We're a bit late here taking a look back at the weather for Baltimore during the past month. Just threw out the last wedding guests.

After a cool and very wet May, June at BWI resumed the warm pattern that has prevailed here since the beginning of the year. Temperatures at the airport averaged 75.3 degrees last month. That was 3.5 degrees above the long-term average of 71.8 degrees, and made it the warmest June since 1994, and the fourth-warmest in Baltimore in 65 years.

1943:  79.8 degrees

1994:  77.2 degrees

1949:  75.6 degrees

2008:  75.3 degrees

So far this year, only May ended cooler than the norm.

Precipitation was close to the June average for BWI, at 3.70 inches. The long-term average is 3.43 inches. Ten days saw measurable rainfall.

The high temperature for the month was 96 degrees, on the 10th. The low was 52 degrees, on June 18. No new records were set.

Not unexpectedly, given the warm temperatures, we ran well ahead on cooling degree-days, a measure of the demand for energy for cooling. We were up 34 percent over the average for June.

Looking ahead, July is typically our hottest month, with average temperatures peaking third week in the high 80s. The all-time record high temperature for Baltimore is 107 degrees, set on July 10, 1936. Only 7 dates have record highs of less than 100 degrees.

The coolest record daily high for the month (and therefore the easiest record to break) is 97 degrees, set on July 12, 1908 and July 24, 1987.

The record low for the month in Baltimore is 50 degrees, set on July 1, 1988 and again on July 3, 2001. The warmest record low is 59 degrees, set July 19, 1962.

The wettest July on record for Baltimore was in 1889, when 11.03 inches fell. The driest was in 1955, with just 0.3 inches in the gauge.

Posted by Frank Roylance at 10:45 AM | Permalink | Comments (0)
                    

Okay, so it will never rival the National Weather Service, or even the BWI data available in the Almanac section of MarylandWeather.com.

But our data archive here at The Sun's little Davis Vantage Pro 2 weather station (like the one at left) is slowly expanding. We have today managed to upload measurements taken between Jan. 1, 2008 and the present, which you can access here.

Next, we plan to upload all the readings we've gathered since the station was established at Calvert & Centre streets, WAY back on Sept. 6, 2006. It's a slow process. It takes about a minute for each day of data, so we will likely have to leave the computer running overnight.

The kink in the system is that, while we're uploading, we can't post current data. That means once the old numbers are moved, we have to go back and recover the readings that we couldn't upload in real time. Then we have to upload those, which means more current data is delayed.  Arrrgghh!

So be patient with us. We're working on it.

In the meantime, if you need to know the barometric pressure at 3:10 p.m. on Feb. 16, 2008 (it was 30.31 inches), or for any other 10-minute interval since Jan. 1, you can look it up here for free. 

The Sun station data has been accessed more than 2,800 times already. Is this Weather Geek Heaven, or what?  

Posted by Frank Roylance at 5:11 PM | Permalink | Comments (0)
                    

Another chilly day for Central Maryland today as the high at BWI stalled  at the 56-degree mark. That is 20 degrees below the normal highs for a May 20 in Baltimore, and just three degrees above the all-time low maximum temperature for a May 20 in Baltimore - 53 degrees, set on this date in 1994.

The high here at Calvert & Centre streets managed to climb all the way to 57 degrees after the sun came out.

Back on May 12 the high at BWI was just 50 degrees, and that did set a record for the date, breaking the 126-year-old record of 51 degrees, set in Baltimore WAY back, on May 12, 1882.

They're calling for a low tonight in the 40s. It's great we haven't had to run the AC yet this year. But we sure did have to throw another blanket on the bed last night. The low at BWI this morning was 44 degrees, just five degrees warmer than the all-time record low for the date - 39 degrees, set in 2002.

So far, we're running almost 2 degrees cooler than normal for the month. Rain is way ahead. We're at 7.52 inches so far through today, making this the second-wettest May on record for Baltimore. The record is 8.71 inches, set in May 1989.  May rainfall has topped 7 inches only three other times:

1894:  7.26 inches

1960:  7.10 inches

1886:  7.07 inches

But warmer, drier days are coming. The new forecast from Sterling says the highs this weekend will stretch into the 70s, and to the 80s in time for Memorial Day. That's - well above the mark predicted in earlier forecasts. 

