Marine Weather and Tide Forecast for Gilbert, AZ

DISCUSSION

Key Messages:

1) Slight cooling with afternoon high temperatures falling below the century mark this weekend

2) Enhanced breeziness this afternoon and evening leading to locally elevated fire danger

3) Dry conditions continue through next week with a slight increase in temperatures to near or slightly above the century mark

Early morning water vapor satellite imagery and objective analysis show quasi-zonal flow still in place over the Desert Southwest.
Although H5 heights have already lowered, as expected, from yesterday and are around 584 dm. H5 heights will continue to fall as a shortwave trough pushes inland over the next couple of days. These height falls will result in cooler temperatures. Afternoon high temperatures this afternoon will be in the 100-104 degree range across the lower deserts and in the mid 90s in the higher terrain.
Although temperatures will be slightly cooler today, there will still be some localized areas of Moderate HeatRisk this afternoon.
The aforementioned shortwave trough will move through our region this weekend resulting in lower desert afternoon high temperatures falling below the century mark. Forecasted afternoon high temperatures this weekend are in the mid-to-upper 90s across the lower deserts and in the upper 80s to low 90s across the higher terrain areas. Although HeatRisk will fall into the Minor category with these cooler temperatures, make sure to continue to practice smart heat safety if outdoors this holiday weekend.

In addition to cooler temperatures the aforementioned shortwave trough will also bring breezy to locally windy conditions to the region during the afternoon and evening hours today through the weekend. Winds will be highest this afternoon and evening, particularly across southeastern California, where gusts of 25-35 mph are likely (>80%). Keeping with previous forecasts and given model agreement, have gone ahead and slightly increased the forecasted wind speeds above the mandated automatic NBM output across southeastern California. Elsewhere across the region expect wind gusts of 15-25 mph. Although winds won't be as strong across the higher terrain of eastern Arizona, given the very low RH and dry fuels there will be elevated fire weather danger.

By the the beginning of next week the upper level flow pattern will become fairly stagnant, with positive height anomalies over Canada and negative height anomalies over the Gulf of Alaska. Global ensembles continue to show this pattern holding throughout the week, keeping heights aloft largely unchanged. This in turn would keep the temperatures and weather conditions rather persistent through the week as well. Forecasted high temperatures are slightly above normal and in the upper 90s to low 100s across the lower deserts and in the mid-to-upper 90s in the higher terrain areas. This weather pattern will also lead to dry conditions continuing. Global ensembles have been consistent with this pattern and are in good agreement, this leads to excellent forecast confidence through most of next week. Forecast confidence starts to decrease by the end of next week as ensembles start to differ on when the blocking pattern will start to break up. Some ensembles show the pattern starting to break up by the end of next week, with ridging building back over the Desert Southwest, which would allow for temperatures to rise even further.

AVIATION
Updated at 1140Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT: No major aviation weather concerns are expected through the TAF period. Winds this morning will favor an easterly direction before gradually becoming more southerly at all terminals. There will likely be a 3-4 hr period of southerly cross-runway winds at KPHX before winds finally become established out of the southwest later this afternoon (around 20Z-21Z). Occasional gusts into the upper teens to around 20 kts can be expected through early this evening.
Skies will remain mostly clear across the region.

Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather concerns are anticipated at the SE California terminals besides some afternoon breeziness. Winds will favor a southerly component at both terminals this morning before becoming westerly at KIPL and southwesterly at KBLH this afternoon.
Afternoon gusts upwards of 20-25 kts will be common at both terminals beginning around 20Z-21Z. There is also around a 40-50% chance that gusts could reach 35 kts at KIPL this evening, mainly after 00Z. Skies will remain mostly clear with the exception of a few passing high clouds.

FIRE WEATHER
Temperatures will steadily cool through the weekend, with a slight increase of a few degrees through the middle of next week. Very dry conditions will also prevail with minRH levels around 5-12% following poor to fair overnight recovery of 20-45%. Typical afternoon upslope breeziness will be common through the period, however enhanced gustiness today and tomorrow will result in an elevated fire danger. Gusts 20-25 mph should be expected on most days, however localized gusts 30-35 mph will be more prevalent today, mainly in southeastern California.

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