Archive for afternoon temperatures
Summer returns today and tomorrow
Posted by: | Comments05/01/10 9:05 AM
Are you ready for temperatures in the 80′s and 90′s with dew points in the 50′s and 60′s? However about afternoon thunderstorms that pop up out of no where? Well, you better get ready, because that’s exactly what on tap over the next seven days!
High pressure to the southeast of the New Jersey coast this morning is producing generally clear skies throughout much of the northern Mid Atlantic. Note the clouds from northwest to southeast over the Hudson Valley through central Connecticut. That’s the 850 MB warm front that is the edge of this warm air mass, and that cloud mass is moving northeast, away from the region. The Philadelphia and New York City metropolitan area will be deep within the warm air mass that is driving north, and with that the potential for temperatures to break 90 degrees.
Now, I should note that most locations away from the coast will be in the mid to upper 80′s today, which is roughly 15 to 20 degrees above normal by the way, the region should be in the mid to upper 60′s for highs. However, with the upper level ridge axis right over New Jersey, there will be some enhanced subsidence. When I combine 850 MB temperatures in the mid 10′s with a strong sinking motion over the region, that screams temperature spikes and than means lower 90′s, especially for the Delaware River Valley.
Clear skies will continue through tonight into tomorrow. The ridge axis will shift to the east, so while the southwesterly flow will now extend up through 500 MB, the sinking motion that supports the potential for temperatures spikes this afternoon will be less impressive. As such, while I expect Sunday to be very warm, the hottest day is clear today. Of course, with dew points in the 60′s tomorrow afternoon, temperatures may be cooler in the upper 80′s, but will feel warmer due to the increased humidity. Look for a heat index in the lower to mid 90′s as a result.
Up to this point, conditions will remain dry as the subsidence on both days will suppress any shower or thunderstorm development through Sunday afternoon. However, that influence disappears by Sunday evening.
Note the 500 MB map for Sunday night. The ridge axis has clearly shifted off the coast and plenty of PVA is moving southwest to northeast, towards the Philadelphia and New York City metropolitan areas. However, the trough is not going to be able to quickly move through the region. Instead, the trough will remain to the west of the northern Mid Atlantic through all of next week as the ridge remains strong over the western Atlantic. As a result, the cold front that approaches, weakens due to a lack of upper level support. Because the upper level winds remain parallel to the surface cold front, the cold front does not have much of a push behind it and the Polar air mass associated with the cold front is shunted to the northeast towards northern New England. All of this indicates a lack of strong upper level support for severe thunderstorms.
However, I am concerned that on Monday there will be several thunderstorms that will train over eastern Pennsylvania and western New Jersey through the afternoon hours before finally exiting east on Monday night. As such, there is a threat for localized flooding on Monday afternoon for the Delaware River Valley and the potential for a few isolated yet rather intense strong to severe thunderstorms. Keep an eye on the low level jet stream at 850 MB. That will be key!
High pressure returns Tuesday through Friday with generally dry conditions and a few isolated disturbances potentially producing a few renegade thunderstorms. Otherwise; dry and warm conditions can be expected through the week with high temperatures averaging 10 to 15 degrees above normal.
For a detailed seven day forecast, go here!
-- Weather When Posted --
- Temperature: 68°F;
- Humidity: 56%;
- Heat Index: 68°F;
- Wind Chill: 68°F;
- Pressure: 29.86 in.;
An excellent way to start the week
Posted by: | Comments04/19/10 6:25 AM
High pressure will continue to build into the Philadelphia and New York City metropolitan area this morning with excellent weather conditions expected through the start of this week.
A few weak disturbances will drop south from the Hudson and Mohawk Valleys of New York from time to time through Friday, however no significant rainfall is expected. In short, a very quiet week of weather can be expected.
As for temperatures, highs today through Friday will average near to slightly above normal with temperatures in the mid 60′s to lower 70′s while lows fall into the 40′s. Overall, conditions can be expected to be rather pleasant.
