Please move this thread to TR if this should be there, which I think is the case.

 The SW US is being forecasted to have a record shattering heatwave late this week into early next week with a progged record strong 500 mb high for March. This was released by the Phoenix NWS office:

REACHING 100 DEGREES IN MARCH IS HIGHLY  
UNCOMMON, WITH THE AVERAGE FIRST 100 DEGREE DAYS BEING IN LATE-  
APRIL TO START OF MAY. SO, OVER A MONTH EARLY AND THE PHOENIX  
CLIMATE SITE WILL SET A NEW RECORD EARLIEST 100 DEGREE, WITH THE  
CURRENT EARLIEST SITTING AT MARCH 26TH. IT GOES WITHOUT SAYING,  
THIS WILL BE AN IMPACTFUL HEATWAVE. EXTREME HEAT WARNINGS BEGIN ON  
WEDNESDAY ACROSS SOUTHEAST CALIFORNIA AND THE REST OF THE AREA  
STARTING THURSDAY.  



LONG TERM /THURSDAY THROUGH MONDAY/  

MODELS ALL AGREE THIS RIDGE WILL BECOME THE STRONGEST RIDGE THE  
SOUTHWESTERN U.S. HAS EVER EXPERIENCED DURING THE MONTH OF MARCH  
AND POTENTIALLY EVEN DURING THE ENTIRE WINTER/EARLY SPRING TIME  
FRAME. H5 HEIGHTS ARE NOW FORECAST TO PEAK AT AROUND 595-596DM ON  
THURSDAY BEFORE GRADUALLY LOWERING FRIDAY AND THROUGH THE WEEKEND  
AS THE RIDGE CENTER BARELY MOVES. NBM FORECAST TEMPERATURES ARE  
STILL SHOWING HIGHS PEAKING ON FRIDAY AND SATURDAY BETWEEN 103-109  
DEGREES ACROSS THE LOWER DESERTS, WHICH IS BETWEEN 7-10 DEGREES  
ABOVE DAILY RECORDS. WIDESPREAD HIGH-END MODERATE HEATRISK TO LOW-  
END MAJOR HEATRISK WILL IMPACT THE AREA FROM THURSDAY THROUGH AT  
LEAST SATURDAY BEFORE THE WEAKENING RIDGE FINALLY ALLOWS  
TEMPERATURES TO START TO DECREASE.

...EXTREME HEAT WARNING IN EFFECT FROM 11 AM THURSDAY TO 8 PM MST  
SUNDAY...  

TONIGHT  
CLEAR. LOWS 59 TO 67. WEST WIND 5 TO 10 MPH IN THE EVENING  
BECOMING NORTHEAST AROUND 5 MPH AFTER MIDNIGHT.    
WEDNESDAY  
SUNNY AND HOT. HIGHS 97 TO 101. EAST WIND AROUND 5 MPH  
IN THE MORNING BECOMING WEST IN THE AFTERNOON.    
WEDNESDAY NIGHT  
CLEAR. LOWS 62 TO 69. NORTHWEST WIND 5 TO 10 MPH  
IN THE EVENING BECOMING NORTHEAST AFTER MIDNIGHT.    
THURSDAY  
SUNNY AND HOT. HIGHS 100 TO 105. EAST WIND 5 TO 10 MPH IN  
THE MORNING BECOMING SOUTHWEST AROUND 5 MPH IN THE AFTERNOON.    
THURSDAY NIGHT  
CLEAR. LOWS 62 TO 70. NORTHWEST WIND AROUND 5 MPH  
IN THE EVENING BECOMING NORTHEAST 5 TO 10 MPH AFTER MIDNIGHT.    
FRIDAY  
SUNNY AND HOT. HIGHS 103 TO 108.    
FRIDAY NIGHT  
CLEAR. LOWS 64 TO 71.    
SATURDAY  
SUNNY AND HOT. HIGHS 103 TO 108.    
SATURDAY NIGHT  
CLEAR. LOWS 65 TO 71.    
SUNDAY  
PARTLY SUNNY AND HOT. HIGHS 98 TO 104.    
SUNDAY NIGHT  
PARTLY CLOUDY. LOWS 62 TO 68.    
MONDAY  
PARTLY SUNNY AND HOT. HIGHS 95 TO 101.    
MONDAY NIGHT  
CLEAR. LOWS 61 to 67.

TUESDAY  
SUNNY. HIGHS 94 TO 100.

So, the forecast is for record highs tomorrow through Monday! Also, the earliest 100+ on record (records back to 1896) is March 26th. So, the forecasted 100+ on 3/19 would beat that by a week. In addition, March 20-21 are forecasted to possibly exceed 105! The record for all of April is 105 with April 20th being the earliest 105. The earliest 106+ is May 2nd. Wow, folks!