 Freckles seeks shelter from light rain during Memorial Day observances in Timonium in 2004. Sun photo by Glenn Fawcett.

Posted by Frank Roylance at 5:39 PM | Permalink | Comments (0)
                    

The National Weather Service forecast office out at Sterling, Va., has issued a revised rainfall map covering all five days of showers and downpours from May 8 through 12. It's pretty darned impressive, especially if you live in Calvert County or parts of Anne Arundel, Prince George's County and Northern Virginia, where there seem to be patches with more than 8 inches. Feast your eyes: 

Posted by Frank Roylance at 10:01 AM | Permalink | Comments (1)
                    

The heaviest rain is moving off to the northeast, but here the drip goes on. We have another half-inch of rain in our rain gauge this morning here at Calvert and Centre streets. That's about what they've receive down at BWI, too. But the airport is well ahead of downtown Baltimore in total rain for the month to date. And they could be headed for a record-wet May.

Chris Strong, the NWS warning coordination meteorologist out at the Sterling forecast office, reports this morning that BWI received 6.17 inches of rain between May 1 and midnight last night. Since then the airport has recorded another .56 inch. That's 6.73 inches in all. And it's only the 16th of May. (The long-term average for May in Baltimore is 3.89 inches.)

Here are some other measurements across the region. Some spots have seen more than an inch.

The record precipitation for a May in Baltimore was 8.71 inches, set back in May 1989. So if we can squeeze out another 2 inches in the next 15 days we'll have a new record.

"It's possible .... 8.71 inches certainly wouldn't be out of the question," Strong said.

Why not? We're already well ahead of the pace when compared with May 1989. In that month, the airport had recorded 5.52 inches by May 16. We've seen 6.73 inches - the most ever here for the first 16 days in May, Strong said.

The creeks are rising again. Here's the streamflow map.

And it's been a month of records. Consider:

May 9: Record rainfall for the date - 1.85 inches. That beat the 1.41 inches that fell on the date in 1919.

May 11: Record rainfall for the date - 1.49 inches. That was more than the previous record of 1.28 inches set on May 11, 1924.

May 12: A record low maximum temperature. The thermometer at BWI reached just 50 degrees Monday afternoon.  The previous record was 51 degrees, set way back, on May 12, 1882. The previous record at BWI, where official observations began in 1950, was 57 degrees, set on May 12, 1960.

May 12: Record rainfall for the date - 2.20 inches, besting the 2.06 inches that fell in 1921.

Continue reading "A month of records in Baltimore" »

Posted by Frank Roylance at 10:41 AM | Permalink | Comments (0)
                    

Whew! That was a lot of water. But just how much, exactly? The numbers, of course, depend on where you were. The National Weather Service map above shows the heaviest concentration of rain south of Annapolis, chiefly in Calvert County. Here are more rain totals from around the region.

The National Weather Service instruments at Baltimore-Washington International Airport recorded 2.2 inches yesterday, a record for the date. The previous record for rain on a May 12 in Bawlmer was 2.06 inches, set in 1921. It was the third record rain total at BWI since Friday.

Altogether, the airport recorded a five-day total of 6.15 inches. That is 2.28 inches more than the long-(30-year) term average for an entire May in Baltimore. We are also running 4.73 inches ahead of the pace for the first 12 days in May.

The heaviest rain, of course, fell to the south of Baltimore. In fact, our instruments here at Calvert & Centre streets clocked in just 1.61 inches during the Sunday/Monday storm, while the airport saw 3.69  inches. Some locations saw far more, including North Beach, in Calvert County, which topped the state at more than 7 inches.

There's more rain in store. These sunny skies and 70-degree temperatures will hang around for today and tomorrow. But by Thursday you can expect increasing chances for showers as the next storm system and cold front move in from the west, much as they did last week. The next sunshine will be Monday.

