Tornado threat for south TX from TS Don this evening: Light
I’m not seeing dry air intrusion on water vapor imagery, no areas of sharp relative humidity gradients on the models, and the sounding and hodograph forecasts don’t impress me very much. Low-level wind speed shear will seem to be at its peak north of the center of circulation and persist through the early evening. The SPC has issued an mesoscale discussion, but they seem to be holding back on issuing a tornado watch for the moment. I would not rule out a couple tornadoes, but don’t see indications of an outbreak based on previous literature. Things could change though as Don moves inland and begins to fill in, but that depends on what kind of kinematics we have later on.
Tropical Storm Cindy has developed in the open Atlantic waters 665 miles east-northeast of Bermuda. Satellite intensity estimates wind speeds near 35 knots. This system will likely be another fish storm as it continues to encounter a southwesterly steering flow.
Oh, Bret (Tropical Update)
As you might be able to tell on the water vapor still image, Tropical Storm Bret doesn’t look so good. It appars that dry air is starting to intrude on the storm’s center and causing all sorts of hell. Visible satellite imagery shows a nice low-level center, but most of the convection is pushed to the southern end of the TC. The shear is just killing Bret.
The storm is moving in a northeasterly direction at around 7 knots, but forward speed could increase in the next three days. As for its future, it doesn’t look good and conditions will remain hostile for sustaining itself.
Invest 98L Now Tropical Storm Bret
A few hours after Sunday’s post, Hurricane Hunters found a closed center of circulation with winds of 35 mph and it was named Tropical Depression 2. Hunters found higher winds when they extrapolated to the surface, but those numbers were questionable. It didn’t matter since it was classified as a tropical storm three hours later.
Before I went to sleep last night, the infrared satellite loop of Bret looked unimpressive and unorganized. It looks better as of late this morning as it has more of a “ball” of convection. It looks to have lost some of its outer banding, though. Water vapor loop shows dry air on the northern and western side of the TC, which could be a limiting factor of intensification.
Bret is now slowly moving towards the north-northeast at 5 mph. The steering currents appear rather weak, but as the ridge to the east strengthens a bit and the trough sits near New England the TC will be begin to accelerate. This looks likely to be a fish storm.
Updates will be given on Bret when warranted.
Invest 98L Becoming an Area of Interest
Over the last day, a tropical disturbance has been sitting off the east coast of Florida. The low helped spark some showers and storms across the state on Saturday. Today, it looks a little better organized and the NHC has increased development chances to 40 percent. An Air Force reconnaissance aircraft is scheduled to investigate the system today.
The last few frames of the visible satellite loop show more of a “spin” to the center of circulation while most of the thunderstorm activity remains on the eastern half of the invest. Infrared imagery shows the highest cloudtops on the southern portion of the low. KMLB radar shows the low off the coast moving in a southerly direction.
The models show steering currents to be really weak and erratic for the near term. Models also show that wind shear in the vicinity will start to go down and be well under 10 knots within 48 hours. Where this invest goes will depend on how strong the system gets. It could move back towards the Florida coast early this week, but I want to wait and see how much this system intensifies and see what the models do.
The NHC is looking for ham radio operators
An email from the ARRL…
The various organizations that assist the National Hurricane Center
(NHC) in Miami are gearing up for what forecasters are predicting to
be a very active storm season. One organization that assists the NHC
is the Hurricane Watch Net (HWN). One of the functions of HWN is to
provide on-the-ground, real-time weather data to the forecasters at
the NHC. The HWN gets this weather data from Amateur Radio operators
who volunteer their time to monitor data from their calibrated home
weather stations and report that data to the HWN. To better assist
the NHC, HWN Manager Kirk Harding, K6KAR, told the ARRL that the HWN
is looking for new members.
“The Hurricane Watch Net relies on volunteer operators — our
members — who serve as our net control stations,” Harding said.
“HWN members are hams who have above-average stations, are capable
of effectively conducting HF net operations and are willing to
commit their time to operating in support of the HWN’s mission
during Net activations.” The HWN net operates on 14.325 MHz, so
prospective members must be able to legally transmit on that
frequency to participate.
Harding said that the HWN is looking for new members with stations
that can effectively communicate with Central America and the
Caribbean, Mexico and South Texas on the 20 meter band. “As we head
into the 2011 hurricane season, we’re looking for qualified amateurs
who are located anywhere within North America or the Caribbean,” he
said. “We are also looking for bilingual hams. We recognize that
some Latin American operators hesitate to check in and send reports
to us if they aren’t fluent in English, so we’re also interested in
hearing from hams who are fluent in both Spanish and English. When
we’re working storms that are either affecting or threatening areas
where Spanish is the language of choice, we always try to have one
or more bilingual HWN members on hand to help with reporting.”
Harding explained that the Hurricane Watch Net is generally
activated when a named Atlantic basin storm is within 300 miles of
landfall. Hurricane season in the Atlantic Ocean runs from June
1-November 30, peaking from late August through September; the
Pacific Ocean season runs from May 15-November 30. Of course,
hurricanes may occur at any time of the year. National Weather
Service’s Climate Prediction Center predicts that the 2011 hurricane
season will see above-average activity with 12-18 named storms, with
6-10 of those storms becoming hurricanes. Of these storms, three to
six could develop into major hurricanes (Category 3, 4 or 5). The
National Oceanic and Atmospheric Administration (NOAA) defines a
normal hurricane season as having 11 named storms — including six
hurricanes — with two becoming major hurricanes.
If you are interested in becoming a member of the Hurricane Watch
Net, please visit the HWN website at http://www.hwn.org for further
Starkville Weather Update
The next few days look dry and hot in the Golden Triangle area. A ridge is in place over the south and that will help keep any lift at bay. Water vapor imagery also shows drier air in the mid to upper levels across Alabama, Mississippi, Arkansas, and Louisiana. Expect highs to be in the mid to upper 90s in the area the early part of the Fourth of July weekend.
By Monday, the GFS shows an easterly flow which could bring some more moisture to the area and bring rain chances to a slight category.