Dolly Near Hurricane Strength

Tropical Storm Dolly strengthened overnight and is on verge of becoming a hurricane. The latest reconnaissance report indicated the pressure has dropped to 991 mb and surface winds measured by the SFMR were 74 mph. It's likely Dolly will be upgraded to a hurricane later this morning or early this afternoon. The recon report also indicated that an eyewall is forming and is only open on the west side of Dolly. When this fills in, which it should happen later today, expect for Dolly to strengthen at a faster rate.

Satellite imagery shows excellent outflow in the north and east quadrants of Dolly, but improving and non-existent outflow exists in the west and south quadrants, respectively. An upper low (located near the NOAA stamp in the linked image) over Mexico is hindering outflow in these quadrants, particularly in the southern quadrant of Dolly. Until this low weakens or moves away from Dolly, significant strengthening is going to be hampered. Still, the warm waters and relatively weak shear should support a modest gain in strength until landfall. I now expect Dolly to be a strong Category 1 or weak Category 2 hurricane at landfall.

The exact landfall of Dolly is uncertain, but model guidance is in agreement with a landfall in northern Mexico. Dolly moved a little more west than expected yesterday and this resulted in the track being shifted south from what it was yesterday. Still, the exact landfall is very difficult to pinpoint due a multitude of reasons, and any wobbles within Dolly could shift the track north or south. However, I do like the NHC's current forecast track. To sum up, I think Dolly will make landfall near Brownsville with winds of 95-100 mph tomorrow morning.


The strong tropical wave that moved off the coast of Africa encountered cool SSTs (~23 C) and development doesn't appear imminent for a few days. This wave will probably develop, but it seems likely to re-curve out to sea given that it is already at a high latitude (16 N).

If you would like to read an excellent tropical weather discussion, I highly recommend Dr. Jeff Masters' blog. You won't find any rants or excessive objections about the NHC, but you will get a well-informed and scientific discussion.

Interesting weather in Nevada yesterday with two tornadoes and other funnel clouds reported east of Reno. This ended a streak of almost 4 years without a tornado report in Nevada! I will post a case study of these tornado at some point in the future.