Posted by Frank Roylance at 12:19 PM | Permalink | Comments (4)
                    

Satellite imagery has enabled meteorologists to calculate the amount of rainfall parts of Burma (Myanmar) received during its three-day seige by Cyclone Nargis. The totals are impressive - from 1 to nearly 2 feet across much of the coastal region. And all that rain came on top of a storm surge that swept inland with the storm, inundating much of the very low Irrawaddy River delta with sea water.

Death toll estimates, of course, have been horrific if they prove accurate - in excess of 100,000 people, with a million made homeless. Here is the rainfall map. Six hundred millimeters equals 23.64 inches.

Posted by Frank Roylance at 11:23 AM | Permalink | Comments (0)
                    

Woke up this morning to a chilly 35 degrees out on the WeatherDeck in Cockeysville. Started out the door with a light jacket, and my wife stopped me. "Is that going to be enough?" she asked me?

Now, you need to understand that she works for the Baltimore County schools, where they turn off the furnaces on April 15. The staff at her school has been freezing for two weeks. (Sorry. No pay raises, and no heat either for the folks who teach our kids.) She can't wear enough clothes to stay warm in the classroom. It took her all evening at home to warm up again. And our furnace kicked on last night.

But I digress. I stepped outside, and it was cold alright. But I kept the light jacket. The sun was bright and warm, and the air has warmed up quickly this morning. Downtown, at Calvert & Centre streets, the overnight low was only 47 degrees - about normal for this time of year.

Out at BWI, the thermometer slipped to 36 degrees this morning. But as chilly as that was, it was just shy of the record low for an April 30 at BWI, which was 32 degrees, set back in 1961, during the Kennedy Adminstration.

Here are some other overnight lows reported this morning from around the region:

Forecasters are looking for a high this afternoon around 60 degrees, about 10 degrees cooler than the longterm average.

Continue reading "A cold morning, but no record here" »

Posted by Frank Roylance at 10:34 AM | Permalink | Comments (1)
                    

The National Oceanic and Atmospheric Administration says March 2007 was the second-warmest on record globally, but cooler than the long-term average for the contiguous 48 states. In fact, the Western snowpack is the healthiest  in more than a decade, thanks to heavy snowfall in December, January and February.

Here's the full report.

And here are some highlights:

* Temperatures in the lower 48 states averaged 42 degrees in March, almost a half-degree lower than the average for the past 113 years.

* Alaska had its 17th-warmest March, 3.8 degrees above the mean from 1971-2000.

* Globally, land and surface water temperatures averaged 1.28 degrees above the 20th century mean, making it the second-warmest March globally. The average was pushed higher by much-warmer-than-normal temperatures in Eurasia.

* While the Western snowpack fared well in March, snow cover across the Northern Hemisphere was the fourth-lowest on record, consistent with the pattern of the past two decades, in which warming temperatures reduced the northern snow cover.

Extreme events during March included a rare downtown tornado in Atlanta, heavy rains in Missouri, widespread flooding from the Ozarks to Indiana, heavy snows in Kentucky and Ohio.

Here's a NOAA map of some other extreme March events around the world:

Posted by Frank Roylance at 3:20 PM | Permalink | Comments (0)
                    

Yesterday's high of 75 degrees at BWI was no record, but it did close the loop on a year in which only one month - December - failed to reach 70 degrees at the airport.

The mid-afternoon high stopped well short of the record high of 88 degrees for the date, set in 1978. From here on out the daily record highs are all in the 80s or higher. And, truth be told, temperatures in the 60s and 70s are not unheard of at any time of year in Baltimore. The record highs for December, January and February are all in the 60s and 70s.

Still, it seemed like we visited the balmy 70s quite often in this past winter.

Jan. 7:  70 degrees

Jan. 8:  70 degrees

Feb. 6:  72 degrees

Feb. 18:  71 degrees

Mar. 4:  71 degrees

Mar. 28:  70 degrees

December, as forecast, was our coolest month of the winter, never reaching the 70s. In fact, we only touched the 60s once, on Dec. 23, when the mercury at the airport reached 63 degrees.

