Archive for May, 2009

And still more rain…
May 30, 2009

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With another round of heavy showers and thunderstorms moving through the area Friday afternoon, the official rainfall for the month of May at BWI-Marshall has topped 8″ for only the second time since weather records began back in 1870.  With just two days left in the month, only May of 1989 ranks wetter than May of 2009.

Tom Tasselmyer

Rainy May
May 29, 2009

It should surprise no one that this May is turning out to be one of the wetter ones in the Baltimore record books.

JC_WettestMays

The list above highlights the five wettest Mays on record for Baltimore. As of the end of Thursday, May 28, this May ranks fourth.

Showers and thunderstorms are in the Friday forecast and it is entirely possible that any rainfall today could push this May into second or third place in the May precipitation records.

John Collins

Friday Tropical Update
May 29, 2009

Tropical Depression 1 continues to move in a northeasterly direction over the relatively warm waters of the Gulf Stream. The storm remains marginal and is expected to weaken as it eventually moves over cooler water.

JC_VisSatFri

The early morning visible satellite image above is interesting. It shows that the significant thunderstorm activity associated with the storm is to the southeast and south of the storm center. The “eye” of the storm is evident in the lower cloud circulation under the edge higher clouds southeast of the storm center.

John Collins

First Tropical Depression of the Season
May 28, 2009

The 2009 Hurricane Season is off to an early start as Tropical Depression 1 has developed off the Mid Atlantic coast. The Hurricane Season officially starts June 1.

GOES15452009148gEc42C

The storm’s position is a bit unusual for this early in the season. The explanation is that the disturbance was able to develop over the rather narrow band of the warmer waters of the Gulf Stream.

SST

The satellite image above shows the sea surface temperatures of the Atlantic Basin. The band of the warmer water of the Gulf Stream is evident running up the east coast of the US. The storm has formed over waters in the 77-79 degree Fahrenheit range.

SFC930aThurj

The National Weather Service surface map of the conditions at 9:30am Thursday shows the storms position in relation to the Mid Atlantic region and the weather system that is moving in from the west.

TD1Track

The official forecast track for Tropical Depression 1 moves the storm to the northeast over the next several days. The forecast calls for the storm to reach marginal Tropical Storm strength. If this should happen, the storm would be named “Ana”. Given the weak nature of the storm and its’ projected path, it should have no affect on weather over the Mid Atlantic Region but will likely produce squally conditions for maritime interests in the Atlantic.

John Collins

Record Rainfall
May 27, 2009

Preliminary numbers are in for Tuesday. Rainfall at BWI-Marshall Airport established a new record for the date. 

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The Climate Summary also shows that the high temperature for the day was at 2:10 in the morning. As the rain moved in and a cool front moved into the area, temperatures had fallen by daybreak and would remain in the mid-upper 50s through the rest of the day.

The National Weather Service list below is an updated summary of rainfall reports from various locations around Maryland. 

24hrrnjNote that most of the reports had a cutoff time of 7:00-8:00am. Additional rain fell after that time and will be submitted to the National Weather Service by observers Wednesday morning. Those numbers may be published at that time.

John Collins

Wet May…again…
May 27, 2009

For the second year in a row rainfall in the month of May has topped 7 inches, with both totals landing in the top 5 wettest of all-time in Baltimore.  A record setting 2.29″ fell at the airport as of late Tuesday evening.  With just under a week to go in May 2009, the 7.10″ inches of rain measured at BWI-Marshall is tied for 4th wettest.  Records for rainfall in Baltimore go back to 1870.

tt_wettest_mays

Tom Tasselmyer

Wet Weather
May 26, 2009

Good weather held together across the region for most of the Memorial Day extended weekend. The chance for rain threatened much of the weekend but nothing substantial happened until Monday Afternoon. Since that time, some significant rains have hit the area.

tueranjNWS Doppler Radar, Sterling, Va. … Storm Total Estimate

The image above shows the rain total from the most recent rains. The heaviest rains have fallen in a band running from central Delaware westward across theBaltimore-Washington area into northern Virginia. Rain totals in the 3-4 inch range have been estimated by radar between Baltimore and Washington. The list below shows actual rainfall reported to the National Weather Service:

PUBLIC INFORMATION STATEMENT
SPOTTER REPORTS
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
828 AM EDT TUE MAY 26 2009

THE FOLLOWING ARE UNOFFICIAL OBSERVATIONS TAKEN DURING THE PAST 12 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

***********************6 HOUR RAINFALL***********************

LOCATION               6 HOUR    TIME/DATE    COMMENTS
                     RAINFALL       OF
                     (INCHES)   MEASUREMENT

