Over the past few weeks, I wrote about the tropics being on the verge of becoming quite active.  The models that were indicating a flurry of activity across the Tropical Atlantic two weeks ago were quite right.   Fortunately, Hurricane Danielle did turn northward to the east of the Caribbean Sea without affecting any land areas.  But now we have Earl, Fiona and the newly-named Tropical Depression Nine (soon to be “Gaston”) to worry about.  First, let’s discuss Hurricane Earl.  Our latest track is shown below.

Hurricane Earl

Currently, Earl is a Category 3 hurricane with winds of between 125 mph.  Although Earl is forecast to make a northerly turn just before reaching the coast of North Carolina tomorrow evening, there is some degree of uncertainty as to the timing of the turn.  The approaching cold front that is forecast to pick up Earl and turn it to the north could arrive a few hours too late, or Earl could speed up a little over the next 24 hours.  Either scenario could result in a major hurricane impact along the Mid Atlantic Coast tomorrow night.  So even though the forecast keeps hurricane force winds just offshore, residents from North Carolina to coastal Maine should be prepared for hurricane conditions from Thursday night through early Saturday morning.

To the southeast of Earl is Tropical Storm Fiona.  The good news for the folks across the northeast Caribbean which just experienced Earl is that Fiona is much weaker, and most of Fiona’s heavy squalls are passing just northeast of the islands.  The future of Fiona is quite uncertain.  Our forecast has it slowing and weakening due to strong shear just southwest of Bermuda in 3-4 days.  However, high pressure could build to its north over the coming weekend.  This could help to reduce the wind shear and allow Fiona to reach hurricane strength as it drifts slowly to the west.   We still think that Fiona would probably not be a threat to the U.S. East Coast if this happens, though.

Tropical Storm Fiona

And if that’s not enough, there is the newly-formed Tropical Depression Nine - soon to become Tropical Storm Gaston in the central Tropical Atlantic.   What’s strange about this depression is that most of the models don’t appear to even see that it’s there. I can assure you, it’s there!   But there is some question as to whether or not wind shear and dry air in its path will allow it to reach hurricane strength.   We think that by the time it nears the northeast Caribbean next Tuesday or Wednesday it could very well be a hurricane.  It’s way to early to even speculate on whether or not it will become a threat to the Gulf of Mexico or the U.S. East Coast, however.

Tropical Depression Nine

Well, that should probably wrap up development chances for this week, right?  Well, maybe you should take a look just a little east of Tropical Depression Nine at what’s about to roll off the coast of Africa.  Take a look at the image below.  Behind tropical depression are 4 more very strong tropical waves all lined up across Africa.   All are moving westward toward the Tropical Atlantic.    At least one or two of these strong waves could well be developing over the next 5-10 days.  And with high pressure building across the North Atlantic, there may be a good chance that one of these systems could impact the Caribbean Sea and possibly reach the Gulf of Mexico.

I mentioned in previous posts that the analog seasons for 2010 all indicated a somewhat late start.  That certainly looks to be the case.   And with a moderate to strong La Nina in place in the Pacific and very warm water all across the Atlantic Basin, I think that the 2010 season will last well into November this year.  Don’t expect things to shut down rapidly after early October as they did in 2009.

Last week I discussed several indicators that pointed to the likely development of several systems across the Tropical Atlantic this week.  Just as the models were predicting, a very strong disturbance over Africa a week ago developed into Hurricane Danielle yesterday.   To the east of Danielle just south of the Cape Verde Islands is a very strong Disturbance 41, which is what I think will become the next named storm of the season, Earl, later today or on Wednesday.

The good news is that it appears both Danielle and Earl-to-be (Disturbance 41) should turn to the north prior to reaching the eastern Caribbean Sea, which is something we were forecasting prior to the start of the 2010 season. The weaker Bermuda High this season would probably result in a number of storms that form in the far eastern Atlantic staying safely out to sea.  It will be the storms that form farther west, in the Caribbean Sea, east of the Bahamas or in the Gulf of Mexico that will be the greater threats to land in 2010.

That’s why we need to keep a close eye on the weakest feature on the map above, Disturbance 37.   The disturbance consists of a westward moving tropical wave that has limited thunderstorm activity associated with it.  But it is in a region where rapid development almost always results in an impact with very little warning.   I do not see much model support for development, but I think that this disturbance could get a little better organized when it moves across the southwestern Gulf on Wednesday and Thursday.  I can’t rule out a tropical depression or a weak tropical storm before it moves inland into northern Mexico on Thursday or Friday.  Most likely, though, it will remain a disturbance or a weak area of low pressure that brings heavy squalls to the southwestern Gulf of Mexico and heavy rain into northeastern Mexico later this week.

