785  
FXUS63 KDMX 191730  
AFDDMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DES MOINES IA  
1130 AM CST SUN JAN 19 2025  
 
...UPDATED FOR THE 18Z AVIATION DISCUSSION...  
   
KEY MESSAGES
 
 
- DANGEROUSLY COLD CONDITIONS THROUGH TUESDAY MORNING WITH WIND CHILLS  
OF -20F TO -30F AT TIMES, ESPECIALLY OVER THE NORTHERN HALF  
OF THE STATE.  
 
- TEMPERATURES WARM BACK TO CLOSER TO SEASONAL NORMS WEDNESDAY  
INTO THURSDAY ALONG WITH CHANCES (AROUND 20%) FOR LIGHT  
SNOWFALL.  
 

 
   
DISCUSSION
 
 
ISSUED AT 242 AM CST SUN JAN 19 2025  
 
OUR ARCTIC COLD SNAP IS WELL UNDERWAY AS A 1040+MB SFC HIGH  
ANCHORED OVER THE NORTHERN HIGH PLAINS AND BENEATH AN EXPANSIVE  
DEEP TROUGH ALOFT CONTINUES TO PUSH BITTER COLD AIR INTO THE  
REGION. WIND CHILLS TONIGHT HAVE FALLEN TO -10F TO -30F OVER  
THE FORECAST AREA. ONLY MARGINAL RECOVERY THROUGH THE DAYLIGHT  
HOURS TODAY WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO AND  
STEADY NORTHWEST WINDS KEEPING WIND CHILLS COMFORTABLY BELOW  
ZERO. ISSUED THE NEXT IN OUR SERIES OF COLD WEATHER ADVISORIES  
FOR TONIGHT INTO MON AM FOR THE NORTHERN 2/3 OF THE FORECAST  
AREA WHERE WIND CHILLS OF -20F OR COLDER ARE HIGHLY LIKELY ONCE  
AGAIN. AIR TEMPS BOTTOM OUT MONDAY NIGHT AS THE SURFACE HIGH  
NUDGES EASTWARD AND WINDS RELAX A BIT, ALLOWING FOR MORE  
EFFICIENT RADIATIONAL COOLING WITHIN A BITTER COLD AIRMASS  
CHARACTERIZED BY HIGHLY ANOMALOUS 850MB TEMPS OF -26C TO -32C.  
STATISTICAL GUIDANCE FROM THE GFS AND NAM SUGGEST LOWS AS COLD  
AS -20F ARE POSSIBLE IN PORTIONS OF NORTHERN IOWA. NBM AND  
GEFS/ECENS ARE NOT QUITE AS AGGRESSIVE WITH <10% PROBS OF LOWS  
REACHING -20F, BUT HAVE STILL BEEN STEADILY TRENDING SLIGHTLY  
COLDER. ANOTHER ROUND OF COLD WEATHER HEADLINES WILL NEED TO BE  
CONSIDERED WITH FUTURE FORECAST UPDATES.  
 
MODELS HAVE BEEN TRENDING A BIT SLOWER TO ERODE THE COLD AIRMASS  
TUE WITH ANOTHER DAY STUCK IN THE SINGLE DIGITS AND TEENS. A  
RETURN TO SOUTHERLY SFC FLOW AND WAA TAKE OVER TUE NIGHT INTO  
WED AND QUICKLY BRINGS TEMPS BACK CLOSER TO SEASONAL NORMS.  
ATTENTION AT THIS POINT TURNS TO INCREASING POTENTIAL FOR LIGHT  
WINTRY PRECIPITATION WED INTO THU AS SUCCESSIVE WEAK SHORTWAVES  
TRAVERSE THROUGH THE PERSISTENT MEAN NORTHWEST FLOW ALOFT.  
CONFIDENCE IN THE PRECIP SCENARIO IS HINDERED BY SKEPTICISM ON  
THE QUALITY AND TIMING OF MOISTURE RETURN BACK INTO THE REGION  
IN THE WAKE OF THE EXCEPTIONALLY DRY ARCTIC AIRMASS. BOTH THE  
GEFS AND ECENS HAVE INCREASING PROBS (40-60%) FOR MEASURABLE  
PRECIP, BUT VERY LOW PROBS (<10%) FOR SNOW ACCUMS EXCEEDING 1".  
MAY BE LOOKING AT A HIGH POP/LOW QPF SCENARIO OF LIGHT SNOW  
AND/OR FLURRIES WHICH IS TYPICALLY POORLY CAPTURED BY THE GLOBAL  
MODELS AND NBM OUTPUT AT THIS TIME RANGE.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
 
 
ISSUED AT 1130 AM CST SUN JAN 19 2025  
 
STREAKS OF SHALLOW MVFR CLOUDS CONTINUE ACROSS THE AREA AND ARE  
EXPECTED TO DISSIPATE THROUGH THIS AFTERNOON. NORTHWEST WINDS  
REMAIN BREEZY WITH GUSTS OF 20-25+ KTS. THESE WILL ALSO DIMINISH  
OVERNIGHT WITH VFR CONDITIONS EXPECTED THROUGH THE REST OF THE  
TAF PERIOD.  
 

 
   
DMX WATCHES/WARNINGS/ADVISORIES
 
 
COLD WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ004>007-  
015>017-023>028-033>039-044>050-057>062-070>075-081>086-  
092>097.  
COLD WEATHER ADVISORY FROM 3 AM TO 11 AM CST MONDAY FOR  
IAZ004>007-015>017-023>028-033>039-044>050-057>059-070-071.  
 

 
 

 
 
DISCUSSION...MARTIN  
AVIATION...HAGENHOFF  
 
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