Archive for October, 2007

Soaking Rains
October 29, 2007

A narrow band of tropical moisture was channeled up the Atlantic Coast from October 23 through October 27 resulting in a drought busting rainfall over much of the Mid Atlantic region.

As of Sunday, October 28, precipitation stood 2.99 inches above average at BWI/Marshall Airport with a total of 5.85 inches for the entire month. The heaviest rain fell over a two day period. The daily history of the rainfall at the airport is as follows:
0.01″ – Tuesday, Oct 23
0.88″ – Wednesday, Oct 24
0.43″ – Thursday, Oct 25
2.49″ – Friday, Oct 26
1.63″ – Saturday, Oct 27
5.44″ – STORM TOTAL

The following are the storm rain totals for other locations around Maryland:
2.74″ – Frostburg
5.03″ – Rivera Beach
5.60″ – Jacksonville
5.30″ – Parkville
5.01″ – Towson
4.48″ – WBAL-TV
5.87″ – Mount Washington
5.20″ – Maryland Science Center
4.50″ – Woodlawn
2.58″ – Westminster
5.25″ – Waldorf
5.66″ – Laurel
4.14″ – Jessup
4.66″ – Ellicott City
7.03″ – Oxon Hill
5.52″ – Bowie
3.21″ – Sharpsburg
1.84″ – Salisbury
3.78″ – Conowingo Dam
3.27″ – Elkton
3.27″ – Federalsburg
4.85″ – Goldsboro
4.27″ – American Corner

This rain event fixed the short term drought but in terms of the entire year the numbers at BWI-Marshall come up short with a precipitation deficit of 5.75 inches.

The slow, steady rainfall was perfect for partially recharging area wells and reservoirs. As far as agriculture is concerned the rain came too late in many cases and the damage to crops is done.

No additional rain is expected through the end of the month so this October will likely go down as the 14th. wettest October on record in Baltimore.

John Collins

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Southern California Fires
October 23, 2007

Santa Ana Winds continue to aggrivate wildfires in southern California. The spectacular satellite picture taken earlier today shows how the strong easterly winds are pushing the smoke from the fires far out to sea.

It doesn’t take much imagination to realize how extensive the fire activity is to generate that much smoke.

Below are two additional satellite pictures enhanced by and courtesy of Storm Center Communications.


This image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite shows the fires on Monday afternoon, October 22, 2007, with a smoke plume extending 480 miles into the Pacific Ocean.


In the false-color image, combination of infrared bands from MODIS have been added to the image to make burn scars (deep red) stand out better from vegetation (bright green), water (black), cumulus clouds (white), cirrus clouds (light blue) and smoke (light blue).

Environmental Impacts:

With some 245,957 acres, or 384 square miles, ablaze, Gov. Schwarzenegger had declared a state of emergency in seven counties on Sunday, and President Bush had called to offer federal assistance with the blazes.

San Diego Mayor Jerry Sanders said the number of evacuees in San Diego County alone topped 300,000. The number was expected to be far greater throughout all of Southern California.

More than 1,000 homes and businesses had been destroyed across Southern California, most in San Diego County or the mountains east of Los Angeles.

Gov. Schwarzenegger said 800 National Guard troops would be diverted from duty on the southern border to assist with evacuation and ground control in the country.

The wildfires claimed one life, in San Diego County, and injured 42, including at least 16 firefighters.

State emergency officials said they feared that the fires, devouring some of the thickest and driest brush in years, could surpass the destruction of 2003, when California experienced its worst fire season on record.

The Ranch Fire in Angeles National Forest is burning approximately 29,000 acres, and it is at 10 percent contained. This fire is seven miles north of Castaic. Currently evacuations are in effect in the Hasley Canyon, Oak Springs, Val Verde and Piru area.

The Buckweed Fire in Los Angeles County, is burning 20,000 acres at zero percent contained. This fire is 14 miles west of Palmdale. Communities of Santa Clarita, Castaic, Leona Valley, Green Valley, Acton, Agua Dulce, Mint Canyon are threatened.

The hot, gusting winds, not expected to let up until late Tuesday, at times grounded fire-fighting airplanes, which are pivotal for their ability to dump tremendous amounts of water and fire retardant.

Santa Ana winds are a California firefighter’s nightmare. These blustery, dry, and often hot winds blow out of the desert and race through canyons and passes in the mountains on their way toward the coast. The air is hot not because it is bringing heat from the desert, but because it is flowing downslope from higher elevations.

