Drier, more comfortable air continues to filter into the region while we are still monitoring the tropics. The frontal boundary that slowly passed through the area over the last several days has moved offshore and will likely become stationary through mid-week. Lower humidity and slightly cooler conditions will be with us through Wednesday with highs staying in the mid-upper 80s while lows drop into the very comfortable mid-60s. Lows Tuesday night into Wednesday morning may even drop into the lower 60s! The respite from heat and humidity will end later this week with higher humidity and slight rain chances possibly returning as early as Friday. Another upper disturbance will roll in from the northwest toward the area this weekend into early next week drawing tropical moisture back from the Gulf and engendering scattered daytime showers and storms. Deeper tropical moisture, higher rain chances and maybe some Gulf developments will be possible later next week into the following weekend.
Speaking of the tropics, we are monitoring a disturbance (94l) that is east of the Windward Islands. Last night and early this morning it looked like it was ready to go, but a distinct surface circulation has not been detectable via satellite imagery so far, and this afternoon there has been some shearing/inhibiting upper winds over the storm canopy. A hurricane hunter is scheduled to investigate this system tomorrow. Tropical and global models are split into three camps: 1-a weak barely detectable system moving west-northwestward, 2-a tropical storm or weak hurricane that moves west-northwestward and then recurves in the open Atlantic, and then, 3-a significant hurricane that may stay just south of the main Caribbean Island chain. Somewhere in betweenthese scenarios lies the truth, but exactly what, time will tell. Meanwhile I would also look for some weak low pressure development along the aforementioned front in the extreme northeastern Gulf of Mexico. While upper level winds will be not favorable for true tropical development it could stay quite wet for parts of Florida mid-late this week. Farther down the road the longer range models have been showing monsoonal “troughiness” developing over the western Gulf of Mexico later next week into the following weekend. I am not sure if the model is capturing remnant moisture from Hurricane Jimena or developing something completely different…but the bottom line is that pressures look low in the Gulf and tropical moisture looks to surge mid-late next week…so something may be up soon. Whether it’ll will be disturbance 94l or something else, we are heading into the meat and potatoes of hurricane season. Finally, Hurricane Jimena this afternoon was sporting 155mph winds and will likely weaken a bit before it directly threatens Cabo San Lucas, the entire Mexican Peninsula, the northwest Mexican coastline, ultimately bringing the threat of heavy rains to the US desert southwest including Arizona this weekend.