Marine Weather and Tides
8/26/2020 The 7 day forecast is taking about 5 seconds to load but it will eventually load. NOAA is still working on it.
8/18/2020 NOAA continues to have trouble. Wind guest will occasionally be left off graphs. I am working with NOAA to resolve the issue.
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
|Sunrise 7:27AM||Sunset 5:50PM||Friday January 22, 2021 8:51 AM MST (15:51 UTC)||Moonrise 1:03PM||Moonset 2:09AM||Illumination 68%|
7 Day Forecast for Marine Location Near Paradise Valley, AZHourly EDIT Help
Area Discussion for - Phoenix, AZ  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS65 KPSR 221251 AFDPSR
Area Forecast Discussion National Weather Service Phoenix AZ 551 AM MST Fri Jan 22 2021
UPDATE. Updated Fire Weather discussion.
SYNOPSIS. Despite lingering shower potential, today will likely be the most pleasant day for the next week before another weather system dives into the western United States over the weekend, resulting in additional chances for rain, high elevation snowfall, and much cooler temperatures. Yet another similar cold and wet system is likely to move through the area early next week with deserts highs dropping into the low to mid 50s by next Tuesday.
DISCUSSION. The latest satellite imagery shows midlevel clouds moving northward out of Maricopa County while new clouds develop farther south near the US/Mexico border. No showers have yet popped up on radar. There is a concern for fog development farther west along the Colorado River area and into southeast California where the dew point depression is only a few degrees. However, the GOES-16/17 night fog channels have yet to show much of anything so far this morning.
For today, quasi-zonal/very slight ridging aloft will persist in the wake of a departing trough. Given the depth of moisture, light precipitation is possible, particularly over the higher terrain of central Arizona and the mountains east of Phoenix, where orographic effects may enhance lift. The NBM places a 20-40% chance for measurable rain across the Valley and a 50% chance for over higher terrain areas through this evening. Rainfall amounts are most likely to be a few hundredths although there is a 20-30% chance some areas could see up to 0.10 inches.
The next several days are shaping up to be much wetter and colder compared to most days this winter. Satellite imagery shows a well defined Pacific low, currently located off the Oregon coast, that will pursue a southward trajectory towards Arizona this weekend. By early next week, global ensemble guidance brings another Pacific low into the region. These systems will bring a much colder air mass as well as additional moisture to an already relatively moist atmosphere. In short, we can expect much cooler temperatures and reasonably high chances for precipitation.
As of now, the entire CWA has at least some chance for precipitation with either (or both) of these systems. Chances are generally better over the higher terrain east of Phoenix with decreasing chances westward into southeast California. Global ensembles of the ECMWF and GEFS indicate two wet periods in concert with the arrival of the two aforementioned systems, with the first period beginning as early as Saturday, peaking Sunday, and the second period occurring Monday into Tuesday. All members of both sets of guidance show measurable rainfall for the lower desert of south-central Arizona and places eastward into Gila County for both periods. More than half of all members show additional precipitation occurring before, between, and after those two periods of peak activity. By Wednesday night, the GEFS mean total rainfall for the Phoenix area is about 0.90 inches while the ECMWF mean is slightly wetter at 1.25 inches. The NBM probabilities for measurable rainfall also reflects these same two wetter peak periods with varying 80-99% chance for at least 0.01" of rain falling around Phoenix and areas eastward. Chances for more rain within any 24-hr period do decrease, although remain relatively healthy, with a NBM probability of rainfall at 50% plus chances for 0.25" of rain by Sunday night and 60-80% chance for 0.25" Monday night/Tuesday across Maricopa, northern Pinal and Gila Counties. The NBM probabilities for 0.50" are much lower in the 20-30% range for those same locations. Altogether, this means is that confidence is high for measurable rainfall for much of south-central Arizona, including the lower desert areas in and around Phoenix. The ensemble means, individual members, and NBM probabilities favor rainfall totals for any 24-hr period to remain below 0.50", although the entire QPF from Saturday through Wednesday could approach 1.00 inch. This type of rain could prove to be more beneficial and below flash flood criteria for most areas. Chances and rainfall totals along the Colorado River and into southeastern California are are comparatively less, nearly half the amount as they are for the Phoenix area.
