Archive for December, 2008

Temperature Trend At Year’s End
December 31, 2008

The region has experienced a couple of brief cold shots so far this winter but most people I’ve talked to feel it has been on the mild side. The past few days would support that idea. The chart below shows the daily highs for the past few days and the direction temperatures will be headed going into the new year.

jc_warmstreak

Speaking of going into the new year, big celebrations are planned for Wednesday night and some of those will be outside. Be prepared for some raw weather. Below is the forecast for midnight New Yerar’s Eve.

jc_newyear

Bundle up ….. have a Happy New Year.

John Collins

Holiday Greetings
December 24, 2008

greetings

The Firm Grip Of Winter
December 23, 2008

Christmas is a couple of days away and much of the nation is in the firm grip of winter. Frigid temperatures have locked in over the northern half of the U.S. and, if my memory serves me correctly, for the first time in a long time snow blankets the northern tier of states from coast to coast before Christmas.

cursnow_usa

The satellite picture below shows upper Midwest snow cover following the most recent storm.

oseiiod1

The good news for Santa is that snow cover over the entire northern hemisphere is fairly extensive as well.

cursnow

It is interesting that, with the exception of the Alps, most of northern Europe is snow free, even southern Scandinavia. The effect of the open waters of the North Sea moderate temperatures over northern Europe make extensive snow cover in that region less likely. The continental land mass of North America allows for more frequent invasions of unmodified arctic air which can mix with storms moving across the U.S. and Canada, increasing the chances for snow.

It looks like one more storm will develop before Christmas. The satellite picture below shows its’ position as of Tuesday morning.

latest2

The first elements of this storm should reach the Mid Atlantic region tonight and temperatures will be cold enough at the surface that some freezing rain or sleet is possible. Temperatures will warm up considerably on Christmas Eve and rain is in the forecast. The storm should clear the area by Christmas Day and dry weather with seasonably cold temperatures is expected.

John Collins

Winter Storms On Parade
December 19, 2008

h5-12z-fri-19dec082

A split flow in the upper atmosphere is delivering a steady supply of winter storms to the United States.  A storm that took the southern route and dumped record snow on Las Vegas, NV earlier this week is moving into the mid Atlantic and northeastern states today.  This one will bring Maryland mostly rain, but it will likely dump some very heavy snow on portions of northern Pennsylvania and central New York.

snowfcst-rpm-neus-fri-19dec081

The next two storms in the parade will ride the northern branch of the steering currents, dropping in from the Pacific northwest, then racing east across the I-70 corridor across the plains before turning northeast just prior to reaching the coast.

goes-west-12z-fri-19dec081

This storm track favors heavy snow and ice for the midwest, Ohio valley, great lakes and northeastern United States.  Here in Maryland we’ll be teased with some snow and sleet on the leading edge of these systems, but the turn to the northeast before reaching the coast means we’ll probably get into the warm sector of the next couple storms to roll through.  This is to be expected when the North Atlantic Oscillation (NAO) is in a positive mode.  The NAO is forecast to stay strongly positive through the end of 2008, but there are indications that it will go negative again around New Year’s Day, which might lead to colder, snowier storms for Maryland in the first weeks of 2009.

Tom Tasselmyer

Las Vegas Snowstorm Heads East
December 18, 2008

sfc-map-18dec08

A record setting snow in Las Vegas, NV hit the headlines this morning and the storm isn’t done yet.  Watches, warnings and advisories for heavy snow and ice have been posted ahead the storm from Kansas City to Chicago to Cleveland to Boston.  The 3.6″ snowfall at the National Weather Service forecast office located two miles southwest of McCarran International airport, was the most ever measured in December in Las Vegas since official record keeping began back in 1937.  In fact, the National Weather Service reports that measurable snow has fallen in Las Vegas only 5 times in the month of December since 1937.  More reports from the National Weather Service on this rare desert snowstorm  are posted below.

For Baltimore, the Vegas snowstorm will likely bring rain as it tracks into the Ohio Valley and passes just north of us Friday night.  The next storm in the pipeline, however, is just now moving into the Pacific Northwest and it may bring some wintry weather into  the Baltimore area on Sunday.  It is forecast to drop southeast toward Denver before making the turn to the east on Saturday.  On a track slightly farther to the south than Friday’s storm, this one could produce some snow and sleet just as winter is set to officially begin with the winter solstice at 7:04 a.m. EST Sunday.