In the long range, today’s computer models are beginning to focus on yet another strong wave still over Africa as the next named storm after Earl.   In fact,  one model yesterday forecast this African wave to reach the Gulf of Mexico as a hurricane by around September 7th.  That’s quite far out to be believed, but it does indicate that the Atlantic Basin may finally be  exhibiting characteristics of the very active hurricane season which was predicted.  I think that the month of September will be very active, with several major threats to the Caribbean and the U.S.   Above-normal activity may persist through October and into November this season.

It’s now the 18^th of August, a few weeks past the typical date that activity really ramps up across the Atlantic Basin, and there are no named storms to be found.   Are all of the forecasts for a very active season going to bust?  I don’t think so, and I’ll attempt to explain why.   First of all, let’s look at our best analog year for comparing to the current setup across the tropics - 1998.   So far, 2010 is progressing very much like 1998 as far as the current La Niña conditions across the Pacific as well as the general atmospheric flow patterns across the Atlantic Basin.  In fact, 1998 is nearly a dead ringer for what we’re seeing across the tropics right now.

In 1998, there were 14 named storms, 10 of which were hurricanes.  Note that it’s a coincidence that the 2010 list of names is mostly the same list that was used in 1998, twelve years ago.  There are 6 years of Atlantic Basin names that rotate each season.   The first hurricane of 1998, Category 3 Bonnie with 115 mph winds, did not form until August 19^th.   It struck the coast of North Carolina late on August 26^th. In 2010, the first hurricane of the season, Category 2 Alex, formed in late June.    The second hurricane of the 1998 season, Danielle, did not form until August 24^th.  But after then, the floodgates were opened and the hurricanes kept coming through November.   Category 2 Georges struck Mississippi.  Category 5 Mitch killed tens of thousands of people in Central America in late October.  Hurricane Nicole formed on the 24^th of November and lasted until the 2^nd of December.

The image above is a snapshot of the activity across the Atlantic Basin on September 26^th of 1998.  There were actually four hurricanes active at the same time.  That date is still over five weeks away, plenty of time for quite a bit of development.  And we’re seeing strong signals that the tropics are about to come alive. 

As I mentioned in last week’s blog posting, the season typically ramps up quite quickly in early August.  That didn’t happen (yet) this August.  The reason for the delayed start this August is that there was a burst of dry, stable air that flowed off the west coast of Africa in late July.  This resulted in a stabilizing of the atmosphere across the deep tropics.  Hurricanes can’t develop in a stable environment.  The graphic below clearly illustrates the drop in instability that occurred in late July (blue line).  But just in the past few days, instability is rising sharply, up to the “normal” line.  I suspect it’s going to rise to above normal levels by next week.  The result may be a burst of development over the next few weeks.

For the past week, most of the global computer models have been forecasting the development of between 2 and 4 named storms starting this coming weekend.  Below is a one-week forecast from the American “GFS” model.  The map is valid Wednesday, August 25^th.   Note what appears to be a tropical storm forming off the U.S. East Coast early next week and what looks like a strong hurricane impacting the northeast Caribbean.  A weaker (developing?) low is indicated east of the Caribbean on this date.   And it’s not just the American model forecasting such development.  The European and Canadian models are also quite bullish on significant development over the next week or two.

Finally, let’s take a look at the sea surface temperatures across the main development region (MDR) that extends from the eastern Caribbean to near the west coast of Africa.  The graphic below indicates that temperatures are at record levels, even higher than 2005 when 28 named storms developed.  So there is plenty of heat available for intensification once development occurs.  There is so much heat content available that I’d be surprised if we didn’t see at least one Category 5 hurricane develop in the coming months.

The bottom line is that our analog seasons suggested a late start to the real action.  And the signals we’re seeing out there across the tropics today indicate that the tropics are about to come alive with development.  Will the named storms total the 17 that we predicted earlier this month?  Possibly.   But with the later start than we expected, that total may be closer to 15 or 16 named storms.  Just remember, it’s not how many that form that counts, it’s where they strike that makes all the difference.   The steering flow we’re seeing still indicates a high impact threat to the central to northeast Gulf Coast and the southeast U.S. Coast.

