Warm with a few light showers Friday

Here’s my big weather “take-aways”:

• Highs of mid 70s will increase to 80 by Wednesday as humidity will rise through Friday. Morning clouds will break up by afternoon.

• Chance of light showers will begin on Friday and extend through Monday. These will be scattered with very light rainfall amounts.

• Next chance for significant rain won’t be until next week with a slow moving cold front….so slow, that I’m not certain whether it will arrive Tuesday, Wed. or Thursday of next week.

• Cold air will return late next week with a night or two in the 40s.

• No frost or freeze expected in the next through March 18. I’m confident we have seen our last freeze, but there’s still a slight chance of a late frost if you live in the country in areas well inland from the Gulf.

The Foreca graphic looks almost perfect except for a few too many shower symbols just below the timeline. Scattered mainly afternoon light showers kick in on Friday. Amounts will be light and chances are a bit higher in western and inland areas such as Tangipahoa, Washington, Northern St. Tammany Parish plus Pearl River Counties. Interesting fact: These areas get more spring rainfall than those of us along I-10 and I-12 near the Lake and Sound. The opposite is true from late August through early October when Gulf moisture prevails.

Foreca is forecasting some patchy fog tomorrow morning while the NWS is silent. Foreca may be on to something. The NWS is overplaying the rain chances next weekend with its “Showers and thunderstorms likely” forecast for Saturday. This isn’t supported by any of this morning’s models.

Here’s why I think the next chance for significant rain is the following week. This is the ECMWF forecast for Wednesday March 11. All those yellows and reds in the South mean thunderstorms and that system is moving east, towards us. Let’s not take this to the bank just yet, but it looks reasonable.

After the front, s the high pressure over Alberta (that’s north of Montana) will be plunging southeast ushering back winter to the Great Plains, Midwest, and Northeast. The long-range ECMWF temperatures shows lows here dipping into the mid 40s which seems reasonable. Beyond this graphic, modeling is hinting at another cold air outbreak around March 21-23.

So, there’s no foolproof, simple answer to whether it’s OK to plant yet. If you live along the I-10/12 and your low temps are consistently higher than Slidell’s airport, yes I think we’re done with frosts and you can plant. If you live in rural areas where you sometimes get a bit colder than Slidell, I’d plant your cold weather vegetables now, wait a week or so to plant tomatoes (soil temperatures might be cold) and be prepared to cover them just in case you get a late March frost.