LAS VEGAS SNOWSTORM WRAP-UP

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1245 AM PST THU DEC 18 2008

…LAS VEGAS HITS THE JACKPOT FOR SNOW IN DECEMBER…

AN ALL-TIME RECORD SNOW FOR THE MONTH OF DECEMBER IN LAS VEGAS WAS SET YESTERDAY DECEMBER 17TH 2008. 3.6 INCHES OF SNOW WAS MEASURED AT THE NATIONAL WEATHER SERVICE OFFICE LOCATED ABOUT 2 MILES SOUTHWEST OF MCCARRAN INTERNATIONAL AIRPORT. THIS BROKE THE RECORD FOR THE MOST SNOW EVER IN THE MONTH OF DECEMBER IN LAS VEGAS SINCE THE START OF OFFICIAL RECORDS IN 1937 WHICH WAS 2.0 INCHES ON DECEMBER 15TH 1967. THIS IS NOW THE 8TH GREATEST SNOWSTORM EVER IN OFFICIAL LAS VEGAS WEATHER RECORDS FOR ANY MONTH. THE 3.6 INCHES OF SNOW MEASURED YESTERDAY ALSO SET A NEW DAILY RECORD FOR SNOW FOR
DECEMBER 17TH BREAKING THE OLD RECORD OF A TRACE SET IN 1992.

MEASURABLE SNOW HAS ONLY FALLEN ON 5 INSTANCES SINCE 1937 IN THE MONTH OF DECEMBER IN LAS VEGAS COUNTING YESTERDAY…2.0 INCHES OF SNOW WAS MEASURED ON DECEMBER 15TH 1967…0.4 INCHES OF SNOW FELL ON DECEMBER 5TH 1972…1.0 INCH OF SNOW WAS RECORDED ON DECEMBER 6TH 1998 AND MORE RECENTLY 1.3 INCHES OF SNOW WAS RECORDED ON DECEMBER 30TH 2003. THUS THE 3.6 INCHES OF SNOW THAT FELL YESTERDAY IS THE MOST SNOW TO EVER FALL ON A CALENDER DAY IN DECEMBER IN LAS VEGAS.

THE 3.6 INCHES OF SNOW THAT FELL AT LAS VEGAS YESTERDAY WAS THE MOST SNOW TO FALL IN LAS VEGAS FROM A SINGLE STORM SINCE 7.8 INCHES OF SNOW FROM JANUARY 30TH THROUGH FEBRUARY 2ND IN 1979.

DECEMBER 2008 WILL NOW RANK AS THE 6TH SNOWIEST MONTH EVER IN LAS VEGAS SINCE 1937. THE SNOWIEST MONTH EVER WAS WAY BACK IN JANUARY 1949 WHEN 16.7 INCHES FELL. THE LAST TIME THIS MUCH SNOW FELL IN ANY MONTH IN LAS VEGAS WAS IN JANUARY 1979 WHEN 9.9 INCHES FELL.

SNOWFALL RECORDS IN LAS VEGAS WERE RECORDED AT MCCARRAN
INTERNATIONAL AIRPORT THROUGH JANUARY 31ST 1996 AND SINCE FEBRUARY 1ST 1996 HAVE BEEN KEPT AT THE NWS OFFICE ON DEAN MARTIN ROAD.

IN ADDITION…A DAILY LIQUID PRECIPITATION RECORD WAS SET AT
MCCARRAN INTERNATIONAL AIRPORT YESTERDAY WITH 0.73 INCHES OF PRECIPITATION RECORDED. THIS BROKE THE OLD RECORD OF 0.44 INCHES FOR DECEMBER 17TH SET IN 1940.

Tom Tasselmyer

Winter’s Grip Expands
December 16, 2008

winterwarnings-16dec08

The official start of winter is still five days away (winter solstice at 7:04 a.m. EST on Dec. 21st), but bitter cold, ice and snow are making headlines for most of the United States this morning.  From Maine to Louisiana and from Maryland to California, 37 states across the nation have winter storm watches or warnings, winter weather advisories or freezing rain advisories in effect.  The arctic air mass centered over Minnesota has dropped temperatures to a frigid 35 below zero at Longville and 31 below at Hibbing.  Those temperatures would be impressive in mid January, but its not even winter yet!  As the arctic air oozes south, freezing rain is a possibility around Shreveport, Louisiana this morning where temperatures have dipped to near 30.  In New England, where clean up from last week’s ice storm is still underway, more freezing rain and sleet will complicate things today, but this time several inches of snow can be expected as well.

Tom Tasselmyer

Winter Contrast
December 15, 2008

A look at the Monday mid day weather map shows quite a winter contrast.

print_usbw1A cold front runs from the Great Lakes to the lower Mississippi Valley. East of that front, mid day temperatures run in the 50s and 60s as far north at the Mid Atlantic region. Arctic air lies west of the front.

High temperatures yesterday in Montana, Wyoming and the Dakotas were all below zero with many areas never reaching -10 degrees. This morning at 9:00am (MST) it was -26 at Lewiston MT, -19 at Bismark ND and -18 at Rapid City SD.

The northern Plaines were hit by a blizzard over the weekend and there is considerable snow cover which is contributing to the cold conditions.

snoNOAA Visible Satellite Image Monday Afternoon

The satellite image above clearly shows the snow cover over the Dakotas, northern Nebraska, northwest Iowa, western and southern Minnesota, northeast Colorado and its’ mountains, all of Wyoming, much of Montana and southern Alberta, Manitoba and Saskatchewan. The white shading over these states and provinces is not clouds but, rather, snow on the ground.

