815
FXUS63 KOAX 271047
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
547 AM CDT SUN JUL 27 2025
KEY MESSAGES
- A RENEWED STRETCH OF DANGEROUS HEAT IS FORECAST FOR THIS
AFTERNOON AND AGAIN ON MONDAY - POTENTIALLY STRETCHING INTO
TUESDAY. AFTERNOON HEAT INDEX VALUES MAY REACH 105 TO 115
DEGREES.
- DRIER CONDITIONS ARE FAVORED THROUGH AT LEAST MID-DAY MONDAY,
WITH HIGHER STORM POTENTIAL RETURNING LATE TUESDAY INTO
WEDNESDAY. SOME OF THESE STORMS COULD BE STRONG TO SEVERE WITH
DAMAGING WINDS AND LOCALIZED FLOODING THE MAIN THREATS.
- COOLER CONDITIONS RETURN FOR NEXT WEEK'S SECOND HALF WITH ON
AND OFF RAIN CHANCES.
DISCUSSION
ISSUED AT 500 AM CDT SUN JUL 27 2025
FOR A THIRD CONSECUTIVE MORNING, PATCHY FOG HAS DEVELOPED WITH
MOST OBS REPORTING CALM WINDS. AGAIN, FOG HAS BEEN NOTED FIRST
IN SOUTHWEST IOWA AND ALONG THE MISSOURI RIVER. TONIGHT'S WINDS
AT H9 ARE A LITTLE STRONGER SO FOG EXPANSION MAY BE MORE
DIFFICULT THAN PAST NIGHTS. GUIDANCE KEEPS THE FOG LIMITED
MOSTLY TO IOWA AND FAR EASTERN NEBRASKA.
IR SATELLITE SHOWS THE ANVIL OF SOME CONVECTION BUILDING INTO
NORTHEAST NEBRASKA AS THE STORMS IN THE CENTRAL PART OF THE
STATE WEAKEN. THEY'RE TRYING TO BUILD INTO A MORE STABLE
ENVIRONMENT. WE EXPECT THIS FORECAST AREA TO REMAIN DRY THROUGH
AT LEAST MONDAY NIGHT.
WV IMAGERY SHOWS NEARLY ZONAL FLOW ALONG THE CANADIAN BORDER
WITH A H5 RIDGE CENTERED OVER ATLANTA. THAT RIDGE WILL
EXPERIENCE RETROGRADE EXPANSION OVER THE NEXT 48 HOURS AS
HEIGHTS CLIMB OVER THE CENTRAL CONUS. MUCH OF THE COUNTRY IS
ANTICIPATING SOME OF THE YEAR'S HOTTEST TEMPS.
TODAY'S HIGHS WILL BE 4-10 DEGREES HIGHER THAN SATURDAY THANKS
TO STRONGER SOUTHERLY WINDS AND WIDESPREAD SUNSHINE. THERE MAY
BE A LITTLE EARLY MORNING HAZE HANGING OVER NORTHEAST NEBRASKA /
NORTHERN IOWA EARLY THIS MORNING. THIS IS WILDFIRE SMOKE FROM
NORTHERN ARIZONA. SKIES SHOULD TURN BLUER QUICKLY AND REMAIN
THAT WAY FOR THE REMAINDER OF THE DAY. HIGHS LEVEL OFF IN THE
MID-90S THIS AFTERNOON WITH DEWPOINTS REACHING STICKY MID-70S.
THE RESULTANT HEAT INDICES JUSTIFY AN EXTREME HEAT WARNING (NEAR
110F) FOR MOST OF THE CWA WITH SALINE, JEFFERSON, GAGE, PAWNEE,
AND SHELBY COUNTIES UNDER A HEAT ADVISORY (NEAR 105F). A HEAT
INDEX OF 110F IS RECORDED AT EPPLEY AT JUST OVER HALF OF
SUMMERS. MOST SUMMERS DO NOT HIT 111F THERE. CONSIDERATION WAS
ALSO GIVEN TO THE FACT THAT UNCOOLED HOMES WON'T SEE MUCH RELIEF
OVERNIGHT AS TEMPS SLIP ONLY INTO THE MID-70S FOR MANY. IT'LL
BE ALL THE WORSE FOR THOSE IN THE HEART OF AN URBAN HEAT ISLAND.
THE HEAT WILL RAMP UP JUST AS HIGH OR HIGHER AGAIN ON MONDAY.
