Marine Weather and Tide Forecast for Guadalupe, AZ

DISCUSSION

Weather Pattern Overview: The synoptic wave pattern over the next several days will stay quite zonal with any disturbances passing across southwest Canada, the Northern Rockies, into the Northern Plains. A Pacific ridge which has set up off the California coast will be the driver of our weather through the end of the week with the ridge center staying to our west and southwest, but still providing above seasonal normal heights and temperatures. H5 heights currently between 581-583dm will gradually rise into Thursday before peaking at around 586-588dm, or just shy of the 90th percentile of climatology for the period. Under the dry westerly quasi-zonal flow and rising heights, temperatures will gradually warm with readings nearing 100 degrees today, to between 100-105 degrees Wednesday, before peaking between 102-107 degrees on Thursday.
Moderate HeatRisk will develop over a good portion of the area Wednesday with the areal extent of Moderate HeatRisk peaking at around 75% coverage on Thursday. Thursday's highs will fall short of daily records by around 3-5 degrees, but they will be nearly 10 degrees above normal.

By Thursday night into Friday, a weak shortwave trough is shown moving across northern California before mostly washing out over the Great Basin later Friday into Saturday. Despite this feature basically washing out before it reaches out region, it is still expected to bring some weak troughing into our region by Saturday allowing for modest cooling. NBM forecast highs on Friday drop closer to 100 degrees before dipping just below 100 degrees on Saturday, or a few degrees above normals. In addition to the roughly 5-8 degrees of cooling into Saturday, we should also see a return of some thin higher clouds and breezier conditions starting Friday. Model uncertainty is still higher for Sunday into Memorial Day as a ridge is likely to build over the Great Basin into the Northern Rockies, but it could get undercut by a weak shortwave trough potentially shifting east northeastward into our region. This shortwave is not likely to do much of anything other then keeping our temperatures fairly stable through early next week.

Forecast Confidence & Deviations: Confidence in the forecast guidance through the latter half of the week remains very good given the small ensemble variation. As eluded to above, the increasing model uncertainty by Sunday is leading to lower forecast confidence, but overall this still shouldn't change the potential forecast temperatures by more than a few degrees either way. No deviations from the NBM were made for this current package.

AVIATION
Updated at 0524Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT: No aviation concerns throughout the TAF period. Easterly winds expected by early tomorrow morning as more diurnal trends are returning now that the trough has migrated to the east of the region. Wind speeds will be aob 10kts. Clear skies will continue to persist.

Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation concerns through the TAF period. At KIPL wind directions will favor SW to SSW for the overnight period, before an E'rly shift late tomorrow morning. At KBLH VRB winds will shift to the S tomorrow afternoon into the evening. At both terminals winds will be aob 07kts and Clear skies will continue to persist.

FIRE WEATHER
High pressure will gradually build over the region through mid week bringing warming conditions and continued low humidities.
High temperatures are expected to reach or even top 100 degrees over much of the lower deserts beginning Wednesday as MinRHs stay between 7-12%. Lighter winds will also prevail through mid week, but with some periodic afternoon breeziness in the teens. Above normal temperatures and seasonably dry conditions will continue through the rest of the week with winds increasing by Thursday into Friday as afternoon gusts between 20-25 mph are more likely.
This could bring another period of elevated fire weather conditions mostly likely occurring on Friday.

PSR WATCHES/WARNINGS/ADVISORIES
AZ...None.
CA...None.