Archive for September, 2009

Weekend Rain Totals
September 28, 2009

The weekend rainfall produced some much needed precipitation for the area.

  • 1.48″  …  TV-Hill
  • 1.38″  …  Inner Harbor
  • 1.31″  …  BWI-Marshall (3.41″ for September)

The rain totals for other Maryland locations are supplied by the National Weather Service.

John Collins

PUBLIC INFORMATION STATEMENT
SPOTTER REPORTS
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1250 PM EDT SUN SEP 27 2009

THE FOLLOWING ARE UNOFFICIAL OBSERVATIONS TAKEN DURING THE PAST 24
HOURS FOR THE STORM THAT HAS BEEN AFFECTING OUR REGION.
APPRECIATION IS EXTENDED TO HIGHWAY DEPARTMENTS...COOPERATIVE
OBSERVERS...SKYWARN SPOTTERS AND MEDIA FOR THESE REPORTS.  THIS
SUMMARY IS ALSO AVAILABLE ON OUR HOME PAGE AT WEATHER.GOV/BALTIMORE

********************STORM TOTAL RAINFALL********************

LOCATION          STORM TOTAL    TIME/DATE    COMMENTS
                     RAINFALL       OF
                     (INCHES)   MEASUREMENT


DISTRICT OF COLUMBIA

...DISTRICT OF COLUMBIA...
   NATIONAL ARBORETUM    1.56  1000 AM  9/27
   DALECARLIA RESERVOIR  1.32  1100 AM  9/27
   WASHINGTON            1.07   800 AM  9/27   2 S TAKOMA PARK

MARYLAND

...ALLEGANY COUNTY...
   FROSTBURG             1.19  1000 AM  9/27

...ANNE ARUNDEL COUNTY...
   ANNAPOLIS             2.00  1200 PM  9/27
   ODENTON               1.67  1000 AM  9/27
   PASADENA              1.58  1000 AM  9/27
   SOUTH GATE            1.58  1000 AM  9/27
   CROFTON               1.55  1000 AM  9/27
   SOUTH GATE            1.54  1000 AM  9/27   3 SW

...BALTIMORE COUNTY...
   KINGSVILLE            1.52  1000 AM  9/27
   CATONSVILLE           1.44  1000 AM  9/27
   TOWSON ESTATES        1.43  1000 AM  9/27   2.5 ENE
   JACKSONVILLE          1.42  1000 AM  9/27
   TOWSON PARK           1.42  1000 AM  9/27
   LONG GREEN            1.34  1000 AM  9/27

...CALVERT COUNTY...
   NORTH BEACH           2.16  1000 AM  9/27
   DUNKIRK               1.91  1000 AM  9/27
   PRINCE FREDERICK      1.46  1000 AM  9/27

...CARROLL COUNTY...
   SYKESVILLE            1.43  1000 AM  9/27
   WOODBINE              1.40  1000 AM  9/27
   ELDERSBURG            1.24  1000 AM  9/27
   MOUNT AIRY            1.09  1000 AM  9/27

...CHARLES COUNTY...
   WALDORF               1.77  1000 AM  9/27   3.6 SSE
   WALDORF               1.70  1058 AM  9/27   3.2 SW
   LA PLATA              1.64  1000 AM  9/27
   WALDORF               1.47  1000 AM  9/27

...CITY OF BALTIMORE...
   HAMILTON              1.47  1000 AM  9/27

...FREDERICK COUNTY...
   THURMONT              0.96   800 AM  9/27

...HARFORD COUNTY...
   BEL AIR               1.14  1000 AM  9/27
   HAVRE DE GRACE        1.14  1000 AM  9/27
   FALLSTON              1.13  1000 AM  9/27
   JARRETTSVILLE         1.10  1000 AM  9/27

...HOWARD COUNTY...
   MARRIOTTSVILLE        1.50  1000 AM  9/27
   ELLICOTT CITY         1.45  1000 AM  9/27
   COLUMBIA              1.42  1000 AM  9/27
   WHITE OAK ESTATES     1.37  1000 AM  9/27