However, heading towards next weekend, a far different weather pattern will unfold. A back door cold front is expected to drop south and west on Saturday with increasing clouds and widespread showers by the evening. A steady rain, heavy at times, is expected to develop Saturday night through Monday as the cold front stalls over the Delaware River Valley. The rain will taper off on Tuesday with lingering showers in the afternoon. Temperatures through the period will significantly depend on the exact location of the cold front, however in general temperatures to the northeast of the cold front will be in the 40′s and 50′s while southwest of the cold front will be in the 60′s and 70′s. A strong thermal gradient will be in place throughout the northern Mid Atlantic. In short, a rather difficult forecast will be coming up this weekend.
For a detailed seven day forecast go here!
-- Weather When Posted --
- Temperature: 39°F;
- Humidity: 69%;
- Heat Index: 39°F;
- Wind Chill: 34°F;
- Pressure: 29.97 in.;
Annoying disturbance exiting, excellent yet cool weekend on tap
Posted by: | Comments04/09/10 5:28 PM
Sometimes the weather can throw a forecaster a curve ball, and today that curveball was a disturbance that was supposed to be too weak to have any significant impact. Well, that disturbance turned out to be a tad stronger, which allowed a surface low to develop along the exiting cold front and kept rain along the coast, especially over Long Island and Connecticut.
High pressure is starting to build into the northern Mid Atlantic with clearing skies rapidly moving towards the coast. Clouds will continue to clear, to the point where freezing temperatures will be possible over the interior. In fact, northeastern Pennsylvania even has some freeze warnings being issued.
As we can see with the visible satellite picture, high pressure is over much of the Mississippi Valley and Southeast with clear skies throughout that region. Those clear skies are expected to be in place over the Philadelphia and New York City metropolitan area tomorrow through Sunday afternoon. Temperatures will be significantly cooler than experienced the past several days with highs in the mid 50′s to lower 60′s, which is actually near normal.
A weak cold front, the first of many, will dive southeast from the Great Lakes towards the Mid Atlantic coast on Sunday evening. This cold front is too dry and weak to produce much in the way of precipitation, however an isolated shower is not out of the question. Otherwise, no significant impact is expected from this cold front.
Through next week, the northern Mid Atlantic will remain in a northwesterly flow dominated by the Polar jet stream. A series of weak disturbance will have the potential to produce a few isolated to widely scattered showers and thunderstorms, otherwise scattered clouds and comfortable conditions are expected. A Canadian air mass will be the dominant theme through next week, which means near normal temperatures and low humidity overall.
-- Weather When Posted --
- Temperature: 55°F;
- Humidity: 50%;
- Heat Index: 55°F;
- Wind Chill: 52°F;
- Pressure: 30.25 in.;
Hot and humid, but not for long
Posted by: | Comments04/07/10 5:20 PM
High pressure off the Southeast coast set up a summer-like Bermuda high pattern for the Philadelphia and New York City metropolitan area this afternoon. Temperatures throughout the northern Mid Atlantic ranged from the mid 80′s over northeastern Pennsylvania to the lower 90′s from the Delaware River Valley to the New York City metropolitan area. The only cool locations was found over eastern Long Island where highs were in the upper 70′s to mid 80′s. Many locations had record breaking high temperatures from Philadelphia to New York City.
High pressure at the surface and upper levels will continue to slide into the Atlantic tonight, however clear skies will continue for most locations. There is a threat of fog along the coast by tomorrow morning with visibilities below 2 miles at times. Otherwise, tranquil and warm conditions can be expected into tomorrow morning.
A strong upper disturbance over the Mississippi Valley this afternoon will continue to move northeast towards the St. Lawrence River Valley by Thursday night. This disturbance will force a strong cold front through the northern Mid Atlantic on Friday morning with showers and thunderstorms. These thunderstorms will have the potential to be rather strong, possibly even severe, with heavy downpours, wind gusts over 40 mph, and frequent lightning. These thunderstorms will move through the Friday morning rush hour with the potential for some complications. The cold front will exit by Friday afternoon with clearing skies and falling temperatures and humidity. High temperatures on Friday afternoon will be drastically cooler in the 60′s.
A new pattern will take shape by the weekend and will continue through early next week with a well established northwesterly flow from the Great Lakes to the Mid Atlantic coast. Weak disturbances will dive southeast towards the region with scattered showers and thunderstorms at times, especially overnight. Otherwise, variable cloud cover can be expected with temperatures near normal. High temperatures through the period will range from the mid 60′s to lower 70′s through early next week.
