April 8-15, 2007 Idea: Winter Takes a Parting Shot

[donsutherland1]

Even as the warmth recently bloomed in the East with the temperature rising above 80° in Philadelphia and the high 70s in New York City, colder air has been massing in Canada. Some of that colder air is likely to push into the eastern United States with the passage of a cold front on April 5. The flow of cold air should continue for several days. As a result, the April 8-15 period should start out with unseasonably cold conditions during the first half of that timeframe. Before the cold eases, there is the chance of a significant coastal storm.

Later, a slow warm up should get underway. There is the potential that the warm up could accelerate if the pattern evolves along the lines of some similar ones in the past. Overall, model and ensemble support is strong, so my confidence is fairly high.

My thinking for the average temperature anomalies during the 4/8-15 period is as follows:

Average Regional Temperature Anomalies (4/8-15):
Northeast: Below normal
Mid-Atlantic: Below normal
Southeast: Near normal
Great Lakes: Below normal
Northern Plains: Somewhat below normal to near normal
Central Plains: Near normal to somewhat above normal
Southern Plains: Somewhat above normal
Pacific Northwest: Above normal
Southwest/Rest of West Coast: Above normal

For the major cities from Washington, DC to Boston, the 4/8-15 period is likely to feature:

- Nights generally in the 20s and 30s in Boston and 30s in New York City, Philadelphia, and Washington, DC.
- Days mainly in the 40s and 50s in Boston and New York City and 50s in Philadelphia and Washington, DC.
- One or two days with a low temperature at or below 32° in Philadelphia, New York City, and Boston. Boston could see a low temperature below 30°

In the Southeast, Atlanta will likely see highs generally in the 60s with some 70s. Lows should generally be in the 40s and 50s. Elsewhere, Burlington will likely see highs mainly in the 30s and 40s. Lows should be mainly in the 20s. and 30s.

Toronto: Most days will likely see highs in the 4.4°C to 9.9°C range (40s). Nights will generally be in the -6.6°C to +3.0°C range (20s to middle 30s).

Occasional Historic Tidbit:

On April 9-10, 2000 a storm delivered 1.6" of snow to Philadelphia and 1.2" in New York City. Central and Upstate New York, southern Quebec, and northern New England received a heavy fall of wet snow. At Albany, 13.3” accumulated. Burlington received 14.4. Montreal was buried by 14.8” (37.7 cm.). Just ahead of the storm, a number of these cities experienced springlike readings in the 70s.

[Stephanie]

I remember that storm quite well don. I was cursing up a storm, if you will! LOL!

Our last average frost date around here is April 15. Seems like Ma Nature is right on schedule with those night time temps. I can handle the 50's for the high temps though!

Thanks for all of your updates and forecasts this season plus your historical tidbits. They've been a fascinating read!

[ohiostorm]

I have been enjoying the warm weather we've been experiencing here in SW PA. I hope it returns fast!

[pwrdog]

I was talking to a 97 year old man I've know for years the other day and he told me the bugs were acting funny here in east texas and we will see another frost or freeze this year.... He loves to talk about the weather and has all kinds of observations about palnts and animals... some good and other very strange.. Will see...

It' has been years since we had an April freeze here in SE Texas... The last one was in 1987 (20years ago) .... It quickly zoomed into the low to mid 90's just a week or so later and we had our warmest late April ever setting 8 record highes in the last two weeks of the month....

The Tyler area sees an april freeze every 8 years on average and it's also been 20 years since thier last freeze.....

Some misc history..

The official latest freeze on record in Houston was April 13, 1940 when we had a record low of 32.

April 7th 1857 Houston fell to 21 degrees with light snowfall... The cold lasted for a solid week and all gardens had to be replanted..

April 13 1857, Alabama: Portions of central Alabama received a surprise 4 inches (10 cm) snow in a late-season storm during a rare prolonged April cold spell.

April 26 1834, Deep Southern States Texas to Florida: Killer freeze hits across all the the Deep South.
Huntsville, Alabama had temps in the low 20's and the freeze reached very close to the gulf of mexico..

[pwrdog]

Looks like he might have been right.... Sure looks like a frost if the cloud cover breaks and the winds are light for many places in Texas to far north Florida..