Archive for southwesterly shear
An overview of the Mid November Nor’ Easter of 2009
Posted by: | Comments7:50 PM
The forecasting of the major Nor Easter that impacted the northern Mid Atlantic from November 11 through November 14 can best be described as very difficult and in the end the model guidance was not very helpful.
The potential for the storm was showing up on the model guidance by November 8th as then Hurricane Ida was intensifying off the Honduras coast. By Monday night November 9th, Hurricane Ida had moved into the Gulf of Mexico and was falling under the influence of a strong mid level disturbance located at roughly 700 MB. This disturbance initially improved the outflow of Ida, which allowed the hurricane to intensify over the southern portions of the central Gulf of Mexico.
By Tuesday morning (11/10) Ida was under strong southwesterly shear and was taking on some extratropical characteristics. Several model guidance at this point was suggesting that Ida or the remnants of Ida would either stall and meander over the Gulf of Mexico or would be shunted east into the Bahamas. This clearly did not happen.
While Ida was becoming absorbed by the 700 MB disturbance, a deeper and stronger disturbance within the Sub Tropical jet stream was pressing to the east over Texas and southern Oklahoma. Meanwhile, a Polar jet stream disturbance was organizing and dropping south of the Northern Plains. The Sub Tropical jet stream would eventually catch up with the 700 MB disturbance and a weakening Tropical Storm Ida on Tuesday night. A few key features were developing with this trough. For one, the developing upper level low with the new coastal storm was much further to the west than expected and was the remnant moisture of Ida was pushing much further north and west than expected. What caused this to happen?
The answer is a poorly forecasted and very influential upper low to the northeast of the Bahamas. This upper low had several key contributions to this storm, but one of them was to slow the entire pattern 
down long enough to allow the new coastal low to develop. On Tuesday night and Wednesday morning, the upper low over the Bahamas was able to enhance the western Atlantic ridge to the east of the Gulf Stream. As a result, the Sub Tropical disturbance was not racing into the Atlantic as forecasted, but rather was pushing into the Tennessee Valley on Wednesday morning. Moisture was racing ahead of a stalling cold front and pushed into much of southeastern Pennsylvania, New Jersey, and southeastern New York including Long Island.
By Wednesday evening, the further north trajectory of the developing Sub Tropical upper level low made the environment favorable for more interaction with the Polar jet stream. At this point, model guidance now suggested that the Polar disturbance would force or kick the Sub Tropical disturbance into the Atlantic. The ECMWF went as far as producing a large upper low off the Southeast coast for several days. Again, neither of these solutions came to reality. Instead, a piece of the Polar disturbance phased with the Sub Tropical Disturbance, which lead to a powerful upper low developing over the Tennessee Valley and later off the North Carolina coast.
An important change was also unfolding along the Southeast and southern Mid Atlantic coast by Wednesday night. A stationary front was sitting off the coast and was an area favorable for new low pressure development. Strong lifting was focusing towards the North Carolina coast and low level winds were strongly converging in these locations. The low level center of Ida was quickly weakening and losing warm core characteristics. By Wednesday night the center of Ida had dissipated and a new area of low pressure had developed along the North Carolina coast.
This is very important to state as many in the media (including some who should know better) continue to claim that this Nor Easter was the direct remnants of Ida. Tropical storm Ida at no time become an extratropical low nor was the main low that produced the heavy rain and coastal flooding over much of New Jersey. The actual Nor Easter was a completely different surface low pressure system from the circulation of Ida. While the moisture and energy from Ida was entrained into this storm, this storm was not the direct remnant low of Ida.
While the new coastal low was developing off the North Carolina coast, a strong high pressure system was also strengthening over the Great Lakes. This high pressure system eventually moved to a position over Northern New England, slowly moving over Vermont and New Hampshire. The high pressure system had a significant impact on the evolution of this storm. One impact was the introduction of very dry air at the lowest levels of the atmosphere, which lead to large bouts of virga over much of the New York City and Philadelphia metro and limited the advancement of moisture to the north on Thursday.
Through the day on Thursday, the coastal low continued to intensify down to a 994 mb low while the high pressure system strengthened to a 1030 mb high. The combination of which produced a very impressive pressure gradient off the Mid Atlantic coast. Through the day on Thursday, the strongest pressure gradient was focused over Virginia were gusts reached impressive levels over 75 mph at times. Winds will also increasing throughout New Jersey with sustained winds ranging from 15 to 30 mph and gusts exceeding 40 mph along the coast. The rainfall however, was limited to the central and southern New Jersey coast through the day as dry air prevented rain from falling over the rest of the northern Mid Atlantic.
