Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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294 FXHW01 KWNH 050652 PMDHI Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 152 AM EST Fri Dec 5 2025 Valid 00Z Sat 06 Dec 2025 - 00Z Sat 13 Dec 2025 A cold front in association with a deep trough and cutoff low west of the state should weaken and retrograde as an easterly wave this weekend. Heavy rainfall along the front is likely to remain west of the main islands though wind speeds across the entire island chain, especially the western islands, look moderate to gusty today/Friday. Winds should moderate back to normal easterly trades by the weekend with the usual windward shower paradigm expected. A compact cut off low will meander east and northeast of the state as late as Wednesday but is forecast to have minimal, if any, impact on precipitation amounts across Hawai`i. Another cold front will get close the western main islands mid to late next week at the leading edge of a positively tilted trough; there remains some timing uncertainty with the 00z GFS a slow outlier while the 00z ECMWF is the quickest. While the consensus is quicker, the upstream ridge is full latitude (particularly within ensemble mean solutions) and could allow for a slower solution like the GFS to materialize; an intermediate solution is advised. Roth $$