In my last blog entry, I wrote about the rapid ramp-up in activity that typically occurs the first week or two of August.  It now appears that the next named storm of the 2010 season is taking shape in the eastern Gulf of Mexico.   A feature that we identified as Tropical Disturbance 34 last weekend is steadily becoming better organized just west of the lower Florida Peninsula.

Although a recon plane is scheduled to investigate the disturbance this afternoon, I really don’t think that they’ll be able to find out anything that we don’t already know.  The disturbance is located in an area that has plenty of good surface observation stations.  These stations indicate that there is no question it has a low-level circulation center, a requirement for classification as a tropical depression.  Winds around the low center are in the 20-25 mph range, too low for tropical storm strength.  Thunderstorms around the low center remain a bit weak and are situated mostly south of the center, a sign of somewhat unfavorable winds aloft.  But recent satellite imagery does indicate that upper-level conditions are steadily becoming more favorable for development.

The bottom line is that though this disturbance may not fully meet all of the criteria for classification as a tropical depression at present, we think that it’s well on its way to becoming a depression by tonight and the fourth named storm of the 2010 hurricane season tomorrow.  Its name would be Danielle.   The next questions would be where will Danielle most likely track and how strong could it get.

Below is the latest model  guidance for the disturbance.  Models have been in very good agreement for days now that the disturbance would track generally toward southeast Louisiana.  We agree, and or track (in dark blue) is similar to most of the guidance though a bit south of guidance to start out with and a little east of guidance across eastern Louisiana.  It’s a tough call as to exactly where it might move ashore.  The current slow westward movement could even increase the risk that it might move inland toward the central or even southwest Louisiana coast.

As for its intensity at landfall, model guidance appears centered around maximum sustained winds of between 50 and 60 mph at landfall.  Basically, a moderate tropical storm.    I am concerned, though, that conditions may become quite favorable for strengthening in the last 12 hours before it reaches the Louisiana coast on Thursday.  In that case, intensification could be quite rapid as it’s making landfall.  So it’s not out of the question that it could reach hurricane strength as it approaches the coast.  I estimate those chances at roughly 30%.

The good news is that with a limited region of moisture and favorable winds aloft, the storm is not likely to be very large.   It should be average or a little below average in terms of its size as a tropical storm. If it reaches hurricane intensity, then its size would be smaller than average.  More than likely, any hurricane force winds would be confined to squalls over the water rather than inland over southeast Louisiana.

Ah, I see that the recon plane just left Keesler AFB in Biloxi a few minutes ago (11:08AM CDT).   With only a short distance to travel to get to the disturbance, it won’t be long before the plane is near the center.

As you can see on the frequency diagram below, the first week of August typically marks the real beginning to the hurricane season. About 90-95% of all named storms occur between August 1^st and October 15^th in a typical season.  The chart below actually shows the frequency distribution of tropical depressions, tropical storms, hurricanes and major hurricanes.  The very peak of the season is generally considered to be the 10^th of September.    And like clockwork, the 2010 season seems to be slowly coming alive this week.

Just a few days ago, Tropical Storm Colin formed east of the Caribbean Sea.  Although I think that Colin may have been named a little too quickly (later data indicated that Colin lacked a well-defined circulation center), it still indicates that the tropics are becoming more active.    But just as quickly as Colin developed, it ran into wind shear associated with an upper-level low which tore the newly-formed storm apart.  The same thing happened to Bonnie a few weeks ago, if you recall.  This does indicate that there are still some pockets of strong wind shear across the tropics, something that’s not uncommon for early August.

Colin may be down, but I’m not sure he’s “out” just yet.  Surprisingly, many of the models still indicate that Colin will get past the shear zone produced by the upper-level low and regenerate into a tropical storm.  The hurricane-specific models even take Colin to hurricane strength in 2-3 days as it passes a few hundred miles off the East U.S. Coast.  That’s certainly possible, but it does look like Colin’s strong winds would not impact any land areas.

In the Caribbean, there’s a disturbance we’ve identified as Disturbance 31.  It’s actually a tropical wave that we have been tracking since it moved off the west coast of Africa about 12 days ago.   Many tropical waves weaken after emerging off the west coast of Africa in the early part of the season, only to strengthen once they reach the Caribbean.  Really, it’s just the associated thunderstorms that weaken, not the waves themselves.   Disturbance 31 is certainly looking more impressive today as it moves westward at 15-20 mph.  There may be a 40% chance that the disturbance will become at least a tropical storm before it reaches the Yucatan Peninsula on Friday night or Saturday morning.  Some models even take it to hurricane strength by then, but those models already assume it’s a tropical depression, something it’s not.