The coastal low slowly drifted north towards the Virginia coastal waters on Thursday night into Friday morning. Waves of rain moved through much of central and southern New Jersey, however the rest of the northern Mid Atlantic remained relatively dry. The strengthening of the pressure gradient continued into Friday morning with the strongest shift of the pressure gradient directed towards the southern New 
Jersey coast. The strong easterly fetch from the surface to 500 MB aided in forcing a marine air mass into the coastal plain, keeping the threat of fog, drizzle, and overcast conditions in place in locations that did not experience heavy rainfall. Meanwhile, coastal flooding became a significant problem on Friday as wave heights built up to 7 to 8 feet, which lead to periods of moderate stages of coastal flooding. Reports of roads being washed out, beach erosion, and flooding of local streets throughout the southern New Jersey coast caused significant damage and costs in the millions.
Once again, the model guidance had a poor handled on the precipitation for much of the region as heavy 
rain was expected through much of the day. However, the same upper low that caused the Sub Tropical disturbance to slow down and eventually stall the storm off the Mid Atlantic coast would eventually force the best upper level dynamics off the coast and southeast of Long Island. The Bahamas disturbance was entraining into the storm, but the added divergence over the Gulf Stream caused a massive explosion of convection south and east of Long Island. As a result of the rapidly rising air off the coast, air was sinking along the coast. This sinking air inhibited any lifting developing at the lower levels along the coast. Therefore, the heavy rain remained off the coast and did not push inland. By Friday evening, the influence of this strong lifting off the coast was abating and rain worked back into the coast line once again. The heaviest rain fell over Long Island and Connecticut on Friday evening as rain also redeveloped over central and southern New Jersey. Waves of rain moved westward into much of New Jersey and into parts of eastern Pennsylvania as well on Friday night and through the day on Saturday. The low pressure system was in a weakening state through Saturday, which allowed the winds to decrease from the northeast.
The following data shows the forecast in place on Wednesday morning, the actual observed rainfall map, and the official data and reports from the National Weather Service.
Forecasted
Official Observed Rainfall
Official NWS data:
Rainfall from 11/12 through 11/14
New Jersey
Atlantic City: 2.15”
Atlantic City CG: 3.59”
Atlantic City Marina: 3.39”
Cape May: 2.11”
Seaville: 2.69”
Green Creek: 2.33”
Flemington: .14”
Freehold: 0.27
Hightstown: 0.58
Millville: 1.59”
New Brunswick: .68”
Pottersville: .14”
Sussex: .28”
Charlotteburg: .47”
Newark: .28”
Pennsylvania:
Allentown: .03”
Blue Marsh Lake: 0”
Glenmorre: 0.56”
Hamburg: 0.01”
Lehighton: 0.06”
Neshaminy: 0.7”
Philadelphia: 0.5”
West Chester: 0.63”
New York:
Bridgehampton: 1.70”
Islip: 1.16”
New York City: .06”
JFK: 0.47”
LGA: .51”
Westchester: .17”
Albany: 1.05”
Poughkeepsie: 0.61”
Upton: 1.81”
Middle Island 1.36”
Brookhaven: 1.35”
