Find us on Google+

Category: Tropical

Joaquin Is Pegging the East Coast Excitement Meter

| 12:15 pm September 30, 2015

Well, the excitement meter has shot up rapidly last night and this morning on Joaquin.

The storm became a hurricane this morning with winds of 80 mph and it continues to strengthen. Air Force reconnaissance found a central pressure of 972 mb after 7 a.m. You can see it tracking southwestward perilously close to the Bahamas with the hurricane watches and warnings outlined in peach and red.

9-30-2015 12-00-47 PM

The system is developing an eye now and will continue to strengthen over warm water. Sea surface temperatures in the vicinity of the hurricane are well over 30C, which is sufficient for rapid strengthening.

It is quite impressive on visible satellite imagery, with intense thunderstorms wrapping around the developing eye and good outflow. Joaquin is expected to become a major hurricane over the next 48 hours. Indeed, with very low wind shear and the warm temperatures, it is not unthinkable that it could become even stronger.

Joaquin wed 11a avn-animated

Hurricane Joaquin is 300 miles east southwest of Nassau in the Bahamas, moving SW at 5 mph. It is expected to turn sharply west, then northwest and then north and northeast over the next 24 hours. It will bring tropical storm conditions to the southern Bahamas tonight and Thursday, and hurricane conditions to San Salvador. Hurricane warnings are in effect for the southern Bahamas. A hurricane watch is in effect for the rest of the Bahamas including Nassau, but I think that is out of a measure of caution, since only the island of Eleuthera should receive tropical storm conditions late Thursday night into Friday morning.

With the northeast turn, you would think it would turn on out to sea and bother no one. But not so fast my friend. Strengthening high pressure to the north of the hurricane may very well deflect it back to the west by the weekend and Joaquin poses a big threat to the U.S. East Coast. (Think Hurricane Sandy from 2012.)

The GFS and the Canadian, as well as the GFDL and HWRF models have been bullish on a solution that takes Joaquin into the Mid-Atlantic Coast between eastern North Carolina and the Delaware/Maryland/Virginia area (DELMARVA). The European model still takes it out to sea without affecting land. But the ensembles (multiple runs of the model with slightly different data to generate a variety of solutions) underscore the uncertainty. The GFS ensemble has members that carry it out to sea with others that bring it ashore. The positions from the various members of the European ensemble actually average out to be closer to the coast as well. The Canadian overnight was right with the American GFS.

So, there has been an increasing trend toward a landfall on the U.S. East Coast in the Mid-Atlantic region. The morning run of the GFS model now shows a landfall near Morehead City, NC Saturday night.

2015-09-30_12-03-52

The overnight run of the GFDL pegged Virginia Beach as the landfall Saturday night as a 115 mph hurricane with a central pressure of 943 mb. That would be a disaster for the Hamptons and the Chesapeake Bay including Washington DC and Baltimore. The HWRF brings it to near Cape Hatteras as a 100 mph hurricane early Sunday morning and on into southern Virginia.

It is too early to say specifically where Joaquin will end up, but all interests along the East Coast of the United States from the Carolinas to New England need to be paying attention to the latest forecasts, official advisories and watches and warnings.

Heavy rains will continue to plague the area from the Carolinas to New England. Flood watches are in effect for a large area of this region. Much of the Mid-Atlantic region is forecast to get 8-10 inches of rain from this storm. Serious flooding was reported this morning in Portland ME.

Coastal flood advisories are in effect along much of the East Coast from the Florida Keys to Massachusetts. High astronomical tides caused flooding around Charleston SC this morning, closing some streets.

We will be tracking Joaquin carefully here on the blog through the weekend as it decides what it is going to do.

Increasing Rain Chances; Update on Gulf Low

| 2:24 pm September 27, 2015

2015-09-27_14-20-55

Moisture levels are high across Alabama on this late September Sunday afternoon. Clouds are thick across the area and light showers are increasing across the Central part of the state.

Temperatures are edging toward the 80F mark, but many spots will hang in the 70s this afternoon. Skies will remain mostly cloudy and scattered showers will be possible.

Expect the rain to expand this evening and most spots will see 30-45 minutes of rain late between this afternoon and tonight. Rainfall amounts will be light, around one tenth of an inch.

SUPERMOON ECLIPSE: I am afraid the only way that you will see the big lunar event tonight is by traveling far away or watching it on SpaceWeather.com. The moon will be eclipsed by the Earth’s shadow this evening in a total eclipse, even as the Moon is at perigee, its closest point in its orbit around the Earth. All for naught I am afraid for us here in Alabama.