But, looking back at the records, last winter - 2006-2007 - saw seven days with readings in the 70s, . The high was 75 degrees on Dec. 1. Only February passed without an afternoon in the 70s. It only rose out of the 40s on four dates, making it the coldest February in 30 years. In March last year we enjoyed five dates with highs of 70 or more.

Here is a map showing yesterday's high readings around the region.

Continue reading "Only December failed to reach 70 degrees" »

Posted by Frank Roylance at 10:18 AM | Permalink | Comments (0)
                    

                                                                                 Image supplied by FreeFoto.com 

As the calendar flips over to March this weekend, take a minute to contemplate this: This Easter, on the 23rd, will be the earliest Easter in the entire lifetimes of everyone living on the planet today.

In fact, it's the earliest for any year in the 250 years between 1875 and 2124. It is matched only by Easter in 1913 - 95 years ago. So, for a few of our oldest neighbors (my mom among them), this will actually be the second time they've enjoyed an Easter this early.

Under the ecclesiastical rules set centuries ago by the Roman Catholic Church, Easter can fall anywhere between Mar. 22 and April 25, according to calculations by M.J. Montes.  But some dates crop up on the list more frequently than others.

For example, in all of those 250 years, Easter never occurs on Mar. 22 - the earliest date possible. It occurs only once on Mar. 24. That was in 1940 - the rarest Easter date of them all in that quarter-millennium. Easter falls on Mar. 23 only twice (in 1913 and 2008) and just twice on April 24 (in 2011 and 2095). All the rest are more common than this year's Easter date.

The most common dates for Easter between 1875 and 2124? Those would be April 10 and April 17 - with 11 Easters each on those dates.

So what are the rules for setting the dates for Easter?

The shorthand answer has always been that Easter falls on the first Sunday after the first full moon after the Vernal Equinox. This year, the Equinox occurs on Mar. 20, the moon is full on the 21st, and so Easter lands on the 23rd.

The actual rules are a bit more arcane. The quirk is that Church fathers did not adopt the astronomical definition for the Vernal Equinox, which can shift across several dates centered on Mar. 21. Instead, the Church fixed its ecclesiastical equinox on Mar. 21.

They also established "lunation" tables to determine when the full moons occur - tables that track the astronomical full moon, sort of, but not always, according to the U.S. Naval Observatory.

As a result, the ecclesiastical equinox can differ from the astronomical, and the ecclesiastical full moon can stray from the astronomical definition. To make it even more confusing, various branches of Christianity, in particular the Eastern churches that still use the old Julian Calendar, follow their own rules, producing different dates.

The rest of us just check the calendar. Happy Leap Day.

UPDATE: An earlier version of this post mistakenly listed April 25 as another date on which Easter does not occur between 1875 and 2124. In fact, it occurs three times in that period: 1886, 1943 and 2038. The WeatherBlog regrets the error.

Posted by Frank Roylance at 10:39 AM | Permalink | Comments (4)
                    

Another disappointment for snow lovers and school kids. Today's Alberta Clipper looked pretty for a while. But unless you live in the western counties of Maryland, the accumulations did not impress. They don't call them clippers for nothing. They scoot by quickly. They're also pretty dry. There's not a lot of moisture out there in Alberta and northern Canada - certainly not like those storms that spin out of the Gulf and bury us.

Anyway, here are some snow totals from across the region today. Allegany County takes the prize.

Posted by Frank Roylance at 6:01 PM | Permalink | Comments (3)
                    

The snow/sleet/freezing rain/rain storm is moving off the coast now. It turns out to have been quite a wet one. Here are some (unofficial) precipitation readings from around the region, as reported by CoCoRaHS. You can multiply each number by 10 to get a rough estimate of how much snow we would have received, had the atmosphere aloft been colder:

Cockeysville: 1.90 inches

Bel Air:  1.82 inches

Ellicott City:  1.77 inches

Columbia:  1.59 inches

Elkridge:  1.49 inches

Havre de Grace:  1.38 inches

Bowie:  1.25 inches

Pasadena:  1.14 inches

Taneytown:  1.06 inches

Frederick:  0.80 inch

For more readings in more locations, click here.