...MONTGOMERY COUNTY...
   MONTGOMERY VILLAGE    1.67  1000 AM  9/27
   WHEATON               1.40  1000 AM  9/27
   TAKOMA PARK           1.39  1000 AM  9/27
   GLENMONT              1.35  1000 AM  9/27
   VALLEYWOOD PARK       1.26  1000 AM  9/27

...PRINCE GEORGE`S COUNTY...
   FRIENDLY              1.95  1000 AM  9/27
   CAMP SPRINGS          1.87  1000 AM  9/27
   FOREST HEIGHTS        1.78  1000 AM  9/27
   OXON HILL             1.75  1000 AM  9/27
   BOWIE                 1.73  1000 AM  9/27

...ST. MARY`S COUNTY...
   LEONARDTOWN           1.95  1000 AM  9/27
   PARK HALL ESTATES     1.81  1000 AM  9/27
   RIDGE                 1.57  1000 AM  9/27

...WASHINGTON COUNTY...
   WILLIAMSPORT POWER    0.94  1000 AM  9/27

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Gloria
September 27, 2009

JC_DateSept27

John Collins

Not Green Everywhere
September 24, 2009

The Mid Atlantic Region has been a little short of rain in the past few weeks (1.06 inches below average in September at BWI) but generous rain fall this past summer has kept everything green.

Down under, spring has begun and eastern Australia is in the grip of a severe drought. The sky in Sydney has turned red from dust being blown over the region.

The NOAA satellite image below clearly shows the dust over the eastern edge of the continent.

OSEIiod

John Collins

Last Days Of Summer
September 20, 2009

Summer is winding down and the numbers show the direction we are headed.

JC_CoolingDown

John Collins

Floyd 1999
September 16, 2009

Today is the anniversary of Hurricane Floyd’s passing along the Mid Atlantic coast.

floyd.vis

floyd1999j

The National Weather Service chart above shows the track of the storm. The deep red and orange shaded part of the track indicate that portion of the path at which the storm was hurricane strength, deep red being the strongest. Highest sustained winds reached 156 mph. The yellow portion of the track indicates the portion of the path that the storm was at tropical storm strength.

On September 16 Floyd moved northeast out of coastal North Carolina as a hurricane and was downgraded to a tropical storm as it moved along the DELMARVA coast.

The biggest impact of Floyd over the Mid Atlantic region was the rainfall. The NOAA image below outlines the rain totals from the storm along the Atlantic coast.

floydtotal.precipThe National weather Service map below is a detailed rainfall report for the area west of the Chesapeake Bay.

Floyd

John Collins

Slow Process
September 13, 2009

The very wet low pressure system that was off the coast Friday spent Saturday over southeast Pennsylvania. This inland position took the bulk of the rain north of Maryland but because of the low’s proximity to the area, cloud cover was considerable on Saturday with periodic drizzle and temperatures stuck in the 60s. There were sun breaks southwest of Baltimore and those locations saw temperatures rise into the low 70s.

The map below shows surface weather conditions Saturday evening.

SATsfcj

The low pressure center is in the process of transitioning back out over the water with a new low developing south of Cape Cod. As the low continues to move farther east, the persistent cloud deck over the area will dissipate. The outlook for Sunday is a little brighter.

The rain on Friday was significant. Below is a sampling of area rain totals:

  • 4.15″   Bel Air
  • 4.02″  Conowingo Dam
  • 3.96″  Norrisville
  • 2.30″  Essex
  • 2.17″  TV-Hill
  • 1.17″  BWI-Marshall
  • 1.66″  Inner Harbor
  • 1.33″  Davidsonville

In the tropics, Fred is losing its’ identity as a tropical system.

