FXUS21 KWNC 261811

PMDTHR

US Hazards Outlook

NWS Climate Prediction Center College Park MD

300 PM EDT June 26 2025



SYNOPSIS: Tied to an active North American monsoon circulation heading into 

July, as well as a potential influx of tropical moisture from the eastern 

Pacific, there are elevated chances for above-normal and locally heavy 

precipitation over the southwestern contiguous U.S. (CONUS). Any heavy 

precipitation may trigger localized flooding and exacerbate saturated ground 

conditions across the lower Four Corners during week-2. Mid-level high pressure 

favored over the Gulf of America is expected to bring above-normal summertime 

temperatures with possible extreme heat conditions for portions of the 

south-central CONUS during the period. 



HAZARDS



Moderate risk of heavy precipitation for parts of the Desert Southwest, Fri, 

Jul 4. 



Slight risk of heavy precipitation for parts of the Desert Southwest, Rockies, 

and Great Basin, Fri-Thu, Jul 4-10.



Slight risk of extreme heat over parts of the Southern Plains and Lower 

Mississippi Valley, Sat-Tue, Jul 5-8. 



Slight risk of high winds along most of the immediate West Coast, Fri-Tue, Jul 

4-8.



Flooding possible over portions of Arizona and New Mexico.



DETAILED SUMMARY



FOR SUNDAY JUNE 29 - THURSDAY JULY 03: 

https://www.wpc.ncep.noaa.gov/threats/threats.php



FOR FRIDAY JULY 04 - THURSDAY JULY 10: By late next week, dynamical models 

continue to advertise a weakness in subtropical ridging over the southwestern 

CONUS and western Mexico. Based on the orientation of the mid-level ridge axis 

and the 700-hPa flow pattern, a healthy North American monsoon circulation 

remains favored heading into July, where there continues to be elevated chances 

for above-normal and potentially heavy precipitation affecting the southwestern 

CONUS. Moreover, added tropical moisture from the eastern Pacific is also 

expected to be a key player, as guidance continues to favor Gulf Surge activity 

in the Desert Southwest associated with the passage of a tropical low (Invest 

95E) near the Gulf of California. The National Hurricane Center continues to 

favor high chances (80%) of formation with this disturbance in the next seven 

days. The advection of additional tropospheric moisture is supported by the 

confluence of positive precipitable water anomalies over the Four Corners, as 

well as in the raw and calibrated precipitation tools, with some of the highest 

totals beginning to time off into week-1. This is reflected in the GEFS and 

ECMWF Probabilistic Extremes Tools (PETs) which indicate a slight reduction of 

the wet signals for days 8 through 10 (Jul 4-6) over the southwestern CONUS 

compared to yesterday. As a result, the high risk of heavy precipitation is 

discontinued in today's outlook, however a corresponding moderate risk area 

remains posted and valid for Jul 4, where there are 30-60% chances for amounts 

exceeding the 85th percentile in the PETs, with 20-30% chances for amounts 

exceeding a half an inch in the uncalibrated ECMWF early in week-2. A broader 

slight risk area for heavy precipitation also remains issued for the entirety 

of week-2 based on favored persistence of enhanced moisture in the region, 

which could trigger additional thunderstorm activity and locally heavy rainfall 

later in the period.   







Due to locally heavy precipitation received over portions of New Mexico, any 

additional precipitation during week-2 is likely to worsen saturated ground 

conditions and possibly trigger additional flooding in the region. A flooding 

possible hazard remains issued and includes many parts of Arizona where locally 

heavy precipitation may also trigger flash flooding and debris flows near 

recently burned areas. In addition to flash flooding, thunderstorm impacts may 

include lightning, gusty winds and blowing dust. However, in spite of these 

potentially adverse impacts, some areas experiencing moderate to exceptional 

drought conditions and wildfires will benefit from the enhanced rainfall. 







As much of the enhanced tropospheric moisture looks to overspread the Interior 

West and enter the Great Plains, there is also the potential for increased and 

possibly heavy precipitation for the central CONUS. The ECMWF favors surface 

low formation in the lee of the Rockies, with increased chances for 3-day 

amounts exceeding the 85th percentile and 1 inch from the Central Plains to the 

Great Lakes early in week-2. However, the GEFS and Canadian are absent of this 

synoptic forcing, with little to no support for heavy precipitation in their 

raw or calibrated tools. As a result of these differences, no corresponding 

precipitation hazard is issued but this potential will continue to be 

monitored. Across the southeastern CONUS, models depict the passage of a 

frontal boundary late in week-1 that looks to stall by early week-2 becoming a 

focal point for enhanced precipitation. Since yesterday, both raw and 

calibrated tools have become less supportive of a heavy precipitation risk 

along the coastal Southeast and Mid-Atlantic, with the highest amounts now 

depicted offshore, and the corresponding slight risk of heavy precipitation is 

removed in the updated outlook. 







Over the northwestern CONUS, much of the 500-hPa ridging predicted late in 

week-1 is favored to deamplify by the outset week-2, resulting in a moderation 

of summertime temperatures mainly over the Northern Intermountain and Northern 

Plains. While the GEFS PET maintains some residual signals for temperatures 

exceeding the 85th percentile for this part of the country, the slight risk of 

extreme heat is removed in the updated outlook.  Downstream, the GEFS and ECMWF 

remain at odds with one another in regards to the evolution of a longwave 

trough over eastern Canada, resulting in uncertainty in regards to the 

potential for a renewed heat risk mainly across parts of the central and 

eastern CONUS. However, both ensembles continue to signal a strengthening of 

the subtropical ridge east of the Rockies, where the GEFS and ECWMF PETs 

continue to highlight increased chances for maximum daytime temperature 

exceeding the 85th percentile over the Southern Plains and Lower Mississippi 

Valley. Therefore, a slight risk of extreme heat is posted (Jul 5-8) and is 

expanded to include portions of the central Gulf Coast due to increased warm 

signals in the ECMWF PET. It is worth noting that sea surface temperatures in 

the Gulf of America remain well above average and nearly record breaking for 

this time of year, which would reinforce the anomalously warm temperatures 

favored across the south-central and southeastern CONUS.       







Surface high pressure over the northeastern Pacific adjacent to mean surface 

low pressure over the Interior West may lead to tight pressure gradients along 

much of the West Coast. This may be enhanced by the aforementioned heat 

potential favored early in the period, which would likely lower surface 

pressure. As a result, a slight risk of high winds remains posted along most of 

the immediate West Coast Jul 4-8 where PETs also indicate increased chances for 

wind speeds exceeding the 85th percentile. 







Numerous wildfires have developed across Alaska and additional fire activity is 

expected to continue with above-normal temperatures predominately favored over 

the Mainland during week-2. The smoke generated by these fires is forecast to 

meander around the state during the period, following low-level wind currents. 

As a result, periods of very poor air quality and low visibility may occur.



FORECASTER: Nick Novella 



$$