One uncertainty at this point is gauging the potential for convection. If the overwhelming majority of ensembles prove correct, the best instability will be over northwestern Arizona, where cooling upper levels and favorable jet dynamics are most likely to be supportive for convection. However, those dynamics could stretch southward along the Colorado River area and western Arizona, and into the central portion of the state, which could enhance showers and/or produce some thunderstorms. If convectively enhanced showers or thunderstorms do develop, the main threats are likely to be locally heavy rain, lightning, strong wind gusts and small hail.
By Monday-Tuesday, a much colder airmass will settle over the region. Snow levels will drop down to 4500-5000 feet with the first system on Sunday and then drop down towards 2500-3000 feet late Monday- Tuesday with the second system. This means snow is most likely over the highest peaks east of Phoenix this weekend and then could spread across most of Gila County and the northern and eastern portions of Maricopa County by Tuesday. The amount of snow will be dependent on the timing of decreasing snow levels and atmospheric moisture levels. For remote eastern Gila County where the elevation exceeds 5000 feet, snow is quite possible the entire time through Wednesday where the NBM 72-hr probability of snow shows nearly an 80% chance for at least 6" of total snowfall, and a 50% chance for up to 12 inches. For lower elevations like Globe, the NBM 72-hr probability of snow for early next week is also a good bet with nearly a 90% chance for measurable snow, a 70% chance for at least 1 inch, and a 30-40% chance for 4-6 inches. Higher snow totals for Globe cannot be ruled out with a 15-20% chance for up to 8 inches. The higher terrain of eastern Maricopa County, such as the Four Peaks and Superstition Mountains, are also likely to see their first significant snowfall of this winter with nearly a 70% chance for at least 2" of total snow but nearly a 50% chance for at least 6 inches.
Perhaps most remarkable depiction of the NBM probability of snow for any measurable snowfall, counted as 0.1" and up, is that probabilities by Wednesday exist through much of northern Maricopa County and as far south as the communities of Anthem, northern Scottsdale, northern Peoria and Surprise. The probabilities for 0.10" of snow is as high as 10-30% for these areas! The probabilities for more snow here drops to near zero but this does indicate how cold the upcoming airmass could be, as well as the potential for some isolated flakes falling even deeper into the Valley. Communities such as Cave Creek and Carefree have slightly better snow chances and could see 1-2" of of snow by Wednesday, although this is not all that uncommon during any particular winter given their higher altitudes. Farther west in Joshua Tree National Park, 1-2 of snow is also possible across the higher terrain in the western portion of the park.
However, there is plenty of uncertainty regarding the snowfall forecast as there seems to be some disconnect with the latest forecast snow totals, particularly for the Monday through Wednesday period, compared to the NBM snow probabilities. The latest forecast snow totals are impressive for portions of Gila County, the Four Peaks and Superstitions, but far exceed the mentioned NBM probabilities. This could be explained by the trend in ensemble guidance towards a wetter and colder period than previously thought, as supported by the higher ECMWF ensemble QPF amounts (as discussed above), while the NBM lags with a drier bias. The current forecast seems to be on the higher end within the "possible scenarios" and must be monitored as the current forecast would undoubtedly require winter weather products to be issued. As of now, this along with general forecast variability create too much uncertainty to issue any products at this time.
Moving beyond Wednesday, moisture levels should be adequate to support lingering precipitation chances through much of the workweek. Much colder temperatures will spread across the region as high temperatures drop into the low 60s Sunday, low to mid 50s Monday through Thursday before warming back into the 60s next weekend. Overnight lows will reach the 30s for most locations Tuesday through Friday. Wednesday is looks like the coldest day of the week with lower desert temperatures starting in the low 30s and only warming up into the low 50s by the afternoon.