As fall progresses, cold air begins to sink into the Great Basin deserts to the east of California. As the air piles up at the surface, high pressure builds, and the air begins to flow downslope toward the coast. When winds blow downslope, the air gets compressed, which causes it to warm and dry out. Not only do the winds spread the fire, but they also dry out vegetation, making it even more flammable.

Here is a Tuesday statement from the National Weather Service in Los Angeles:

AN UPPER LEVEL HIGH PRESSURE SYSTEM LOCATED OFF THE NORTHERN CALIFORNIA COAST COMBINED WITH SURFACE HIGH PRESSURE OVER THE GREAT BASIN WILL CONTINUE TO BRING HOT…DRY…AND STRONG SANTA ANA CONDITIONS WITH EXPLOSIVE FIRE GROWTH POTENTIAL TO MUCH OF SOUTHERN CALIFORNIA THROUGH TODAY. WINDS ARE EXPECTED TO SLOWLY DIMINISH LATE THIS AFTERNOON THROUGH WEDNESDAY. HOWEVER…THE CONTINUATION OF VERY WARM AND DRY CONDITIONS WILL CONTINUE THE RED FLAG WARNING THROUGH WEDNESDAY AFTERNOON. THERE WILL BE A LONG DURATION OF SINGLE DIGIT HUMIDITIES THROUGH WEDNESDAY…WITH VERY POOR HUMIDITY RECOVERIES EACH NIGHT. THE VERY LOW RELATIVE HUMIDITIES MAY CONTINUE THROUGH THURSDAY…WHICH MAY REQUIRE THE EXTENSION OF THE RED FLAG WARNINGS INTO THURSDAY. A WEAK UPPER LEVEL LOW PRESSURE SYSTEM IN THE VICINITY OF THE CALIFORNIA COAST SHOULD BRING SOME ADDITIONAL COOLING AND MOISTENING FOR THE WEEKEND.

Here in the East we are waiting for rain. The approaching cold front may produce disappointing results. Keep up to date on the rain on this web site or check with Tom Tasselmyer tonight at 5, 6 and 11pm on TV-11 and on WBAL-TV InstaWeather Plus for updates on the storm’s progress.

John Collins

Minimal Drought Relief
October 20, 2007

The Friday (Oct 19) rainfall provided only minimal relief from the drought conditions.

BWI/Marshall .28″
Inner Harbor .43″
Ellicott City .14″
TV Hill .38″
Elkton .65″

In the official Baltimore record books, precipitation remains way below the 30 year average …

1.59″ below average for October
5.22″ below average since September 1
10.33″ below average for the year

Below is a map showing drought conditions across the U.S. as of October 18.

The worst drought conditions are in the southeastern part of the country with the Mid Atlantic region at the top edge of this area with severe drought conditions reaching into parts of northern Maryland. Tom’s blog below includes a map indicating that drought conditions will persist.

Going hand in hand with the drought are unseasonably warm temperatures. Sixteen days in October have recorded above average temperatures. Three of those days had high temperatures in the 90s and seven days had highs in the 80s.

John Collins

D.C. Drought Record…Bone Dry In Baltimore
October 18, 2007


As of late Thursday evening, the few scattered showers that tracked through the area today failed to produce any measurable rain at Reagan National Airport in Washington, D.C. The last time measurable rain fell in D.C. was September 15th, going on 34 full days. The old record dry spell in the nation’s capital was 33 days set in August and September of 1995. Here in Baltimore, we’ve had just .13″ of rain since mid September and our precipitation deficit for the year has grown to 10.51″. There is a decent chance of showers and thunderstorms Friday, perhaps 1/4″ to 1/2″, as a cold front moves east of the mountains. This won’t end the drought, however, and the hydrologists at the U.S. Geological Survey issued an update to the drought watch today, which I have posted below.

Tom Tasselmyer

U.S. Geological Survey U.S. Department of the Interior
News Release
Date: October 18, 2007
Contacts: Daniel J. Soeder (443) 498-5513 dsoeder@usgs.gov
Wendy McPherson (443) 498-5555 wsmcpher@usgs.gov
_____________________________________________________________________________
Drought Watch:

Some Mid-Atlantic Streams and Wells Reach Record Lows The drought continues to intensify in parts of Maryland, Delaware and the District of Columbia, with many area streams reaching record to near-record low flows. Ground-water levels also continue to fall. According to hydrologists at the U.S. Geological Survey (USGS), the areas most strongly affected by the drought include Northern Virginia, Southern Maryland, Central Maryland, the lower Eastern Shore, and southern Delaware, although even the mountains of Western Maryland and the West Virginia panhandle are feeling the effects.

