124  
FXUS63 KDDC 180500  
AFDDDC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DODGE CITY KS  
1100 PM CST SAT FEB 17 2018  
   
..UPDATED AVIATION
 
 
   
SYNOPSIS
 
 
ISSUED AT 429 PM CST SAT FEB 17 2018  
 
WINDS WILL CONTINUE TO SUBSIDE THROUGH THE EVENING. AFTER MIDNIGHT  
THE WINDS WILL SWITCH TO THE SOUTH AND STRENGTHEN TO 20-30 MPH  
WITH HIGHER GUSTS AS THE PRESSURE GRADIENT TIGHTENS. SIGNIFICANT  
FIRE DANGER WILL EXIST SUNDAY WITH THESE WINDS COMBINING WITH THE  
ONGOING DROUGHT.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH SUNDAY)  
ISSUED AT 205 PM CST SAT FEB 17 2018  
 
A VIGOROUS UPPER LEVEL TROUGH THAT WAS MOVING INTO WESTERN  
WASHINGTON STATE EARLY THIS AFTERNOON WILL MOVE RAPIDLY ACROSS THE  
NORTHERN ROCKIES TO EASTERN MONTANA BY SUNDAY MORNING. PRESSURES  
ALREADY WERE BEGINNING TO FALL IN THE LEE OF THE ROCKIES BY 19Z,  
AND LITTLE PRESSURE GRADIENT WAS EVIDENT IN WESTERN KANSAS. GUSTY  
NORTH WINDS WILL DIMINISH QUICKLY WITH LOSS OF MOMENTUM TRANSFER  
LATER THIS AFTERNOON AND SHOULD BECOME LIGHT AND VARIABLE BY EARLY  
EVENING BEFORE RETURNING TO THE SOUTH AND INCREASING DURING THE  
NIGHTTIME HOURS. THE STRONG JET ALONG THE BRITISH COLUMBIA WILL  
CONTINUE TO DIG INTO THE WESTERN UNITED STATES TONIGHT AND SUNDAY,  
AND STRONG FLOW PERPENDICULAR TO THE ROCKIES WILL RESULT IN  
DEEPENING OF THE LEE TROUGH. AS THE INITIAL TROUGH MOVES ACROSS  
THE DAKOTAS SUNDAY, LOW LEVEL FLOW WILL VEER, AND A PLUME OF VERY  
WARM AIR WILL SPREAD INTO THE CENTRAL PLAINS. LOW LEVEL MOISTURE  
IN SOUTHWEST TEXAS WILL BEGIN TO FLOW NORTH SUNDAY MORNING, AND  
DEWPOINTS WILL RISE INTO THE 30S IN SOUTH CENTRAL AND CENTRAL  
KANSAS BY AFTERNOON. HOWEVER, MOST OF WESTERN KANSAS WILL REMAIN  
IN THE DRY, DOWNSLOPE REGIME WITH CRITICAL OR NEAR-CRITICAL FIRE  
CONDITIONS.  
 
TEMPERATURES TONIGHT WILL BE MILD FOR THIS TIME OF THE YEAR SINCE  
LOW LEVEL WINDS WILL PROVIDE GOOD MIXING BY LATE EVENING.  
TEMPERATURES SUNDAY WILL BE ANOMALOUSLY WARM WITH HIGHS MOSTLY IN  
THE LOWER 70S. THERE WILL BE SOME INCREASE IN CIRRIFORM CLOUDINESS  
AS THE PLUME OF HIGH LEVEL MOISTURE EVIDENT ON SATELLITE IMAGERY  
FROM THE TROPICS TO THE SOUTHWESTERN UNITED STATES SPREADS  
NORTHEAST IN RESPONSE TO THE DIGGING TROUGH.  
   
LONG TERM
 
(SUNDAY NIGHT THROUGH SATURDAY)  
ISSUED AT 205 PM CST SAT FEB 17 2018  
 
AN ACTIVE FLOW REGIME CAN BE EXPECTED WITH A MEAN TROUGH IN  
WESTERN NORTH AMERICA AND A STRONG UPPER LEVEL RIDGE FROM THE GULF  
OF MEXICO ACROSS FLORIDA INTO THE WESTERN ATLANTIC. THE VERY DEEP  
CYCLONE CENTERED NORTHWEST OF HUDSON BAY SHOULD WEAKEN SLIGHTLY  
AND PROPAGATE TOWARD GREENLAND EARLY NEXT WEEK BEFORE REDEVELOPING  
BACK WESTWARD BY NEXT WEEKEND. THERE WILL BE A CONTINUED STREAM  
OF MINOR UPPER LEVEL TROUGHS DIGGING INTO THE WESTERN UNITED  
STATES AND SUBSEQUENTLY LIFTING OUT ACROSS THE CENTRAL PART OF THE  
COUNTRY, BUT THE TROUGHS WILL BE SO PROGRESSIVE AND FREQUENT THAT  
IT WILL BE DIFFICULT FOR DEEP MOISTURE TO RETURN TO WESTERN  
KANSAS. AS SUCH, THE POTENTIAL FOR BENEFICIAL RAINFALL IN WESTERN  
KANSAS IS LOW FOR MOST OF NEXT WEEK.  
 