-- Weather When Posted --
- Temperature: 55°F;
- Humidity: 50%;
- Heat Index: 55°F;
- Wind Chill: 52°F;
- Pressure: 30.25 in.;
Warm and muggy conditions continue today
Posted by: | Comments04/07/10 6:46 AM
I am pretty sure this is one of the best starts to April I have seen in a long time.
Once the fog, which has developed in some locations along the coast in Connecticut, New York, and New Jersey, has lifted; clear skies can be expected with a breezy southwesterly wind around 10 to 15 mph by this afternoon. Temperatures on the back of this southwesterly wind and strong April sun will warm into the upper 70′s to mid 80′s along the coast and mid to upper 80′s away from the coast. Yes, that’s correct, mid to upper 80′s. Apparently the northern Mid Atlantic has warped into summer, however these conditions won’t last long.
A strong ridge seen on the water vapor satellite picture, is transitioning from the Ohio Valley to the Mid Atlantic coast this morning while a strong upper low slowly progresses eastward through the Plains. High pressure and very warm conditions will continue through tomorrow with similar warm conditions as seen this afternoon. However, by Thursday night clouds will increase as a strong cold front approaches from the west.
The cold front will move through the Philadelphia and New York City metropolitan area on Friday morning with showers and strong to severe thunderstorms. These thunderstorms will be capable of heavy downpours, strong wind gusts over 40 mph, and frequent lightning. The cold front will exit by early Friday afternoon with clearing skies and much cooler conditions.
The pattern will transition from the summer like warmth to more normal temperatures for this time of year as a northwesterly flow takes hold. This change in the pattern however will be a rather active pattern for showers and thunderstorms. The northern Mid Atlantic will be impacted by disturbances diving southwest from the eastern Great Lakes towards the coast with showers and thunderstorms. Otherwise, scattered clouds can be expected through this weekend and into early next week with low humidity and high temperatures in the 60′s.
-- Weather When Posted --
- Temperature: 66°F;
- Humidity: 63%;
- Heat Index: 66°F;
- Wind Chill: 66°F;
- Pressure: 29.73 in.;
Tranquil and perfect, a look at this evening
Posted by: | Comments5:02 PM
This is the second afternoon of perfect conditions with clear skies, low humidity, and temperatures pushing into the upper 50′s to lower 60′s along the immediate coast and lower to mid 60′s throughout the rest of the Philadelphia and New York City metropolitan areas.
The tranquil conditions will continue into this evening as temperatures slowly fall through the 50′s and into the 40′s under clear skies and light winds. With dew points in the teens throughout the Northeast and Mid Atlantic, temperatures will have no problem crashing in the early morning hours into the upper 20′s to lower 30′s over the northern interior and mid to upper 30′s along the coast. So expect a slightly chilly start to Thursday.
Otherwise, high pressure will remain in control with perfect Spring conditions through Friday and for much of the weekend. In fact, high temperatures for Friday, Saturday, and Sunday will easily push into the 60′s even along the immediate coast and may touch 70 degrees away from the beaches, especially over the Delaware River Valley. Clearly a far different weather weekend than last weekend or compared to the past several weeks.
A cold front will approach late on Sunday with increasing clouds and showers late in the evening. Periods of heavy rain and embedded thunderstorms can be expected through Monday afternoon with the potential for some flash flooding in areas already prone to flooding this afternoon. Temperatures on Monday will likely linger in the 40′s and 50′s due to the rainfall.
High pressure will return on Tuesday, Wednesday, and Thursday with clearing skies and temperatures rebounding into the 50′s and 60′s once again.
Cold front passage brings Arctic air back
Posted by: | Comments7:30 AM
A cold front with an Arctic air mass behind the passage of the front is moving through the region this morning with scattered snow showers for much of the region. The cold front is currently located in western Pennsylvania and will move east through the day. Winds initially from the southwest will allow afternoon temperatures to rise into the 30′s and lower 40′s throughout the northern Mid Atlantic, changing the snow this morning into a rain/snow mix.