2015 09 27 avn_lalo-animated

TROPICAL LOW? A broad low is over the Yucatan early this afternoon, with lots of disturbed weather extending northward from the system all the way into the coastal waters of the Florida Big Bend from Apalachicola to Tampa. More storms are over the Texas and Louisiana coastal waters, associated with the upper level low. I think we are seeing better outflow this morning from the storms each of the Yucatan where ridge is building.

The National Hurricane Center has dropped their probability that this low might become a tropical cyclone to 30%. Wind shear has relaxed a bit in the region where the low is situated now, but it still about 20 knots, which makes conditions unfavorable for significant development. And to the northwest, there is over 40 knots of shear. Even if it doesn’t become a tropical depression, with will have significant impact along the Gulf Coast, with heavy rain, winds of around 40 mph, seas of 6-8 feet and a high rip tide threat until the low comes ashore Tuesday. We will look at the beach forecast shortly.

WET START TO THE WORK WEEK: As the low moves northward on Monday, waves of showers will spread northward. Monday won’t be an all day rain by any stretch, but should will have to dodge at least a couple of rounds of rain. The low should reach the coast Monday night or early Tuesday. Showers will be the rule again on Tuesday as the low turns northeastward. They will begin to diminish from the south Tuesday afternoon, but they won’t be done. &0s will be the rule Monday and Tuesday with the clouds and showers.

MIDWEEK MOISTURE: The leftover moisture will hang around into midweek. Meanwhile, a developing trough to the north will link with the upper low over Louisiana, forming a bigger trough and pushing a cold front our way. There should be one last hurrah of showers and storms Wednesday afternoon as the front pushes through, and then the front.

BUT THEN, WAIT: We had thought there would be improved weather for the remainder of the week into the weekend, but the GFS has introduced the idea that an upper level low may cut off in the deep trough that is left over the Ohio and Tennessee Valleys. If that happens, we probably will see enough atmospheric energy and moisture to trigger a few showers Thursday. Expect improving conditions as we head toward the weekend.

ROCKET CITY WEATHER FEST: Speaking of the weekend, the annual Rocket City Weather Fest is this coming weekend at UAH in Huntsville. Lots of fun activities for kids and education things for everyone. There will even be a weather balloon launch at 1 p.m. Check out their website.

TD Nine Forms

| 10:56 am September 16, 2015

Tropical Depression Nine has formed in the middle of the south Atlantic. As we’ve been telling you, the depression is no threat to land, only to shipping in the middle Atlantic. I’ve pasted the public advisory into this post below. The forecast graphic is below the advisory, so you’l need to scroll down to see it.

-Brian-

WTNT34 KNHC 161433
TCPAT4

BULLETIN
TROPICAL DEPRESSION NINE ADVISORY NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092015
1100 AM AST WED SEP 16 2015

...NEW TROPICAL DEPRESSION FORMS FAR FROM LAND IN THE CENTRAL
TROPICAL ATLANTIC...

SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.0N 43.1W
ABOUT 1215 MI...1950 KM E OF THE LESSER ANTILLES
ABOUT 1270 MI...2050 KM W OF THE CAPE VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...1010 MB...29.83 INCHES

WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 1100 AM AST (1500 UTC), the center of Tropical Depression Nine
was located near latitude 15.0 North, longitude 43.1 West. The
depression is moving toward the north-northwest near 8 mph (13 km/h)
and this motion is expected to continue through Thursday. A turn
toward the northwest is forecast on Thursday night.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.
Little change in strength is forecast during the next 48 hours.

The estimated minimum central pressure is 1010 mb (29.83 inches).

HAZARDS AFFECTING LAND
----------------------
None

NEXT ADVISORY
-------------
Next complete advisory at 500 PM AST.
TD 9 Forecast Graphic

TD 9 Forecast Graphic

55th Anniversary, Hurricane Donna

| 7:34 am September 11, 2015

It was 55 years ago that an impressionable young man in the 6th grade experienced the fury of Hurricane Donna. His interest was further heightened through the presentation of the storm by one of the Nation’s first on-air degreed meteorologists, Roy Leep. It was this encounter which set him firmly on the road to a career in meteorology. And today the Hurricane Research Division of NOAA’s Atlantic Oceanographic and Meteorological Laboratory in Miami has put together a great page documenting Donna. You can find that page by clicking on this link.

Below is a map of the Atlantic Basin showing the complete path of Hurricane Donna as well as the paths of the other six tropical storms for 1960.

