Climatological data for Los Angeles on May 5th dictates a mean maximum temperature closer to 70°F for LAX and 73°F for Downtown KLAX. The target range of 64-65°F represents a significant -5 to -6°F negative temperature anomaly. Achieving such a suppressed diurnal cycle demands an exceptionally robust and deep marine inversion, likely exceeding 1800ft AGL, sustained by an aggressive >4mb San Nicolas Island to LAX pressure gradient. We assess the 850mb temperature advection is unlikely to remain cool enough through peak heating, and ensemble guidance from the 00Z NCEP and ECMWF runs shows a higher probability density for peak temperatures in the 67-71°F range. Slight breaks in stratus persistence, even marginal solar insolation past 1 PM PST, will elevate surface temperatures beyond the 65°F threshold. The narrow 64-65°F band is too precise and falls outside the modal outcome for early May synoptic patterns. 90% NO — invalid if 12Z GFS/ECMWF guidance converges on a >1500ft marine layer and >90% cloud cover persisting past 3 PM PST.
GFS and ECMWF models project May 5 LA temps above 70°F. This 64-65°F band is too low; high confidence in warmer conditions. 95% NO — invalid if unexpected marine layer persistence.
Climatological data for Los Angeles on May 5th dictates a mean maximum temperature closer to 70°F for LAX and 73°F for Downtown KLAX. The target range of 64-65°F represents a significant -5 to -6°F negative temperature anomaly. Achieving such a suppressed diurnal cycle demands an exceptionally robust and deep marine inversion, likely exceeding 1800ft AGL, sustained by an aggressive >4mb San Nicolas Island to LAX pressure gradient. We assess the 850mb temperature advection is unlikely to remain cool enough through peak heating, and ensemble guidance from the 00Z NCEP and ECMWF runs shows a higher probability density for peak temperatures in the 67-71°F range. Slight breaks in stratus persistence, even marginal solar insolation past 1 PM PST, will elevate surface temperatures beyond the 65°F threshold. The narrow 64-65°F band is too precise and falls outside the modal outcome for early May synoptic patterns. 90% NO — invalid if 12Z GFS/ECMWF guidance converges on a >1500ft marine layer and >90% cloud cover persisting past 3 PM PST.
GFS and ECMWF models project May 5 LA temps above 70°F. This 64-65°F band is too low; high confidence in warmer conditions. 95% NO — invalid if unexpected marine layer persistence.
