April 2011
North Country Monthly Climate Summary
TEMPERATURE SUMMARY...
Overall, for the entire North Country area, April temperatures were close to average.
There were two significant warm periods: the period of April 9th through the 11th where high temperatures reached the upper 60s to the lower 70s. The warmest temperatures during the month would be observed during a period between April 24th and April 29th. Highs reached the upper 70s to lower 80s across many locales on April 27th.
The coldest low temperatures - in the teens and lower 20s - were observed earlier in the month on April 5th-8th. Sub-freezing low temperatures become increasingly less frequent as the North Country transitioned out of winter and into early spring.
TEMPERATURE STATISTICS ACROSS THE NORTH COUNTRY FOR THE MONTH OF APRIL...
| |
Burlington |
Montpelier |
Massena |
Saint Johnsbury |
| Avg. Temp |
45.4 |
41.2 |
45.1 |
42.2 |
| Departure |
+1.9 |
-0.2 |
+1.9 |
-1.3 |
| Highest |
82 on 27th |
80 on 27th |
77 on 28th |
81 on 27th |
| Lowest |
22 on 7th |
13 on 7th |
20 on 7th |
19 on 7th |
Below are daily temperature graphs for the month of April for Burlington, Montpelier, Massena, and Saint Johnsbury.
Click to enlarge
Click to enlarge
Click to enlarge
Click to enlarge
PRECIPITATION SUMMARY...
April was a very wet month for Vermont and northern New York.
Monthly totals ranged from a low of 3 to 5 inches across Windsor and Rutland Counties of Vermont, with the highest amounts (over 8") across the northern Adirondacks of New York and the northern Green Mountains of Vermont. The heaviest precipitation tended to fall during the 2nd half of the month. Burlington received over 2 and a half inches of precipitation on the 26th. Combined with snowmelt associated with warming temperatures, significant river and stream flooding would be observed.
The heaviest snowfall totals were mainly confined to the Northeast Kingdom and across the slopes of the Green Mountains where monthly snow accumulations of 8 to 10 inches were measured. Much lower amounts - less than 5 inches - were observed across the remainder of the North Country. Most of these snow accumulations often occured in frequent transient precipitation-type changeover events, rather than from 1 or 2 major snowstorms.
PRECIPITATION STATISTICS ACROSS THE NORTH COUNTRY FOR THE MONTH OF APRIL...
| |
Burlington |
Montpelier |
Massena |
Saint Johnsbury |
| Monthly Total " |
7.88 |
6.10 |
5.21 |
3.70 |
| Departure |
+5.00 |
+3.55 |
+2.31 |
+1.13 |
| Greatest 24hr |
2.85 on 26th-27th |
1.22 on 10th-11th |
1.37 on 10th-11th |
1.72 on 7th-7th |
| SNOW/SLEET |
0.8 |
|
|
|
| Monthly Total " |
29.3 |
|
|
|
| Greatest 24hr |
17.1 |
|
|
|
BURLINGTON FORECAST AREA ACCUMULATED MONTHLY PRECIPITATION (IN INCHES) FOR THE MONTH OF APRIL
Click to enlarge
BURLINGTON FORECAST AREA ACCUMULATED MONTHLY SNOWFALL (IN INCHES) FOR THE MONTH OF APRIL
Click to enlarge
MONTHLY WEATHER PATTERNS AND GLOBAL CLIMATE DRIVERS...
The 500 MB geopotential height anomalies for April show large negative anomalies over northern Canada and the Arctic (cool colors in Fig. 5), and slightly above average height anomalies were evident across the southern and eastern coasts of U.S. (warm colors in Fig. 5). An extension of the below-normal height anomalies (associated with upper-level troughing) extended from the Arctic low into the northwestern portion of the U.S.
In this pattern, the jetstream was generally positioned from the southwestern U.S., the Midwest and into the Northeast. This jetstream position helped contribute to periodic surges of milder air across the Northeast.
Click to enlarge
The ongoing weak La Nina would continue to weaken through April. While below-average sea surface temperatures (SST's) persisted across the central equatorial Pacific Ocean, the warmer than average SST anomalies that had begun to emerge over the western South America coastline would also continue to strengthen. The Climate Prediction Center's official ENSO forecast called for La Nina to transition toward ENSO-neutral conditions by June.
Figure 1: Burlington Monthly Temperature Trend
Figure 2: Montpelier Monthly Temperature Trend
Figure 3: Massena Monthly Temperature Trend
Figure 4: Saint Johnsbury Temperature Trend
Figure 5: Monthly Precipitation Map
Figure 6: Monthly Snowfall Map
Figure 7: 500MB Geopotential Height Anomalies
Figure 8: Climate Prediction Center Precipitation Outlook
Figure 9: Climate Prediction Center Temperature Outlook
|
weather.gov 
