95L growing more organized; Pakistan's Indus River flood peaking downstream
A tropical wave (Invest 95L) in the far eastern Atlantic about 350 miles southwest of the Cape Verdes Islands has become more organized this morning. Satellite loops show that the wave has some rotation, and heavy thunderstorm activity has increased in recent hours, after a period overnight with little change. Water vapor satellite loops show that there is some dry air to the north of 95L, but this dry air currently appears to be too far away to significantly interfere with development. The main impediment to development is the moderate 10 - 20 knots of wind shear over the system. The shear is forecast to remain in the moderate range through Monday, then decrease. This should allow 95L to develop into a tropical depression Monday or Tuesday. NHC is giving 95L a 30% chance of developing into a tropical depression by Monday morning. With 95L's recent increase in organization, these odds should probably be 50%.

Figure 1. Morning satellite image of 95L.
Forecast for 95L
A ridge of high pressure will force 95L to the west or west-northwest for the next five days, and the system should increase its forward speed from its current 5 - 10 mph to 15 - 20 mph by Monday. A series of two powerful troughs of low pressure are predicted to move off the U.S. East Coast next week and cross the Atlantic; these troughs should be able to pull 95L far enough to the northwest so that it will miss the Lesser Antilles Islands. If 95L stays weak or does not develop in the next five days, as predicted by the NOGAPS model, it has a chance of eventually threatening Bermuda. If 95L develops into a hurricane, as predicted by most of the computer models, it will probably recurve to the east of Bermuda and not threaten any land areas.
Elsewhere in the tropics
The ECMWF model is predicting formation of a tropical depression in the western Gulf of Mexico off the coast of Texas 6 - 7 days from now.
Pakistan's monsoon rains diminish; Indus River flood crest nears the coast
The flooding on Pakistan's largest river, the Indus, has slowly eased along the upper and middle stretches where most of the heavy monsoon rains fell in late July and early August. However, a pulse of flood waters from these heavy rains is headed southwards towards the coast, and flood heights have risen to near all-time record levels today at the Indus River gauge station nearest to the coast, Kotri (Figure 2.) The new flooding has forced the evacuation of an additional 150,000 people in Pakistan today. Flood heights at every monitoring station along the Indus have been the highest or almost the highest since records began in 1947. Fortunately, the monsoon has entered a weak to moderate phase, and heavy rain is not expected over the flood region over the next few days, according to the Pakistan Meteorological Department.

Figure 2. August flow rates along the Indus River, courtesy of the Pakistan Meteorology Department.
Some aid agencies helping with humanitarian crisis in Pakistan:
Doctors Without Borders
The International Red Cross
MERLIN medical relief charity
The mobile giving service mGive allows one to text the word "SWAT" to 50555. The text will result in a $10 donation to the UN Refugee Agency (UNHCR) Pakistan Flood Relief Effort.
Jeff Masters
Reader Comments
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12.1N....33.4W
Now at....
12.7N and 34.1W
Moved.6N and .7W. Almost a true NW movement.
WTNT31 KNHC 221450
TCPAT1
BULLETIN
TROPICAL DEPRESSION SIX ADVISORY NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
1100 AM AST SUN AUG 22 2010
...TROPICAL DEPRESSION HAS NOT STRENGTHENED YET...
SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...12.7N 34.1W
ABOUT 665 MI...1075 KM W OF THE SOUTHERNMOST CAPE VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/HR
PRESENT MOVEMENT...NW OR 310 DEGREES AT 12 MPH...19 KM/HR
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
I think that was the right call. The satellite presentation is marginal and until we see improvement the NHC will not likely upgrade with the limited TS vectors we saw in the ASCAT pass.
WTNT41 KNHC 221452
TCDAT1
TROPICAL DEPRESSION SIX DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
1100 AM AST SUN AUG 22 2010
THE UPWARD TREND IN ORGANIZATION OF THE DEPRESSION APPEARS TO HAVE
STOPPED FOR THE TIME BEING. THE SYSTEM HAS A WELL-DEFINED
CENTER...BUT THE CIRCULATION IS A LITTLE STRETCHED FROM NORTHEAST
TO SOUTHWEST DUE TO ANOTHER DISTURBANCE LOCATED ABOUT 350 N MI TO
THE NORTHEAST. THIS HAS ALSO CAUSED THE CENTER TO MOVE ALMOST DUE
NORTH OVER THE PAST FEW HOURS...PULLING IT FARTHER AWAY FROM THE
DEEP CONVECTION. SATELLITE INTENSITY ESTIMATES ARE 30 KT AND 45 KT
FROM SAB AND TAFB...RESPECTIVELY...AND AN 1134 UTC ASCAT PASS
SHOWED A MAXIMUM OF 30 KT. THE INITIAL INTENSITY WILL BE KEPT AT 30
KT SINCE THERE HAS BEEN LITTLE CHANGE IN ORGANIZATION.