Oceanside: .53”
Connecticut:
Bridgeport: 0.76”
Danbury: 0”
Norwich: 1.77”
Wind Gusts:
NEW JERSEY
…ATLANTIC COUNTY…
ATLANTIC CITY MARINA 59 259 PM 11/12
ATLANTIC CITY 47 940 AM 11/13
…BURLINGTON COUNTY…
WRIGHTST/MCGUIRE 39 1057 AM 11/13
CHATSWORTH COYLE FIELD 38 1100 AM 11/13
…CAPE MAY COUNTY…
CAPE MAY 57 709 AM 11/13
OCEAN CITY 52
WILDWOOD 51 914 AM 11/12 MOREY`S PIER
CAPE MAY 50 537 AM 11/12 LA MER BEACHFRONT
WOODBINE 35 300 PM 11/12
…CUMBERLAND COUNTY…
MILLVILLE 41 1006 PM 11/12
…MERCER COUNTY…
TRENTON 38 1036 AM 11/13
…MONMOUTH COUNTY…
SEA GIRT 43 300 PM 11/12
KEANSBURG 41 1100 AM 11/13
SANDY HOOK 38 1200 PM 11/12
…OCEAN COUNTY…
BARNEGAT LIGHT 59 1000 AM 11/13
TUCKERTON 55
HARVEY CEDARS 54 200 PM 11/12
SEASIDE HEIGHTS 52
BARNEGAT BAY 49
BRICK 45
TOMS RIVER 38 1055 AM 11/13
WEST CREEK 38 800 AM 11/12
LAKEHURST NAS 35 550 AM 11/13
…SOMERSET COUNTY…
SOMERVILLE 39 1110 AM 11/13
…BERGEN COUNTY…
TEANECK 44 1100 AM 11/14 MESONET
…ESSEX COUNTY…
NEWARK 44 440 PM 11/13 ASOS
CALDWELL 29 354 PM 11/13 ASOS
…HUDSON COUNTY…
ROBINS REEF 56 536 PM 11/13 MESONET
JERSEY CITY 42 1100 AM 11/14 SKYWARN SPOTTER
HARRISON 36 1100 AM 11/14 SKYWARN SPOTTER
PENNSYLVANIA
…LEHIGH COUNTY…
ALLENTOWN 35 1053 PM 11/12
…NORTHAMPTON COUNTY…
FORKS TWP 38 100 PM 11/13
…PHILADELPHIA COUNTY…
PHILADELPHIA 40 1219 PM 11/13
PHILADELPHIA/NE 39 1142 AM 11/13
MARINE BUOYS
44009 26 NM SE CAPE MAY 60 350 PM 11/12
BRND1 BRANDYWINE SHOAL 57 321 PM 11/12
LWSD1 LEWES, DE 57 306 PM 11/12
AVAN4 AVALON, NJ 54 259 PM 11/12
BRBN4 BRANT BEACH 54 459 PM 11/12
CMAN4 CAPE MAY FERRY 47 230 PM 11/12
SJSN4 SHIP JOHN SHOAL 46 406 PM 11/12
SDHN4 SANDY HOOK 43 718 AM 11/13
CONNECTICUT
…FAIRFIELD COUNTY…
BRIDGEPORT 41 719 AM 11/14 ASOS
…NEW HAVEN COUNTY…
NEW HAVEN/TWEED 37 802 AM 11/14 ASOS
MERIDEN 31 836 AM 11/13 ASOS
EAST HAVEN 25 1100 AM 11/14 MESONET
BRANFORD 24 1100 AM 11/14 MESONET
…NEW LONDON COUNTY…
GROTON/NEW LONDON 46 805 PM 11/13 ASOS
NOANK 41 1100 AM 11/14 MESONET
STONINGTON 35 1100 AM 11/14 MESONET
NEW LONDON 21 1100 AM 11/14 MESONET
NEW YORK
…NEW YORK COUNTY…
NYC/CENTRAL PARK 39 330 PM 11/13 ASOS
…ORANGE COUNTY…
MONTGOMERY 31 449 AM 11/14 ASOS
…PUTNAM COUNTY…
LAKE PEEKSKILL 22 1100 AM 11/14 MESONET
…QUEENS COUNTY…
NYC/JFK ARPT 46 823 PM 11/13 ASOS
NYC/LAGUARDIA 45 1229 AM 11/13 ASOS
BREEZY POINT 39 1250 PM 11/13 COASTAL STATION
…SUFFOLK COUNTY…
SHINNECOCK HILLS 59 1027 PM 11/13 LIGHT TOWER
ISLIP 46 446 PM 11/13 ASOS
WESTHAMPTON BEACH 46 547 PM 11/13 ASOS
FARMINGDALE 44 429 PM 11/13 ASOS
LINDENHURST 41 642 PM 11/13 SKYWARN SPOTTER
MONTAUK 40 815 PM 11/13 ASOS
ORIENT 37 920 PM 11/13 PUBLIC
SHIRLEY 37 616 AM 11/13 ASOS
…WESTCHESTER COUNTY…
WHITE PLAINS 40 707 PM 11/13 ASOS
MILLWOOD 20 1100 AM 11/14 MESONET
-- Weather When Posted --
- Temperature: 59°F;
- Humidity: 82%;
- Heat Index: 59°F;
- Wind Chill: 59°F;
- Pressure: 29.94 in.;
Ida weakens while models come to a consensus
Posted by: | Comments4:03 PM
Afternoon Water Vapor-NWS/NOAA
Ida has weakened significantly this morning and is now a strong tropical storm approaching the Mississippi/Alabama coast line. The influence of the mid level disturbance to the west is apparent as strong southwesterly shear is tearing apart Ida and quickly weakening the tropical warm core mechanism of the storm.