Tonight, the cold front will exit off the coast with winds veering to the northwest and temperatures crashing through the 30′s and into the 20′s. The combination of strong northwesterly winds around 10 to 15 mph and the cold temperatures will create wind chills in the single digits and teens for many locations by tomorrow morning. So get those jackets and sweaters ready, cause you will need them! The rest of the day on Friday will have increasing clouds but very cold conditions with temperatures struggling in the 20′s and wind chills in the single digits and teens.
The water vapor satellite image this morning shows a lot of potential but also illustrates the one factor that will negate any potential for a significant snowfall for the Philadelphia and New York City metropolitan area. As we can see to the left, a strong Sub Tropical disturbance is developing over the Southern Plains and driving a significant amount of moisture northward into the central Plains, Gulf Coast, and Mississippi Valley. This disturbance is set to draw plenty of moisture from the Gulf of Mexico and is a display of what is now a very active Sub Tropical jet stream. Unfortunately for snow lovers, there is one factor on the field that will keep much of that moisture to the south, and that would be the strong Polar Vortex diving into Ontario. Note the area of dry air (in black) over the Mid West and south-central Great Lakes. This is an area of convergence and confluence between the Polar and Sub Tropical jet streams. On Friday through Saturday, that area of convergence will suppress any moisture from move north into much of the region, thus keeping the potential for snow near zero.
I don’t expect much change in this snow map over the next three days as there is pretty strong agreement on the model guidance and we can see the culprit that will suppress much of the moisture in the actual observations. For much of the northern tier, only overcast skies are expected on Saturday through Sunday with no impact otherwise. For the New York City and Philadelphia metropolitan areas, with the exception of a few snow showers or flurries, only overcast conditions are expected. A stray snow show may produce a dusting of snow in this area given the very cold temperatures in place. The accumulating snowfall will be focus over extreme southern New Jersey, basically in a line from Atlantic City to Salem. The majority of the precipitation will remain south of New Jersey, however the northern extent of the precipitation shield will clip southern New Jersey with a light snowfall of 1 to 3 inches on Saturday evening. The snowfall accumulations of up to 3 inches will be possible due to the thermal environment supporting a ratios of 15:1 with up to .2″ of precipitation possible.
Although I don’t expect any changes in the forecast, I will continue to monitor the storm for any changes, especially the position of the Polar Vortex, but any deviation northward in this storm looks to be minor at this point.
High pressure will dominant the weather pattern Sunday afternoon through Tuesday with dry conditions, scattered clouds and temperatures remaining in the 20′s and 30′s for highs on Sunday and Monday. Moderation will begin to take hold on Tuesday afternoon as the high pressure system slides east and temperatures rising into the lower to mid 30′s over the interior and mid to upper 30′s along the coast.
A strong cold front and a Sub Tropical disturbance will move through the northern Mid Atlantic on Wednesday with scattered rain and snow showers coupled with falling temperatures in the afternoon. At this time, the Sub Tropical disturbance is expected to remain weak.
-- Weather When Posted --
- Temperature: 30°F;
- Humidity: 68%;
- Heat Index: 30°F;
- Wind Chill: 25°F;
- Pressure: 30.09 in.;
Light snow likely with first impulse
Posted by: | Comments9:26 PM
This evening, the movement of high pressure into the Atlantic highlights an environment not favorable for a significant snowfall over the northern Mid Atlantic. Temperatures, although cold, are still hovering around freezing along the coast. As the surface high pressure system slides to the east, winds will back to the south leading to a moderation of the boundary layer to above freezing for many locations along the coast.
Although the 12Z and 18Z NAM have trended colder at 850 MB and the surface, boundary layer conditions with this first impulse will likely keep much of the region from experiencing any sort of significant snowfall late tomorrow morning through tomorrow afternoon. So while I have little doubt in the development of snowfall throughout the northern Mid Atlantic tomorrow, I think the most likely areas to have accumulation will be away from the coast.
The current forecast from this morning has no changed with 
snowfall totals. The highest accumulations of 1 to 3 inches with an isolated 4th inch in some locations is expected to occur from northeastern Pennsylvania through northern New Jersey, the southern Hudson Valley, and off towards Connecticut and New England. The immediate coast will have a trace to a dusting of snow, which will mix with rain at times. As the heaviest precipitation moves through on Thursday afternoon, temperatures will be rising into the mid 30′s along the coast, suggesting a high water content in the snowfall and a snow that will likely have difficulty accumulating.