WITH THE RECENT NORTHWARD MOTION...THE SMOOTHED INITIAL MOTION IS
ROUGHLY 310/10. ONCE THE DEPRESSION ESCAPES THE INFLUENCE OF THE
DISTURBANCE TO ITS NORTHEAST...THE SUBTROPICAL RIDGE CENTERED ALONG
26N SHOULD STEER THE CYCLONE GENERALLY WEST-NORTHWESTWARD WITH
INCREASING FORWARD SPEED THROUGH THE NEXT 72 HOURS. BY DAYS 4 AND
5 THERE IS GREATER UNCERTAINTY WITH THE TRACK FORECAST DEPENDING ON
HOW THE MID-LATITUDE LONGWAVE PATTERN EVOLVES IN RELATION TO WHEN
THE DEPRESSION ACTUALLY BEGINS MOVING WESTWARD. THE GLOBAL MODEL
GUIDANCE IS IN GOOD AGREEMENT SHOWING AN AMPLIFYING TROUGH NEAR 45W
BY DAY 4...WHICH SHOULD BE TOO FAR EAST TO INDUCE SIGNIFICANT
RECURVATURE. THIS PATTERN...HOWEVER...SHOULD CAUSE THE SYSTEM TO
SLOW DOWN A LITTLE BY DAYS 4 AND 5 AS IT BECOMES TRAPPED TO THE
SOUTH OF A MID-LEVEL RIDGE. THE OFFICIAL FORECAST HAS BEEN SHIFTED
A LITTLE SOUTH AND WEST BY DAY 5...VERY CLOSE TO THE GFS...GFDL
...AND HWRF MODELS...AND LIES A LITTLE TO THE RIGHT OF THE MODEL
CONSENSUS TVCN.
THE DEPRESSION IS EXPECTED TO REMAIN UNDER THE INFLUENCE OF MODERATE
EAST-NORTHEASTERLY SHEAR FOR THE NEXT 24 HOURS OR SO...BUT
THEREAFTER THE UPPER-LEVEL ENVIRONMENT BECOMES MORE CONDUCIVE FOR
STRENGTHENING. HOWEVER...THE SYSTEM MAY STILL HAVE TO CONTEND WITH
DRY AND RELATIVELY STABLE AIR TO ITS NORTH AS IT MOVES ACROSS THE
ATLANTIC...AND MOST OF THE INTENSITY GUIDANCE NOW SHOWS A SLOWER
RATE OF INTENSIFICATION. THE OFFICIAL FORECAST HAS BEEN NUDGED
DOWN A LITTLE FROM THE PREVIOUS FORECAST BUT IS STILL HIGHER THAN
EVERY INTENSITY MODEL AT DAY 5 EXCEPT FOR THE GFDL. BASED ON AN
EXPERIMENTAL INTENSITY PROBABILITY PRODUCT AT NHC...THE DEPRESSION
CURRENTLY HAS A 1 IN 5 CHANCE OF REACHING MAJOR HURRICANE STATUS AT
SOME POINT OVER THE NEXT FIVE DAYS.
FORECAST POSITIONS AND MAX WINDS
INITIAL 22/1500Z 12.7N 34.1W 30 KT
12HR VT 23/0000Z 13.0N 35.6W 35 KT
24HR VT 23/1200Z 13.8N 38.1W 40 KT
36HR VT 24/0000Z 14.7N 40.8W 50 KT
48HR VT 24/1200Z 15.9N 43.7W 60 KT
72HR VT 25/1200Z 19.0N 49.0W 70 KT
96HR VT 26/1200Z 22.0N 53.0W 80 KT
120HR VT 27/1200Z 24.5N 56.0W 85 KT
$$
FORECASTER BERG
Its been a long time since 1992's hit by andrew and that in itself is worrysome that this is such a hard flowing system.
DATA BUT YIELD AN INITIAL MOTION OF 295/08...A LITTLE TO THE RIGHT
AND FASTER THAN THE PREVIOUS ESTIMATE.
From 0500 AST discussion..no kiding ..I don't feel so bad now..I couldn't discern actual heading either
WTPZ34 KNHC 221449
TCPEP4
BULLETIN
TROPICAL STORM FRANK ADVISORY NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092010
800 AM PDT SUN AUG 22 2010
...DEPRESSION BECOMES TROPICAL STORM FRANK...TROPICAL STORM WARNING
ISSUED FOR THE COAST OF MEXICO...
SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...14.0N 95.3W
ABOUT 140 MI...230 KM SE OF PUERTO ANGEL MEXICO
ABOUT 175 MI...280 KM SE OF PUERTO ESCONDIDO MEXICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/HR
PRESENT MOVEMENT...W OR 270 DEGREES AT 7 MPH...11 KM/HR
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES
We have Frank in the E-Pac
Tropical Cyclone Advisory #4
TROPICAL CYCLONE FRANK (EP092010)
15:00 PM UTC August 22 2010
================================
SUBJECT: Tropical Depression Strengthens Into A Storm And Is Named "FRANK"
At 15:00 PM UTC, Tropical Storm Frank (1002 hPa) located at 14.0N 95.3W or 125 NM southeast of Puerto Angel, Mexico has sustained winds of 40 knots with gusts of 50 knots. The cyclone is reported as moving west at 6 knots.
Gale Force Winds
================
30 NM from the center
Forecast and Intensity
=========================
24 HRS: 14.2N 97.8W - 60 knots (Tropical Cyclone)
48 HRS: 15.1N 100.8W - 65 knots (SVR Tropical Cyclone - SSHS 1)
72 HRS: 16.5N 103.5W - 70 knots (SVR Tropical Cyclone - SSHS 1)
Tropical Cyclone Warnings/Watches
====================================
A Tropical Storm Warning is in effect for Mexico from Puerto Angel westward to Punta Maldonado
A Tropical Storm Watch is in effect for Mexico from Salina Cruz westward to Puerto Angel and from Punta Maldonado westward to Tecpan de Galeana
Well here was the intensity estimate for the 12z run. Im not really jumping onto the bandwagon that this will now affect land, but if the models continue to shift we may have a problem.
5 THERE IS GREATER UNCERTAINTY WITH THE TRACK FORECAST DEPENDING ON
HOW THE MID-LATITUDE LONGWAVE PATTERN EVOLVES IN RELATION TO WHEN
THE DEPRESSION ACTUALLY BEGINS MOVING WESTWARD. THE GLOBAL MODEL
GUIDANCE IS IN GOOD AGREEMENT SHOWING AN AMPLIFYING TROUGH NEAR 45W
BY DAY 4...WHICH SHOULD BE TOO FAR EAST TO INDUCE SIGNIFICANT
RECURVATURE.
201008221500 12.7 -34.1 (.5N, .3W) = NNW
201008221200 12.2 -33.9 (.3N, .9W) = WNW
201008220600 11.8 -33 (.6N, .7W) = NW
201008220000 11.2 -32.3 (.3N, .5W) = WNW
201008211800 10.8 -31.8
Overall, that's 1.9 north and 2.3 west.
Ha Ha !!.
Everything sounds more authoritative when you give it a TLA.
WITH THE RECENT NORTHWARD MOTION...THE SMOOTHED INITIAL MOTION IS
ROUGHLY 310/10. ONCE THE DEPRESSION ESCAPES THE INFLUENCE OF THE
DISTURBANCE TO ITS NORTHEAST...THE SUBTROPICAL RIDGE CENTERED ALONG
26N SHOULD STEER THE CYCLONE GENERALLY WEST-NORTHWESTWARD WITH
INCREASING FORWARD SPEED THROUGH THE NEXT 72 HOURS.
Based on an experimental intensity probability product at NHC...the depression currently has a 1 in 5 chance of reaching major hurricane status at some point over the next five days.
Edit: I should clarify, because that is a lower chance than I would have expected from the talk on the blog last night.
That just silenced the..."it's moving west" crowd.
LOOKS TOO ME LIKE A DECOUPLING IS OCCURING
Bingo!
SUNDAY 10 AM
NOT SO FAST MY FRIEND ( WITH THE RECURVE)
One of the "dangers" in this years hurricane forecast was the idea that a storm could hit the coast moving west of north further north than normal. By that I mean storms of the genre if Isabel, and Fran, or the 1933 hurricane or the brave attempt by Felix in 1995. This occurs in years when ridges are prone to build further north than normal during the meat of the hurricane season.
I have been hemming and hawing about what is now td 6 for a while and how in spite of the models turning out, we should not write it off. Truth is, the pattern forecasted day 8-12 is ripe for the US coast to get hit.. I say US coast because one has to watch for activity popping up in the gulf out of this.
But the models have been trending west, most disturbingly the Euro which has major hurricane on day 10 moving west northwest near 30 north and 65 west.