Dry conditions in the Mid-Atlantic are part of a larger, regional drought affecting the southeastern United States, centered on northern Georgia and western South Carolina. Although declining streamflows and falling water tables are expected in late summer and early autumn, by mid-October the ground water normally begins to recharge. This year, the abnormally dry summer has been followed by an equally dry autumn, and ground-water levels continue to decline. Fortunately, normal precipitation throughout the previous winter and spring had appreciably recharged ground water, so the decline is not as severe as it could have been. If the dry weather continues through the winter/spring recharge period this year, however, ground-water levels and streamflow could be severely impacted by next summer.

Record low flows have been measured by USGS scientists in the Monocacy River in Frederick County, the Patuxent River in Montgomery County, Piscataway Creek in Charles County, Winters Run in Harford County, the Choptank River in Caroline County and Nassawango Creek in Worcester County. Low flow in the Patuxent is breaking previous monthly records set during in 1986, and flow on the Monocacy broke a monthly record set in 1963. Piscataway Creek had no measurable flow for the month of October, and has set a new record low. Information on water conditions in the MD-DE-DC area is available on the web at: http://md.water.usgs.gov/waterdata/

Several streams that did respond to a brief runoff event several weeks ago from scattered local showers, such as the Northeast Branch of the Anacostia River, quickly returned to low flow conditions within a matter of hours. Reagan National Airport has recorded only a trace of rain since October 1, and BWI has recorded 0.13 inches over the same period, with less than a half inch total since September 1. Normal rainfall for the first two weeks of October should be nearly 2 inches. Rain forecast for this weekend is expected to help, but will not alleviate the drought.

Water levels in five of the 22 observation wells monitored by the USGS in Maryland and Delaware reached record monthly lows for October, breaking previous record lows from the mid-1980’s. A water-table well near LaPlata in Charles County is at an all-time low, and also set record lows in September and July.

Prior to the last drought in 2002, there were several months in the autumn of 2001 in which precipitation was significantly below normal. This is the time of year when ground-water usually begins to recharge. Precipitation remained abnormally low throughout that winter, with only 0.36 inches of rain recorded at BWI in February 2002. By March, rainfall had returned to near-normal, but the lack of winter ground-water recharge resulted in water shortages that summer. The drought ended with significant above-normal rainfall in October 2002. This year, above-normal precipitation in the fall and early winter of 2006 fully recharged the ground water, bringing water tables up to normal. Both May and September 2007 were very dry months, with less than one inch of rain each. Adequate ground-water levels provided ample water supplies through the dry May, but by September, water tables had declined. September 2007 was the fourth-driest on record, and both ground-water levels and streamflows have been dropping rapidly. Water levels for October 2007 will be record-setting unless there is a major storm.

Water supplies in the Baltimore City reservoirs and in the Potomac Basin are reported to be generally adequate. The USGS will begin more frequent monitoring of ground-water levels in response to the abnormally dry conditions, and data will be available again in early November.

Fall Colors Creeping Closer
October 16, 2007

With the second half of October beginning Tuesday the fall foliage season has arrived in the mid Atlantic. Peak color in the highest elevations of western Maryland now, will creep closer to the Baltimore area over the next two weeks. To keep tabs on the changing conditions and some suggested drives and hikes try the Maryland Department of Natural Resources Fall Foliage Update or The Foliage Network

Tom Tasselmyer

The Streak Is Over
October 11, 2007

After 24 straight days without measurable rain at BWI-Marshall, the rain gauge at the airport finally had some work to do last night. Between 10:44 p.m. and 11:59 p.m. exactly 0.10″ of rain was recorded, making it the first rainfall of more than a trace since .02″ hit the gauge back on September 15th. With the end of the dry streak, the record of 32 days without measurable rain that dates back to September/October of 1963 will remain the benchmark for Baltimore dry spells. A few more showers are expected today as low pressure in the mid levels of the atmosphere moves through the mid Atlantic states, but we have a long way to go in order to erase the precipitation deficit. For the year we are 9.74″ below normal with nearly half of that shortage (4.63″) coming since September 1st.

Tom Tasselmyer

It’s Snow Season!!
October 9, 2007

October 9, 1903: A trace of snow in Baltimore…the earliest officially recorded occurrence of snow in Baltimore. Thus begins the snow season in the Baltimore area. And, if we use the same logic, the snow season extends exactly 7 months, terminating on May 9th of next year, the latest in the year snow has ever been recorded in Baltimore (a trace on May 9, 1923). So, snow lovers, as you swelter in the summer-like heat today, cheer up! It’s snow season! By the way, snow was reported at Bemidji and Hibbing Minnesota this morning, so not everyone is having August in October.

