WILL BE PRESENTED HERE…. for the General Public… for the 1st time
You DO have to to register for this events. IF you have a Chesterfield County Public Library card that has a PIN then you can register online at www.library.chesterfield.gov or you can Bon Air Library at 804-320-2461 . If you do NOT have a Chesterfield Library card then call to reserev your spot .
Seating is somewhat limited…
2030 SEPT 18
Well here we are are in the Middle September and suddenly the active Cape Verde season which was roaring from the Middle of August into Labor Day ….has shut down. There has been a lot of talk and speculation about why this change and what is going on… so I thought to take some time this surly Sunday evening and make a analysis and post about this .
This image represents the current satellite images from the far eastern Atlantic and from the central and western Atlantic and Caribbean Basin as of Sunday afternoon. There are a couple of weak features trying to get organized in the far tropical Atlantic… But absolutely nothing of any significance over the Gulf of Mexico the entire Caribbean and the southwestern Atlantic.
It looks more like the middle or late October than it does the middle of September. Lets take a look WHY.
Probably the most overlooked aspect of detecting increases in hurricane activity across the MDR –the main development region of the tropical Atlantic– has to do with the 200 MB vertical velocity progs care of CPC— the climate prediction center. If you go back and look at my earlier posts from the early portion of the middle of August I correctly forecasted a significant increase in Cape verde tropical wave activity that will continue for 25 to 30 days. I did so because I used this particular product which a lot of forecasters for some reason do not seem to use.
Moreover this is a really easy product to use and understand even for the casual weather hobbyists. This image shows us the 200 MB vertical velocities as of August 18. The growing areas show regions of strong vertical upward motion at the high levels of the atmosphere which support tropical wave development in the various tropical regions around the world. This product can also be used during the cold weather seasons but I will get into that another time. The point here is that if you look over Africa and the eastern portions of the tropical Atlantic you will see large areas of GREEN ( rising or UPWARDS atmospheric motion) and some areas of convection which we can see by the BLUEe-ish Blobs. In fact if you notice carefully over the far eastern portions of the tropical north Atlantic there are two distinct blobs that moves off the southwest African Coast. One of these features in fact ended up becoming hurricane IRENE.
The hostile areas –represented by the BROWN squiggly lines are restricted to the Pacific Basin — and represent sinking or downward motion which of course restricts and supresses any thunderstorm development.
Over the next few weeks we can track the movement of the 200 MB Veritcal Velocities — NOTE the BLACK line… And the favorable GREEN areas are rapidly being pushed back into Africa Europe and the Indian Ocean while the hostile BROWN areas become increasingly stronger—- with more of the squiggly lines are showing up on August 25 and August 30. By September 8 these large hostile or negative Veritical Velocities ( SINKING AIR) now cover the entire Atlantic Basin except maybe for the western portions of the Gulf of Mexico. And by September 17 nothing really has changed…. as the entire western and Central Atlantic Basin is experiencing hostile conditions and sinking air as shown by the BROWN squiggly lines.
In addition if we look at the overall large scale or synoptic pattern will see that for over the past seven days or so there has been a large UPPER LEVEL LOW over the entire eastern Atlantic at 500 MB which is dominating that entire region. This feature is also producing very hostile conditions for any sort of tropical wave activity coming off the southwest coast of Africa and try and organize as it crosses were passes south of the Cape Verde islands.
Even more significant is the fact that the overall pattern between New York and North America ensures that this large upper low in the tropical Atlantic Ocean is not going anywhere. It is essentially trapped aned NOT going anywhere.
This is WHY the cape Verde Hurricane has shut down… the dominace of SINKING air and the trapped huge Upper Level Low — ULL- had ended the Cape Verde Hurricane season 10-14 days early.
First let me apologize for not updating the web site with some new information over the past few days. Given how busy it’s been a last two weeks and all the other non weather family issues which have to be dealt with I kind of needed a break for few days. This is even more the case now that we have to deal with tropical storms Maria tropical storm Nate the remains of KATIA and large areas of persistent torrential rainfall across portions of the northeast us in the last 36 hours. And we may even be dealing with the first significant cold air shot of the early autumn season sometime around the middle the month.