Posted by Frank Roylance at 5:48 PM | Permalink | Comments (0)
                    

Records have been tumbling all over the place this afternoon.

At BWI, we reached a high temperature of 72 degrees between 1 and 2 p.m., besting the old record of 72 degrees, set on this date in 1938.

There was also a new high temperature record at Reagan National Airport. It was 74 degrees there this afternoon, breaking the 69-degree record set in 1938.

Dulles International also set a new record of 71 degrees today. They broke the old record of 66, set in 1990.

That's all about to come crashing to an end. Here is the Hazardous Weather Advisory posted for this area:

"A STRONG COLD FRONT WILL MOVE EAST ACROSS THE MID ATLANTIC THIS AFTERNOON.
THE COLD FRONT IS EXPECTED TO APPROACH THE METROPOLITAN AREAS OF
WASHINGTON DC AND BALTIMORE...THE TIDAL POTOMAC AND CHESAPEAKE BAY
THIS EVENING BETWEEN 7 PM AND 11 PM. SHOWERS AND THUNDERSTORMS
WILL ACCOMPANY THE FRONTAL PASSAGE. SOME OF THE THUNDERSTORMS WILL
BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS...IN EXCESS OF 70
MPH...AND VERY HEAVY RAINFALL. IN ADDITION...THERE IS THE
POTENTIAL FOR ISOLATED TORNADOES."

Posted by Frank Roylance at 5:14 PM | Permalink | Comments (0)
                    

A surge of warm air from the South, pushing in ahead of a potentially dangerous cold front later today, has driven temperatures at BWI close to a new record this morning.

It was already 66 degrees at BWI at 7 a.m. Our weather station here at Calvert & Centre streets is reading 69 degrees. The record high for this date at BWI is 70 degrees, set back in 1938. With just another little surge of air from Dixie, we will set a new record for today's date.

We nearly set an overnight record, too. The low at 4 a.m. this morning at BWI was 45 degrees. That was just two degrees below the record high minimum temperature for this date - 47 degrees - set in 1991.

After that low was reached, the temperature at the airport jumped 15 degrees, to 60, in just an hour.

All bets are off this afternoon, when a cold front - the same one that has triggered a deadly rash of tornadoes across the South overnight - will cross our region. Forecasters at Sterling say the excitement will begin here after 3 p.m., as showers, thunderstorms, heavy rain and gusty winds mark the frontal passage. Isolated tornadoes are possible. Here's the radar loop.

We can expect up to a quarter-inch of rain, and more in some storm cells. The rain and storms will continue into the early evening, with another qaurter-inch of rain possible.

After the front passes by, we'll notice a wind shift from the southwest to the west, the air will begin to dry out and the skies will clear.

Tomorrow will be sunny and cooler, but daytime highs will still be near 50 degrees - well above the 43-degree norm for this time of year at BWI.

Another cold front will scoot by late on Friday, bringing a bit more rain and dropping our weekend temperatures to the below-normal range. The high on Sunday won't get much above freezing, and the overnight low Monday morning will sink into the teens in many locations.

Posted by Frank Roylance at 10:39 AM | Permalink | Comments (0)
                    

There's a warm front on the move through our area today, and by tomorrow we could be threatening a 70-year-old record high temperature for Baltimore.

Forecasters say the high at BWI this afternoon could reach 63 degrees. It was 75 this afternoon in Fredericksburg, Va. But as warm air continues to flow in from the south and southwest, temperatures here tomorrow could reach 69 degrees. That's just one degree shy of the 70-degree record set for Baltimore on a Feb. 6 in 1938. A little sunshine in the afternoon could push us into record territory.

The 30-year average for the 5th and 6th of February in Baltimore is 43 degrees. So we're cruising for a 20-degree departure from the norm this week. Tonight's low may stall at 55 degrees - 12 degrees warmer than the average HIGH for the date. Here's AccuWeather.com's take.

That's a big break for homeowners struggling to keep up with their heating bills this winter. Demand for heating energy, as measured by the degree-day count, is running about 11 percent behind the long-term average for Baltimore.  That's money in our pocket.

