Late May, Early June Tropical Storm?

Long-range models are starting to hint of conditions favoring a very early tropical storm in the Western Caribbean or Southeast Gulf of Mexico in late May or early June. I’ll discuss that in the long-range section.

In the meantime: Geesh, what a tough weekend for forecasters. Expected dry mid-level air from Florida didn’t make it completely into Southeast Louisiana. Though it didn’t rain a drop at my house in Slidell, many places got storms on Friday, including Robert, LA which got drenched with several inches. Today, most of us were dry except for mid-city New Orleans where the Jazz Fest got soaked by a mid-afternoon storm.

The rainfall map shows the extreme rainfall differences across our area and confirms what I mentioned a week ago, that rain is easier to come by the further west you go this time of year. Expect this type of hit or miss pattern to show up with the next shower system coming in from Thursday - Saturday. Until then, hot afternoons mid-upper 80s with no rain — honest.

Not much to say, but….

1) Though high temps will stay in the mid-upper 80s, the low temperatures and the humidity will slowly increase from Monday to Wednesday.

2) Next shower system arrives on Thursday with the better chances in the west - Tangipahoa, Western St. Tammany, and Washington Parishes. The Foreca graphic for Hammond (not shown), actually shows more rain on Thursday than Friday. However, if a strong thunderstorm system gets going to our west, all bets are off - not only will it rain in these areas but the system could march all the way through the Southshore, Eastern St Tammany Parish, and perhaps Coastal MS in the evening or overnight hours.

3) Expect more showers and storms on Friday - Eastern areas and the Southshore may be more favored than the western ones.. Saturday should feature less showers and storms - perhaps confining themselves to parts of the Southshore or near Baton Rouge.

4) Note the cooler morning temperatures and lower humidity for next weekend on the Northshore and Coastal MS.

Expect another nice stretch of dry weather with reasonable humidity Sunday May 4- Wednesday May 7. Highs mid - upper 80s. Still expecting a drier than normal May.

One of the more amazing developments in meteorology that I did not see coming was the improvement in two-week to one-month forecasting through numerical models. I was taught this was impossible when I went to college in the stone ages (1970s). However, signals found in ocean temperatures and stratospheric level winds are much less variable than low level weather, yet drive the bigger picture. Models have locked into this stuff and, at times, show skillful trends. This looks to be one of those times…

These models are showing above normal rainfall in the Western Caribbean in late May and a favorable upper level wind pattern for a tropical system to develop there or the Southeast Gulf.

Though we won’t know an exact location and date for storm formation, most of these early season storms only marginally develop and tend to be more rain makers than big wind producers, Furthermore, if they come northward, they favor the Eastern Gulf more than the Western Gulf.

Nothing else can be said, except it’s a good time to start planning for hurricane season. I will post my latest hurricane season thoughts later this week.

Foreca graphic for Pensacola Beach where the big story is the high onshore winds from Tuesday through Friday morning. Surf will be way up and red flag warnings — probably small craft ones will be out. Highs almost 80 with a chance of showers and storms there this Friday.