This snow map is for the forecast up until Thursday midnight and does not include any potential impacts from the second disturbance will may or may not impact the region on Friday afternoon through Saturday.
As for current trends, there is little doubt that this first impulse does not lack moisture. 
The latest water vapor satellite image shows a strong mid level jet streak racing from the Gulf of Mexico as moisture races northward towards the Mid Atlantic. The heaviest precipitation and best lifting dynamics are expected to remain south of the Philadelphia and New York City metropolitan areas. However, the development of this first disturbance will be a key indicator on what to expect for the second storm in terms of timing, phasing potential, and impact. The second Sub Tropical disturbance is already entering the southern Plains.
What are my thoughts for this second storm? Now, that sounds like a new premium post to me!
-- Weather When Posted --
- Temperature: 28°F;
- Humidity: 50%;
- Heat Index: 28°F;
- Wind Chill: 22°F;
- Pressure: 30.33 in.;
Enjoyable conditions won’t last long
Posted by: | Comments10:48 AM
There is a lot of data I was looking at this morning that frankly it can be a bit overwhelming when organizing my thoughts on how to discuss what I’m seeing. In the medium range, the storm that was expected to cut towards the Great Lakes is now trending on guidances towards the East coast. Why? The negative NAO has developed slightly faster than thought just 24 hours ago, which is pretty telling of what is going on in the atmosphere, and certainly gave me pause last night. Further, the extended range (the period of December 5th) is showing signs in the teleconnections of not only being cold, but very stormy. Okay, so let’s dive into all the data and discuss this, then everyone can ponder the outcome while watching some football or decorating for the holidays!
Let’s first discuss the forecast for the next few days. High pressure will be in control through
Water Vapor-NOAA
this evening, however a strengthening cold front over the Mid West and Great Lakes will approach by tomorrow morning, which will lead to increasing clouds through tonight. This cold front will mark the beginning the Polar/Arctic air mass becoming established over the northern Mid Atlantic, which will make for a very eventful period of weather for much the eastern United States. The cold front will clear the coastal waters by the early afternoon. Temperatures will be very warm in the morning, with many locations along the coast rising into the 50′s, however as strong cold air advection takes hold over the northern Mid Atlantic, temperatures will crash through the 40′s along the coast and into the 30′s over the interior. This cold front will stall along the southern Mid Atlantic coast through the Southeast and along the Gulf Coast, which will set up an environment favorable for low pressure developing along the Texas coast.
The forecasts the past few days strongly suggested that a storm track towards the Great Lakes was highly likely as the guidance suggested that the negative NAO would not mature fast
NAO Data
enough to force a storm track further east. However, model guidance, even the ECMWF, have trended much further east with a storm track right over New Jersey and towards southern New England.
To the left I posted the latest NAO data from the CPC. I’m not so much concerned about the forecasts on these charts, but the actual observed data. Note that a negative NAO is now clearly established in the data, which is going to force any low pressure system moving north along the Appliachains to redevelop towards the coastal plain. Now, let me be VERY clear. This storm is a rain storm. There is no way this storm produces any type of frozen precipitation for anyone in the region. The reason why is that even with a negative NAO clearly developing and a storm track further east, the air mass in place just does not support frozen precipitation for any location. However, the key here to take from this storm is the trend to the east with this storm. The negative NAO influence in what is clearly a period of transition in the pattern should be noted because this feature will be a major player once the cold winter pattern is locked in and established.
So, to take a step back. The Polar air mass takes hold on Tuesday with scattered rain/snow showers and below normal conditions. High pressure will slide east on Tuesday night and Wednesday with slowly increasing clouds and moderating conditions. A strong low pressure system tracks through the northern Mid Atlantic (basically right over New Jersey) on Thursday with periods of heavy rain.
Strong Polar/Arctic high pressure takes hold on Friday and Saturday with dry conditions and below normal temperatures. Conditions will certainly feel like Christmas as temperatures will struggle in the 30′s and lower 40′s throughout the region. In short, the cold pattern is finally established and well entrenched by the end of this week.
