Harvey, LA 70059 Weather

Key Messages

Updated at 533 AM CDT Wed Oct 21 2026

- Conditions will remain somewhat favorable for the development of fires through the remainder of this week and into the weekend due to low humidity and drought/abnormally dry conditions across most of the area.

Short Term

(Now through Saturday) Issued at 212 AM CDT Wed Oct 21 2026

Very quiet forecast in hand with the main focus on temperatures and some fire weather concerns. The mid lvl ridging that was dominating the western Gulf and into the Lower MS Valley has shifted to the west and is expected to build over northern Mexico and western TX. The ridge will continue to build through the 2nd half of the work week and shift east a touch with the ridge axis extending NNE from the Big Bend region of TX through MN and just into Hudson Bay. This ridge will continue to dominate the region as it slides east becoming centered over the Lower MS Valley by Saturday. This will place the region under northwest flow today to the ridge centered almost directly over the region by Saturday leading to NNE winds aloft. What does this mean, look for warming temps and no rain. At the sfc broad high pressure will continue to dominate the region through Friday before becoming centered over the mid Atlantic/ northeast states tightening the pressure gradient this weekend. This will lead to light easterly to east- northeasterly winds through Friday and then slightly stronger winds this weekend. This will keep us from seeing any recovery in the LL through the short term portion of the forecast. With this there is some fire weather concerns and that will be covered in the fire weather portion of the discussion.

Overall the NBM looks like it finally adjusted a little lower with afternoon highs given with it had the previous night so with that very little if any adjustments made to the latest NBM forecast. Today's is much better than what it had the previous day and it much more in line with the thinking and the LL temps expected over the area. Highs yesterday struggle to get out of the 70s and with no significant increase in the LL temps for today the highs should be only a degree or two warmer and that is what the NBM has instead of the mid 80s it did have 24 hours earlier. The NBM may still be a touch warm tomorrow but it is atleast closer to current thinking so no to only very minor adjustments made from the NBM. Overnight lows will continue to range from the upper 40s to near 60 thanks to the very dry conditions and know recovery in dewpoints. /CAB/

Long Term

(Saturday night through Tuesday) Issued at 212 AM CDT Wed Oct 21 2026

On Sunday evening, an upper level trough will extend from the Atlantic Coast to Florida to the western Caribbean, with another over the Intermountain West. A skinny ridge will extend from the western Gulf and lower Mississippi River Valley to Lake Michigan. At the surface, high pressure centered near New York City will extend southwest into Texas.

The upper ridge will gradually break down by Tuesday, with troughing extending from the Great Lakes to Colorado. Forecast soundings indicate that we won't have any deep onshore flow through early next week. For most of that period, precipitable water values will remain below the climatologic mean for late October (1.1 inches) across large portions of the area. Current expectation is that any significant precipitation remains offshore through most of next week. Pressure gradient between surface high to our northeast and low pressure over the western Caribbean will mean a bit stronger winds over land areas south of Lake Pontchartrain, but especially so over the open coastal waters.

Temperature-wise, above normal highs are expected to continue, although there will be somewhat of a trend to drift back closer to normal for a day or two around Sunday. With dry air in place, overnight lows will probably be near or slightly before normal. Not a great deal of day to day variance in highs or lows. /RW/

Aviation

(12Z TAFS) Issued at 533 AM CDT Wed Oct 21 2026

All terminals are currently in VFR status however, some very shallow BR/FG may try to impact one or two sites as we cool down to the dewpoint. NBG which is not one of our TAF terminals, is on the westbank which like ASD and PQL has some cold air drainage potential and can cool quite efficiently (it is already 8 degrees cooler than MSY and 15 below NEW) is showing 4SM BR and can't completely rule out ASD or PQL possibly seeing shallow/ground fog leading to 4-5SM BR but both may need the temperature to drop a few more degrees to get that to occur otherwise VFR status will persist through the forecast. /CAB/