The good news for those across the northern Gulf of Mexico is that the same high pressure that’s been producing the above-normal temperatures should remain in place for at least another week.  That means any developing storm in the western Caribbean Sea would be driven westward toward Mexico rather than turn toward the northern Gulf of Mexico.  Therefore, we think that Disturbance 31 will probably remain to the south of 23N-24N latitude, whether or not it develops.

Finally, out in the far eastern Atlantic is Disturbance 32.   The disturbance certainly has a good bit of energy associated with it, though it is somewhat lacking as far as its organization.   A number of computer models indicate that this disturbance will develop into a tropical storm in 4-5 days as it passes well north of the eastern Caribbean.  Both the American GFS model and the European ECMWF model take the system safely north and east of the Caribbean and out to sea into the open Atlantic next week.  As far north as the disturbance is now, I’d say that such a track out to sea is most likely.

All in all, the various computer models which extend out to 10-15 days are showing an increase in development over the coming weeks, something that I’d expect to see in early August.  Over the last 15 years, we’ve witnessed about 1 named storm per week forming in the month of August, and I don’t think that this August will be much different.  Look for activity to gradually ramp up over the next week or two as wind shear slowly declines.  Longer range signals are pointing to a very active September, but that’s the subject of my next update here.

Early last week I discussed the potential for the development of Tropical Storm Bonnie later in the week.  Long-range models correctly predicted the increasing thunderstorm activity across the tropics the second and third week of July, which did lead to the development of Tropical Storm Bonnie.  Fortunately, Bonnie formed very near a large upper-level low pressure system which helped to keep its intensity in check. So the models did a fair job in at least identifying that the conditions would be suitable for development last week.

We can often follow pulses of increased tropical activity starting in the Indian Ocean, progressing eastward across the West Pacific and eventually reaching all the way to the Atlantic Basin.  Computer models are getting better at predicting these periods of increased likelihood of development. The current models are predicting that drier, sinking air is now moving into the Atlantic Basin.

Figure 1: Sinking Air (red-brown) and Rising Air (green) Through 8/14

Figure 1 is from the climate forecast system website (http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml).  It depicts areas of sinking air (reddish-brown) and rising air (green) in 5 day intervals starting on July 25th.  Note the deep reddish-brown area of sinking air forecast to dominate much of the Atlantic Basin over the next week.  The sinking air moves out after about the first week of August and is replaced by the green color of rising air by the 9th of August.  More rising air means increased thunderstorms across the Atlantic Basin, and an increasing chance of tropical development.

Figure 2, below, from the Santa Barbara, CA Research Group (http://www.icess.ucsb.edu/asr/mjo_forecasts.htm) represents another forecast for the next few weeks. This one predicts what’s called “Outgoing Long-wave Radiation” or “OLR” for short.  It’s a little complex to explain fully here, but OLR is greatest when thunderstorm activity is less across the tropics.  More thunderstorms, on the other hand, means decreased OLR.  The blue areas in Figure 2 represent decreased OLR, meaning increasing thunderstorms.  The reverse is true for the areas of greens and yellow.

Figure 2: Outgoing Long-wave Radiation

Figure 2 is also indicating that rising air, meaning increased thunderstorms, moves into the Gulf of Mexico and the Caribbean Sea after about the 4th of August, peaking the second and third week of August.  While a prediction of increased thunderstorm activity alone doesn’t mean an increased chance of tropical development, wind shear is also forecast to diminish over the next few weeks.  The combination of lower wind shear and increased thunderstorm activity is pointing toward a burst of tropical cyclone development starting around the 10th of August.

This will likely be the real start to the 2010 hurricane season. After about August 10th, we may experience very few days without at least one active named storm in the Atlantic Basin through about mid October.   Use the next 5-10 days to complete any remaining hurricane preparations, as I don’t think we’ll be seeing such a prolonged break in activity until mid October.

Last week I wrote about hurricane climatology and the fact that the tropics typically come alive right around the end of July.  I also mentioned that models were indicating increased thunderstorm activity across the Caribbean Sea and southwest Atlantic for this week, and that we may well be looking at possible tropical storm development by about now.  And as it turns out, we are seeing what quite possibly could be Tropical Storm Bonnie in its formative stages near the northeast Caribbean today.  Here’s a satellite shot showing what we’re identifying as Disturbance 22 and the location where we think that a low center could be forming.