Tom Tasselmyer

Multiple 90s in October
October 8, 2007

With the temperature hitting a record 91 at BWI-Marshall Monday afternoon, we have had multiple October days in the 90s for the first time since 1947. The Baltimore-Washington National Weather Service Forecast Office in Sterling, VA reported that Baltimore’s record for 90 degree days in October was set in 1941 when five days reached or exceeded 90. Here’s a list of Octobers with more than one day in the 90s:

1941 … 5 days
2007 … 2 days (so far)
1947 … 2 days
1939 … 2 days
1922 … 2 days

The first week of October 2007 has been summer-like, but it’s only the 7th warmest first week of October on record. The warmest ever was 1941 when the first seven days had an average temperature of 80.1. The first week of October 2007 had an average temperature of 71.4, which is 11.2 degrees above average.

Changes appear headed this way. A cold front is expected to move through Maryland Tuesday night. Temperatures will drop about 10 degrees behind this front with another 10-15 degree temperature drop expected Friday into the weekend as low pressure in the mid levels of the atmosphere moves southeast from the great lakes into the mid Atlantic states.

Tom Tasselmyer

Dry Streak Passes 3 Weeks
October 8, 2007

The last time the rain gauge at the National Weather Service’s BWI-Marshall weather station recorded more than a trace of precipitation was more than three weeks ago, back on September 15th, and that was just .02″. Without rain today we will have recorded 23 straight days without measurable precipitation. Another week of dry weather would put us near the record for dry spells in Baltimore which dates back to September and October of 1963. From September 30, 1963 through October 31, 1963, a stretch of 32 days, no measurable rain fell at BWI. We have two chances to end the dry weather this week. The first is a chance for a few showers as a front moves through Tuesday night. The second chance comes as an area of low pressure in the middle levels of the atmosphere drops from northern Michigan Wednesday morning into the mid Atlantic states on Friday. These weather systems not only bring us a chance of rain, they are expected to drop temperatures back to near normal levels by next weekend.

Tom Tasselmyer

New Severe Weather Warning System
October 3, 2007

With the start of October, the National Weather Service has begun a new way of issuing severe weather warnings. In the past the warnings for severe thunderstorms and tornadoes were issued for entire counties, now the warnings will be for specific areas within the county. The hope is that this will reduce the sense of false alarms and give people more specific information to act on. For example, around here this might mean if a storm is moving along the Maryland – Pennsylvania line a warning may be issued for northern Baltimore County near Prettyboy reservoir and not for the southern part of the county near Dundalk. The complete news release from the National Oceanic and Atmospheric Administration is posted below.

Tom Tasselmyer

NOAA to Provide More Specific Warning Information for Severe Weather

September 29, 2007

Display of new storm-based warnings on National Weather Service radar.
Display of new storm-based warnings on National Weather Service radar.

+ Full view comparing county- and storm-based warnings (Credit: NOAA)

NOAA’s National Weather Service will begin issuing more geographically specific warnings for tornadoes, severe thunderstorms, floods, and marine hazards starting October 1. The new “storm-based warnings” will allow forecasters to pinpoint the specific area where the threats are highest, reducing the area warned by as much as 70 percent when compared to today’s county-by-county system.

“These are potentially deadly, short duration events that can develop very rapidly,” said Vickie Nadolski, acting deputy director of NOAA’s National Weather Service. “Our technology has evolved to support better warnings, and we are adapting to meet public expectation to receive weather information on demand.”

“By focusing the threat, we can reduce the warned area by as much as 70 percent, which equates to more than $100 million in savings to the public,” said Vice Admiral Conrad C. Lautenbacher Jr., under secretary of commerce for oceans and atmosphere and NOAA administrator. “The real bottom line is that this will potentially save more lives. Eliminating areas needlessly warned builds confidence that you do indeed need to take action when a warning is issued.”

Storm-based warnings are displayed graphically and are extremely adaptable to cell phones, PDAs, and the Web. The Emergency Alert System is geared toward counties and NOAA Weather Radio All Hazards will still alarm if there is a warning anywhere in the county. However, text and audio messages will provide more specific information about where in the county the storm is, and the direction the storm is moving. Storm-based warnings will reference landmarks such as highways, shopping centers, and parks, and will use directional delimiters to indicate county location.

The National Oceanic and Atmospheric Administration, an agency of the U.S. Commerce Department, is celebrating 200 years of science and service to the nation. From the establishment of the Survey of the Coast in 1807 by Thomas Jefferson to the formation of the Weather Bureau and the Commission of Fish and Fisheries in the 1870s, much of America’s scientific heritage is rooted in NOAA.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of our nation’s coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 70 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.