But enjoy it while you can, because it won't last. A storm system headed for New England will drag a cold front across Maryland late Wednesday. It could come with showers and thunderstorms in the late morning or early afternoon. As much as a quarter-inch of rain could fall.

Behind the front we'll see clearer, drier weather, and temperatures will fall back to more seasonable numbers. By Saturday night we'll be looking at lows in the mid-20s again. Sunday and Monday won't get out of the mid-30s, if the forecast holds up. That would be 10 degrees below the norms.

The colder air, in turn, could set us up for some wintry weather if the right storm comes along. And next week is, at least statistically, the snowiest of the year. For now, 2007-08 is shaping up as the least snowy in six years. We've had just 7.2 inches at BWI. Our long-term average is 18 inches.

Posted by Frank Roylance at 11:10 AM | Permalink | Comments (2)
                    

This new storm has already dropped more than a half-inch of rain on instruments here at The Sun, and out on the WeatherDeck in Cockeysville. Officially, out at BWI, they've clocked just over eight tenths of an inch. If you accept the rule of thumb equating an inch of rain to 10 inches of snow (a rule that is not always reliable), we could have been looking at up to 8 inches of snow this morning, with more to come.

UPDATE at 3 p.m.:  We've topped 1.1 inches here at The Sun. BWI has exceeded 1.3 inches. Here are the watches and warnings.

EARLIER: Now try to imagine all this rain as snow, falling on Maryland's Presidential Primary day, Feb. 12. Nice mess, huh? That sort of thing never happened when we voted in May. But I digress.

Icing does not seem to be affecting BGE customers, but Allegheny Power, to our west, has quite a few customers in the dark in West Virginia and Pennsylvania.

Radar suggests we'll catch a little break this morning, then see more rain in the afternoon.

Here are some more rainfall counts from around the region, as gathered by the NWS. Here are more for Maryland, from volunteers with CoCoRaHS.

Freezing rain to the north and west of the urban corridor produced enough ice to worry school officials. Frederick, Carroll and Harford schools elected to close, and Baltimore County shuttered schools in the Hereford Zone, leaving my favorite teacher with nothing to do today.

Remember, you can get all regional schools closing information from BaltimoreSun.com, and even have us email you alerts and updates. Just click here. 

Not much risk of closings next week. They're expecting sunny skies and highs near 50 for the next three days, and near 60 on Tuesday. The long-term forecast holds some more precipitation, all of it liquid. Forecasts of a mild, mostly snow-free winter appear to be holding up well.

Posted by Frank Roylance at 10:15 AM | Permalink | Comments (2)
                    

The mercury sank to an official low of 8 degrees over night at Baltimore-Washington International Airport. That is plenty cold for Maryland, but far from a record. The record low for Baltimore on a Jan. 21 is minus-6 degrees F, in 1985.

It was 8 degrees out on the Weatherdeck in Cockeysville, too. Here are some other readings from around the region. Feel free to drop us a comment and report your overnight lows. Be sure to include your location.

BWI:  8 degrees

Washington DC:  18 degrees

Dulles International:  7 degrees

Inner Harbor:  16 degrees

Frederick:  5 degrees

Martinsburg:  10 degrees

These mid-winter cold snaps always arrive with big high-pressure systems from the arctic. The barometer reading at BWI at this writing was 30.79 inches. It was 30.82 inches at Washington. That's darn high. You can track the barometer's meanderings on a nifty fever chart, here.

Posted by Frank Roylance at 8:28 AM | Permalink | Comments (0)
                    

Sure, it's headed for the teens in Baltimore this weekend. But there's a reason we live here and not in Warroad, Minn. Check out this forecast. Arctic air pouring out of Canada is nothing new for them.

Here's a graph of the average daily temperatures in Warroad.

Posted by Frank Roylance at 2:47 PM | Permalink | Comments (0)
                    

When two federal scientific behemoths disagree, what's a mere citizen to conclude? Or does it even matter?

Yesterday, both NASA and the National Oceanic and Atmospheric Administration released their data on global average temperatures for 2007. The bottom line? I