Lets keep in mind that years coming off El Ninos, things like this happen The only year in history a major hurricane struck the Old Coast of Florida from the east.. 1964, ( that was Dora) came off the Nino. Isabel came off the Nino.. Felix came off the nino. And it has to do with the same overall climate response that we caught for the hot summer this year.. post nino years are almost always hot in much of the nation.
Overnight assoicated w a trough split....oh yea i see you changed the color of ur jogging hat!!!:)
Now the flip side of this.. is alot of storms like to turn out quickly. Felix in 1995.. Bonnie, which hit the NC coast in 1998 turned out quickly.
I will be in later today to do the videos. A look at the euro ensembles
http://www.ecmwf.int/products/forecasts/d/charts/medium/eps/ensm/essential!MSLP !North%20America!240!pop!od!enfo!plot_ensm_essential!2010082200!!/
show how far west the variance is by the color spread, as several runs have the storm approaching the NC coast day 10...
The 500 mb shows this too
http://www.ecmwf.int/products/forecasts/d/charts/medium/eps/ensm/essential!Geop otential%20at%20500hPa!North%20America!240!pop!od!enfo!plot_ensm_essential!2010 082200!!/
I apologize for not yet having the moveable type so you dont have to copy and paste the links.
This is an intereting test in that my theory that the ky to getting the season to start was to raise pressures in N America is something that is causing people some degree of consternation ( they disagree). Thats fine, but we will see. There is one heck of a cool shot coming into the nation this week before the summer ends boiling for much of the nation and its interesting to note that in previous years that the change in the weather pattern, or greater variances, suddenly would invite storm development. Which makes sense, because give a set of parameters that WERENT PRODUCING STORMS if you change that, it would make sense to go the other way.
One of the "problems" with TD 6 and perhaps the models is there are two systems.. one off to the northeast, and the modeling may be trying to pick out a mid point between the two. In addition , the cloud shot shows a big system coming off Africa this morning behind this:
http://www.nhc.noaa.gov/satellite.shtml
In any case, this is "tugging" at td 6, retarding quicker westward movement so its now on the east side of its thunderstorms, with a look of the opposite kind of shear that we normally look to inhibit storms. However once the energy is bundled, and this is what the euro is seeing and why it develops this into a major hurricane on the 00z run, it will be free to deepen. This usually takes a few days ( again a look in the Pacific at typhoon evolution is what one needs to do. Many systems out there are double and even triple areas of low pressure within a large "envelope" Interestingly enough, Dora, the 64 storm I referenced, started in much the same manner
A look at the wide cloud shot of the atlantic examplifies my comment a few days ago that before a parade, one can "hear" the band coming before you see it. Like magic, 4 systems show up from the southeast Pacific to Africa
http://www.ssd.noaa.gov/goes/east/tatl/avn-l.jpg
The one on the Pacific side of Mexico is not a US concern but is a case of in close development for Mexico and a problem there.
One sees the depression and what may be two systems, and of course the bomb coming off Africa. Also thunderstorms lurk in the northeast gulf. Notice also if you will how waves with virtually no cloudiness before now have some thunderstorms with them, once they approach and then get by 60 west.
For the gulf.. while there is modeling showing development in the northeast gulf, this trough leaving on
I think the NHC will name the system when they have the data to verify Tropical Storm intensity. It's a really good method!
The discussion mentions moderate wind shear. The northward motion must be adding some secret sauce shear.
As of SUN 22 Aug 2010 15:00:02Z
Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico
TROPICAL DEPRESSION 06L.SIX
Active Tropical Warnings in the Northwest Pacific, North Indian Ocean, Central Pacific, Eastern Pacific, or Southern Hemisphere
Current Central/Eastern Pacific Tropical Systems
Tropical STORM 09E.FRANK
2010 Storms
All Active Year
Atlantic
06L.SIX
East Pacific
09E.FRANK
Central Pacific
West Pacific
06W.SIX
Indian Ocean
Southern Hemisphere
I just find it funny. I was telling people that this short term change wouldn't make that much of a difference because of it not being due to a major steering shift but nobody listened to me lol
whatever this needs to bear watching. I see people criticizing the Frances crowd again and I would like to reiterate that I am a member of the Frances crowd not because I think the track will be the same as Frances but I see the same complex synoptic pattern shaping up that led to a quick major shift of the models. Granted the models in 2010 are much better than those in 2004 but it could still happen and I think we are seeing it already. Interesting to see if the 12z gfs continues the trend sw. The GFS likes to swing. It is one of the few models in which the track can change drastically run by run. Just watch it closely
Weaker Trof, Stronger Ridge
Maybe the points I mentioned in post 3058 ??
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