392  
FXUS63 KGID 192137  
AFDGID  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE HASTINGS NE  
437 PM CDT WED SEP 19 2018  
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY NIGHT)  
ISSUED AT 437 PM CDT WED SEP 19 2018  
 
THE MAIN WEATHER STORIES OF THESE NEXT 36 HOURS INCLUDE: 1)  
MARGINAL RISKS FOR SEVERE STORMS BOTH TONIGHT (MAINLY IN OUR FAR  
NORTHWEST ZONES) AND AGAIN THURSDAY AFTERNOON-EVENING (MAINLY  
WITHIN THE SOUTHEAST HALF OF THE COVERAGE AREA/CWA...2) OUR "LAST  
BLAST" OF LATE-SEASON HEAT, AS ESPECIALLY SOUTHEAST PORTIONS OF  
THE CWA MAKE YET ANOTHER RUN AT 90 DEGREES BEFORE THE BIG COOL-  
DOWN ARRIVES FOR FRIDAY (AS OUTLINED IN THE LONG TERM SECTION  
BELOW).  
 
TAKING A LOOK AT THE CURRENT/RECENT WEATHER SCENE AS OF 21Z/4PM:  
CERTAINLY NO BIG SURPRISES TODAY FOR MOST OF THE CWA. AS EXPECTED,  
THE VAST MAJORITY OF THE AREA HAS SEEN YET ANOTHER DAY OF  
UNSEASONABLY-HOT CONDITIONS FOR MID-SEPTEMBER, AS IF ANYTHING HIGH  
TEMPS EXCEEDED EXPECTATIONS BY A FEW DEGREES IN VARIOUS SPOTS,  
WITH MOST PLACES TOPPING OUT IN THE 91-94 RANGE. IN CASE YOU  
MISSED OUR SOCIAL MEDIA GRAPHICS YESTERDAY, FOR MUCH OF OUR CWA  
THIS HAS BEEN THE MOST SIGNIFICANT/PROLONGED STRETCH OF HEAT THIS  
LATE IN THE YEAR SINCE 1955...63 YEARS AGO! THE HEAT TODAY HAS  
BEEN ACCOMPANIED BY BREEZY SOUTH WINDS, SUSTAINED GENERALLY 15-20  
MPH/GUSTING TO AROUND 30 MPH. THE ONLY EXCEPTION TO THE 90S HAS  
BEEN ACROSS OUR FAR NORTH (MAINLY VALLEY/GREELEY/NANCE/POLK),  
WHERE THE NEARLY STATIONARY WEST-EAST FRONT LARGELY STALLED-OUT  
MUCH OF THE DAY, KEEPING WINDS CONSIDERABLY MORE EASTERLY AND THUS  
KEEPING TEMPS A BIT "COOLER", ALTHOUGH EVEN THESE AREAS ARE NOW  
SEEING A LATE-DAY SURGE INTO THE MID-UPPER 80S. OTHER THAN A  
SMATTERING OF FAIR WEATHER CUMULUS, SKIES HAVE AVERAGED NO WORSE  
THAN PARTLY CLOUDY, AND ANY WEAK CONVECTION HAS REMAINED WELL OFF  
TO THE NORTH/WEST OF OUR CWA. IN THE BIGGER PICTURE OF THE MID-  
UPPER LEVELS, WATER VAPOR IMAGERY REVEALS THAT THE CENTRAL PLAINS  
IS GRADUALLY BECOMING INCREASINGLY-INFLUENCED BY THE LEADING EDGES  
OF A LARGE- SCALE TROUGH CENTERED OVER THE WESTERN CONUS, WHILE  
AN EXPANSIVE UPPER RIDGE CONTINUES TO DOMINATE THE SOUTHEASTERN  
STATES.  
 
NOW LOOKING AHEAD FORECAST-WISE THROUGH THE NEXT 36 HOURS...  
 
