Tuesday, April 24, 2007
More Typical Spring Weather for Midweek
Matt Ross @ 1:00 AM
Midweek will feature a slight cool down as a front approaches the region. However, we should eek out one more summery day before moderation. Despite the recent heat, April is still more likely than not to finish as DC's coldest since 1966.
Cloudy, Breezy. Today will be mostly cloudy and mild, with afternoon high temperatures nearing 80 degrees. A late day shower or thunderstorm cannot be ruled out (40%) as a front passes through the area.
Cooler, Rain. Tonight will be mostly cloudy and mild with overcast conditions holding our temperatures in the mid 50s. There is a 40% chance of showers and maybe a thunderstorm. On Wednesday, clouds will be predominant again with daytime highs in the mid to upper 60s. Showers and thunderstorms are likely (75%) as we head through the afternoon into the evening. Refer to Jason's forecast for the rest of the week and weekend.
Depicted Above courtesy of the Climate Prediction Center: Sea Surface Temperatures(SST's) in the Equatorial Pacific remain near normal for most areas. However, note the cold pool just south of the Equator off the coast of South America. This area, known as Nino Region 1+2, has SST's running over a degree below normal. It is likely that in the coming months we will see this cold pool spread westward and initiate a La Nina event, the strength and duration of which is still to be determined.
There is no doubt that winter, extended or otherwise, is behind us. We issued our 3rd consecutive winter outlook in November, and while not a complete disaster, there was more wrong with it than right. First we will take a look at the temperature aspect of our outlook.
December finished almost 6 degrees above normal. While we did call for December to be our warmest month of the winter with respect to average, our call of normal to leaning slightly above was quite a ways off. You can read more detail here where I graded us D+/C- for the month. We had January as our coldest month at 2 to 4 degrees below normal, but it finished almost 5 degrees above normal. There is no way to dodge this one. We get an F for January. We correctly called for February to be below normal at Normal to -2, but we were off with the degree/extent of cold as February finished over 7 degrees below normal. For February we grade a C. March finished slightly above normal versus our call of slightly below, but at +1.2 against our call of Normal to -2, it was sadly our best monthly call of the winter. March gets a grade of B-/C+.
Overall we called for the December through March period to average -1.25 degrees below normal, and it finished +1.1. Not too bad, but the route we took to get there was a rocky one. For the overall winter departure we grade a C+/B-, but for the monthly departures we grade a C-/D+. Overall for temperatures we grade a C. Now on to snow.
Our snow forecast was for 20-30% above normal snowfall for the winter. Despite a decent number of wintry events, some with major impact, most DC area locations finished with snowfall amounts 30-40% below normal. National Airport's total of 9.5" versus an average close to 16" was the lowest since the 2001-02 winter. On snowfall we get a D/D+.
Our overall outlook grade when combining temperatures and snowfall is a D+/C-. We underestimated the degree and duration of the warmth during the December 1st through January 15th period, and when the cold finally did arrive in late January we underestimated that as well. The lack of any sizable all snow events killed our snowfall outlook, as DC rarely nickels and dimes its way to large seasonal totals. Our lack of success this winter is disappointing and humbling, but there is always next winter, and you can be sure I will be talking about it when it's still in the 80s later this summer.
Today
Cloudy, Breezy. Today will be mostly cloudy and mild, with afternoon high temperatures nearing 80 degrees. A late day shower or thunderstorm cannot be ruled out (40%) as a front passes through the area.Tonight and Tomorrow
Cooler, Rain. Tonight will be mostly cloudy and mild with overcast conditions holding our temperatures in the mid 50s. There is a 40% chance of showers and maybe a thunderstorm. On Wednesday, clouds will be predominant again with daytime highs in the mid to upper 60s. Showers and thunderstorms are likely (75%) as we head through the afternoon into the evening. Refer to Jason's forecast for the rest of the week and weekend. Depicted Above courtesy of the Climate Prediction Center: Sea Surface Temperatures(SST's) in the Equatorial Pacific remain near normal for most areas. However, note the cold pool just south of the Equator off the coast of South America. This area, known as Nino Region 1+2, has SST's running over a degree below normal. It is likely that in the coming months we will see this cold pool spread westward and initiate a La Nina event, the strength and duration of which is still to be determined.
2006-07 Winter Outlook Review
There is no doubt that winter, extended or otherwise, is behind us. We issued our 3rd consecutive winter outlook in November, and while not a complete disaster, there was more wrong with it than right. First we will take a look at the temperature aspect of our outlook.
December finished almost 6 degrees above normal. While we did call for December to be our warmest month of the winter with respect to average, our call of normal to leaning slightly above was quite a ways off. You can read more detail here where I graded us D+/C- for the month. We had January as our coldest month at 2 to 4 degrees below normal, but it finished almost 5 degrees above normal. There is no way to dodge this one. We get an F for January. We correctly called for February to be below normal at Normal to -2, but we were off with the degree/extent of cold as February finished over 7 degrees below normal. For February we grade a C. March finished slightly above normal versus our call of slightly below, but at +1.2 against our call of Normal to -2, it was sadly our best monthly call of the winter. March gets a grade of B-/C+.
Overall we called for the December through March period to average -1.25 degrees below normal, and it finished +1.1. Not too bad, but the route we took to get there was a rocky one. For the overall winter departure we grade a C+/B-, but for the monthly departures we grade a C-/D+. Overall for temperatures we grade a C. Now on to snow.
Our snow forecast was for 20-30% above normal snowfall for the winter. Despite a decent number of wintry events, some with major impact, most DC area locations finished with snowfall amounts 30-40% below normal. National Airport's total of 9.5" versus an average close to 16" was the lowest since the 2001-02 winter. On snowfall we get a D/D+.
Our overall outlook grade when combining temperatures and snowfall is a D+/C-. We underestimated the degree and duration of the warmth during the December 1st through January 15th period, and when the cold finally did arrive in late January we underestimated that as well. The lack of any sizable all snow events killed our snowfall outlook, as DC rarely nickels and dimes its way to large seasonal totals. Our lack of success this winter is disappointing and humbling, but there is always next winter, and you can be sure I will be talking about it when it's still in the 80s later this summer.
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