAT LAKES INTO CENTRAL WEST VIRGINIA. A 1012MB CYCLONE WAS LOCATED IN SOUTHWEST VIRGINIA...WITH A COLD FRONT STRETCHING SOUTHWEST THROUGH CENTRAL ALABAMA. THE WARM/STATIONARY BOUNDARY SNAKES EAST ACROSS CENTRAL WEST VIRGINIA..THEN SOUTH AND EAST ALONG THE SOUTHERN VIRGINIA BORDER. RIDGING WAS OBSERVED FROM NEW ENGLAND SOUTHWEST INTO THE MID ATLANTIC REGION. THE 15Z MESOANALYSIS PLACED THE WARM FRONT ALONG THE SOUTHERN BORDER OF THE FORECAST AREA. A LOOK AT 18Z OBSERVATIONS PLACES THE WARM FRONT CLOSER TO A LINE FROM PETERSBURG WV TO WASHINGTON DC. DURING THE DAY...THE DEFORMATION PRECIPITATION HAS PRESSED NORTHEAST OF THE FORECAST AREA...WHILE THE LINEAR CONVECTION ASSOCIATED WITH THE FIRST AND WEAKER OF THE WAVES MOVES EAST OF THE REGION. THE SECOND AND STRONGER WAVE IS RESPONSIBLE FOR THE MESOLOW AND STRONG/SEVERE CONVECTION ACROSS SOUTHEAST VIRGINIA...WHICH WILL LIKELY AFFECT A PORTION OF LOWER SOUTHERN MARYLAND AND THE SOUTHERN MARINE AREAS LATE THIS AFTERNOON. THE 12Z NAM/WRF-NMM/GFS STILL INSIST THAT A SECOND LINE OF STRONG CONVECTION WILL DEVELOP NEAR THE COLD FRONT (NOW WITHIN THE APPALACHIANS). GIVEN THE ACTIVITY (AND AREAS OF LACK OF ACTIVITY) ON THE REGIONAL RADAR...CONFIDENCE IN THIS SOLUTION IS DECREASING RAPIDLY. FIRST...THE CONVECTION THE THE SOUTHEAST (LIFT/SUBSIDENCE ASSOCIATED WITH THE MID LEVEL WAVE) MAY BE INTERFERING WITH MOISTURE CONVERGENCE ON THE ACTUAL COLD FRONT. ALSO...THE COLD POOL IS MEAGER...WHICH ALSO TAKES AWAY FROM THE CONVECTIVE INITIATION PROBABILITIES. THEREFORE...THE FORECAST REFLECTS A LOW CHANCE OF PRECIPITATION...EXCEPT ACROSS LOWER SOUTHERN MARYLAND AND THE BORDERING WATERS. A CONCERN OVERNIGHT IS THE POSSIBILITY OF DENSE FOG. ALREADY HAVE DENSE FOG ABOVE 1500FT ALONG AND WEST OF THE BLUE RIDGE (THIS IS MIXING OUT SOUTH TO NORTH). ONCE THE WEAK COLD FRONT MOVES SOUTHEAST ACROSS THE FORECAST AREA...WINDS BECOME LIGHT WHILE THE LOW LEVEL LAPSE RATES REMAIN WEAK...ENCOURAGING MOISTURE TO REMAIN NEAR THE SURFACE. LOW LEVEL MOISTURE SHOULD MIX OUT BY MIDDAY SUNDAY...AHEAD OF A SECONDARY VORTICITY MAXIMUM ASSOCIATED WITH THE UPPER LOW TO THE NORTHWEST. THIS WILL BRING A CHANCE OF SHOWERS...WITH STEEPENING MID LEVEL LAPSE RATES SUPPORTING THUNDERSTORMS AS WELL. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... UNSETTLED WEATHER STILL ON TAP FOR THE LAST PART OF THE WEEKEND INTO THE FIRST PART OF NEXT WEEK. BY SUNDAY NIGHT SURFACE LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARIES WILL BE EXITING THE CWFA. THE SYSTEM SHOULD BE OFFSHORE BY FIRST THING MONDAY MORNING. A BRIEF RESPITE IN THE RAINFALL IS EXPECTED DURING THE FIRST PART OF MONDAY BEFORE ANOTHER FRONTAL BOUNDARY EXPECTED ON TUESDAY. HAVE KEPT THE THUNDER WORDING FOR TUESDAY AS THE FRONT COMES THROUGH. THE SURFACE INSTABILITIES LOOK TO BE SUPPRESSED TO THE SOUTH...HOWEVER MID LEVEL FORCING AND JET DYNAMICS LOOK TO BE PRESENT. HIGH PRESSURE IS EXPECTED TO BUILD IN FOR THE LAST HALF OF THE WEEK. MONITORING THE NEXT FRONTAL SYSTEM AND UPPER LOW FOR THE WEEKEND. GUIDANCE WAS PRETTY CLOSE AND GENERALLY SPLIT THE DIFFERENCE. MEX NUMBERS ARE APPROACHING FREEZING TUESDAY NIGHT AND WEDNESDAY NIGHT. WILL CONTINUE TO HAVE TO MONITOR THE SITUATION FOR FROST/FREEZE PRODUCTS. && .AVIATION... LOW CIGS AND FOG NORTH OF WARM FRONT...WHICH WILL GRADUALLY LIFT NORTH INTO NORTHERN VIRGINIA THIS EVENING. TIMED A POTENTIAL SQUALL LINE (AS SEEN IN MODELS) ACROSS TAF SITES. CONFIDENCE IS RATHER LOW (DUE TO REASONING ABOVE)...SO RESOLVED IN TAFS AS A 2 HOUR PERIOD OF RA WITH A MENTION OF CB. CONCERN OVERNIGHT REVOLVES AROUND REFORMING LOW CIGS AND FOG WITH ONLY WEAK COLD ADVECTION OFFERED BY THE COLD FRONT. && .MARINE... SMALL CRAFT ADVISORY LOOKS IN GOOD SHAPE. WIND GUSTS ARE OBSERVED NEAR 20KT. THERE IS A POTENTIAL OF SEEING HIGHER GUSTS CLOSER TO THE VIRGINIA WATERS WHERE THE WARM FRONT EDGES NORTH. WATER LEVELS ARE CURRENTLY ABOUT A FOOT ABOVE PREDICTED VALUES. PERSISTENT E/SE FLOW WILL ALLOW THE NEXT TIDE CYCLE TO BE CLOSER TO A FOOT AND A HALF ABOVE NORMAL. THE LUNAR CYCLE IS WANING TOWARD A NEW MOON. