Welcome to spring!

Spring - the vernal equinox - officially arrives at 10:46 a.m. today (Friday). The sun's rays will be directly overhead at the equator, due to the combination of Earth's 23.5º tilt and the position in its orbit around Sol (our sun's official name). This diagram illustrates:

I'll let astronomers explain why the dates can vary a bit, since these are astronomical designations. (Meteorological seasons are consistent, with the arrival of spring designated as March 1st every year.)

Temperatures today and throughout the weekend will resemble spring as well, with daily maxima warming into the 70s and even the 80s by Sunday. After a chilly start in the upper 30s this morning Mecklenburg County will see plenty of sunshine accompanied by a southwesterly breeze. Clouds will move in this afternoon ahead of an approaching cold front, which will usher in chances of showers after 8 o'clock this evening. That rain looks to end before sunrise Saturday.

The cold front will take its time, finally edging across the area Saturday morning. This boundary is rather weak, not having particularly cold air behind it. In fact, tomorrow looks to be even warmer than today, with local thermometers topping out in the mid-70s under sunny skies and amid light winds.

Sunday will then dawn with temperatures only dipping to the lower 50s. Add 30 degrees to those readings under strengthening March sunshine and the afternoon highs will indeed reach into the 80s, almost twenty degrees above the average for the first weekend of spring. Enjoy the outdoors!

Chilly midweek temperatures will climb as the weekend nears

Monday's severe weather outcome proved to be difficult to forecast. Several factors were in play, with one being more rain showers across the Piedmont early Monday morning than expected. That precipitation robbed the available instability ("storm fuel") and complicated the setup at the last minute. I'll leave the detailed explanations to the professional meteorologists, but suffice it to say that even Sunday evening things still looked grim. 

There was a weak EF0 tornado verified by NWS Blacksburg in Martinsville - not shown on the graphic below -, but the widespread tornado potential thankfully didn't manifest. Still, there were a myriad of wind damage reports as the cold front itself blasted through Monday evening.

Power outages occurred as a result of these winds, with many Halifax County residents dealing with no electricity as temperatures plummeted behind the front. 

Today (Wednesday) began under somewhat cloudy skies around Mecklenburg County, with pre-dawn temperatures diving into the mid- and upper 20s. High pressure is in control of East Coast weather today, and skies will gradually clear after the lunch hour. Winds will be light, and local thermometers look to top out in the upper 40s this afternoon. That's fifteen degrees below the average at this point in March.

Thursday will begin similarly, with early morning temperatures again dropping into the mid-20s. Tomorrow will then begin a warmup as that high pressure center moves off the coast. Winds will turn around out of the south and usher in warmer air. Afternoon highs will climb to near the 60º mark under mostly sunny skies. Friday through Sunday then appears to bring back a taste of late spring, with 80º possible by the end of the weekend!

Dangerous weather for Monday!!

Remember last week when it was Virginia's Severe Weather Awareness Week? Hopefully folks took the safety information to heart, because it'll definitely be needed tomorrow (Monday). But first... Sunday is currently sunny and pleasant as this morning's blog entry is being written. Temperatures around Mecklenburg County began the day in the low 40s except in Clarksville, which "won" the prize at 48º thanks to a northeasterly breeze off the warmer lake waters.

A weak cold air damming wedge will hold down this afternoon's highs. Cloud cover will increase as the day goes on, with easterly breezes ushering in cool moist air from off the Atlantic. The forecast high for today is in the low 70s, but don't be surprised if local thermometers struggle to rise above the mid-60s. There will be a few showers as well, with the coverage increasing near the dinner hour.

Then the weather will take a very serious turn for the worse. A powerful surface low pressure center will cross the Great Lakes region overnight, dragging an equally powerful cold front across the Appalachian Mountains. All the ingredients will be in place for severe weather Monday, prompting the Storm Prediction Center to issue a rare Moderate Risk - level 4 out of 5 - for much of the Piedmont.

All severe weather hazards are possible, including damaging straight-line winds, tornadoes, large hail, and local flooding. Rotating thunderstorms with the potential to produce tornadoes could arrive before dawn tomorrow, with more continuing throughout the lunch hour. A powerful squall line will push out ahead of the cold front itself and reach western parts of Mecklenburg County by mid- to late afternoon. That feature will bring an even higher potential for damaging winds, tornadoes, and hail.

It goes without saying that folks need to keep more than one method of receiving weather warnings at hand tonight and tomorrow. This graphic provides some suggestions (ignore the outdoor siren part...they're not widespread nor audible enough for folks inside buildings):

Remember, a WATCH means conditions are ripe for severe weather. A WARNING means severe weather is imminent. If a warning is issued take shelter inside a sturdy building on the lowest floor. Put as many walls between you and the outdoors as possible. Folks in mobile homes should evacuate to a nearby building, as mobile homes are very susceptible to damage from severe weather.

