psu_met's Blog

Hurricane Dean
As of 8:35pm, 8/20/07: Winds: 160mph G: 190mph
                                              Movement: W 19mph
                                              Pressure: 914mb (26.98in.)
                                              Position: 210 E of Chetumal, Mexico

Numerous Hurricane/Tropical Storm watches and warnings have been issued.

Hurricane Dean
As of 11pm, 8/19/07: Winds: 145mph G: 180mph
Movement: W 19mph
Pressure: 925mb (27.31in.)
Position: 135 WSW of Kingston, Jamaica

Numerous Hurricane/Tropical Storm watches and warnings have been issued.

Dean's eye passed just to the south of Jamaica and spared the island of CAT 4 winds. However, most of the island will still see CAT 2-3 winds and severe damage is still expected. Add up to 20in. of rain and you have the makings of a lot of destruction. Still, it could have been much worse.

Dean finally has only one eye-wall again around 15 N mi. and the pressure has dropped since 5pm. This could mean another round of intensification is about to begin. Dean will continue racing to the west Monday passing south of the Cayman Islands. The models have shifted even further south today and landfall in Mexico seems likely. As the track shifts south Dean will be over the Yucatan longer and over the Gulf of Mexico less. This will help reduce the intensity when he does hit Mexico.

Didn't think I'd have time for an update today but since RobBen insisted...LOL

Hurricane Dean
As of 2am, 8/19/07: Winds: 145mph G: 180mph
                                       Movement: WNW 17mph
                                       Pressure: 921mb (27.19in.)
                                       Position: 295 ESE of Kingston, Jamaica

Numerous Hurricane/Tropical Storm warnings have been issued.

Dean's current structure is a little in flux. A recent Air Force Hurricane Hunter plane spotted two eye walls and only measured the top winds at 130mph. The NHC kept Dean at 145mph in case the plane didn't sample the strongest winds and because the pressure keeps dropping. If Dean completes the eye-wall replacement soon and the pressure doesn't rise by then, I think the winds will quickly come back up and Dean could reach CAT 5. A pressure below 920mb is usually the benchmark for a CAT 5 storm.

The computer models are coming into better agreement and confidence in the forecast track is increasing. Dean will pass very near or over Jamaica tomorrow and could be the worst hurricane to affect them since 1832. Right now they are just praying that at the last minute Dean might wobble a bit and just miss hitting the island directly. This is what happened with Ivan in 2004. In about 48hrs. Dean will be making landfall on the Yucatan, probably as a CAT 4/5. It looks like Dean's second landfall will now be south of the border in Mexico. Even the GFDL is now predicting this, as yesterday is showed a landfall in central LA.

Just have time for a quick update today. I'll try an get an update out tomorrow but between wiffle ball and work...

Hurricane Dean
As of 11pm, 8/17/07: Winds: 145mph G: 180mph
Movement: W 18mph
Pressure: 937 mb (27.66in.)
Position: 755 ESE of Kingston, Jamaica

Numerous Hurricane/Tropical Storm watches and warning have been issued.

Dean is now a very dangerous CAT 4 major hurricane. I think he will reach CAT 5 unless an eye-wall replacement cycle occurs. We are not able to forecast these until they have already begun. Confidence is high in the track for the next 2 days as Dean continues racing west near Jamaica and the Cayman Islands. After that 3 of the 4 main computer models take Dean over the Yucatan, into the Gulf of Mexico, and then have a second landfall near the Texas/Mexico border. The one outlier is the GFDL which takes Dean over extreme western Cuba and makes a second landfall in LA. While this model can't be ruled out (and we'll continue to watch to see if the other models shift this way at all), the best bet is to go with the consensus.

At 11pm, the recent model trends are taking Dean farther south into Mexico.  Either way the one thing that we are confident in is that Jamaica is on pace to get slammed by a CAT 4/5 hurricane.  Let's hope Dean can pull an Ivan and at the last minute just miss hitting the island directly.

Hurricane Dean
As of 11pm, 8/16/07: Winds: 95mph G: 120mph
Movement: W 25mph
Pressure: 976 mb (28.81in.)
Position: 160 ESE of Martinique

Numerous Hurricane/Tropical Storm watches and warning have been issued for the Lesser Antilles. A Tropical Storm Warning is in effect for the US Virgin Islands and Puerto Rico.  A Tropical Storm Watch is now in effect for portions of the Dominican Republic.