-Brian-

1960 Tropical Storm Tracks

Peeking in on Grace

| 1:49 pm September 6, 2015

I was looking through some images of Grace, and I thought people might like to see a couple of different views of this storm. These two images were taken about 15 minutes apart just before 1 pm CDT.

The first one below comes from the eastern GOES satellite operated by the NOAA Satellite and Information Service. This is a visible image, so this is what it would look like if we were on the satellite looking down with special black and white glasses. Grace is showing some good banding on the south and east sides of the storm but is pretty open in the northwest quadrant.

vis0-lalo-2

Looking more westerly is a visible image from the European Meteorological Satellite. Fred can be seen in the upper left quadrant of the image.

vis

I just can’t imagine life without weather satellites.

-Brian-

TD 7 Becomes Grace

| 3:57 pm September 5, 2015

It really did not take long for tropical depression 7 to move up the ladder to a full fledged tropical storm dubbed Grace.

203225W_sm

NHC forecasters are keeping their official track on the south side of the overall envelope of the various computer guidance tracks. Synoptic conditions should be conducive for some intensification during the next 24 to 36 hours, with the storm embedded in an environment of light easterly shear and over warm SSTs. The one caveat is that a general drying of the lower to middle troposphere
in the near-storm environment is forecast, possibly due to increasing subsidence, which could squelch additional strengthening. After 48 hours, the cyclone is expected to encounter westerly flow aloft associated with an enhanced upper-level trough extending from near the Antilles to the eastern tropical Atlantic. This pattern should produce enough vertical shear to cause weakening or possibly
even dissipation by day 4 or 5 of the forecast as it nears the Lesser Antilles.

-Brian-

TD 7 Emerges

| 9:58 am September 5, 2015

In the Weather Xtreme Video this morning, I mentioned that we could see the development of our seventh tropical storm of the 2015 hurricane season in the Atlantic. Well, we made a giant leap in that direction just before the 10 o’clock hour with the National Hurricane Center issuing the first advisory on Tropical Depression (TD) Seven. I’ve pasted into this post the discussion from the National Hurricane Center. It’s worth noting that the environment ahead of the depression appears favorable for gradual strengthening as it moves on a generally westerly course for the next several days. With wind estimated to be around 30 knots, it won’t take much for it to be named. That name will be Grace.

Scroll down for a satellite view of TD 7.

-Brian-


TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072015
1100 AM AST SAT SEP 05 2015

Satellite imagery and ship observations indicate that the
disturbance south of the Cape Verde Islands has become better
organized, and is now Tropical Depression Seven. The convection is
not very deep at this time, but animation of visible images show a
good circulation. In fact, earlier microwave data clearly depict a
mid-level center associated with the developing depression. Based on
Dvorak estimates from TAFB and SAB of 2.0 and 2.5, respectively, the
initial intensity has been set at 30 kt. No ASCAT data were
available at the time of this advisory.

The environment appears to be favorable for gradual strengthening
during the next 2 to 3 days. After that time, most of the global
models forecast a significant increase in shear. This should halt
any additional strengthening, and most likely the cyclone will
weaken or could even dissipate well east of the Lesser Antilles.

The best estimate of the initial motion is toward the west or 280
degrees at 12 kt. A moderately strong subtropical ridge is centered
north of the depression. This pattern calls for a continuation of
a general westward track for the next 3 days.  After that time,
the ridge is expected to weaken, and the cyclone will likely turn
more toward the west-northwest with a decrease in forward speed.
This is the solution of the models, except the ECMWF that does not
acknowledge the existence of a cyclone.


FORECAST POSITIONS AND MAX WINDS

INIT  05/1500Z 12.3N  25.2W   30 KT  35 MPH
12H  06/0000Z 12.5N  26.9W   30 KT  35 MPH
24H  06/1200Z 12.8N  29.2W   35 KT  40 MPH
36H  07/0000Z 13.0N  32.0W   40 KT  45 MPH
48H  07/1200Z 13.5N  34.7W   45 KT  50 MPH
72H  08/1200Z 14.5N  40.0W   50 KT  60 MPH
96H  09/1200Z 15.0N  45.5W   45 KT  50 MPH
120H  10/1200Z 15.5N  50.0W   40 KT  45 MPH

$$

TD-7

A Look at Fred

| 11:21 am August 30, 2015

Somehow, I just can’t get too excited about the tropical storm named Fred. I have nothing against the name, but “Fred” just doesn’t sound very mean or menacing like tropical storms are supposed to be. Here’s a look at a visible image of Fred I grabbed from the NOAA Satellite and Information Service.

vis0-lalo

The Meteorological Service of the Cape Verde Islands has issued a Hurricane Warning for the Cape Verde Islands. This replaces the Tropical Storm Warning and Hurricane Watch that were previously in effect for them.

