Jacksonville escaped a brief freeze with a low of 33 on February 28. The eastern U.S. is still under the grip of the early March Arctic chill while it now appears likely that northeast Florida may only have one or two mornings in the upper 30s around March 14, but no freezes. We should be having a good season for spring planting beginning with March 15.
This is the time to plant tomatoes in North Florida in order to have a bountiful harvest before summer heat reduces the yield in June. The main concern is the risk of a sudden freeze in March. But it’s worth the risk because it is easy to shelter the plants with boxes or buckets should an overnight freeze occur.
The worst of winter is behind us. While January had 8 freezes and only 6 days reaching 70 degrees or higher, February has had only one freeze and 13 days reaching 70 degrees or higher. NOAA’s Climate Prediction Center indicates that the 90-day period March through May should be warmer than normal. That should be good news for North Florida and Southeast Georgia gardeners!
The National Oceanic and Atmospheric Administration (NOAA) released this map showing snow touching every state, except Florida. Not shown, Alaska and Hawaii also had snow. The wicked ice and snow storms paralyzed cities as close as Atlanta, while we mainly got the bitter cold delivered by the Polar Jet Stream. I hope you enjoy this ride with weather changes as we wind up February.
During our winter outbreaks of Polar air, high pressure systems often send cold, dry air into the Sunshine state. But not so much this winter.
This year upper level winds have been blowing warm, moist air towards us. The warm air, being lighter than cold air, overruns the more dense air creating clouds and precipitation. This week’s high pressure is not as cold as the one last week that produced freezing rain and sleet along the Gulf Coast and snow farther north; therefore, we’ll be seeing only spells of rainy weather this time.
Instead of feeling a chill from the eastward charges of the Polar Vortices over the Great Lakes and northeastern U.S., the Atlantic high pressure will be keeping our weather on the mild side, except for some chilling local breezes from the cold Atlantic waters along our coast. The boundary between the cold and warm air will be causing, a series of snowstorms from the Great Lakes to New England and parts of the Mid-Atlantic states. At times, the Jet Stream may dip southward against our warm, moist air to cause a few outbreaks of severe thunderstorms and a few tornadoes during this month and into the spring.
ARCTIC OSCILLATIONS INDICATE LESS COLD IN THE SOUTH
While we were shivering in January, Nome Alaska had a high temperature of 51 degrees on January 28. That was the warmest winter temperature there since 1907! Our cold month was related to the Polar Vortex and a blocking high pressure along the Canadian and western U.S. coast. As it kept winter rains and snows away from the western U.S., the drought threatened the water supply in California.
NOAA’s 500 MB PREDICTION FOR MID-FEBRUARY
NOAA’s upper level predictions for February indicate an erosion of the blocking ridge of high pressure on the Pacific coast and the approach of a low pressure trough from the west. Since the time is running out for California to receive its seasonal precipitation, this pattern change is hopeful news for them. It’s also better news for us after a month of such bitter cold in January.
With this new pattern, the Jet Stream can reduce the flow of Polar air masses into the Deep South. The only fly in the ointment is that any penetration of Polar air can cause outbreaks of severe thunderstorms and tornadoes. Late winter and spring is our season for our most destructive t’storms and tornadoes. It seems like there’s always something bad to watch for while we live in Paradise!