A departing low pressure system to the south allowed very cold air to funnel from the north and generate areas of dense fog. With temperatures falling into the teens, fog froze on contact.
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.
A departing low pressure system to the south allowed very cold air to funnel from the north and generate areas of dense fog. With temperatures falling into the teens, fog froze on contact. |Automated Observations from Manassas Regional Airport/Harry P. Davis Field reported freezing fog reducing visibilities to a quarter mile or less.
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 Mar 7, 10:28 PM EST, 1 hour 32 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1028 PM EST WED MAR 7 2007 .SHORT TERM /REST OF TONIGHT/... JUST A QUICK UPDATE TO ISSUE A FREEZING FOG ADVISORY FOR AN AREA ROUGHLY FROM THE NORTHERN POTOMAC HIGHLANDS EASTWARD TO CARROLL COUNTY MD...THE EASTERN PANHANDLE OF WV AND LOUDOUN COUNTY VIRGINIA. SFC OBS HAVE INDICATED LOW VISIBILITIES IN FOG WITH 1/4 SM AT FDK...1/2 SM AT W99 AND 3/4 SM IN MRB. THIS COUPLED WITH REPORTS OF ICE DEPOSITION ON CARS BY SPOTTERS IN THE AREA AND NEARLY SATURATED BOUNDARY LAYER AFTER SNOWFALL EARLIER TODAY POINTS TOWARD THE POTENTIAL FOR WIDESPREAD FREEZING FOG ACROSS THE REGION. UPDATED ZONES SENT AT 1020 PM EST. && .PREV DISCUSSION... /ISSUED 925 PM EST WED MAR 7 2007/ SHORT TERM /REST OF TONIGHT/... SATELLITE AND RADAR IMAGERY SHOW MOISTURE DEPARTING SOUTHEAST OF THE CWA AT 02Z...AS SFC CENTER OF SFC LOW PRESSURE HAS NOW MOVED INTO NORTHEASTERN NC. SFC HIGH CENTERED OVER SOUTHERN LAKE MI SI BUILDING SLOWLY SOUTHEASTWARD. LIGHT NORTHERLY FLOW AROUND THE LARGE SFC HIGH IS SLOWLY ADVECTING DRIER AIR INTO CENTRAL AND SOUTHERN PA WITH DEWPOINTS FALLING INTO THE UPPER SINGLE DIGITS AND LOWER TEENS. 18Z RUNS OF THE GFS AND NAM INDICATE THAT THIS LOWER DEWPOINT AIR WILL MOVE INTO THE NORTHERN TIER OF MD...THE EASTERN PANHANDLE AND POTOMAC HIGHLANDS OF MD AND PORTIONS OF FAR NORTHERN VIRGINIA BETWEEN 06Z AND 12Z. THE SNOW COVER ACROSS THIS AREA COMBINED WITH DECREASING DEWPOINTS...CLEARING SKIES AND WINDS AROUND 5 KT SHOULD ALLOW FOR FAIRLY STRONG RADIATIONAL COOLING. DECREASED LOW TEMPERATURES TONIGHT FOR THESE AREAS BY 3 TO 6 F WITH LOWER TEENS COMMON AND A FEW READINGS IN THE UPPER SINGLE DIGITS. LIGHT WINDS AND RAPIDLY FALLING TEMPERATURES ACROSS THIS REGION THROUGH MID EVENING HAVE CAUSED FREEZING FOG TO FORM. LOWER DEWPOINT AIR MAY NOT ADVECT INTO THE REGION QUICKLY ENOUGH TO PREVENT THIS FREEZING FOG FROM LINGERING OVERNIGHT...SO INCLUDED FREEZING FOG IN THE FORECAST THROUGH 12Z FROM ALLEGANY COUNTY MD EAST TO CARROLL COUNTY MD AND FROM MINERAL COUNTY WV TO LOUDOUN COUNTY VA. UPDATE THE ZONE FORECAST SENT AT 906 PM EST. PREV DISCUSSION... /ISSUED 247 PM EST WED MAR 7 2007/ SHORT TERM /TONIGHT/... LOPRES