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FOR ANZ530>537 UNTIL 11 PM SATURDAY. && SHORT TERM/AVIATION/MARINE...ROGOWSKI LONG TERM...LISTEMAA
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 316 PM EDT SAT APR 22 2006 ANZ530>537-DCZ001-MDZ002>007-009>011-013-014-016>018-VAZ021- 025>031-036>042-050>057-WVZ048>055-231930- CHESAPEAKE BAY NORTH OF POOLES ISLAND MD- CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD- CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD- CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD- CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA- TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD- TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD- TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA- DISTRICT OF COLUMBIA-ALLEGANY-WASHINGTON-FREDERICK MD-CARROLL- NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE- PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT-HIGHLAND- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-FAUQUIER-LOUDOUN- ORANGE-CULPEPER-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE-GRANT-MINERAL-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON- PENDLETON-HARDY- 316 PM EDT SAT APR 22 2006 THIS HAZARDOUS WEATHER OUTLOOK IS FOR MARYLAND WEST OF THE EASTERN SHORE INCLUDING THE CHESAPEAKE BAY AND EAST OF GARRETT COUNTY...EASTERN WEST VIRGINIA...NORTHERN AND CENTRAL VIRGINIA... WASHINGTON DC AND THE TIDAL POTOMAC RIVER. .DAY ONE...THIS AFTERNOON AND TONIGHT AREAS OF DENSE FOG ARE EXPECTED OVERNIGHT AS COOLER AIR WILL SETTLE BEHIND A COLD FRONT. THE SHALLOW LAYER OF COOLER AIR WILL COMBINE WITH A VERY WET GROUND...PRODUCING AREAS OF FOG. VISIBILITIES MAY BE REDUCED TO A QUARTER OF A MILE OR LESS IS SOME LOCALES. SOUTHEASTERLY WINDS THIS EVENING WILL CAUSE TIDES ON THE CHESAPEAKE BAY...TIDAL POTOMAC AND OTHER ESTUARIES TO BE ABOVE NORMAL. LEVELS AROUND ONE FOOT ABOVE NORMAL ARE LIKELY...CREATING MINOR OVERFLOWS AT TIME OF HIGH TIDE IN VERY LOW LYING PORTIONS OF ANNAPOLIS AND ALEXANDRIA. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE TIDAL POTOMAC AND MARYLAND PORTION OF THE CHESAPEAKE BAY UNTIL 11PM TONIGHT. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED.
The Sterling radar (KLWX), 38 km away, was scanning. The volume nearest the first event began at 22:14 UTC.
6 flash flood, 1 heavy rain. Local standard time, as filed.
Mudslide and closures reported on US route 29
Several road closures with high water
Catharpin Run flowing across Pageland Road
Hospital roof collapsed due to heavy rainfall, estimated at 3 inches in only a few hours.
Road closures occurred along Route 123 in Burke.
Intersection of US 29 and Baldwin Street flooded with several inches of flowing water
Bull Run Post Office Road closed due to high water
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2006Every state in 2006This day in weather historyWarnings in Virginia, April 2006
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: 5507177, 5507178, 5507179, 5507180, 5507181, 5507182, 5507249.