Archive for bahama islands
Unexpected clouds move in, but warm conditions remain
Posted by: | Comments05/22/10 8:58 AM
High pressure exiting to the east was supposed to hold the clouds off for another 12 hours, however a mid level disturbance had different ideas.
The water vapor satellite picture this morning shows plenty of mid and upper level moisture over the Philadelphia and New York City metropolitan area. A few mid level disturbances at 700 and 600 MB are enhancing some of the lifting over the region, thus the overcast skies and the isolated shower here and there. However, it is important to note the the lower levels of the atmosphere are still relatively dry with dew points in the lower to mid 50′s.
I should note that the upper low that was once well defined and significantly influential in creating damaging severe weather throughout the Plains is now looking more disorganized by the hour. Still, the upper low is strong enough to produce strong lifting over western Pennsylvania to produce areas of moderate to heavy rainfall. This rainfall is expected to remain to the west of the northern Mid Atlantic through this evening.
As the upper low moves east, the 500 MB upper low will open up into a open, weakening trough will limited PVA moving through the northern Mid Atlantic. What that means is the lifting associated with this upper disturbance will weaken and as a result the showers will become widely scattered to isolated this evening through tomorrow.
Once the upper disturbance exits into the Atlantic on Monday, the disturbance will be absorbed by another upper low developing to the northeast of the Bahama Islands. This Atlantic disturbance will retrograde towards the Mid Atlantic coast on Tuesday with overcast skies and scattered showers. Showers will linger on Wednesday as well, however this upper low will not create rainfall all day and high temperatures will remain warm in the 70′s and lower 80′s.
A weakening cold front will follow on Thursday with additional showers and thunderstorms, however the precipitation will be widely scattered and temperatures will remain above normal in the 70′s and 80′s.
Great news for the end of the week however as all guidance suggest that high pressure at all levels of the atmosphere will be in control with dry conditions and temperatures in the lower to mid 80′s throughout the region!
For more details for your location, check out your NY NJ PA Weather seven day forecast!
-- Weather When Posted --
- Temperature: 60°F;
- Humidity: 77%;
- Heat Index: 60°F;
- Wind Chill: 60°F;
- Pressure: 30.25 in.;
Tropical Weather Update for Sunday, September 6 2009
Posted by: | Comments4:45 AM
After what was a rather active period of tropical weather for the Atlantic, it appears we have transitioned back to a rather quiet period of weather. A series of upper lows and strong upper level troughs once again dominates the Tropical Atlantic. One such upper level trough is keeping the Gulf of Mexico active with showers and thunderstorms, however the developing upper level shear will continue to prevent any development in this area through the next 48 to 66 hours. Meanwhile, a weakening upper low, the same which put an end to Erika, continues to produce southwesterly shear throughout much of the Caribbean. A more impressive upper low is parked to the northeast of the Bahama islands and south of Bermuda and is produce strong shear through much of the western Atlantic under a strong western Atlantic ridge at 500 MB. This is an interesting features in itself as this upper low is basically strongest at 700 MB and is overwhelmed at 500 MB by the western Atlantic ridge. Another trough is located over the central Atlantic and digs down towards the Inter Tropical Convergence Zone. This trough is also producing strong southwesterly shear from the central Atlantic to the Cape Verde Island. A strong disturbance is located to the east of the Cape Verde Islands, but is not expected to develop or strengthen through the next 48 hours.
-- Weather When Posted --
- Temperature: 68°F;
- Humidity: 77%;
- Heat Index: 68°F;
- Wind Chill: 68°F;
- Pressure: 30.21 in.;
Tropical Storm Erika, a threat or just another swing and miss?
Posted by: | Comments9:00 PM
Tropical Storm Erika formed this afternoon after plenty of speculation that this tropical system was well on the way of being an organized tropical low pressure system. Sustained winds are currently at 50 mph and is barely moving. While Erika looks much more impressive than Danny ever did, the fact is that the center of low level circulation is located on the western edge of all the large convection this evening due to strong southwesterly shear from an upper level trough over the Caribbean Sea.
The one interesting feature this evening is that the convection continues to grow and expand despite the strong southwesterly shear. All upper level indications would point to Erika having no shot of intensifying nor even having convection expanding, yet that’s what is always interesting about tropical systems. Sometimes when all odds are against a tropical system, tropical storm can still overcome. That is exactly what appears to be happening with Erika this evening. I suspect that Erika is showing better organization this evening due to the very warm waters this system is over.
So what can we expect with Erika? Tropical Storm Erika will continue to track to the west-northwest towards the Bahama Islands through this week. There is a lot of uncertainty with the model guidance and once again, much of the forecast is based on the timing of the passage of upper level trough exiting the Eastern United States. The more reliable tropical model guidance not only push Erika into hurricane strength in the next 48 hours, but the HWF actually is forecasting Erika to become a major Category 3 hurricane approaching the East coast.
I think we are looking at tropical system that will be tough to kill off as the shear is just as bad as it is going to get through the next seven days. The upper level shear will gradually slacken off in the next several days. I think Erika will become a hurricane in my opinion and I am leaning towards an upper level environment that will allow Erika to approach the East coast. Just how close? That is an unknown until we can get a better handle on the timing of each trough.
-- Weather When Posted --
- Temperature: 64°F;
- Humidity: 67%;
- Heat Index: 64°F;
- Wind Chill: 64°F;
- Pressure: 30.26 in.;
Freehold
77°
New York
75°
Sussex
73°
Allentown
77°
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