A STRONG STRATOSPHERIC WARMING EVENT THAT DEVELOPED QUICKLY OVER  
THE NORTH ATLANTIC AND THE SCANDINAVIAN COUNTRIES THE FIRST WEEK  
OF FEBRUARY HAS CONTINUED TO EXPAND IN RECENT DAYS, AND  
ANOMALOUSLY WARM TEMPERATURES IN THE STRATOSPHERE COVERED MUCH OF  
THE POLAR REGION BY LATE THIS WEEK. THERE ALWAYS IS UNCERTAINTY  
ABOUT HOW THE TROPOSPHERE WILL RESPOND TO SUCH EVENTS, BUT IT IS  
LIKELY THE HIGH LATITUDE FLOW WILL BECOME WEAKER AND MORE BLOCKY  
THROUGH LATE FEBRUARY AND EARLY MARCH. THE GLOBAL MODELS ARE IN  
REASONABLY GOOD AGREEMENT WITH BUILDING STRONG UPPER LEVEL RIDGING  
IN WESTERN EUROPE WITH SUBSEQUENT RETROGRESSION OF THE HIGH  
LATITUDE RIDGE TOWARD GREENLAND AROUND 1 MARCH AND INTO EASTERN  
CANADA THE FIRST WEEK OF MARCH. THE DEEP HUDSON BAY VORTEX LIKELY  
WILL WEAKEN AND RETROGRADE INTO THE WESTERN PART OF THE CANADIAN  
ARCTIC WHILE THE MAIN LOBE OF THE POLAR FLOW SHIFTS TOWARD ASIA.  
IF THE HIGH LATITUDE RIDGE DOES RETROGRADE AS SUGGESTED, AN AREA  
OF LOW PRESSURE MAY DEVELOP UNDER THE RIDGE IN THE MIDWEST WITH A  
FLOW OF COLD AIR INTO THE CENTRAL PART OF THE COUNTRY BY MID  
MARCH.  
 
A MADDEN JULIAN OSCILLATION IN THE PACIFIC OCEAN WILL PROPAGATE  
THROUGH THE WESTERN HEMISPHERE AND REACH THE WESTERN INDIAN OCEAN  
BY THE LAST WEEK OF FEBRUARY. ALTHOUGH THE MADDEN JULIAN  
OSCILLATION IS LIKELY TO WEAKEN AS IT PROPAGATES TOWARD THE INDIAN  
OCEAN, IT LIKELY WILL MAINTAIN ENOUGH AMPLITUDE INTO EARLY MARCH  
TO HAVE SOME EFFECT ON MID LATITUDE FLOW. THIS EVOLUTION FAVORS  
TROUGHING IN THE WESTERN UNITED STATES AND AT LEAST SOME CHANCE  
FOR PRECIPITATION AT TIMES IN THE CENTRAL PART OF THE COUNTRY INTO  
EARLY MARCH. IF THE BLOCKY HIGH LATITUDE FLOW EVOLVES AS PLANNED  
IN EARLY MARCH, THE POTENTIAL FOR BENEFICIAL PRECIPITATION IN THE  
CENTRAL PLAINS MAY BE DELAYED TO AROUND THE EQUINOX. AS WITH ANY  
EXTENDED PERIOD FORECAST, CONFIDENCE IN DETAILS IS EXTREMELY LOW.  
 
THE STRONG JET NEAR THE BRITISH COLUMBIA COAST WILL DIG INTO THE  
SOUTHWESTERN UNITED STATES MONDAY, AND A COLD FRONT WILL SAG  
SLOWLY SOUTH ACROSS KANSAS. TEMPERATURES ARE A REAL CHALLENGE IN  
SOUTHERN KANSAS MONDAY SINCE THE FRONT MAY STALL NEAR THE OKLAHOMA  
BORDER AS CYCLOGENESIS OCCURS IN SOUTHEAST COLORADO. THERE WILL  
BE A SHARP GRADIENT ALONG THE BOUNDARY WITH TEMPERATURES IN THE  
LOWER 70S SOUTH OF THE FRONT AND ABOUT 35 DEGREES COLDER ON THE  
COLD SIDE OF THE BAROCLINIC ZONE. THE COLD FRONT WILL SURGE SOUTH  
MONDAY NIGHT AND TUESDAY AS AN UPPER LEVEL TROUGH LIFTS OUT ACROSS  
THE CENTRAL AND NORTHERN PLAINS. LOW LEVEL MOISTURE LARGELY WILL  
BE SHUNTED EAST OF SOUTHWEST KANSAS, BUT THERE COULD BE SOME  
CHANCE FOR LIGHT RAIN IN SOUTH CENTRAL KANSAS TUESDAY MORNING.  
 