This first image I am presenting to show you the official surface map as of Thursday morning.
As you can see hurricane KATIA is due east of the North Carolina Coast and is passing between Bermuda and North Carolina. This is a classic surface Map of a “slot hurricane” and verifies the forecast that I made with regard to this system back on August 30. Although hurricane KATIA is not going to hit the East Coast and has now turned and is beginning her Re-curve out to sea… the close proximity of this slot hurricane has indirectly contributed to the exceptionally heavy rainfall which has affected much of the northeast US and eastern portions of the Middle Atlantic states.
One of the reasons why the rains have been so heavy was that the heavy thunderstorm clusters and bands of heavy showers which developed over eastern Virginia …eastern North Carolina and eastern Maryland continue to move due north into eastern Pennsylvania and central and Eastern New York State. In addition the moisture feed was coming directly from the Gulf stream eastern of Florida and almost from the tropics. This means that there was a lot of Precipitable water and high water vapor content in the atmosphere over the eastern US. And third all this excessively humid moisture laden air would produce extremely heavy rainfall as it moves over higher and higher terrain in northeastern Pennsylvania ( the Poconos) and central and eastern York State— the Adirondack Mountains.
We can see this by taking a look at these images which are enlarged to focus mostly on the eastern US. The upper air pattern shows that the cause of the impact on the jet stream from KATIA as a strong ridge developed over the northwest portions of the northern Atlantic— reaching into far southeastern New England. At the same time with the two large areas of cool High pressure over the Midwest have driven a cold front pressing in and trying to reach the East coast. In addition the deep trough in the jet stream over the eastern third of the nation combined with the close proximity of KATIA off the coast has set up a pronounced and very strong flow of southerly winds from east of Florida all away into New York State and Eastern New England.
NATE… The global or large scale weather models have been all over the place with the early track of tropical storm NATE in the far southern portions of the Gulf of Mexico (an atrea called the bay of Campeche) . The GFS and the Canadian models have been trying to lift the system north the cause of the trough over the Midwest and eastern US. The argument here would be the trough would act as a weakness in the pattern so Nate W would get a chance to come north. Normally that sort of forecast would make sense but the problem is that the base the trough is at 32° N latitude all Nate is still below 20° N latitude. That makes a gap of 12° latitude which is simply too far apart for Midwest trough like this to capture or pull Nate northward. The established rule shows that when the trough base gets thrown about 10° of the tropical cyclone than it begins to affect the overall path.
Over the next two or three days and trough over the Midwest is gonna get progressively weaker and the ridge will build been across the deep south of the Gulf coast states which means that eventually need will have to turn to the west and move into the northern portions of old Mexico and not into southern U.S.
MARIA… All day long she has looked very weak and has probably fallen below tropical storm status from time to time. As I stated several times before the weakening of the tropical storm into a bear minimal system greatly enhances the chance that the system is going to stay due west for prolonged period of time. Not surprisingly this trend has shows up in all of the hurricane models from earlier today. This image shows the track from 18z THURSDAY SEPT 7… and te next one is from 0z SEPT 8. As you can see the models are in very strong agreement that a weak tropical storm Maria is going to swing through the Bahamas before it begins to get a chance to develop. Whether not the system is going to come north into the middle antics states greatly depends upon whether not a strong cold front can arrive in time from the Midwest.
The 12z European model clearly does not think so. The model is very clear that as a tropical storm MARIA moves in to the Bahamas a large and strong cold front with a impressively large cool air mass will drive into the East coast on the 15th of September just as a tropical storm or hurricane Maria and getting pushed harmlessly out to sea. MY view right now is to think that that is the probable solution. There is a chance that tropical storm Maria might get very close to southeastern North Carolina before the cold front arrives. If that were to happen this system could end in making a sharp right turn and be kicked out to sea quite rapidly because it looks like this cold front on the 15th of September means business
1915 EDT 3 SEPT
Omce again the BIG scale or Global Models played flipped flop with MOST of them early Saurday morning showing KATIA a more East or “OTS” …Out to sea track…. while the 12z Global Models bringing Katia MUCH closer to the East coast …from NC to Cape Cod Mass. And on top of that the Hurircane Models have been Just as inconsistent with SOME of them showing a more rapid turn to the NNW then N then NNE (out to sea) but some Hurricane Models show KATIA heading WNW and THREATENING the NC coast.