THIS EVENING/TONIGHT:  
REALLY, NO BIG CHANGES FROM THE PREVIOUS FORECAST. CONFIDENCE  
REMAINS FAIRLY HIGH THAT AT LEAST THE SOUTHEAST HALF (IF NOT TWO-  
THIRDS) OF THE CWA WILL REMAIN DRY/STORM-FREE OVERNIGHT, AS THE  
PRIMARY BATCH OF MID-UPPER LEVEL ENERGY AND ALSO THE INCREASINGLY-  
SHARP SURFACE FRONTAL ZONE REMAINS MAINLY (ALBEIT BARELY) OFF TO  
THE NORTH-NORTHWEST OF OUR CWA THROUGH THE NIGHT. BY SUNRISE, A  
FAIRLY WEAK SURFACE LOW PRESSURE CENTER WILL BE NEAR THE DAWSON  
COUNTY AREA BY SUNRISE. THUS, MOST AREAS WILL CONTINUE TO SEE DRY  
CONDITIONS, BREEZY SOUTH WINDS AND UNSEASONABLY MILD OVERNIGHT  
TEMPS WITH LOWS ONLY DROPPING INTO THE UPPER 60S/LOW 70S. HOWEVER,  
IT MAY BE A BIT MORE ACTIVE STORY ESPECIALLY WITHIN OUR FAR  
NORTHERN/WEST-CENTRAL COUNTIES (ESPECIALLY NORTHWEST OF A LINE  
FROM BEAVER CITY-GREELEY), WHERE THERE ARE AT LEAST MODEST CHANCES  
FOR THUNDERSTORMS THIS EVENING ALONG THE EDGE OF THE STOUT MID-  
LEVEL CAPPING INVERSION. HAVE KEPT RAIN CHANCES/POPS BELOW  
"LIKELY" PERCENTAGES IN MOST OF THIS AREA, BUT AT LEAST A FEW  
STORMS ARE VERY POSSIBLE. CANNOT ARGUE WITH THE SPC MARGINAL RISK  
OF SEVER FOR THE NORTHWEST FRINGES OF OUR CWA, AS EVEN ELEVATED  
PARCELS SHOULD HAVE AT LEAST 1000-2000 J/KG INSTABILITY TO WORK  
WITH, IN THE PRESENCE OF DEEP-LAYER SHEAR AROUND 40KT. IN THEORY,  
THE MAIN SEVERE THREAT FOR OUR CWA SHOULD FOCUS BETWEEN SUNSET-  
MIDNIGHT, BUT EVEN LATE NIGHT STORMS COULD BE ON THE STRONG SIDE  
FOR SURE. ON ONE LAST OVERNIGHT NOTE, AM NOT EXPECTING FOG TO BE  
MUCH OF AN ISSUE IN OUR FAR NORTH AGAIN, BUT THIS WILL ALSO BEAR  
WATCHING, ESPECIALLY IF WINDS LIGHTEN AND THERE IS A LACK OF  
CONVECTION TO KEEP THE BOUNDARY-LAYER MIXED.  
 
