Prognostic Meteorological Discussion
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FXHW01 KWNH 250720

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
319 AM EDT Sun Oct 25 2020

Valid 00Z Mon Oct 26 2020 - 00Z Mon Nov 02 2020

...Heavy rain possible mid week...

Guidance indicates an upper low developing Monday to the northwest
of the area, dropping southward or southwestward toward Hawai`i.
The 00Z ECMWF was still the farthest west of the deterministic
models followed by the UKMET while the Canadian and GFS tool the
upper low southward along 160W over Kauai late Wed. The ensemble
spread has decreased a bit, mainly be eliminating farther east
members, but a much farther ECMWF-like scenario remains in play.
Prefer to stay somewhat in the middle or larger consensus near the
00Z GFS/Canadian until a larger shift in the ensembles develops.
Regardless, this would bring in deep tropical moisture over the
island chain (precipitable water values over 2 inches) around
Tuesday for at least a few days but perhaps continuing into next
weekend. Several inches of rain are possible each day in this
scenario which may result in localized flooding.


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