THREATENING… not hitting the NC or east coast… just looking more Threatening.
Before we begin… keep in mind some RULES… or strong guidelines. FIRST keep in mind that in the days before IRENE hit ALL of the Hurricane models swung WAAAAAAAAY east. This is why so many TV mets… why TWC ( the weather channel) and why NHC kept insisting Irene was NOT going to be a big deal and she was going to pass over or east of Hatteras. However starting about 3 days before IRENE Saturday AUG 27 landfall… the Hurircane Models finally got a clue and shifted well west.
Long story made short… this sort of north and East bias in the Hurricane Models is well know by those who dont have to tow the NHC/ NWS party line. This bias occurs because ALL of the Hurricane Models are based off the GFS model grid. Recall the GFS model awful performace with IRENE in the 84 to 144 hours time frame . It is NOT a coincidence that the GFS was also waaaaay to east with IRENE in the 72 to 144 hour time frame… and the Hurricane models has the same sort of bias.
NEXT once we get within 72 hours of POSSIBLE Landfall with Katia the GFS and Hurricance Models are MUCH better and DO matter.
THIRD RULE… Hurricanes ONLY hit the East coast when the overall pattern FORCES the Hurricane into the coast (IRENE… FLOYD…) or on the coast then inland (ISABEL).
FOURTH Models reflect the atmosphere … NOT the other way around. In other words IF Katia hits the NC outerbansk on say SEPT 9 it is because the pattern supports that NOT because the Nogaps or GFS model says so. REGARDLESS of what ANY Model says if the pattern does not support the idea of KATIA hitting the NC or somewhere on the East coast… the Model is probably wrong.
The weakening of KATIA is important …. since weaker Tropical Cyclones are far more likely to track W or WNW than strong Hurricanes. Here is the 12z SEPT 3 run of the GFS …. VALID for sept 9… and it is much further east than any other Global or large scale model.
Nere is the 12z much improved Nogaps model… with a much further West track for Katia… clssic SLOT Hurricane track. ( the 0z SEPT 3 nogaps actually had Katia making landfall in the northern Middle Atlantic)
12z CMC / Canadian… again showing a clearly much west track — clearly a SLOT HURRICANE ” track
12z SEPT 3 EUROPEAN MODEL … again passing within 100-200 miles of far eastern NC and se of Cape Cod
The 12z vs the 18z Hurricane Models … note the WEST shift
The 12z SEPT 3 European Model ensembles
2145 edt SEPT 1 2011
Hello from WINTERGREEN RESORT in the Shenandoah mountains. Need to get sway from the lies and crap spewing from Dominion Power about how all these work crews are headed for Chester VA. Day after day … the lying gets to be a bit much. OK lets get to it.
The early morning THURSDAY Models all clearly showed KATIA turning out to sea and tracking fair close to Bermuda and NOT being a threat to anyone. The early morning models did so BECAUSE they have Katia too far to the N so the cold front and trough in Je stream have to grab Katia and take her east. And the developing system in the Gulf that will beome Lee was shown to be moving into western and southern TX and NOT bringing heavy / torrential rains to the interior SE CONUS and into EWVA and VA.
Much has changed – EXACTLY as I said they would in Yesterdays –AUG 31 update. ALL the models on this Thursday afternoon has KATIA tracking due West and NOT getting picked up by the SEPT 5 East coast trough that moves out into the western Atlantic ocean. KATIA is STILL a threat and still has to be watched .
This is important because this allows Katia to turn WEST. In fact KATIA all day has moved due West and NOT WNW ….and is still moving WEST right now. In addition the weakening today also favors Katia staying West for a PROLONGED period of time. ( reasoning– weaker Tropical depreessions or Storms do not build or extend higher into the atmosphere so they follow the Low levels winds where was Hurricanes Follow Upper Levels much more so).