Overview: Hurricane Dean is continuing to plow toward the Lesser Antilles and has now developed an eye. Wind Shear is down to 5 knots and the only thing slowing Dean from rapid intensification is dry air surrounding the storm. However, Dean is well on it's way to becoming a major hurricane.
Track Forecast: The computer models are very similar to yesterday's runs. They bring Dean through the Caribbean and into the Yucatan Peninsula. The GFDL is the outlier pulling Dean across the extreme western tip of Cuba and into the Gulf of Mexico.
Intensity Forecast: Steady strengthening should continue as Dean pushes westward. The western Caribbean has a very deep layer of warm water, which could really make him a very dangerous storm. Cat 4 is likely and CAT 5 status is not out the question. Of course this is very hard to predict, especially when a well-organized Dean starts going through eye-wall replacement cycles.
My Thoughts: I think Dean will cross the Lesser Antilles as a CAT 2 hurricane. On the islands where Dean's center crosses, severe wind damage may occur. Due to his very quick speed, 2-7in. of rain may fall, but nothing extreme. Wind damage is the biggest concern for the islands. After that the Yucatan Peninsula and the Texas/Mexico border continue to look like the best bets for landfall. We'll have to continue watching the models though. If some others move farther north like the GFDL then an adjustment to the forecast will be needed. A Hurricane Hunter mission into Dean will be flown this afternoon. This will give us a better idea of how strong he really is.

Tropical Depression Erin: Tropical Depression Erin made landfall early this morning over South Texas. She never strengthened above a 40mph TS and the last advisory on her was issued at 11am. Flooding is still a concern in parts of Texas though.

2pm Update: The Hurricane Hunter plane just reached Dean. In it's first pass through the storm they measured 90mph winds and estimated the pressure at 970mb, 7mb lower then 11am's estimate. Considering they most likely didn't hit the strongest part of the storm in their first pass though and with the lower pressure, I expect to see the 5pm advisory upgrade Dean to a CAT 2.

5pm Update: Dean is now indeed a CAT 2 hurricane. An eye-wall is still forming but due to dry air it has a gap on the the west side. Once it is completely formed expect him to reach CAT 3 status. Dean will cross the Lesser Antilles late tomorrow morning or early afternoon.

11pm Update: The appearance of Dean has deteriorated over the past several hours.  There is no longer an eye visible on satellite but don't let this fool you.  Dean will still continue to strengthen over the next couple of days.  He will be crossing the Lesser Antilles in 6-12hrs.  There are now signs that upper air conditions could be a little less favorable when Dean reaches the W Caribbean.  We'll see what the models show overnight and adjust the forecast as needed.  Either way Dean will still be a very dangerous hurricane racing through the Caribbean.

Tropical Storm Dean
As of 11pm, 8/15/07: Winds: 70mph G: 85mph
Movement: W 23mph
Pressure: 991 mb (29.25in.)
Position: 625 E of Barbados

Overview: TS Dean is looking healthier by the hour as it continues to move west toward the Lesser Antilles. Wind Shear is down to 10 knots and the only thing stopping Dean from rapidly intensifying is dry air surrounding the storm. Due to the lower wind shear Dean is much more round today and an eye could start to develop soon.
Track Forecast: All of the computer models bring Dean through the Lesser Antilles as the trough moving off US East Coast is weaker than earlier thought. This means that the threat to the Mid-Atlantic and New England is now very small. As Dean enters the Carribbean high pressure will move in behind the trough pushing Dean west, not north. Some computer models bring Dean into Central Mexico, others over Jamaica and into the Gulf of Mexico. Depending on how strong the ridge of high pressure is the east coast of Florida still needs to keep an eye on Dean.
Intensity Forecast: Nothing but dry air stands in the way of a strengthening Dean. By the time he enters the Carribbean, the dry air will be replaced by moist air, further fueling the storm. The NHC has Dean as a hurricane by the time it crosses the Lesser Antilles and a major hurricane in 5 days. The only thing preventing this, would be if Dean is closer to land than presently forecast. The new HWRF model continues to show Dean as a strong CAT 4 over Jamacia.
My Thoughts: Looking at the latest satellite images I think Dean has a chance of becoming a hurricane later tonight and definitely by tomorrow. The Lesser Antilles are just a sitting duck, waiting for Dean. I continue to think the odds are greatest that Dean will enter the Gulf of Mexico and make landfall somewhere along the Gulf Coast. There is still plenty of time left to adjust the forecast. (don't you just the love the decisiveness of weather forecasting LOL)

Tropical Storm Erin:
As of 11pm, 8/15/07 Winds: 40mph G: 50mph
Movement: WNW 13mph
Pressure: 1004mb (29.64in.)
Position: 140 SE of Corpus Christi, TX

A Tropical Storm Warning is in effect for the Texas cost from San Luis Pass south to Brownsville.
Overview: Tropical Storm Erin formed over the Gulf of Mexico this morning around 11:30am. Wind Shear is only 5-10 knots over Erin, and she is in an ideal condition for rapid development. Luckily, she has only 24 hrs before landfall and will probably due so tomorrow as a 55mph TS. The biggest impact will be 3-5in of rain with isolated amounts up to 8in.