The model guidance this afternoon has taken a significant shift in a direction that I’m sure many along the New Jersey coast will be happy to hear. Instead of the Polar jet stream disturbance phasing with the Sub Tropical Ida enhanced disturbance, the Polar disturbance will kick the Sub Tropical disturbance into the Atlantic. In effect, the Polar Jet Stream, in such a progressive state, will not allow the phase to occur and thus the storm will not move as far north nor become as intense as some guidance the past few days had suggested.
However, given the amount of moisture moving into the Southeast and Tennessee Valley and the pressure falls off the Mid Atlantic and Southeast coast, a case can be made for showers and a period of steady rainfall to race up into the Philadelphia metropolitan area and the southern/central New Jersey coast before being forced into the Atlantic by Wednesday night or early Thursday morning.
Note on both pressure fall maps from Penn State E-wall, that a trough is forming off the North Carolina/ Virginia board back southwestward towards 
the Alabama coast where Ida is moving towards. This area of weakness at the surface will allow the moisture and some latent heat energy to translate northward towards the Mid Atlantic, but will be no where near as intense as what was once thought.
So expect a period of rain on Wednesday morning through the early afternoon for the southern Delaware River towards the New Jersey coast, running from Trenton on south through Cape May, New Jersey. The rest of the region will be at a risk of scattered showers, but nothing more.
I admit I am still very uneasy about this whole scenario given the trends on the radar and water vapor images. For example, I still don’t buy that a tropical system is going to do a dead stop off the Gulf Coast while Ida is currently moving north at 18 mph as the NAM is suggesting this afternoon. However, the idea presented by the guidance this afternoon is more reasonable than what I’ve seen the past few days. The guidance now takes into consideration that this is a progressive pattern and one of the characteristics of a progressive pattern is for a Polar disturbance to kick the Sub Tropical disturbance east rather than phase. Conversely, the two disturbances can still phase and produce a fast moving yet intense low pressure system, however the idea of this storm stalling was simply an unrealistic scenario.
I will continue to follow the progression of this storm through this evening and will update if any significant changes are needed.
-- Weather When Posted --
- Temperature: 62°F;
- Humidity: 59%;
- Heat Index: 62°F;
- Wind Chill: 61°F;
- Pressure: 30.32 in.;
The unknown impacts of Hurricane Ida
Posted by: | Comments7:35 AM
Another round of model guidance and another host of solutions to consider. To say the model guidance throughout the life of Ida and the disturbances over the Plains were not very consistent would be an understatement. However, I have a sneaking suspicion that this will not be the first time we’ll be discussing the uncertainty in the model guidance for a short range, mid range, or long range event.
Today I’m going to focus on the problem of figuring out the outcome of Hurricane Ida and hopefully find a solution to all of this mess. My ideas do not follow any one model guidance, however I took the general theme of the guidance and threw in some hypothesis of where this pattern is going.
Through today the ridge that built over the Mid Atlantic yesterday is sliding east off the coast, providing a very warm day once again for the region. The position of this ridge is also going to help drive Hurricane Ida right into the western Florida Panhandle by Tuesday morning.
Water Vapor Satellite This Morning- NWS/NOAA
Lets break down all the players once again this morning. Hurricane Ida is moving towards the eastern Gulf Coast at 16 mph. Ida has weakened overnight back down to a category 1 hurricane with 80 mph. Hurricane Ida appears to have peaked in strength. A mid level disturbance over the western Gulf of Mexico is producing strong southwesterly shear over Ida, which is causing the hurricane to weaken. The disturbance is starting to entrain Ida’s moisture and latent heat energy into the mid level disturbance. Meanwhile, a subtropical disturbance over the Southwest is racing to catch this mid level disturbance and Ida over the Mississippi Valley by Tuesday afternoon. Finally, we have the final part of the puzzle which is the Polar disturbance over the Northern Plains. So now the question is how do all of these pieces fit together to make up the picture for Wednesday and Thursday?
Here is what I am throwing out in the mix of solutions available.
1. This storm is not going to stall either off the New Jersey coast nor off the Florida coast. I’ve seen this solution in the GFS, CMC, ECWMF, UKMET, Korean, and almost any guidance I can think of. However, I have a hard time buying a solution of an upper low just sitting anywhere off the East coast in such a progressive flow, especially off the Mid Atlantic coast.