Satellite Image of Disturbance 22 Taken 12:30PM CDT July 20th

One thing that’s apparent on the satellite image above is that thunderstorms are on the increase and there is some curvature or banding present.  That’s a sign of a developing circulation center.  Currently, wind shear across the disturbance is a bit on the high side, making its appearance on satellite even more impressive.  But that wind shear should be steadily diminishing over the next 48 hours, leaving a favorable environment for development.  With that in mind we’re now estimating that the chances of Disturbance 22 developing into the second tropical storm of the season to be 60%.  And there may be a good chance that if it does become a tropical storm that it could reach hurricane strength in 3-4 days.  But where will it go?

Past July Storms Which Passed Within 100 Miles of Projected Track of Disturbance 22

The graphic above represents all past July tropical storms and hurricanes which passed within 100 miles of the projected track of the disturbance.  There weren’t very many such storms, but climatology does suggest that Florida is the typical target of storms in this region.  Now let’s examine where current model guidance is projecting the disturbance/potential storm to track.

Model Guidance for Disturbance 22

As one can see from the latest computer model plots above, there is quite good agreement among the better models in a track toward southeastern Florida.  Now, just because there is good model consensus doesn’t always mean that they’re right.  In this case, though, I think that the models have a fairly good handle on things.  The biggest uncertainty is just when the disturbance will develop.  And where it develops will ultimately play a large role in where it tracks.  If it develops earlier, then a track more to the right is more likely.  Later development may increase the risk to the Gulf of Mexico, perhaps as far west as Louisiana.  You can see our track in dark blue on the graphic above, taking the system inland near Miami and clipping the northeast Gulf on its way to a final landfall along the central Florida Panhandle on Sunday.

Anyone living or working anywhere from Louisiana to the Carolinas should be paying very close attention to this disturbance.  While I don’t think there is a high chance that it will be a large and powerful hurricane at landfall, there is most definitely a chance it could become a hurricane before it reaches Florida.  And even a small hurricane can produce considerable damage.

After a rather active period covering the last week of June and the first week of July, the tropics have certainly quieted down this week.    A significant factor responsible for the lack of activity in the past week is the current outbreak of dry, dusty Saharan air.  The Azores-Bermuda High strengthened temporarily about a week ago, driving a large mass of dry air off the west coast of Africa.  This dry air can be seen in the image below.  The dry air is represented by the yellow and orange colors on the image.

But it looks as though this dry air intrusion into the tropics will be short-lived.   Computer model guidance indicates that the Azores-Bermuda High will continue to weaken and shift eastward over the coming week.  This should reduce the amount of dry dusty air being driven off the west coast of Africa.   In addition, several very large tropical waves with plenty of moisture are poised to slip off the west coast of Africa over next 3-5 days.  Such bursts of dry Saharan air are not uncommon in June and July.  It’s one reason why most seasons never really get started until the first week of August, as can be seen in the image below.

When looking at the frequency of Atlantic Basin tropical cyclones over the past 100 years, one can see that there is typically a sharp ramp-up in the number of storms right at the end of July into early August.   Around that time, the last remnants of moderate wind shear and dry Saharan air depart the deep tropics, leaving a very favorable environment for tropical cyclone development.  That’s what we’re expecting to happen in a few weeks.  However, some models are suggesting that development could occur even sooner.

Over the past few days, several models have been indicating that something might flare up in the western Caribbean by late this coming weekend or early next week.  Now it’s not uncommon for the models to predict such development on a regular basis during the hurricane season.  Fortunately, the models are in error in predicting such development much of the time.  But with the Saharan air thinning out by this weekend, and with a moderate tropical wave reaching the western Caribbean around that time, it’s an area that we’ll be keeping a close eye on.

As for the rest of the season, there is one thing that’s bothering me today.  June and the first two weeks of July have been unseasonably warm across the northeastern U.S.    This indicates that the high pressure we were expecting to remain over the central U.S. may be taking up residence a little farther to the east this summer.  If such a pattern continues, then that may increase the risk of a major hurricane landfall farther west along the northern Gulf Coast - all the way to Texas.  Previously, our outlook had indicated the highest risk from southeast Louisiana east through Florida.  We may need to indicate a significantly increased risk of a landfalling hurricane farther west to Texas on our August update.  Stay tuned…

A feature that we’ve identified as the 16^th tropical disturbance of the 2010 hurricane season is located near the northern Yucatan Peninsula as of noon Tuesday, as can be seen in the satellite image below.  In a normal hurricane season, such a disorganized disturbance would get less attention.  But given the expectations for the high level of activity in the 2010 season, and considering the present activity off the southeast Louisiana coast, everyone across the northern Gulf is paying very close attention to any tropical threat.