IN WRN VA ATTM. BAND OF SNWFL HAS BEEN SLOW TO SAG SWD DUE TO BIG DEWPT DEPRESSIONS. H7-5 F-VECTOR CNVGNC REMAINS ACRS NRN SHEN VLY-DC METRO THRU 00Z...BUT MSTR PULLS EWD W/ LOW. MORE OR LESS KEEPING POP/WX LINEUP FOR THE REST OF THE AFTN HRS. NOT MUCH PCPN XPCTD PAST 00Z AS DEEPER MSTR WL BE IN THE ATLC BY THEN. GIVEN ENVIRONMENT OF GOOD FORCING...A QUICK INCH OR TWO STILL PSBL...AND THUS WL LV ADVY/WRNGS AS IS. NRN EDGE OF PCPN CROSSING M-D LINE ATTM...SO A REFRESHER WL BE NEEDED TO PKG SOON AFTR THIS ISSUANCE. REST OF THE NGT WL BE COLD AND DRY AS CLDS SCT OUT. MIN-T IN THE TEENS-LWR 20S...IN LINE W/ MOS CONSENSUS. SEE PUBLIC INFO STMT /WBCPNSLWX/ FOR SNW TTLS. PTMC HIGHLANDS HIT THE JACKPOT. LONG TERM /THURSDAY THROUGH WEDNESDAY/... OBSERVATIONS... 500MB HEIGHT/ANOMALY NORTHERN HEMISPHERIC PATTERN DURING THE PAST 5 DAYS INDICATES FAIRLY ZONAL FLOW ACROSS THE NORTHERN CONUS IS TRANSITIONING TO A RIDGE ACROSS THE WESTERN CONUS...AS A TROUGH DEVELOPS ACROSS THE EAST COAST. THIS IS OCCURRING AS THE PATTERN ACROSS THE NORTHERN HEMISPHERE BECOMES BLOCKED. WATER VAPOR LOOP SHOWS A SHORT WAVE SLIDING SOUTHEAST ACROSS THE GREAT LAKES...AS A SECOND SHORT WAVE MOVES ACROSS THE CENTRAL ROCKIES. 12Z SURFACE ANALYSIS PLACED A 1018MB CYCLONE ACROSS SOUTHERN ILLINOIS. A COLD FRONT EXTENDS EAST ACROSS THE OHIO VALLEY AND ACROSS SOUTHERN PENNSYLVANIA. A STATIONARY BOUNDARY DIPS SOUTHEAST FROM THE CYCLONE ACROSS THE TENNESSEE VALLEY AND SNAKES ACROSS THE CAROLINAS. THE NEXT COLD FRONT STRETCHED SOUTHWEST FROM QUEBEC INTO THE UPPER MIDWEST. A 1032MB ANTICYCLONE DOMINATES SOUTH CENTRAL CANADA. MODELS... THE 12Z NAM (WRF-NMM)/GFS/CANADIAN AND 00Z EUROPEAN/UKMET WERE INVESTIGATED. MODELS ARE IN DECENT AGREEMENT ON THE SYNOPTIC SCALE. HIGH PRESSURE BUILDS IN FROM THE NORTH DURING THE END OF THE WORK WEEK...AS THE FIRST IN A SERIES OF SHORT WAVES MOVES ACROSS THE GULF STATES. DURING THE END OF THE WEEKEND...RIDGING ACROSS THE SOUTHWEST CONUS IS EXPECTED TO AID IN THE DEVELOPMENT OF A SOMEWHAT DEEPER SHORT WAVE OR UPPER LOW...IMPACTING THE GULF STATES AND TENNESSEE VALLEY EARLY DURING THE WORK WEEK. RISING HEIGHTS ARE EXPECTED DURING THE MID WEEK. ENSEMBLE DATA... 00Z MARCH 7 GFS 500MB ENSEMBLES INDICATE A -2.5 STANDARD DEVIATION TROUGH MOVES OFF OF NEW ENGLAND...AS FAIRLY FLAT FLOW RESUMES ACROSS THE CONUS THROUGH THE EARLY WEEKEND. A WESTERN CANADIAN TROUGH AND WESTERN CONUS RIDGE DEVELOP DURING THE WEEKEND...ENCOURAGING A WEAK DUAL STREAM SYSTEM TO DEVELOP ACROSS THE EAST CENTRAL CONUS EARLY NEXT WORK WEEK. THE VARIANCE IN HEIGHTS BECOMES GREAT ACROSS THE NORTHERN STREAM DURING THE EARLY WORK WEEK 00Z MARCH 7 GFS ENSEMBLE MOS INDICATE MEAN HIGHS RISING FROM NEAR 40F THURSDAY AND MID 30S FRIDAY...INTO THE UPPER 50S AND LOWER 60S SUNDAY AND BEYOND. MEAN LOWS BEGIN IN THE UPPER TEENS FRIDAY MORNING...RISING INTO