That’s about it, everything else is pretty much on the table within the realm of reasonable solutions. So here is how I am going to play this situation until the models get into a consensus and more data is available.
On Tuesday, Hurricane Ida moves head long into the Florida panhandle and right into central Alabama. The forward movement of Ida and the upper level features around Ida would suggest that this hurricane is not going to do a dead stop and turn around to head back to the Gulf of Mexico. This idea kind of goes against some principles we learned in physics.
By Tuesday evening, the remnants of Ida will become entrained into the mid level disturbance, which in turn is entrained into the Sub Tropical Disturbance racing towards the Southeast coast. A NEW LOW is born off the North Carolina coast by Wednesday morning. Let me pause to address this.
Although Ida will be moving into Alabama, the idea that the low level circulation will be able to jump the Appalachian Mountains and run towards the North Carolina coast in less than 24 hours is not likely. For one, the speed in which Ida would have to move would tear apart the low level circulation. What develops off the North Carolina coast is a total separate and new low pressure system. A low pressure system born of the original extratropical low from the Sub Tropical disturbance and the remnant moisture and latent heat energy from Ida. The circulation of Ida will either meander towards the Bahamas or dissipate completely over the Southeast. Again, the coastal low that forms is not Ida, but a result of Ida’s moisture and energy being entrained by the Sub Tropical short wave.
By Wednesday morning the new coastal low is developing. The Polar jet stream short wave is moving through the Ohio Valley. Now here is what’s interesting. All model guidance now has this Polar jet stream interacting with the Sub Tropical disturbance off the Carolina coast. Some models shunt the storm towards the Bahama coastal waters, other produce a monster upper low off the New Jersey coast, and some guidance just forces the whole mess off the coast like a cold front. No development at all. Again, I don’t buy the monster upper low/stalling idea at this time given the progressive pattern we are in. I’d need to see a huge turn in the guidance with 100% support to buy that. However, with this much energy involved in the pattern, I don’t buy the idea that this storm will simply fall apart and disappear into the Atlantic.
The question lies in the trough axis of the two disturbances. The Sub Tropical disturbance is negative and the Polar jet stream disturbance is positive. The eventual outcome of the new short wave should minor out into a neutral oriented trough axis over eastern Pennsylvania through central Virginia. This will place the strongest PVA and upper level dynamics over eastern Maryland, Delaware, New Jersey, and the New York City metropolitan area on Wednesday evening. If we consider a southwesterly flow aloft over the Gulf Stream, I would expect the low pressure system to track just to the southwest of the benchmark by Thursday morning.
As a result, periods of heavy rain and strong northeasterly winds can be expected along the coast with the potential of some snow mixing in at the height elevations of northeastern Pennsylvania and northwestern New Jersey. However, the heaviest precipitation will be focused towards the coast. Rainfall amounts of 1 to 2 inches can be expected with this type of storm given the speed of the surface low pressure system and the potential rainfall intensity given the tropical influences, however locally higher amounts are possible in mesoscale influences. Winds will likely be sustained between 20 to 35 mph with gusts exceeding 45 mph. The storm exits the northern Mid Atlantic by Thursday morning with clearing conditions by the afternoon.
Polar high pressure will dominate the rest of the week with scattered cloud cover and temperatures near to slightly below normal. A cold front will follow on Saturday to reinforce the Polar moderated air mass, keeping temperatures near normal.
So this is where I stand with this storm potential right now. My confidence is relatively low, but this is the best shot I have right now given all the data and the uneasiness of the model guidance. As more data comes in, I’ll be sure to change the forecast accordingly.
-- Weather When Posted --
- Temperature: 46°F;
- Humidity: 87%;
- Heat Index: 46°F;
- Wind Chill: 46°F;
- Pressure: 30.43 in.;
Tropical Weather Update for October 9 2009
Posted by: | Comments4:45 AM
Tropical Atlantic Water Vapor
Henri weakened into a remnant low pressure system yesterday afternoon under the influence of strong southwesterly shear. If Henri had hung on for a few more hours, the tropical system may have had a chance to survive.
A large ridge is expanding from the Gulf of Mexico into the western Caribbean and western Atlantic. Dry air will continue to dominate these locations with no signs of development expected for the next 48 hours. A deep trough remain over the central and eastern Atlantic, producing strong westerly and southwesterly shear to the African coast. No tropical development is expected over the next 48 hours.