VIRGINIA

...LOUDOUN COUNTY...
   DULLES AIRPORT DAM    3.63   811 AM  5/26
   STERLING NWS/WFO      2.79   812 AM  5/26

**********************12 HOUR RAINFALL**********************

LOCATION              12 HOUR    TIME/DATE    COMMENTS
                     RAINFALL       OF
                     (INCHES)   MEASUREMENT

MARYLAND

...PRINCE GEORGE`S COUNTY...
   GREENBELT             2.50   809 AM  5/26

**********************24 HOUR RAINFALL**********************

LOCATION              24 HOUR    TIME/DATE    COMMENTS
                     RAINFALL       OF
                     (INCHES)   MEASUREMENT

MARYLAND

...PRINCE GEORGE`S COUNTY...
   GREENBELT             4.00   809 AM  5/26

The band of rain that produced all of this lies just north of a nearly stalled cool front that will be in the area for at least the next 24 hours. Clouds, cool temperatures and periods of rain will be the dominant weather feature.

latest

 

The satellite image above shows the moisture feed coming in to the Mid Atlantic region from the Atlantic Ocean and a storm complex to the west. It will take the rest of the week for all of this to work its’ way eastward so it appears that the rain threat will continue until the weekend.

John Collins

NOAA 2009 Hurricane Outlook
May 21, 2009

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The Moon, Mars and Venus
May 20, 2009

With strong high pressure over the mid Atlantic region producing clear skies, early risers on Thursday will be treated to a triangular arrangement of three heavenly bodies.  Look east just before dawn to see the crescent Moon along with Mars and Venus just above the horizon.  Spaceweather.com provided the map below to navigate your way to the right spot in the sky.

venus mars moon triangle

Tom Tasselmyer

Record Low Temperature
May 19, 2009

A new record low temperature was established in Baltimore Tuesday morning. The temperature dropped to 37.9 degrees around daybreak at BWI-Marshall Airport. This is a preliminary reading and after verification it will probably be rounded up to 38 degrees. The old record low was 39 degrees, set in 2003.

latest

The morning satellite picture shows clear skies over the Chesapeake Bay region. The clouds to the south are related to the weather system that passed through the area over the weekend. The cloud mass over Florida is a weather system that was thought could possibly develop some tropical characteristics. As of Tuesday morning, hurricane forecasters think that significant development is unlikely and a hurricane hunter flight into the storm has been cancelled. It is a reminder, though, that the official start of the hurricane season is only a couple of weeks away. The weak organization of the storm over Florida is an indication that oceanic and atmospheric conditions are becoming more favorable for tropical storm and hurricane development.

While on the subject of hurricanes, on May 1, NOAA announced that four hurricane names have been retired. Here is the text of the news release:

———-

Four Hurricane Names Retired From List of Storms

May 1, 2009

Three hurricane names in the Atlantic and one in the eastern North Pacific were retired from the official name rotation by the World Meteorological Organization’s hurricane committee because of the deaths and damage they caused in 2008.

The names Gustav, Ike and Paloma in the Atlantic and Alma in the North Pacific will not be used again. Those names would have been used again in 2014. In their place will be Gonzalo, Isaias and Paulette in the Atlantic and Amanda in the North Pacific. The committee issues the list of potential names for tropical cyclones to be used every six years for both the Atlantic basin and eastern North Pacific basin.

Details of the retired 2008 named storms are shown below:

  • Gustav became a hurricane on Aug. 26, making landfall in Haiti as a Category 1 hurricane. Gustav then struck western Cuba as a Category 4 hurricane, making its final landfall near Cocodrie, La., on Sept. 1 as a Category 2 hurricane. Hurricane force winds, storm surge and heavy rain produced more than $4 billion damage in Louisiana. Gustav killed 112 people, including 77 in Haiti.
  • Ike became a hurricane on Sept. 3 and rapidly intensified to a Category 4 hurricane northeast of the Leeward Islands. The storm struck the Turks and Caicos Islands and Great Inagua Island in the Southeastern Bahamas on Sept. 7, and the northeast coast of Cuba later that day. Ike made its final landfall at Galveston Island, Texas on Sept. 13 as a Category 2 hurricane. Ike killed more than 80 people across the Caribbean and Bahamas, and another 20 in Texas, Louisiana and Arkansas. Total estimated U.S. property damage from Ike is estimated at $19.3 billion.
  • Paloma reached hurricane intensity on Nov. 7 and became the second strongest November Atlantic hurricane on record the next day, reaching Category 4. According to the Cuban government, more than 1,400 homes were destroyed on that island with $300 million U.S. dollars in damage. 
  • Alma was the first eastern North Pacific basin tropical cyclone to make landfall along the Pacific Coast of Central America since records began in 1949. The storm formed quickly on May 28 west-northwest of Cabo Blanco, Costa Rica. Alma was responsible for two direct deaths and the destruction of thousands of homes. 

———-

John Collins