Storms until Tuesday, then turning dry

Radar shows a lot of storms in our area with those in Northern Tangipahoa and NW Washington Parish coming down from the northwest in response to a weak front in central Mississippi. Those draped across Northern St. Tammany are holding there own pushed northward by moist low level winds and an afternoon sea breeze. Yet despite all this, it still hasn’t rained a drop in Slidell today which is why you’ll rarely hear that the rain chances are 80% or more during the summer.

Tomorrow will feature similar dynamics but the atmosphere will be even more moist and the E-W bands should reform 20-30 miles further south of the present location in the morning. So, expect another day with 70% shower/storm coverage which should peak early in the day, say anytime from 9:30 - 2 PM. Since they will be slow moving, a few places could get several inches while others won’t see a drop. The reasons for the wetter and cloudier than normal weather: A surface and upper air low that will be near Tuscaloosa, AL late Monday but with a broad trough stretching in several directions. That enhances low level convergence of the air and a temperature structure that keeps air rising. Note the huge ridge or heat dome to the north and west over the Rockies and Upper Midwest (dark reds and violet)

But, but late week everything changes. The next graphic, a European forecast for Friday shows that the ridge has moved south and east with high pressure directly over us. This will greatly reduce the showers by Wednesday and cut them off by Thursday.

The Foreca graphic captures the timing well. Tomorrow should feature the best chance of storms and the most rainfall, especially on the Northshore and Mississippi. There’s a chance that the NWS will issue a flash flood warning for a few locations there - but I really doubt this will be the epic 10” variety. Southshore chances should be more like 50-50. With extensive cloud cover, highs will be held down into the mid 80s, some models suggest as cool as 82! but that seems extreme. Tuesday will feature more sun, but highs might still struggle to hit 90. Shower and storm chances a bit above normal, maybe 50-60% on the Northshore (< 50% south). Amounts will be lighter and the action could start in the morning hours.

Wednesday will be a transition day with sun and more of the typical summer afternoon showers and storms, 30% chance. Then, sunny, hot, humid, with no rainfall on Thursday and Friday as temperatures soar into the mid 90s. Next Saturday could be the hottest day of the year. A chance of showers (20%) returns Saturday evening (not well shown by Foreca) and next Sunday and Monday.

Tropics still quiet — nothing new here. Locally, above normal shower chances from July 20-23, then dry. Highs after next Saturday’s scorcher, about average for the rest of the month. Ho hum…ho hum….

The Foreca graphic for Pensacola Beach shows a similar pattern with a wet start, then a few days of dry weather. However, rain chances and amounts there will be higher. Plus they have small craft advisories and high SW winds should kick up the surf through Wednesday. Not ideal beach weather until Thursday.