THE UPPER 30S AND LOWER 40S FOR THE LATE WEEKEND AND BEYOND. MEAN POPS RISE INTO THE SLIGHT CHANCE CATEGORY SATURDAY AND SATURDAY NIGHT...AND THE CHANCE CATEGORY SUNDAY AND MONDAY (SLIGHT CHANCE AGAIN THROUGH THE MID WEEK). THE GREATEST VARIANCE FOR TEMPERATURES IS FRIDAY NIGHT AND SATURDAY. VARIANCE IS FAIRLY HIGH FOR THE POPS SUNDAY INTO MONDAY. FORECAST RATIONALE... HIGH PRESSURE BUILDS IN BEHIND THE CYCLONE DURING THE LATER PORTION OF THE WEEK. AM CONCERNED THAT WHEN THE HIGH RETREATS LATE FRIDAY...SOUTHEAST FLOW MAY ENCOURAGE ATLANTIC MARINE MOISTURE TO INVADE IN THE FORM OF LOW CLOUDS. MODELS ARE CONSISTENT WITH THE NORTHERN STREAM LOCKING UP ALONG THE CANADIAN BORDER DURING THE LONG TERM. WHILE SEVERAL MODELS INDICATE A CUTOFF LOW DEVELOPS ACROSS THE PLAINS AND MOVES EAST ACROSS THE GULF STATES...ITS STRENGTH AND SPEED REMAIN A QUESTION. HEIGHTS RISE DURING THE MID WEEK...ALLOWING FOR A WARM UP. AVIATION /20Z-18Z/... MVFR-LCL IFR IN SN REST OF TAFTN. VSBYS IMVPG 1ST...THEN CIGS RISE THIS EVNG. VFR OVNGT-TMRW. MARINE... WNDS AOB 10 KT TNGT. 12Z ETA/GFS MOS AT THOMAS POINT INDICATE SUSTAINED WINDS WILL BE AROUND 10KT THROUGH SATURDAY. 12Z NAM/GFS PROXIMITY FORECAST SOUNDINGS INDICATE LITTLE TO NO ADDITIONAL WIND GUST POTENTIAL DURING THE SAME TIME PERIOD. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SHORT TERM...SMITH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1036 PM EST WED MAR 7 2007 ANZ530>537-DCZ001-MDZ003>007-009>011-013-014-016>018-501-502- VAZ021-025>031-036>042-050>057-WVZ050>055-501>504-081000- 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-WASHINGTON-FREDERICK MD-CARROLL- NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE- PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-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-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-PENDLETON-HARDY- WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- 1036 PM EST WED MAR 7 2007 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...OVERNIGHT AS TEMPERATURES FALL WELL BELOW FREEZING OVERNIGHT...EXPECT CONDITIONS TO REMAIN VERY HAZARDOUS...EVEN AS THE SNOW HAS COME TO AN END. A FREEZING FOG ADVISORY HAS BEEN ISSUED FOR MUCH OF CENTRAL AND WESTERN MARYLAND...NORTHWEST VIRGINIA AND THE EASTERN PANHANDLE OF WEST VIRGINIA. AREAS OF FREEZING FOG WILL OCCUR OVERNIGHT AND MAY CAUSE A THIN GLAZE TO FORM ON MANY SURFACES...INCLUDING BRIDGES AND OVERPASSES. MOTORISTS ARE URGED TO USE EXTREME CAUTION IF THEY ARE OUT AND ABOUT. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY BLACK ICE MAY CONTINUE TO BE A SIGNIFICANT HAZARD THURSDAY MORNING. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. JB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 903 PM EST WED MAR 7 2007 MDZ003>005-501-502-VAZ028-031-042-WVZ050>053-503-504-080700- WASHINGTON-FREDERICK MD-CARROLL-EXTREME WESTERN ALLEGANY- CENTRAL AND EASTERN ALLEGANY-FREDERICK VA-CLARKE-LOUDOUN- HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-WESTERN MINERAL- EASTERN MINERAL- INCLUDING THE CITIES OF...HAGERSTOWN...FREDERICK...WESTMINSTER... FROSTBURG...CUMBERLAND...WINCHESTER...LEESBURG...MARTINSBURG... CHARLES TOWN...EMORYVILLE...HARTMANSVILLE...KEYSER...FORT ASHBY 903 PM EST WED MAR 7 2007 ...FREEZING FOG DEVELOPING IN MANY AREAS THIS EVENING... THE DEPARTURE OF LOW PRESSURE TO THE SOUTH IS ALLOWING VERY COLD AIR TO FUNNEL FROM THE NORTH AND GENERATE AREAS OF FOG. WITH TEMPERATURES DROPPING INTO THE TEENS ACROSS THE PANHANDLE OF WEST VIRGINIA AND CENTRAL AND WESTERN MARYLAND...THIS FOG WILL FREEZE ON CONTACT. USE EXTREME CAUTION IF YOU ARE OUT AND ABOUT THIS EVENING...CONDITIONS COULD BE EXTREMELY HAZARDOUS IN SOME AREAS. BRIDGES AND OVERPASSES WILL BE ESPECIALLY SUSCEPTIBLE TO ICY SPOTS. ALWAYS USE LOW BEAM HEADLIGHTS IN AREAS OF FOG. STAY TUNED TO NOAA WEATHER RADIO OR MEDIA OUTLETS FOR THE LATEST WEATHER INFORMATION FROM YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE. JB/SMITH
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1009 PM EST WED MAR 7 2007 MDZ003>005-501-502-VAZ028-031-042-WVZ050>053-055-501>504-080730- WASHINGTON-FREDERICK MD-CARROLL-EXTREME WESTERN ALLEGANY- CENTRAL AND EASTERN ALLEGANY-FREDERICK VA-CLARKE-LOUDOUN- HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY-WESTERN GRANT- EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- INCLUDING THE CITIES OF...HAGERSTOWN...FREDERICK...WESTMINSTER... FROSTBURG...CUMBERLAND...WINCHESTER...LEESBURG...MARTINSBURG... CHARLES TOWN...BAYARD...PETERSBURG...EMORYVILLE...HARTMANSVILLE... KEYSER...FORT ASHBY 1009 PM EST WED MAR 7 2007 ...FREEZING FOG IN MANY AREAS THIS EVENING... THE DEPARTURE OF LOW PRESSURE TO THE SOUTH IS ALLOWING VERY COLD AIR TO FUNNEL FROM THE NORTH AND GENERATE AREAS OF FOG. WITH TEMPERATURES DROPPING INTO THE TEENS ACROSS THE PANHANDLE OF WEST VIRGINIA AND WESTERN AND CENTRAL MARYLAND...THIS FOG WILL FREEZE ON CONTACT. USE EXTREME CAUTION IF YOU ARE OUT AND ABOUT THIS EVENING...CONDITIONS COULD BE EXTREMELY HAZARDOUS IN SOME AREAS. BRIDGES AND OVERPASSES WILL BE ESPECIALLY SUSCEPTIBLE TO ICY SPOTS. ALWAYS USE LOW BEAM HEADLIGHTS IN AREAS OF FOG. STAY TUNED TO NOAA WEATHER RADIO OR MEDIA OUTLETS FOR THE LATEST WEATHER INFORMATION FROM YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE. JB/SMITH
1 freezing fog. Local standard time, as filed.
Automated Observations from Manassas Regional Airport/Harry P. Davis Field reported freezing fog reducing visibilities to a quarter mile or less.|
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2007Every state in 2007This day in weather historyWarnings in Virginia, March 2007
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: 18673.