COLD HIGH PRESSURE WILL INVADE WESTERN KANSAS AS THE COLD FRONT  
SURGES SOUTH TUESDAY, AND HIGHS LIKELY WILL BE MOSTLY IN THE 20S  
AND LOW 30S TUESDAY WITH SOME MODERATION WEDNESDAY AND THURSDAY.  
THE NUMERICAL MODELS DIFFER IN SYNOPTIC SCALE DETAILS LATE NEXT  
WEEK. THE ECMWF AND GEM MAINTAIN A DEEPER TROUGH IN THE  
SOUTHWESTERN UNITED STATES THAN THE GFS, AND THERE ARE DIFFERENCES  
IN TIMING AND AMPLITUDES OF MINOR TROUGHS RIPPLING THROUGH THE  
FLOW. IT DOES APPEAR THAT THERE MAY BE ANOTHER OPPORTUNITY FOR  
LIGHT PRECIPITATION IN WESTERN KANSAS FRIDAY, BUT DETAILS ARE  
HIGHLY UNCERTAIN. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE  
CLIMATOLOGICAL AVERAGES.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)  
ISSUED AT 1100 PM CST SAT FEB 17 2018  
 
VFR IS EXPECTED THROUGH TAF PD. A VERY STRONG LOW LEVEL JET IS EXPECTED  
TO DEVELOP SHORTLY THROUGH THE OVERNIGHT PERIOD. LLWS OF 50-60 KT WITH  
PSBL 70 KT IS EXPECTED ACROSS THE TERMINALS IN ASSOCIATION WITH THE  
LLJ. SURFACE WINDS WILL INCREASE LATER TODAY AND BE SOUTHWESTERLY 25-35  
KT. GUSTS OF 50 KT COULD BE POSSIBLE DURING THE EARLY AFTERNOON PERIOD.  
WINDS WILL DECREASE TONIGHT BY DUSK. ANOTHER LLWS PERIOD IS PSBL AT  
END OF TAF PD.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 205 PM CST SAT FEB 17 2018  
 
LOW LEVEL WINDS WILL BECOME SOUTH TONIGHT AS PRESSURES FALL IN THE  
LEE OF THE ROCKIES AND WILL INCREASE TO 25 TO 35 MPH WITH GUSTS TO  
NEAR 50 MPH BY LATE SUNDAY MORNING. CRITICAL FIRE WEATHER IS  
LIKELY WITH RELATIVE HUMIDITIES FALLING TO AROUND 15 PERCENT WEST  
OF A LINE FROM LIBERAL TO HAYS. LIMITED LOW LEVEL MOISTURE RETURN  
IN SOUTH CENTRAL KANSAS SUNDAY AFTERNOON LIKELY WILL KEEP RELATIVE  
HUMIDITY VALUES ABOVE THE RED FLAG CRITERION, BUT EXTREMELY DRY  
FUELS AND VERY STRONG WINDS WILL MAKE FIRES VERY DIFFICULT TO  
CONTROL. IN ADDITION, THE ABSENCE OF SNOW OR ICE THIS WINTER IN  
MUCH OF WESTERN KANSAS HAS ALLOWED GRASSES TO STAND TALL INSTEAD  
OF BEING MATTED TO THE GROUND. THIS FAVORS VERY HOT FIRES THAT  
SPREAD RAPIDLY. THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG  
WARNING IN THE AREA MOST LIKELY TO EXPERIENCE RELATIVE HUMIDITIES  
AT OR BELOW 15% WITH A WATCH FARTHER TO THE EAST. THE MOISTURE  
RETURN CAN BE EVALUATED LATER TO DETERMINE IF THE WARNING AREA  
NEEDS TO BE EXPANDED.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
DDC 36 76 44 65 / 0 0 0 0  
GCK 34 76 36 58 / 0 0 0 0  
EHA 37 75 42 70 / 0 0 0 0  
LBL 35 76 46 72 / 0 0 0 0  
HYS 34 74 32 42 / 0 0 10 0  
P28 34 71 54 73 / 0 0 10 10  
 

 
   
DDC WATCHES/WARNINGS/ADVISORIES
 
 
RED FLAG WARNING FROM 1 PM CST /NOON MST/ TO 7 PM CST /6 PM MST/  
SUNDAY FOR KSZ030-043>045-061>063-074>077-084>086.  
 
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING  
FOR KSZ031-046-064>066-078>080-087>089.  
 

 
 

 
 
SYNOPSIS...TATRO  
SHORT TERM...LJR  
LONG TERM...LJR  
AVIATION...SUGDEN  
FIRE WEATHER...RUTHI  
 
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