THURSDAY DAYTIME:  
FIRST OFF, WANT TO EMPHASIZE THAT IT'S NOT REALLY GOING TO BE  
"THAT MUCH" COOLER THAN TODAY IN MOST OF THE CWA, AND IF ANYTHING  
HIGHS HAVE BEEN CREEPING UP THE PAST FEW DAYS AS THE COLD FRONT  
HAS CONTINUED TO SLOW. THAT BEING SAID, THERE WILL STILL BE A  
MODEST RANGE, AS WE ARE AIMING FOR ONLY MID 70S TO NEAR 80 FAR  
NORTH /WEST-CENTRAL (ORD AREA), LOW-MID 80S CENTRAL (TRI CITIES)  
AND FAIRLY HOT UPPER 80S/LOW 90S ESPECIALLY IN OUR SOUTHEAST ONE-  
FOURTH. IT WILL ALSO BE ANOTHER BREEZY ONE, BUT THIS TIME MORE OUT  
OF THE SOUTHWEST FOR MUCH OF THE DAY, AS THE MAIN SURFACE LOW  
PRESSURE MIGRATES INTO NORTHEAST NE. FINALLY, BY MID-LATE  
AFTERNOON, THE TRUE/LONG-AWAITED COLD FRONT WILL START PUSHING  
INTO THE CWA FROM NORTHWEST-SOUTHEAST, MARKED BY A SWITCH TO  
NORTHWEST BREEZES. PRECIP-WISE, IT'S A BIT TRICKY, AS HONESTLY  
MUCH OF THE MORNING/EARLY AFTERNOON IS PROBABLY GOING TO BE DRY  
FOR ALL BUT MAYBE THE FAR NORTHERN CWA (DESPITE THE FACT WE ARE  
CARRYING LOW POPS AREA-WIDE). THEN, AS THE AFTERNOON WEARS ON, A  
BROKEN TO PERHAPS SOLID LINE OF THUNDERSTORMS SHOULD ERUPT IN  
NORTHEAST-SOUTHWEST FASHION SOMEWHERE OVER THE CENTRAL TO  
SOUTHEASTERN CWA, MEANING THAT SEVERAL NORTHWESTERN COUNTIES COULD  
MISS OUT ON THIS ACTIVITY ALTOGETHER. AT ANY RATE, ANOTHER  
MARGINAL RISK OF SEVERE SEEMS VERY JUSTIFIED, AS THERE WILL BE A  
CORRIDOR OF PERHAPS 2000-3000 J/KG MIXED-LAYER CAPE ALONG THE  
FRONTAL ZONE. WHILE THE INITIAL STORMS COULD FEATURE LARGE HAIL,  
EXPECT MAINLY A WIND/BRIEF HEAVY RAIN THREAT AS THE MAIN  
CONVECTIVE LINE GRADUALLY MARCHES SOUTHEAST.  
 
THURSDAY EVENING-NIGHT:  
AT SUNSET, VIGOROUS STORMS WILL LIKELY BE ONGOING IN OUR SOUTHEAST  
ZONES WITH AN ATTENDANT SEVERE THREAT, BUT BY THE 10 PM-MIDNIGHT  
TIME FRAME THE MAJORITY OF THIS ACTIVITY SHOULD BE STEADILY  
DEPARTING TO OUR SOUTH/EAST, AND THE SEVERE THREAT SHOULD BE ON  
THE DECLINE. POST-MIDNIGHT, WE ONLY HAVE LOW STORM CHANCES  
LINGERING MAINLY IN OUR SOUTHEAST ONE-FOURTH, AND THE ENTIRE CWA  
WILL ALMOST SURELY BE RAIN-FREE BY SUNRISE FRIDAY. FOR MOST OF THE  
CWA, THE BIGGER STORY THURSDAY NIGHT WILL BE THE INVASION OF  
COOLER/DRIER AIR, WITH LOW TEMPS DROPPING WELL INTO THE 50S MOST  
AREAS, AND PERHAPS EVEN FLIRTING WITH UPPER 40S FAR NORTH.  
   
LONG TERM
 
(FRIDAY DAYTIME THROUGH WEDNESDAY)  
ISSUED AT 437 PM CDT WED SEP 19 2018  
 
GENERAL OVERVIEW OF THIS 6-DAY PERIOD:  
BY FAR THE BIGGEST STORY WILL BE THE LONG-ANTICIPATED CHANGE IN  
OUR WEATHER PATTERN TOWARD COOLER AND MORE FALL-LIKE WEATHER. TO  
BE SURE, WE ARE NOT TALKING ABOUT TRULY "COLD" WEATHER BY ANY  
MEANS FOR LATE SEPTEMBER (FOR EXAMPLE, NO APPARENT THREAT OF FROST  
OR SUB-FREEZING TEMPS), BUT COMPARED TO THE INCREDIBLE LATE-  
SEASON WARMTH WE HAVE SEEN FOR THE PAST WEEK, THIS WILL BE A  
NOTICEABLE CHANGE FOR SURE. PRECIPITATION-WISE, THERE IS HIGH  
CONFIDENCE IN THE GOING DRY FORECAST FOR FRIDAY NIGHT-SUNDAY NIGHT  
(ALL WEEKEND), BEFORE THE NEXT CHANCE OF SHOWERS/THUNDERSTORMS  
ARRIVES FOR MAINLY THE MONDAY-TUESDAY TIME FRAME, AND PERHAPS  
ANOTHER CHANCE ON WEDNESDAY AS WELL, ALTHOUGH THIS IS LESS-  
CERTAIN.  
 