-- Weather When Posted --
- Temperature: 57°F;
- Humidity: 71%;
- Heat Index: 57°F;
- Wind Chill: 56°F;
- Pressure: 30.04 in.;
Tropical Weather Update for Thursday, October 8th 2009
Posted by: | Comments4:45 AM
Tropical Atlantic- Water Vapor NWS/NOAA
Tropical Depression Henri continues to fall under the influence of strong southwesterly shear with the center of circulation located southwest of the strongest convection this morning. Henri will continue to weaken over the next 24 hours and likely dissipate by Friday morning.
The rest of the tropical Atlantic remains quiet. A deep trough and upper low will produce southwesterly shear from the central Atlantic to the African coast. Another trough and jet streak will also prevent any type of development over the eastern Caribbean over the next 48 hours. A ridge of high pressure will support more favorable conditions for tropical low pressure development over the Gulf of Mexico through the western Caribbean. This area will have to be monitored carefully over the next several days, however there are no signs of disturbances entering this area for development in the next 48 hours.
-- Weather When Posted --
- Temperature: 51°F;
- Humidity: 57%;
- Heat Index: 51°F;
- Wind Chill: 47°F;
- Pressure: 29.96 in.;
Tropical Weather Update for Wednesday, October 7 2009
Posted by: | Comments4:45 AM
Tropical Storm Henri
The Tropical Atlantic remains slightly more active compared to the previous few weeks. Tropical Storm Grace is now history as the remnants race into western Europe. However, a new tropical storm, Henri, has formed to the east of the Leeward Islands.
Tropical Storm Henri continues to get slightly better organized overnight, however it is clear the strongest convection remain to the northeast of the center of circulation at the surface. Strong southwesterly shear will remain over Henri over the next 48 hours, which should force Henri to weaken and dissipate.
The rest of the tropical Atlantic is quiet as a deep trough from the western Atlantic into the Caribbean continues to produce unfavorable conditions. A ridge will build over the Gulf of Mexico over the next 48 hours, however a lack of any signs of disturbances will limit any potential for development. The eastern Atlantic remain quiet as there is no sign of any wave showing signs of development.
-- Weather When Posted --
- Temperature: 64°F;
- Humidity: 88%;
- Heat Index: 64°F;
- Wind Chill: 63°F;
- Pressure: 29.6 in.;
Tropical Weather Update for Wednesday, September 30 2009
Posted by: | Comments4:45 AM
The tropical Atlantic continues to be dominated by strong westerly shear throughout the region. No development is expected over the next 48 hours as a deep trough dominates from the Gulf of Mexico through the Caribbean. Another strong upper trough is producing strong southwesterly shear over over the eastern Atlantic, prohibiting development off the African coast.
-- Weather When Posted --
- Temperature: 53°F;
- Humidity: 81%;
- Heat Index: 53°F;
- Wind Chill: 52°F;
- Pressure: 29.74 in.;
Tropical Weather Update for Thursday, September 24 2009
Posted by: | Comments4:45 AM
The Tropical Atlantic continues to remain quiet as strong shear dominates the region.
A deep trough remains over the central and western Atlantic, producing southwesterly to westerly shear over much of the central Atlantic.
Southwesterly shear from an upper low over the southern Plains continues to dominate the Gulf of Mexico while an upper low remains in control over the Caribbean.
No development is expected over the next 48 hours.
-- Weather When Posted --
- Temperature: 69°F;
- Humidity: 94%;
- Heat Index: 69°F;
- Wind Chill: 69°F;
- Pressure: 30.03 in.;
Tropical Weather Update for Tuesday, September 15 2009
Posted by: | Comments4:45 AM
The strong upper level troughs and upper level low pressure systems throughout the tropical Atlantic this morning continues to inhibit any significant development throughout the region. Any tropical wave exiting the African coast is running into strong southwesterly shear that will tear apart any potential system.
Meanwhile the deep trough moving through the Gulf of Mexico has introduced dry air into the western two-thirds of the Gulf of Mexico, ending any potential threat for tropical development while strong shear inhibits development over the eastern Gulf of Mexico and much of the Caribbean.
Now tropical development is expected over the next 48 hours.
-- Weather When Posted --
- Temperature: 62°F;
- Humidity: 82%;
- Heat Index: 62°F;
- Wind Chill: 62°F;
- Pressure: 29.91 in.;
Freehold
77°
Philadelphia
81°
Sussex
73°
Allentown
77°
Facebook
LinkedIn
Twitter
RSS