FredSat

In the satellite image above, the remnant low is centered just south of the bright plume of clouds on the far right. The remnant low is expected to move to the west-northwest over the next few days. Given the right set of circumstances there is a remote chance that the storm could reorganize and strengthen at some point in the future. There is quite a bit of thunderstorm activity along the Gulf coast. Tropical development is not expected but the unsettled weather and moisture is likely to move toward the Mid Atlantic region by the middle or end of the coming week.

John Collins

Selected Rain Totals
September 12, 2009

tt_md_precip_stormtotal

The “Friday Soaker” that John analyzed below produced some impressive rainfall totals from southern Pennsylvania to southern Maryland.  The map of selected reports shown here matches well with the radar estimated rainfall.  A solid 2-5″ fell in a band from Ocean City northwest to York and Lancaster.  Cecil County was hit hard with over 5.5″ at Colora!

Tom Tasselmyer

Friday Soaker
September 11, 2009

The storm off the Mid Atlantic coast finally pushed close enough to the coast to generate some significant rain across the area.

precipfrij

The image above is the radar rainfall estimate from the Sterling, VA radar.

frisatj

The late afternoon satellite image shows the storm spinning slowly toward New England. The image below shows the late afternoon surface conditions.

frisfcj

As the storm pulls away Saturday, a disturbance rotating around its’ southwest quadrant may stir up some spotty shower activity over Maryland but, by and large, the day should be dry. The weekend should be capped off Sunday with some nearly perfect late summer weather.

In the eastern Atlantic, Fred has been downgraded to a tropical storm and is forecast to continue the weakening trend.

ir4-l

Southeast of Fred a new tropical wave is coming off the west African coast and has a small chance for further tropical development.

John Collins

Thursday Weather Overview
September 11, 2009

Well, the storm off the Mid Atlantic coast is still stalled.

irthur

Most of the significant rain activity is north of the storm center. A high pressure ridge over the northeast U.S. has more or less prevented the storm and its’ rain from moving very much so rainfall over the Baltimore-Washington area has been spotty and the weather has actually been fairly decent.

thursfcj

Rainfall has been pushing westward onto the DELMARVA Peninsula Thursday evening and the trend is expected to continue. Areas east of the Bay, including northeast Maryland could receive up to one inch of rain in the next 24 hours. West of Baltimore, however, rain totals may amount to one half inch or less.

qpfA bulls-eye for up to three inches of rain is forecast for parts of New Jersey.

atlthurj

The beautiful satellite image above show the active weather over the Atlantic Ocean Thursday evening. Two non-tropical storms are churning in the western Atlantic. One is the storm off the Mid Atlantic Coast and the other is a disorganized cluster of storms reaching north from Cuba. In the eastern Atlantic, Hurricane Fred continues to spin 740 miles west of the Cape Verde Islands. Fred’s winds have weakened to 90 mph and the storm is expected to stay out at sea.

John Collins

Wednesday Weather Update
September 9, 2009

Wednesday weather remains unsettled over the Mid Atlantic states.

WedSatFeatjI have annotated a few features on the midday satellite image. An upper level low pressure area (yellow “L”) is centered over the upper Ohio River Valley. It is an extension of a much larger low over northeastern Canada. At the surface, a low (red “L”) is still off the Mid Atlantic coast and a high (red “H”) reaches from Canada into the Great Lakes and New England. The drier air air under the high is evident from the clear conditions over the Great Lakes and upstate New York. Sun breaks have developed in the clouds over Maryland and sunshine dominates over much of the southern half of Virginia. The combination of these systems will be in place in some manner, shape and form for the next couple of days and will be responsible for unsettled conditions over the region.

sfcwedj

The chart above is the National Weather Service surface map for midday Wednesday. The influence of the Canadian high is reaching into Pennsylvania and western Maryland and, for the time being, suppressing rain chances around Baltimore.

The presence of the upper low and the prospect of the surface low moving westward to the DELMARVA Peninsula is expected to increase rain chances in the next 24 hours.

Out in the eastern Atlantic, Fred has been upgraded to a hurricane.

vis-l

Fred is still forecast to turn northward and remain far out in the Atlantic.

John Collins