Folks, this won't be the typical summertime thunderstorm event. This setup is dangerous, so heed the warnings and be safe.

Severe Weather Awareness Week ends on a warming note

Today - Friday - marks the end of Virginia's Severe Weather Awareness Week. Many folks are much more interested in (or disgusted with!) wintry weather, but severe weather is more common and dangerous in these parts than people realize. Lightning is a threat from thunderstorms that should be heeded more than it is. This video is from today's severe weather emphasis on outdoor safety:

After very warm conditions earlier this week the weather took quite a turn behind Thursday's cold front. This graphic shows the jaw-dropping temperature changes from Wednesday to yesterday:

This morning's thermometer readings around Mecklenburg County sagged into the upper 20s. Fortunately today will bring a warmup as high pressure moves off the East Coast. Gusty southerly winds will pump warmer air into the area, and afternoon highs will climb back into the upper 50s. That's still a bit below average for the date, but strong March sunshine will make up the difference.

The weekend will feature a split weather personality. After a weak cold front passes through tomorrow morning Saturday will be sunny, with afternoon highs reaching the low 60s. As that boundary pushes south into the Carolinas another cold air damming wedge will be in place on Sunday. That will bring clouds, easterly winds, and temperatures likely to top out near 60º (vs. the official forecast high near 70º). Showers are likely Sunday afternoon and evening.

Another strong cold front on Monday could foster severe weather, so this week's emphasis on it could prove prescient. Stay tuned!

 

Summer-like Wednesday, with a return to March conditions Thursday

Much above average temperatures will continue today (Wednesday) around Mecklenburg County. After morning lows near 60º local thermometers will top out in the upper 80s this afternoon. A small area of showers is crossing the county as this is written, but there will be plenty of sunshine today.

The summer-like heat will be accompanied by gusty southwest winds, which are pumping copious amounts of moisture into the region. All this is occurring ahead of a powerful cold front which will cross the Appalachian Mountains tonight. As that boundary rolls through near sunrise Thursday more showers and perhaps a thunderstorm will pass through the area.

The timing of this front will create a topsy-turvy temperature profile for Thursday. The official high temperature will be near 70º, but that will happen just after midnight tonight. Those readings will fall all day long tomorrow behind the boundary as gusty northwest winds usher in cooler air. By 2:00 p.m. air temperatures will have dropped to the mid-40s (wind chill, anyone?) on their way to the freezing mark early Friday morning. 

Meanwhile, it's still Severe Weather Awareness Week here in Virginia. Today's emphasis is on severe thunderstorms, including hail, lightning, and wind. This video from NWS Wakefield talks about the different types of severe thunderstorms:

Foggy start to Severe Weather Awareness Week

Thick fog covers much of the area east of U.S. Route 29 this Monday morning, with a Dense Fog Advisory in place until 10:00 a.m. The cold front which slowly crossed the Appalachians yesterday has settled nearby as it dissipates, leaving enough moisture in place to condense into fog as temperatures neared the air's dew point overnight. Visibility will improve as the sun does its warming thing, "mixing out" - not "burning off" - the fog.

Local thermometers will climb from this morning's mid-50s into the mid-70s this afternoon under sunny skies. Meanwhile, today's emphasis during this Severe Weather Awareness Week centers on the difference between Watches and Warnings. This video explains:

Tonight, temperatures will drop into the low 50s under clear skies and with light winds. More fog could be on the weather menu early Tuesday morning as thermometer readings again approach the dew point. Tomorrow afternoon's highs will boost into the low 80s under continued clear skies, providing another preliminary taste of spring.

Also occurring on Tuesday morning, there will be a statewide Tornado Drill conducted at 9:45 a.m. Organizations and individuals are encouraged to register for and participate in this event as part of their severe weather plans. It's important to know where safe places are and when to head there if severe weather is imminent.

The warmth continues this week

The jet stream remains well north of Mecklenburg County this week, keeping the cold air at bay for at least another week. Today - Sunday - will be mostly cloudy while still being much warmer than average for early March. After morning lows in the mid- and upper 60s(!) afternoon temperatures will top out in the mid-70s. 

A few showers will dot the landscape today ahead of a cold front which is still west of the Appalachians as this is written. That boundary will slowly make its way eastward, finally easing through the area near midnight. The Storm Prediction Center has southeastern Virginia under a Marginal Risk - level 1 of 5 - for severe weather today, but any stronger storms look to occur south and east of Mecklenburg County.

However, this nearby potential for severe weather sets the stage for the upcoming work week, which is Virginia's Severe Weather Awareness Week.

Each day information will be available on different severe weather threats, including the annual Tornado Drill Tuesday at 9:45 a.m. Schools, businesses, and households can sign up for this drill and participate. The emphasis for understanding severe weather and having a safety plan in place ahead of time is important. As the saying goes, "Hope is not a plan".

Temperatures will remain well above average the first part of the week, dropping back a bit by Friday. A return to more typical March weather will hold off until St. Patrick's Day.