The map below is from National Operational Hydrologic Remote Sensing Center. It shows snow depths across the nation as of Monday morning.

nsm_depth_2008121505_nationalSource: NOAA/National Weather Service

The coldest air behind the front will not move toward the eastern seaboard. The front is expected to become a bit more east-west oriented and stall just south of the Baltimore-Washington region, placing us in colder air but nothing extreme. Several disturbances are expected to move along the stalled front this week, keep the weather unsettled over the Mid Atlantic region.

John Collins

Big, Bright Moon Tonight
December 12, 2008

The full moon tonight will be the biggest and brightest it has been in quite a while. The moon’s orbit around earth is not a perfect circle. The coincidence of lunar perigee(closest point) and a full moon is not very common. Tonight is one of those nights.

jc_fullmoon1212

Enjoy the view.

John Collins

Lots Of Rain
December 12, 2008

The past couple of days have been quite wet. A sampling of rain totals around the area is shown below.

jc_raintotals1212

John Collins

November Weather … National Review
December 12, 2008

On December 1 Tom entered a blog reviewing the local November weather. NOAA has now released the national statistics for November 2008. The press release is below.

The November 2008 temperature for the contiguous United States was warmer than the long-term average, according to NOAA’s National Climatic Data Center in Asheville, N.C. The January-November 2008 temperature was near average. 

The average November temperature of 44.5 degrees F was 2.0 degrees F above the 20th Century average. Precipitation across the contiguous United States in November averaged 1.93 inches, which is 0.20 inch below the 1901-2000 average.

 For the January-November period, the average temperature of 54.9 degrees F was 0.3 degree above the 20th century average.  The nation’s January-November temperature has increased at a rate of 0.12 degrees per decade since 1895, and at a faster rate of 0.41 degrees each decade during the last 50 years. All findings are based on a preliminary analysis of data based on records dating back to 1895.

U.S. Temperature Highlights

  • November temperatures were cooler than average across the Southeast and Central regions, and much warmer than average in the Southwest, Northwest and West regions.

  • The West region had its fourth warmest November on record.  This contrasted with the Southeast, which was much below normal.  
  • Persistent above-average temperatures for the last six months have resulted in a record warm June-November period for the West region. California set a record for its warmest June-November, while both Nevada and Utah had their fifth warmest June-November period.  
  • Based on NOAA’s Residential Energy Demand Temperature Index, the contiguous U.S. temperature-related energy demand was 0.6 percent below average in November.

U.S. Precipitation Highlights

  • The United States measured above-normal precipitation across the northern Great Plains from eastern Montana to western Minnesota.  However, November was drier than normal across much of the South and Central regions.  
  • Precipitation across most of the Midwest was only 50-75 percent of normal and some areas from southern Missouri through central Illinois received less than 50 percent of normal precipitation.

  • The January-November period has been persistently wet across much of the country from the central Plains to the Northeast.  The 11-month period was the wettest on record for New Hampshire and Massachusetts, second wettest for Missouri, third wettest for Vermont and Illinois, and fifth wettest for Maine and Iowa.  
  • At the end of November, 22 percent of the contiguous United States was in moderate-to-exceptional drought, about the same as October.  Meanwhile, extreme-to-exceptional drought conditions continued in the western Carolinas, northeast Georgia, eastern Tennessee, southern Texas, and Hawai’i.   
  • About 26 percent of the contiguous United States was in moderately-to-extremely wet conditions at the end of November, according to the Palmer Index. This was a decrease of about three percent compared to October.

Other Highlights

  • It was the wettest November on record in Yuma, Ariz., with 2.2 inches (5.6 cm) of precipitation – all of it falling on November 26.  This was more than five times the November average.  
  • An early November blizzard forced more than 100 businesses and schools, and Interstate 90, to close in western South Dakota on Nov. 5 and 6.  The blizzard brought total snow accumulations of 3 to 4 feet and drifts up to 20 feet in places.  
  • Several periods of strong northwesterly winds during the month resulted in mountain-enhanced snowfalls across the mountains of western Virginia, North Carolina, and extreme northern Georgia.  Banner Elk, N.C. recorded 6.2 inches (15.7 cm) of snow during the month making it the snowiest November since 1983.  
  • Three separate wildfires, which scorched 41,000 acres in Southern California, destroyed 1,000 homes and prompted 15,000 people to evacuate from November 13-17.  

NCDC’s preliminary reports, which assess the current state of the climate, are released soon after the end of each month. These analyses are based on preliminary data, which are subject to revision.  Additional quality control is applied to the data when late reports are received several weeks after the end of the month and as increased scientific methods improve NCDC’s processing algorithms. 

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.   

On the Web:

NOAA’s National Climatic Data Center: http://www.ncdc.noaa.gov

NCDC November 2008 analysis: http://www.ncdc.noaa.gov/oa/climate/research/2008/nov/nov08.html

NOAA has also produced several maps that help to show the scope of the statistics.

11_11_2008_dvtemprank_pg

reg110dv00elem02_11112008_pg

11statewideprank_pgreg110dv00elem01_11112008_pg1

John Collins