TEMPERATURE OVERVIEW:  
AGAIN, THIS IS CLEARLY THE BIG STORY. ONLY MINOR TWEAKS/VERY FEW  
CHANGES WERE MADE VERSUS THE PREVIOUS FORECAST, AS EACH ONE OF  
THESE DAYS IS EXPECTED TO AVERAGE NEAR-TO-BELOW NORMAL FOR A  
CHANGE, INSTEAD OF WELL-ABOVE NORMAL AS WE'VE RECENTLY SEEN. MORE  
SPECIFICALLY, HIGHS FRIDAY WILL ONLY RANGE FROM MID-60S NORTHEAST  
TO LOW 70S SOUTHWEST, WITH LOWS FRIDAY NIGHT THEN DROPPING WELL  
DOWN INTO THE MID-UPPER 40S AREA-WIDE. AGAIN, NOTHING THAT UNUSUAL  
FOR LATE SEPTEMBER, BUT THOSE VENTURING OUT LATE FRIDAY  
NIGHT/EARLY SATURDAY WILL NOTICE A DEFINITE CHILL IN THE AIR. THE  
WEEKEND THEN LOOKS VERY SEASONABLE WITH HIGHS SATURDAY MAINLY LOW-  
MID 70S, AND THEN BUMPING UP A BIT TO MID-UPPER 70S SUNDAY AND  
INTO MONDAY. ANOTHER MODEST SHOT OF COOLER AIR IS THEN PROGGED TO  
ARRIVE FOR TUESDAY AND WEDNESAY WITH HIGHS MAINLY IN THE UPPER 60S  
TO AROUND 70, AND OVERNIGHT LOWS AGAIN FALLING INTO THE 40S.  
HOWEVER, ESPECIALLY FOR WEDNESDAY, THERE IS SOME TYPICAL  
UNCERTAINTY IN THE TEMP FORECAST AT THE DAY 7 RANGE, AS THE ECMWF  
CURRENTLY FAVORS 70S VERSUS 60S FOR HIGHS, SO STAY TUNED FOR SOME  
ADJUSTMENTS HERE.  
 
PRECIPITATION OVERVIEW:  
AS EARLIER MENTIONED, HIGH CONFIDENCE IN THE GOING DRY FORECAST  
FRIDAY THROUGH THE WEEKEND AS BROAD RIDGING ALOFT AND SURFACE HIGH  
PRESSURE ARE THE MAIN FEATURES. THEN, SHOWER/THUNDERSTORM CHANCES  
RETURN FOR MONDAY-TUESDAY AS THE NEXT BROAD UPPER TROUGH PASSES  
THROUGH THE REGION. WHILE INSTABILITY WILL BE LACKING MUCH OF THIS  
TIME (ESPECIALLY IN OUR NEB ZONES), THE ENTIRE CWA LOOKS TO HAVE A  
SHOT OF THUNDERSTORMS WITH THE INITIAL FORCING/COLD FRONTAL  
PASSAGE MONDAY INTO MONDAY NIGHT. PROBABLY CANNOT RULE OUT A FEW  
STRONG TO EVEN SEVERE STORMS, BUT THIS IS PLENTY FAR OUT TO HAVE  
MUCH CONFIDENCE IN THE DETAILS. AS WITH THE TEMP FORECAST,  
WEDNESDAY ALSO CARRIES SOME MODEST UNCERTAINTY PRECIPITATION-WISE,  
AS THE LATEST ECMWF FAVORS DRY CONDITIONS, WHILE THE GFS SOLUTION  
BRINGS THROUGH A SECONDARY DISTURBANCE WITH AT LEAST SOME LIGHT  
RAIN SHOWER POTENTIAL. FOR NOW, WE ONLY HAVE A LOW-CONFIDENCE,  
SLIGHT CHANCE OF SHOWERS ACROSS MUCH OF THE CWA.  
 
