03:31 UTC SEPTEMBER 20 2026

DISCUSSION:   A LIGHT WIND FLOW PREVAILS OVER THE AREA AND THIS SPARKED DAYTIME HEATING EPISODES OVER PORTIONS OF THE LEEWARD TODAY WHERE COASTAL LOCALIZE SHOWERS POPPED UP DUE TO THE THERMAL FORCING. WHILE THERE WERE NO THUNDERSTORMS REPORTED OR OBSERVED ON SATELLITE LIGHTNING MAPPER, SOME OF THE LOCALIZE SHOWERS WERE MODERATE TO LOCALLY HEAVY. THE LIGHT WINDS ARE AS A RESULT OF A SLACK PRESSURE GRADIENT NOTED ON THE 18Z SURFACE CHART. THE INSTABILITY CONTINUED OVER THE AREA THIS EVENING AS LIGHT SPOTTY SHOWERS WERE STILL OBSERVED ON LATEST RADAR IMAGERY.

FOR THE NEXT 24 HOURS: LATEST MODEL DATA SHOWS THAT A LOW TO MID-LEVEL TROUGH WILL DEVELOP OVER THE AREA TOMORROW: HOWEVER, THERE ARE SOME CONFLICTING DETAILS THAT ARE EMERGING. BASED ON THE LATEST GFS SOUNDING, A REDUCTION IN MOISTURE  WILL TAKE PLACE  OVER THE ISLANDS TOMORROW. THIS COULD STIFLE SIGNIFICANT CLOUDS GROWTH AS MODEL SOUNDING DATA FROM THE GFS SUGGESTS THAT A TEMPERATURE OF 34 C IS NEED TO BREAK THE CAP IN RESPONSE; BUT SIMILAR DATA FROM THE ECMWF AND AEROME MODEL SUGGEST A LOWER TEMPERATURE IS NEEDED. BASED ON THE ECMWF AND THE HIGHER RESOLUTION MODEL, THE LIGHT WINDS AND DAYTIME INSTABILITY ALONG WITH THE TROUGH, THE BATTLE OF THE THERMAL FORCING COULD STILL FORCE LOCALIZE BUILDUPS FOR A BRIEF PERIOD IN THE EARLY AFTERNOON AFTER WHICH THE LOWER MOISTURE COULD CHOKE THE CONVECTION. GIVEN THE UNCERTAINTY AT THIS TIME, GREATER WEIGHT IS STILL PLACED ON THE EXPECTATION OF SOME LOCALIZE SHOWERS DUE TO DAYTIME HEATING AND AS A RESULT NO CHANGE WILL BE MADE TO THE FORECAST AT THIS TIME.

FORECASTER

LENARD JOSIAH