Wednesday, May 23, 2018 3:08 PM

Entire Gulf Coast Needs To Stay Alert!

Christopher Nunley

The official start of the Atlantic hurricane season is still a week out (June 1st) but that is not slowing things down. A surface low is currently spinning near the Yucatan Peninsula. The National Hurricane Center (NHC) has given this area of low pressure a 60% chance of development (see Fig. 1) over the next five days. This low will move into the southern Gulf of Mexico late this week and move towards the northern Gulf Coast of the United States by the weekend.

Fig. 1: NHC Graphic

Numerical guidance is struggling with the track and intensity of this low, but regardless of intensity, heavy rainfall will impact parts of the Southeast. This low may develop into a tropical depression or low-end tropical storm over the weekend. The European, CMC, and NAM are all indicating this is a possibility. Sea-surface temperatures (SSTs) in the Gulf are marginal right now but above average SSTs exist across much of the northern Gulf of Mexico (see Fig. 2). The wind shear is currently strong (see Fig. 3), which is aiding in preventing this low to develop quickly. This shear should lessen by late week into the weekend (see Fig 4), which is why the NHC has given this low a 60% chance of development.

Fig. 2: Current SST Anomalies

Fig. 3: Current Wind Shear

Fig. 4: Future Wind Shear (GFS: Friday Afternoon)

Right now, the best region to see the track of the center of the low is from Pensacola, FL to New Orleans, LA by late weekend into early next week (see Fig. 5). Regardless of the track of the center of the low and intensity, very heavy rainfall is likely for parts of the Southeast from lat week into early next week. The best chance for heavy rainfall exists across the northern Gulf Coast and east of the Mississippi River (see Fig. 6).

Fig. 5: Latest Spaghetti Plot

Fig. 6: WPC Rainfall Map Through 7 Days

Some areas may see flash flooding and rainfall amounts in excess of 6-12″. A few damaging wind gusts and weak tornadoes may occur, too. This situation is fluid and evolving so keep checking back for updates to this forecast. All states along the Gulf (from Texas to Florida) need to keep a close eye on the forecast.