3/16/12 Friday Update - 70's and maybe an 80 returns next week

A warm front with showers and a possible thunderstorm will slowly push through the Boston area between 2-6 PM today.  Ending by sunset. The showers are expected to be light, but could be heavier if a thunderstorm develops. Cold air at the surface should inhibit any wide spread thunderstorms.

A major warm up is in store as the weekend progresses. A cooler marine layer will keep coastal areas around 50 tomorrow, but as a west and southwest wind builds around high pressure moving off the Carolina coast into the week, expect high temperatures to soar into the 60's 70's and even an 80 is not out of the question by mid week next week.

More details to come on Saturday morning.

A strong area of high pressure (typically seen in the summer months) will position itself off the east coast, allowing for a southerly flow of air to build over the Plains. This warms, will then get funneled into the northeast as the flow of air around the high pressure which is clockwise gets stronger, boosting temperatures well above normal.

With cold water temperatures, the temperature spread across the area will be great especially Sunday into Wednesday with highs ranging from 58 on the Cape to 80 inland. Boston itself may not see 80 on Wednesday, but some areas will.

3/14/12 Backdoor Cold Fronts are not Welcome!

A weak little low pressure system is making for a cool dreary day along the coast of Eastern New England.  Low clouds have moved little throughout the day, whereas just outside the 128/95 line, sunshine has been present all day and temperatures have warmed nicely.

Temperatures at 1 PM

A backdoor cold front has pushed through Eastern New England, as an area of low pressure off the coastline is moving back to the west.  

Most weather systems move from west to east in the mid latitudes,  so when they move in the opposite direction of normal, they are called backdoor. The entire weather pattern is not changing, just one small area in the east is "retrograding"  

Expect today and Thursday to be cooler than it has been with lower clouds and fog especially at the coast line.

This area will wobble back and forth over the next week in fact. So we can expect warmth to come back followed by a day or two of cool.

Note: I drew the cold front backwards -should be pointing west

As the front pushes back through on Friday, expect some rain showers.

Warmer weather will return again, as the high builds to the south and warmer air also builds into the plains into next week. We should expect high temperatures to reach the 60s by next week and perhaps a few 70s as well.  

Note:  The average high temperature today March 14 is only 44 degrees!!

3/12/12 Bring on the Warmth.. (Unless you like snow)

The winds that drive the weather patterns has decided to take a Spring Break vacation into Eastern Canada for the next 10 days. If you like mild spring like weather, then you are in luck. If you were looking for lots of snow, well, you may need to head out west.

Unlike this past winters jet stream which featured a zonal flow across the US. This jet is more pronounced and will usher in warmth from the south into much of the Eastern US.

A warm air bubble will form over the Eastern US for the next 10-12 days, allowing above normal temperatures for most areas. The only issue is that on the eastern end, the stream may fluctuate back and forth some. This means that the Northeast US may see more variation in the weather than areas directly under the bubble of High pressure.

 The warmest day of 2012 so far will happen today across most of New England, with many places reaching 70. A west wind will help bring temperatures up**.  Areas along the extreme Atlantic coast will see temperatures a few degrees cooler and the Cape and the Islands will be coolest as the wind blows over the 42 degree water temperature.

A wide variation is expected in temperatures across Southern New England today. A west wind will help bring temperatures into the 70s, but along the immediate coastline it will be 5-8 degrees cooler and out on the Cape and Islands temperatures will stay in the 50s.

A storm system over the upper mid west will push through on Tuesday with some clouds and a few showers, but it will weaken as it approaches New England.

Technical Meteorological Note: Adiabatic Lapse Rates!

The reason it will be warm in Boston today has to do with the Berkshire and Green Mountains in the west.  As a west wind rises over the mountains, it will cool somewhat.  However as that air flows down off of the mountains, it will compress and warm up (notice how when you put air in a tire, it gets warm) in a perfect atmosphere, the air will warm 5 1/2 degrees F for every 1000 feet lost in elevation when the air is dry.  Today the wind is set up perfectly from the west to come off of the higher elevations of these ancient mountain ranges to warm the air to the east.  (Typically a warm wind for Boston comes from the SW, and therefore there is little in the way of compression and the warming is primarily transported from the heating of the landmass from the south)  Note:  The 42 degree water ocean temperature will keep extreme coastal areas cooler today, as the wind is light today. If the wind were say above 10-15 mph, it would force itself and overtake the cold air.