Currently, the disturbance remains disorganized.  In fact, the disturbance is less organized than it was a few days ago.  The problem is that it is forecast to move into the south-central Gulf of Mexico tomorrow.  Once there, it’s potentially less than 24  hours away from impacting offshore operators.  Though we are currently estimating the chances for any significant development at no more than 30%, the fact that any development would most likely come with very little time for offshore operators and onshore facilities to to prepare is making everyone nervous.

I went back through the Atlantic hurricane database and identified all hurricanes which actually formed in the Gulf of Mexico since 1940.  As you can see in the image below, there were quite a few hurricanes which actually developed inside the Gulf of Mexico, many of which just a day or two from making landfall somewhere in Mexico or along the northern Gulf Coast.  Such close-in developments leave very little time for preparations.  And although the disturbance is clearly advertised as one with a 30% chance of developing, most companies are reluctant to activate their hurricane plans until the disturbance does indeed develop and get a name.

So what do I think is going to become of this disturbance?  I think that it will track toward the northwest as forecast, probably reaching the upper Texas coast by late Thursday as a disorganized area of thunderstorms.  Associated squalls will produce gusty winds and rough seas offshore on Thursday and Friday.  Inland, the disturbance will produce areas of heavy rainfall across Texas and possibly eastward into Louisiana.  That’s the most likely scenario, anyway.

But if it does take the least likely course and develop into a tropical storm, then that won’t happen until probably late tomorrow or on Thursday, not long before it reaches the northwest Gulf Coast.  Fortunately, the close-in development will leave little time for intensification before the center moves inland.  This would limit the chance of the disturbance reaching hurricane strength prior to landfall.

There is not much to do now but continue to closely monitor this disturbance as it moves away from the Yucatan Peninsula on Wednesday.  That’s something we’ll likely be doing a lot of this season.

As I discussed on my blog entry last Friday, the disturbance in the western Caribbean looked poised to develop.   Our thinking was that it would eventually strike northeastern Mexico, possibly as a hurricane, on Wednesday evening, June 30^th.   When I compared our initial 5-day forecast for Tropical Depression One (which became Hurricane Alex), our 5-day track point just offshore of northeast Mexico at 6pm Wednesday, June 30^th was off by only 12 miles! I’d say that forecast was extraordinary. But now the bar is raised quite high for the other 17 named storms we’ve predicted for 2010. Unfortunately, we may have our next opportunity to forecast a developing storm by the end of next week.

Over the last 3-4 model runs (which come in every 6 hours), several models are predicting that a storm will develop in the western Caribbean Sea around July 8-9. First it was the American GFS model, then the Canadian, and now the European model is predicting the same thing. All the models seem to be keying on a very strong tropical wave located in the central Tropical Atlantic that we’ve identified as “Disturbance 17″. We’ve been following this wave since it moved off the west coast of Africa 3-4 days ago. Although it’s presently lacking in any organized thunderstorms, it contains a tremendous amount of moisture and we can see evidence of rotation in the mid levels of the atmosphere. In fact, it looks very much like the disturbance which produced Alex did about two weeks ago. This tropical wave should be reaching the western Caribbean Sea around the date that the models are predicting development late next week.

A check of the current wind shear situation across the Western Atlantic reveals some quite strong winds aloft across the Gulf and northwest Caribbean (below).  Much of that wind shear is due to the clockwise outflow from Alex over northeastern Mexico.

Unfortunately, the upper-level wind pattern is constantly changing out across the tropics.  The image below is the latest model projection for July 9^th, a little over a week from now.  That’s quite a change, but not too abnormal for July.  Typically, as the season progresses from June into July, wind shear across the tropics decreases significantly.

So, at least three models are now in agreement that there may be an elevated risk of tropical development in the northwest Caribbean or the  southwestern Gulf of Mexico late next week. The next question to ask is where might such a developing storm track?    The same models that are predicting development also provide guidance as to the steering currents that will be in place next week.   As of today, indications are that the strong area of high pressure across the central U.S. which helped steer Alex westward into Mexico may not be present next week.  That would mean a more northward track toward the northern Gulf Coast would be a good possibility.  That’s something we certainly don’t want to see for a number of reasons.  But any possible impact across the northern Gulf of Mexico is still a good a good 9-10 days away.  Development is by no means certain, but it’s something we’ll be watching for very closely through the holiday weekend.