IN THE INTEREST OF TIME, WILL NOT GO INTO MORE SPECIFIC DAY-TO-DAY  
DETAILS BEYOND WHAT WAS ALREADY DISCUSSED. HOWEVER, ON ONE LAST  
NEARER-TERM NOTE, PLEASE NOTE THAT FRIDAY WILL BE RATHER BREEZY  
FROM THE NORTH AS SURFACE HIGH PRESSURE BUILDS IN, WITH SUSTAINED  
SPEEDS COMMONLY AROUND 15 MPH/GUSTS TO AROUND 25 MPH.  
 

 
   
AVIATION
 
(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY)  
ISSUED AT 1243 PM CDT WED SEP 19 2018  
 
GENERAL OVERVIEW:  
CONFIDENCE REMAINS RELATIVELY HIGH THAT VFR CEILING/VISIBILITY  
WILL PREVAIL, WITH THE ONLY CAVEATS BEING A ROGUE OVERNIGHT  
THUNDERSTORM (MAINLY AT KEAR) AND PERHAPS A NEAR-MVFR CEILING LATE  
IN THE PERIOD AS A COLD FRONT BEGINS PASSING THROUGH. OTHERWISE,  
STEADY SOUTHERLY BREEZES THE MAJORITY OF THE TIME, WITH SEVERAL  
HOURS OF AT LEAST MARGINAL LOW LEVEL WIND SHEAR (LLWS) OCCURRING  
OVERNIGHT INTO THURSDAY MORNING. READ ON FOR MORE ELEMENT-SPECIFIC  
DETAILS...  
 
CEILING/VISIBILITY:  
CONFIDENCE IS VERY HIGH IN VFR THROUGH THE MAJORITY OF THE PERIOD  
(ESPECIALLY THE FIRST 12 HOURS). DURING THE LATTER HALF, THERE  
APPEARS TO BE AN OUTSIDE CHANCE FOR A NEAR-MVFR CEILING FORMING  
ALONG/NEAR A PASSING COLD FRONT, BUT HAVE KEPT IT VFR FOR NOW.  
UNLESS WINDS GO LIGHTER THAN EXPECTED, AM NOT ANTICIPATING ANY  
LIGHT FOG DEVELOPMENT AND SUB-VFR VISIBILITY.  
 
SHOWER/THUNDERSTORM POTENTIAL:  
ODDS ARE PRETTY HIGH THAT BOTH TERMINALS (ESPECIALLY KGRI) REMAIN  
PRECIP-FREE, WITH SOMEWHAT BETTER CHANCES FOR CONVECTION HOLDING  
OFF UNTIL THE NEXT VALID PERIOD THURSDAY AFTERNOON. HOWEVER, THERE  
ARE AT LEAST SMALL HINTS THAT KEAR COULD CATCH THE EASTERN EDGE OF  
SOME THUNDERSTORM ACTIVITY OVERNIGHT, AND THUS HAVE INTRODUCED A  
GENERIC "VICINITY" (VCTS) MENTION FROM 06-10Z TO ACCOUNT FOR THIS  
POSSIBILITY.  
 
WINDS (INCLUDING LLWS):  
AT THE SURFACE, A SOUTHERLY COMPONENT WILL PREVAIL THROUGH MOST OF  
THE PERIOD, WITH GUST POTENTIAL THIS AFTERNOON INTO THE 20-25KT  
RANGE BEFORE EASING UP OVERNIGHT. LATE IN THE PERIOD AFTER SUNRISE  
THURSDAY, WINDS WILL START TO TURN MORE SOUTHWESTERLY, WITH  
RENEWED GUST POTENTIAL TO AROUND 25KT. AS FOR LLWS, HAVE FOCUSED  
THIS DURING THE 03-14Z TIME FRAME, AS WINDS WITHIN THE LOWEST FEW  
THOUSAND FEET ACCELERATE INTO GENERALLY THE 40-45KT RANGE FROM THE  
SOUTH-SOUTHWEST.  
 

 
   
GID WATCHES/WARNINGS/ADVISORIES
 
 
NE...NONE.  
KS...NONE.  

 
 

 
 
SHORT TERM...PFANNKUCH  
LONG TERM...PFANNKUCH  
AVIATION...PFANNKUCH  
 
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