At 11:00 AM AST (1500 UTC), the center of Tropical Storm Fred was located near latitude 13.4 North, longitude 19.9 West. Fred was moving toward the northwest near 12 mph and this motion was expected to continue through Tuesday. On this forecast track, the center of Fred is expected to move through the Cape Verde Islands on Monday through early Tuesday. Maximum sustained winds have increased to near 50 mph with higher gusts. Some additional strengthening is expected during the next day or so, and Fred was forecast to become a hurricane before reaching the Cape Verde Islands on Monday.

Here’s the forecast track graphic from the National Hurricane Center.

144844W_sm

Fortunately, other than the Cape Verde Islands, Fred is only a threat to shipping.

-Brian-

Rain For South Florida

| 10:27 am August 29, 2015

While nobody wants to be hit by a tropical storm or hurricane, there is no doubt that these systems do provide some needed assistance. Tropical weather systems can produce moderate to heavy rain events which help ease drought conditions. Of course, we want and look for a good soaking and not too much rain to produce flooding. As the map below shows, South Florida is rated a D3, or extreme drought, so they can really use a good soaking event.

20150825_southeast_none

According to projections by HPC, Hydrometeorological Prediction Center, Florida could see on the order to 3 to 5 inches (see map below) over the next five days. As long as that rain does not come down all at once, but is spread out over much of the next 3 to 4 days, it should help to ease the drought conditions currently affecting South Florida.

p120i-2

-Brian-

Bye Bye Erika

| 8:16 am August 29, 2015

erika sat 8a avn_lalo-animated

Tropical Storm Erika has completely fallen apart this morning, the victim of wind shear and the mountainous terrain of the island of Hispaniola.

Reconnaissance into the storm was unable to find evidence of a closed circulation.

The system will continue northwest into the Gulf of Mexico and bring heavy rain to the Florida Peninsula and the Gulf Coast. Regeneration does not look likely.

Erika Forms

| 11:23 pm August 24, 2015

erika 001a avn-animated

The NHC has named the system in the Central Atlantic about 950 miles east of the Leeward Islands tonight. It is Tropical Storm Erika.

Here are the Fast Facts on Erika:
SUMMARY OF 1100 PM AST…0300 UTC…INFORMATION
———————————————–
LOCATION…14.4N 47.7W
ABOUT 955 MI…1535 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS…45 MPH…75 KM/H
PRESENT MOVEMENT…W OR 275 DEGREES AT 20 MPH…31 KM/H
MINIMUM CENTRAL PRESSURE…1003 MB…29.62 INCHES

Erika is in a favorable environment for intensification with an envelope of moisture, low shear and warm water. That should continue for at least 48 hours before it encounters some shear. It is expected to become a strong tropical storm, but could become a hurricane, as depicted by the HWRF model.

2015-08-24_23-11-11

There is some uncertainty in track, but there is a good chance this could affect the United States. If it is weaker, it could be shunted south toward the Gulf of Mexico. A stronger storm would be pulled further north and could be near the Bahamas by the end of the wekeend, with a threat to the East Coast.

Erika will be interesting to watch.

Danny dissipated this morning as expected over the northern Leeward Islands.

I Think I Can, I Think I Can…

| 4:56 pm August 23, 2015

danny avn-animated

But I am afraid it probably can’t…

Danny made a bit of a comeback this morning according to satellite pictures, with an expanded circulation and a flare of convection around the center. But he rally was short lived, the short term effect of approaching shear that will eventually tear the storm apart, and the death rattle will begin soon.

2015-08-23_16-58-39
Tropical storm warnings are in effect for Antigua, Barbuda, Montserrat, St. Kitts, Nevis, and Anguilla with tropical storm watches for Puerto Rico, the U.S. and British Virgin Islands and the rest of the northern Leeward Islands.

Danny will move across the islands of Guadeloupe and Antigua late tonight into Monday then across southern parts of Hispaniola by Tuesday night.

This should effectively knock the stuffing out of the little hurricane that could. It is yet to be seen whether the plucky little storm will be able to regenerate later this week as it moves a long the North Coast of Cuba. The smart money is on no for now.

BUT: Having said that, watch the system behind Danny. It will likely become Tropical Storm Erika this week, on a similar trajectory to Danny. The European does ramp this back up into a powerful storm as it moves through the Bahamas around September 1, but recurve it between the U.S. East Coast and Bermuda early that week.