AVIATION. Updated at 1145Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
As a very weak and flat short wave ridge moves into the area today, humidity stays very high in the low levels and will result in areas of low clouds this morning with BKN-OVC decks in the 5-8k foot range. Additionally there will be some lower cloud with FEW-SCT down to 1500-2000 feet. There may be a CIG at times down to that level mainly in the KSDL or KDVT area but KPHX could see a brief BKN deck below 5k at times. During the afternoon expect some clearing along with rising cloud bases. While we don't expect any precip this morning could not rule out an isolated sprinkle at times. As we move through the evening and into the overnight hours, clouds will likely thicken up with CIGS dropping again to the 5k range, along with SCT decks down to 3k or so. Additionally there will likely be isolated showers at times after 06z this evening. Winds today should tend to be rather light and favoring diurnal tendencies; light east wind becoming more southeast to south after 17z, then increasing a bit from the southwest after 21z with sustained up to around 10kt. Winds then return to southeast after 05z this evening.
Southeast California/Southwest Arizona including KIPL and KBLH:
A somewhat drier west flow aloft will move across the lower deserts today although humidity will remain high in the low levels so we can expect FEW-SCT decks from 3k to 8k feet at times. During the morning hours, through about 16z, there may be patchy fog across the low deserts including the TAF sites. Don't expect vis values to go overly low but maybe down to 5-6SM at times. Winds will be rather light through mid morning, then increase from the south to southwest; by 22z expect sustained southwest winds up to 20kt at KIPL and breezy south winds are likely at KBLH with gusts at times over 20kt. Winds to taper off as we move through the evening with sustained SW to W to around 10kt after 06z.
FIRE WEATHER. Sunday through Thursday: Multiple weather systems will bring chances for precipitation across all fire districts with the best chances east of the Colorado River. Some lower desert areas could see 0.25-1.00 inches of rain by Thursday with locally heavier amounts possible. Isolated thunderstorms cannot be ruled out. Snow is likely to fall for elevations above 5000 feet through the period but lowering snow levels could allow for accumulation as low as 2500-3000 feet. Rain chances and rainfall totals are less certain along the Co River and into southeastern California but some showers are possible. The peak windows for precipitation are Sat-Sun and then again Mon-Tue. Breezy conditions are also likely to affect the entire area at times. Temperatures will also be significantly cooler with highs often in the 50s while lows reach at least the 30s. The increased moisture levels and cooler temperatures should keep RH values above 40%.
SPOTTER INFORMATION STATEMENT. Spotters should follow standard reporting procedures.
PSR WATCHES/WARNINGS/ADVISORIES. AZ . None. CA . None.
DISCUSSION . AD AVIATION . CB FIRE WEATHER . AD
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|Scottsdale Airport, AZ||5 mi||59 min||SSE 5||10.00 mi||Overcast||56°F||48°F||75%||1015.8 hPa|
|Phoenix, Phoenix-Deer Valley Municipal Airport, AZ||6 mi||59 min||SE 6||10.00 mi||Overcast||55°F||49°F||80%||1015.6 hPa|
|Phoenix, Phoenix Sky Harbor International Airport, AZ||12 mi||61 min||ESE 8||10.00 mi||Mostly Cloudy||55°F||49°F||80%||1015.4 hPa|
|Glendale, Glendale Municipal Airport, AZ||17 mi||2 hrs||N 0||10.00 mi||A Few Clouds||54°F||50°F||88%||1016.9 hPa|
|Mesa / Falcon Field, AZ||18 mi||58 min||SE 5||10.00 mi||Overcast||56°F||48°F||75%||1015.4 hPa|
Link to 5 minute data for KSDL
Wind History from SDL (wind in knots)
|1 day ago||E|
|2 days ago||N||NE||NE||NE||N||NE||N||NE||NE||NE||NE|
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NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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