Tropical Storm Lowell

[Somerset Squall]

Invest 99E has been upgraded to Tropical Storm Lowell overnight, with an initial intensity of 35kts. Very deep convection is blowing up to the southwest of the well defined centre, and this convection is expected to wrap around the centre in the next 24hrs as the shear affecting Lowell is expected to ease. Lowell is pushing northwestwards along the southwestern side of a subtropical steering ridge over Mexico, but this motion may not last long, as a trough is expected to push southwards according to the NHC which will create a weakeness in the ridge and force Lowell northeastwards. The timing of this turn if it occurs is uncertain, Lowell may pass south of Baja California or indeed make landfall there. With the more southward option, Mexico itself is more at risk. Favourable conditions of hot waters, lowering shear and good instability will strengthen Lowell beyond 24hrs, and the storm could become a hurricane within the next couple days, before he reaches cooler waters. Needs watching as it could be a big rainmaker next week for Baja or Mexico. It's also worth noting that surface pressures are low in the area, and Lowell already has a pressure of 1000mb which is quite low for a weak tropical storm, and this may aid further development.

[Cookie]

thanks for the update somerset

[Somerset Squall]

Lowell has intensified this afternoon, and is now at 45kts. Very deep convection persists, though it's still sheared to the southwest of Lowell's LLC. This shear is expected to ease tomorrow and this is when Lowell has potential for further strengthening. A northeastward turn is still forecast but exactly when this will occur is very much uncertain.

[Somerset Squall]

Lowell peaked at 50kts this morning, but convection has since retreated to the southwest side of the circulation again as shear persists. Shear will ease tomorrow, but it may be too late for Lowell by then as the northwestward track will take the storm over increasingly colder waters. This will induce weakening until predicted landfall in Baja California. After landfall, Lowell will move into the sea of Cortez then make a second landfall in Mexico. There is not expected to be much left of Lowell by then, a mere tropical depression if anything and if Lowell continues to struggle it may not even be that.

[Cookie]

new update

Storm Alert issued at 9 Sep, 2008 9:00 GMT

Tropical Storm LOWELL is forecast to strike land to the following likelihood(s) at the given lead time(s):

Green Alert Country(s) or Province(s)

Mexico

probability for TS is 35% in about 33 hours

Note that

Green Alert (Low) is TS to between 31% and 50% probability.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Cookie]

new update

Storm Alert issued at 10 Sep, 2008 3:00 GMT

Tropical Storm LOWELL is forecast to strike land to the following likelihood(s) at the given lead time(s):

Green Alert Country(s) or Province(s)

Mexico

probability for TS is 40% in about 21 hours

Note that

Green Alert (Low) is TS to between 31% and 50% probability.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Somerset Squall]

Lowell has weakened to a tropical depression, with an intensity of 30kts. The LLC is becoming ill defined but deep convection is managing to flare up from time to time, which is sustaining Lowell for now. If these convectional flare-ups continue then Lowell may hold on to tropical depression status till landfall in Baja California in 24 hours. After which, land interaction will definitely kill him off.

[Somerset Squall]

The centre of Tropical Depression Lowell is become detached from the deep convection, and intensity has been reduced to 25kts. However, the area of convection to the northeast of the centre is bringing torrential rains to southern Baja California and are now spreading into Mexico. These rains could bring floods and mudslides. Although Lowell will dissipate in the next 24hrs, heavy rains are likely to continue over western Mexico over the next couple days.

[Cookie]

thanks for the updates mate

[Somerset Squall]

Interesting snippet of information from Wunderground:

O'Hare airport in Chicago broke its 20-year old 24-hour rainfall record Saturday, when 6.81" fell. The heavy rain triggered the worst flooding on record for the Des Plaines River in Chicago's western suburbs. The heavy rain was due to a cold front that was packed with moisture from the remnants of Tropical Storm Lowell.

6.81mm may not sound much compared to totals from the Atlantic storms but for Chicago is certainly is.

[Somerset Squall]

I had no idea Lowell caused this much trouble! Chicago is seeking aid after serious flooding:

http://www.cnn.com/2008/US/weather/09/14/c...fall/index.html

[Cookie]

nor did I!