Tropical Storm Flossie: Flossie (50mph) spared the Island of Hawaii as she quickly fell apart overnight. She went from a CAT 2 hurricane to a TS in 6hrs. Radar estimates show only a coupe of inches of rain fell, far less than the 10+ originally expected. The highest wind gust I could find was 48mph along the southern coast. Thankfully for them this turned out to be a near miss.

11pm Update:  Dean:  Hurricane watches has now been posted for the Lesser Antilles.  Dean is very near hurricane strength and it looks like an eye may be beginning to form.  The models are in very good agreement for the next 3 days, moving Dean into the Caribbean.  After day 3, they diverge a little, but generally move Dean into the NW Caribbean btwn Cuba and the Yucatan Peninsula.  He should continue to steadily strengthen and I think he will cross the Lesser Antilles as a CAT 2.  By day 5 Dean could be a very impressive storm.  An Air Force Reserve hurricane hunter aircraft will investigate Dean tomorrow afternoon.
Erin:  She has not strengthened since this afternoon, but may due so slightly by landfall.  Landfall should be near Corpus Christi around 12 noon tomorrow.  The biggest impact will be 3-5in of rain with isolated amounts up to 8in.  Storm Surge of 2-3ft may occur right at the point of landfall. 

Full update tomorrow afternoon.

Just a quick update on the tropics below.  For more details see my blog post from earlier today.

Tropical Storm Dean
As of 11pm 8/14/07  Winds:  50mph  G:  65mph
                                     Movement:  W 18mph
                                     Pressure:  1000mb (29.52in.)
                                     Position:  1295 W of Lesser Antilles
This evening Dean looks less ragged due to a new burst of convection.  The winds at 50mph might be a little conservative.  The models are in good agreement in bringing Dean across the Lesser Antilles in about 3 days but diverge after that.  The recent trends have shifted Dean farther south since yesterday.  The models bring Dean to hurricane strength in the next 36-48 hrs.

Tropical Depression #5
As of 11pm 8/14/07  Winds:  30mph  G:  40mph
                                     Movement:  NW 10mph
                                     Pressure:  1006mb (29.70in.)
                                     Position:  425 ESE of Brownsville, TX
At 11pm TD 5 formed in the Gulf of Mexico.  A Tropical Storm Watch has been issued for the Texas coast from Freeport south to Rio San Fernando in Mexico.  The depression has a chance to become a TS before making landfall near the Texas/Mexico border in about 36-48 hrs.  The biggest threat is rain in the amount of 3-5in. with isolated amounts up to 8in.

Hurricane Flossie
Flossie (95mph) is currently 155 miles south of Hilo, HI.  A Tropical Storm Warning and Hurricane Watch are still in effect on the Big Island.  They should see wind gusts to 50mph, up to 10in of rain, and waves heights of 20-25 ft.

Tropical Storm Dean
As of 11am, 8/14/07: Winds: 40mph G: 50mph
Movement: W 23mph
Pressure: 1004 mb (29.64in.)
Position: 1430 E of Lesser Antilles

Overview: TD #4 has improved only slightly since yesterday, but enough to be upgraded to Tropical Storm Dean.  The TS should continue to move in a general westward direction for the next fews days after which a curve to the north could occur. It is moving very fast at this hour but should slow down gradually over the next few days.  Wind Shear is still about 15-20 knots.
Track Forecast:  Several Models today develop Dean into a hurricane that will approach the N Lesser Antilles by Friday night or Saturday.  Two models don't develop Dean at all.  Given the current conditions this seems very unlikely to occur and these 2 models are pretty much being ignored.  In about 3 days a trough will move off the US East Coast.  If the trough is weak Dean will plow into the Gulf of Mexico.  If strong enough this might pull the storm further north than currently forecast.  If the storm does get pulled north one of two things are likely to happen. 1.) A ridge of high pressure moves in forcing Dean into Florida.  2.) An upper-lever low forms off the SE coast forcing Dean even farther north and threatening New England or the Mid-Atlantic Coast.  It is still way to early to predict which of these has the best chance to occur.
Intensity Forecast:  Most of the models don't show much strengthening until Wednesday.  After Wednesday steady strengthening is expected into a hurricane and possibly a major hurricane.  One model has Dean as a CAT 4 or 5 by the time it approaches Puerto Rico.  This is mostly likely over done but a CAT 3 major hurricane could be possible by that time (5 days from now).

My Thoughts:  I think Dean will hit the northern Lesser Antilles as a minimal hurricane around Friday night.  After that Dean will probably continue to strengthen but how much and where it goes are still big questions.  I know that is not necessarily what people want to hear but I'm just being honest.  After 3 days the models are not sure how the trough will affect Dean.