12z THURSDAY SEPT 1 GFS RUN… again has KATIA much further North than ANY other model… which is a strong sign the Model’s cold or poleward Bias with Tropical cyclones is working. The GFS has Katia so far North that the SEPT 9-10 cold front HAS to kick her east.
The 12z THURSDAY SEPT 1 EURO has KATIA hundreds of miles to the SW and she turns due west and comes close — within 200 miles of southeast FL. These maps show WHY… essentially IF Katia is that far south at SEPT 4 the East coast trough of SEPT 5 will by pass her and Katia turns WEST. This increases the threat of KATIA making a close pass to the se or middle Atlantic coast.
BUT….odds still favor OTS– Out to sea track. But It could be close.
The 18z GFS has seen reality and has Katia still missing the East coast but passing within 150 miles of Cape Hatteras.
The 12z SEPT 1 day 7.5 Canadian also shows Katia coming due west THEN getting picked up by a MASSIVE east coast trough SEPT 8.
The 12z NOGAPS with its vastly improved 4DVAR package shows this WEST track and also has Katia getting close to FL and the south east US coast. BUT again it also has the massive East coast trough and cold front SEPT 9 kicking her N then NE…
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1800 EDT AUG 31 2011
God I am tired. and NOT happy at all and very stressed. Let get right to it.
The 12z GFS Model AUG 31 screws up the development of LIKELY TC– tropical Cyclone – in the Gulf of Mexico over the long holiday weekend. The Model develops this system — LIKELY to be called “LEE“ by foming it over the central Gulf then moving it into the LA/ DELTA region by SEPT 4. NO other model does this– as you will see. BUT this has MAJOR complications for the Forecast for the ENTIRE EAST COAST.
The GFS Model still brings in pretty good early Autumn Trough in the jet stream / cold front at the surface into the Midwest the East coast BY SEPT 4-5 . That is Unchanged . However because the wretched GFS has LEE or LEE’s remains over the Delta ….the Model pulls LEE and his rains Northeast UP the front and into SC NC VA MD DE PA NJ NY and eastern New England MONDAY SEPT 5.
Since so many TV weather folks and TWC kiss the GFS ass every day… their forecasts are LIKELY to be quite wet for Labor day along the East coast. My forecast is NOT nearly as wet. To be sure there may be SOME showers SEPT 5th with the cold front passage BUT nothing like the heavy rains the 12z AUG 31 GFS is showing.
But beyond that the 12z GFS Model STALLS the SEPT 5 cold front over the Appalachian Mountains from NE GA to western NC western VA WVA western MD western and central PA…. and this right is deluge by the Model in the 6-10 day.
My view ? Bullshit…
The EUROPEAN Model as well as the Canadian and British model– the Ukmet —ALL have LEE over far western Gulf through n SEPT 6. These models either develop LEE into a Hurricane near the TX coast OR move him inland BUT the key point here is that they do NOT bring LEE North into the LA Delta . Since Lee on these models is NJOT there… these Models have NO heavy rains on the East coast SEPT 5.
Got it?
KATIA.. she is cranking along Nicely as you can see here.
A quick Glance at all the data seems to show a recurve out to sea track. But I am NOT yet confident about that … Yet. The Key point remains WHERE will KATIA be SEPTM 4-5 as she moves NJE then N of Puerto Rico.
The 12z european Model and the new 18z Hurricane Models shows KATIA turning back West SEPT 5 -6-7 as the 1st cold front misses here and she neats the central Bahams. The Euro show the 2nd cold front.. a major trough sweeping through the Midwest and East coast SEPT 9-10 will kick her east.
18z HURRICANE MODELS
So far so good. BUT there is a risk that the 2nd cold front COULD be weaker or delayed. IF that happens as Katia is heading West NW she could come very close to the NC eastern coast. I am NOT forecasting that right now But I am NOT ruling it out right now. Sometimes in science we just dont things. Rather than BS you I tell you wnat I know what I dont know and when I will know some more.