GFS, PARA GFS, AND OTHER MODELS:
I want to take some time to discuss these models and what I think is going to happen as we continue on through December. I especially want to address the changes that will happen with the GFS. The GFS guidance is going to be upgraded with several features improved upon, officially taking hold on December 15th. NCEP has been displaying the new GFS and the improvements in the guidance are obvious. For example, the current GFS guidance with this Thursday’s storm is too far to the east and progressive while the PARA GFS is more on para with the ECMWF. The improvements include a better handle with lifting parameters, isentropic lifting vorticity, better data intergration, and a whole host of upgrades that will make the GFS more competitive in forecasting versus the ECMWF. Why is this important?
The PARA GFS has constantly shown a colder and stormier outlook for December than the
MJO Phase
operational guidance and is pretty close in aggreement with the ECMWF. It is interesting to note that the GFS and Ensemble guidance from the GFS has been horrible in forecasting the MJO wave progression this month and it will be very interesting to see how the guidance improves beyond mid December as the new GFS is used. I’m going to assume that the PARA GFS takes the MJO wave into stage 7, which is why the GFS is cold and stormy through December 15.
Continued Extended Thoughts:
However, models are just models and nothing beats reality and what I see this morning
200 MB vertical Velocity
certainly gives me pause. To the left is the current 200 MB vertical velocity field. The areas in green are areas of strong lifting. Naturally, with the El Nino going strong, lifting is very impressive along the Tropical Pacific. However, note where the lifting is strongest! The best lifting is focused towards the date line or just south of the Aleutian Islands. When the best lifting and thus convection is focused along the Data Line, several features unfold to give the Eastern United States very favorable conditions for winter conditions. The strong lifting in this location produces a favorable environment for a negative EPO/postive PNA pattern and keeps the upper low from reaching the Gulf of Alaska and remain around the Aleutians. Regardless of what models project beyond 240 hours, this feature can not be ignored and should not be underestimated.
AO Data
Another feature that has my attention this morning is the current state of the Arctic Oscillation. It is clear that the stratospheric warming I’ve been advertising is starting to take hold in the lower levels of the atmosphere as the Arctic Oscillation (AO) is falling to a negative state. Again, the GFS ensemble guidance (though clearly negative) is not important here. What is important is to note the state of the atmosphere and how the various atmospheric components are working together over the past several weeks. The warming in the stratosphere weakens the Polar Vortex, leading to a negative AO and now a negative NAO. As a result, what was once a lake cutter is now a storm focused towards the coastal plain.
Going beyond December 5th, I see no indications in the stratosphere nor the Tropical Pacific to suggest that a combination of a negative EPO/postive PNA/negative AO/negative NAO pattern will not take hold and lock in. The way the atmosphere has unfolded the past 15 to 30 days and the trends of the features discussed over the last several days clearly point to a cold and stormy pattern for much of the eastern two-thirds of the nation, especially for the northern Mid Atlantic.
Enjoy the brief time period of warm conditions as they will be the last after Thursday as a new regime takes hold and the winter of 2009/2010 begins.
-- Weather When Posted --
- Temperature: 48°F;
- Humidity: 45%;
- Heat Index: 48°F;
- Wind Chill: 44°F;
- Pressure: 29.97 in.;
NFL Football Weather
Posted by: | Comments10:45 AM
The Eagles and the Jets play home today in what will be rather wet conditions!
Eagles: The Eagles play the KC Chiefs at 1:00 PM today. The steady rain is at an end, however showers will remain a threat through the game. Winds will veer from the southeast to west around 5 to 15 mph through the afternoon. Temperatures will hold in the mid to upper 60′s.
Jets: The Jets play the Titans at 1:00 PM today. Like in Philadelphia, the steady rain is over however showers will continue to be a threat. Winds will be from the southeast around 5 to 15 mph. By the fourth quarter, winds will veer to the west around 5 to 15 mph and may have an influence on the kicking game. Temperatures will hold in the mid to upper 60′s.
-- Weather When Posted --
- Temperature: 64°F;
- Humidity: 93%;
- Heat Index: 64°F;
- Wind Chill: 63°F;
- Pressure: 29.7 in.;
Freehold
77°
New York
75°
Sussex
73°
Allentown
77°
Facebook
LinkedIn
Twitter
RSS