Invest 91L:  The disturbance in the Gulf of Mexico this afternoon has gotten better organized since yesterday.  Wind Shear is only 5-10 knots currently.  An Air Force Reserve reconnassiance plane should be investigating the system as I write this (1pm).  There is a decent chance that the system may already by a depression.  The disturbance will make landfall along the Texas/Mexico border tomorrow afternoon.  It could be a minimal TS.  The biggest impact will be heavy rain over an area that doesn't need any.  There could be serious flooding.  A TS watch or warning may need to be issued with little advance notice.

Hurricane Flossie: Flossie (110mph)  should pass 70-100 miles south of the Big Island of Hawaii today.  A tropical storm warning and hurricane watch remain in effect.  Tropical storm force winds extend out 150 miles from the center so some wind damage can be expected.  Rainfall amounts of 10-15 in. is the biggest concern.  Hawaii is in a drought and could use some rain, but obviously not this much, this fast.

TD #4
As of 11pm, 8/13/07: Winds: 35mph G: 45mph
Movement: W 19mph
Pressure: 1005 mb (29.67in.)
Position: 740 WSW of southern Cape Verde Islands

Forecast: The TD should continue to move in a general westward direction for the next fews days after which a curve to the north could occur. Wind Shear is about 15 knots down from 20 yesterday. This should continue to decrease to about 10 knots by Wednesday. SSTs (Sea Surface Temperatures) will gradually increase as the storms moves west. Between the lower shear and warmer water strengthening is likely, however not very rapidly. By the time the depression approaches the Lesser Antilles, there exists the chance of more rapid intensification.
Models: The models are not in very good agreement at this hour which leads to lots of uncertainty regarding both the track and intensity of TD 4. Several models develop the storm and bring it across the Antilles at different intensities. A couple others don't develop the storm at all. One of the models has it approaching the NJ coast by Aug 25th :-)
Longer Range: There are several possible outcomes for TD 4 at this time. The only one that doesn't seem likely at this time is the best possible outcome (storm curves harmlessly out to sea). It is possible that the storm will never get it's act together and never strenghtren above a minimal TS. If it does develop it will be influenced by a trough moving off the US East Coast. The strength of this trough will determine how far north the storm will travel. The stronger the trough the farther north. A stronger trough could mean a landfall along the East Coast, a weaker trough means a landfall along the Gulf Coast.
My Thoughts: The pattern across the Eastern US recently has been for weak troughs to quickly move off the coast. Due to this and the current model runs my best guess would be for TD 4 to continue to grow stronger reaching the Lesser Antilles as a minimal hurricane. The trough moving off the coast will only have a minimal impact on the storm as it pushes into the Gulf Coast, possibly as a major hurricane. It really is to early though to forecast the track that far out with any certainly and almost impossible to forecast the intensity.

Invest 91L: There is a disturbance moving into the Gulf of Mexico this afternoon that bears some watching. It should move to the west and make lanfall near the Mexico/Texas border sometime Wednesday or early Thursday. Conditions should improve and allow for some slow development before landfall. Even with the best conditions there is only time for the disturbance to reach minimal tropical storm strength.

Hurricane Flossie: Flossie (140mph) refuses to weaken despite cool waters and increasing wind shear. A Hurricane Watch has been issued for the Big Island of Hawaii. The hurricane is likely to pass 50-100 miles south of the island tomorrow afternoon with the biggest concern being flooding rains with some minimal wind damage. Storm surge shouldn't be a factor, but high waves are already beginning to occur.

5pm Update: The new advisory keeps TD 4 at 35mph moving W at 19mph. The official forecast track has been shifted slightly to the north, but remains highly uncertain after 2-3 days. Hurricane Flossie has finally started to weaken (125mph) but is still expected to pass Hawaii as a moderate hurricane to the south. A Tropical Storm Warning in addition to the Hurricane Watch is now in effect for the Big Island.

11pm Update: TD 4 has not changed much since this morning and remains a depression. The system at this hour looks elongated from the east-west most likely due to moderate shear. The forecast track essentially remains unchanged from the 5pm advisory. The disturbance in the Gulf (invest 91L) remains disorganized but could become a depression as early as tomorrow as upper air conditions become more favorable. A Air Force Reserve reconnassiance plane may investigate the storm tomorrow afternoon if needed. Hurricane Flossie continues to slowly weaken (120mph CAT 3) but still poses a threat to Hawaii. Some parts of the Big Island could see over 10in. of rain with 5-10in. common. A tropical storm warning and hurricane watch remain in effect for the Big Island.

Will try and get an update out tomorrow afternoon before I go to work.

Here's my call for the approaching nor'easter:

Expect some rain and wind over the next two days!!!!!!!!!!!!!!!!!!!

NO SNOW!!!!!!!!!!!!!!