The Atlantic hurricane season is effectively over; heavy rains in the Northwest
Only two weeks remain in the Atlantic hurricane season, but the hurricane season of 2009 is effectively over. While the Western Caribbean is still warm enough to support development of a hurricane--as it is year-round--wind shear over the entire North Atlantic has risen to levels prohibitively high for tropical storm formation to occur. Wind shear is forecast to remain very high for at least the next ten days (Figure 1). This is a fairly typical occurrence in the Atlantic for this time of year, though it usually occurs sooner in El Niño years. As you probably know, El Niño conditions in the Eastern Pacific commonly create high levels of wind shear over the tropical Atlantic. This year was no exception, though the shear created by El Niño was not as strong as we've seen in other recent El Niño years. Wind shear was uncharacteristically low in the first half of November, allowing Hurricane Ida to form. Within the past ten days, though, El Niño conditions over the Eastern Pacific have intensified from moderate to strong, and wind shear over the tropical Atlantic has increased significantly, making it unlikely any significant tropical cyclones that affect land will occur the remainder of this hurricane season. Formation of a subtropical storm over the open Atlantic far from land is still a possibility, but such a storm would only be a concern to shipping.
Figure 1. Wind shear forecast for the Atlantic for ten days from now made by last night's 00Z run of the GFS model. The GFS model is forecasting very high wind shear over the entire North Atlantic over the next ten days.
Late season tropical storms in El Niño years
In the 17 hurricane seasons since 1950 where an El Niño event has been present, only three of those years featured named storms that formed after November 15. Tropical Storm Otto formed on November 29, 2004, from the remains of an extratropical storm that got cut off from the jet stream over the middle Atlantic. Otto meandered for a few days far from land before dissipating. Category 1 Hurricane Frances formed on November 19, 1986 in the open Atlantic south of Bermuda, and died after three days without affecting land. Category 1 Hurricane Martha formed on November 21, 1969 in the extreme southwestern Caribbean, off the coast of Panama. Martha weakened to a tropical storm before making landfall in Panama, and was the only named storm in the Atlantic ever to make landfall in Panama.
Typhoon season not over yet
Note that typhoon season in the Western Pacific is not over--we commonly get typhoons well into December. In fact, the ECMWF model is predicting formation of yet another typhoon east of the Philippines, sometime late this week or early next week. Tropical cyclone season is also not over in the Bay of Bengal near India, where some models are predicting an enhanced chance of a tropical storm forming late this week. And in the Southern Hemisphere, hurricane season is just beginning, with the formation of Category 3 Tropical Cyclone Anja near Maritius Island off the coast of Madagascar.
Figure 2. Category 3 Tropical Cyclone Anja in the South Indian Ocean at 1 am EST Monday November 16, 2009. Image credit: NASA.
Heavy rains hit Washington and British Columbia
A strong branch of the polar jet stream laden with moisture is streaming into Washington State and Canada's British Columbia today, and is forecast to bring heavy rains, high winds, and the threat of avalanches to the coastal mountains today through Wednesday. Heavy rains in the Pacific Northwest this time of year are often dubbed the "Pineapple Express" due to Hawaiian origin of the air, and these events are common during El Niño winters, and can strike from Southern California to British Columbia. However, I've been told by Doug McCollor, a forecaster with BC Hydro, that this rain event is not a true Pineapple Express, since the airflow is more west-to-east, rather than from the southwest. He adds, "also, freezing level at Quillayute WA was only 1800m this morning...not that high. In a Pineapple Express the freezing level would be 3500 to 4000m or so. The media here is calling it a Pineapple Express because they look out the window and it's raining all day. It is raining moderately here, no doubt, but it's because there is a downstream Rex block forming over central North America that is impeding the usual west-to-east progression of these storms".
Rainfall amounts in excess of three inches have already been recorded over Vancouver Island, and rains of up to seven inches (Figure 3) are forecast for the region over the next three days. Wind gusts of 44 mph have been recorded at La Push this morning on Washington's Olympic Peninsula.
Figure 3. Forecast precipitation for the 3-day period ending 7 am EST Thursday, November 19, 2009. Up to seven inches of rain are predicted for Washington State and coastal British Columbia. Image credit: NOAA/HPC.
I'll have a new post Tuesday or Wednesday.
Jeff Masters
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The mercury hit the roof today across New South Wales ahead of the scorcher predicted tomorrow and Friday.
Temperatures on and west of the ranges were enough to make lava look cool. Most towns peaked between eight-to-thirteen above the November norm. Broken Hill Airport recorded it's hottest November in twenty years, reaching 43, but it's meant to beat this again on Thursday, reaching 45.
Along the coast, though, sea breezes kicked in early enough and strong enough to make walking along the beach comfortable. Sydney city only reached 24 degrees, but it was sweatier in the west, with Penrith peaking at 31.
By Friday and Saturday the rubber will really hit the road... and melt!
Northwesterly winds will force in hot interior air. Inland, many November records will be broken as the 40 degree mark is passed. On the coast, temperatures will reach the low to mid-thirties.
Sydney will peak at 33 on Friday, but even more amazingly, Penrith and surrounds will hit 41, a feat not seen in November in five years.
A gusty change will push through the state over the weekend, although this may bring little relief. There is also a chance of dust storms similar to that of a few months ago.
- Weatherzone
It's at least 8 days out and can change, but it looks like the winter "El Nino" pattern in the east and SE USA is about to begin.
Low at my house this morning...42.1.
Christmas lights don't provide enough heat,but lots of people put heater coils along the edge of their roof to keep the ice from forming.
There is some low level stratus in the Bay of Campeche. Some cooler air right behind the last front moving over warm waters. Not a worry.
wonder what it will be like in here during my season?
Your not talking about this blog are you??
A non-tropical Surface Low will develop near that area and move into the Northern Gulf Coast and emerge on the Atlantic Seaboard as a very nice NorEaster just in time for Thanksgiving. Here is my Tropical Update from Yesterday as Models are now supporting even more!
LOL.
Shouldn't be near as bad.
Well, I guess I did not understand her question. There is nothing in the GOM right now.
Yep, same here in Fort Worth. Looks like the first little touch of winter has arrived in Texas...
So how is everyone this morning?
I'm fine...fixing to head out the door and try and make a dollar.
Good luck on your surgery.
Yes Ike, it is nice to see no arguments :)
Next HURR Season should be interesting... :)
Thanks, Ike...good luck on that dollar...may it be two!
I envy you your cold temps this morning...I moved south some years ago and I really miss the brisk mornings (I know, I'm crazy, but what the hell, at least it's not dangerous crazy...LOL)
LOL..SHHHHH! Speak of the devil and he will appear!
Clear, calm, and 46F after a low of 42F. Fairly stout 1020mb on the pressure.
Should be a nice day. See ya'll later.
Hope you got the firewood and snow shovel handy. Unless the pattern changes your gonna be in for one heck of a winter im afraid.....That Southern jet stream is not a good position for you all in the NE!!!
Enjoy it!
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