FOR THIS REASON, THE HEADLINES WILL REMAIN IN PLACE OVERNIGHT.
BTW: WE ARE IN THE MIDDLE OF AVERAGE PEAK "CORN SWEAT" SEASON
WHEN EVAPOTRANSPIRATION OF CORN TYPICALLY PEAKS (JULY 20-AUGUST
10 LAST YEAR). WHEN CONDITIONS ARE CORRECT, THIS CAN PUSH
DEWPOINTS HIGHER AND PREVENT TEMPERATURES FROM HITTING EXPECTED
PEAKS.
MONDAY
WITH THE LAUNCHING PAD OF MID-70S, TEMPS SHOULD ZIP THROUGH THE
80S AND APPROACH THE CENTURY MARK BY MONDAY AFTERNOON. IT'S BEEN
A MONTH SINCE THAT'S HAPPENED. MOST CITIES WILL FALL SHY, BUT
HEAT INDICES WILL LOOK LIKE SUNDAYS PLUS A DEGREE OR TWO. 95
DEGREES AND A 55 DEGREE DEWPOINT IS ONE THING, BUT THIS
HEAT/HUMIDITY COMBO IS JUST PLAIN DANGEROUS. MAKE PLANS NOW TO
KEEP COOL.
SOME SEVERE WEATHER POTENTIAL EXISTS FOR MONDAY NIGHT, BUT
PLENTY OF QUESTIONS REMAIN. A RING-OF-FIRE TYPE OF STORM IS
EXPECTED TO INITIATE ON THE NORTHERN EDGE OF THE BUILDING RIDGE.
THE STORM COMPLEX IS MOST LIKELY TO DEVELOP IN CENTRAL SOUTH
DAKOTA JUST SOUTH OF THE COLD FRONT AND TREND TOWARD SOUTHERN MN
/ NORTHERN IA OVERNIGHT. SOME THUNDERSTORM ACTIVITY COULD (20%)
CLIP OUR NORTHERNMOST COUNTIES IN THIS SCENARIO, MOSTLY IN THE
EVENING HOURS AS UPSCALE GROWTH INTO AN MCS PRODUCES A WIND
THREAT. THE REST OF THE AREA WOULD REMAIN DRY.
TUESDAY
CONSIDERED ADDING HEAT HEADLINES FOR TUESDAY, BUT MUCH
UNCERTAINTY STILL EXISTS. WE'RE CURRENTLY CALLING FOR
TEMPERATURES IN THE UPPER 80S TO MID-90S AND ADVISORY CRITERIA
HEAT INDICES ALONG AND SOUTH OF I-80. MUCH DEPENDS ON THE FINAL
LOCATION AND TIMING OF THE FRONT THAT WILL BE SETTLING INTO THE
CWA. OUTFLOW BOUNDARIES FROM MONDAY NIGHT'S CONVECTION COULD
THROW A WRENCH INTO THE CONVECTIVE FORECAST, TOO. AS IT STANDS,
SHEAR AND INSTABILITY LOOK ROBUST. SPC HAS HIGHLIGHTED THE AREA
AND MACHINE LEARNING PROCESSES AGREE. AN MCS COULD DEVELOP ALONG
THE FRONT AND POPS PEAK AFTER MIDNIGHT (40-70%) THANKS TO THE
LLJ.
THE REST OF THE FORECAST
COOLER AIR BUILDS IN FROM THE NORTH AS AN H5 TROF DEVELOPS OVER
THE GREAT LAKES. AFTER DANGEROUS HEAT BRINGS AN END TO JULY,
DAYS FIVE, SIX, AND SEVEN OF THE FORECAST - THE FIRST THREE OF
AUGUST - WILL HAVE TO TOLERATE HIGHS FALLING WELL SHY OF
SEASONAL NORMS WITH TUESDAY'S COLD FRONT NOW WELL SOUTH OF THE
CORN BELT.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 545 AM CDT SUN JUL 27 2025
SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE TAF PERIOD AND VFR
CONDITIONS ARE FORECAST. SOUTHERLY WINDS WILL BECOME QUICKER
THIS AFTERNOON WITH SOME GUSTS OF UP TO 20 KNOTS. LATER TONIGHT,
LOW LEVEL WIND SHEAR IS EXPECTED TO DEVELOP AS SURFACE WINDS
CALM AND STRONGER WINDS CONTINUE JUST OFF THE SURFACE FROM THE
SOUTHWEST.
OAX WATCHES/WARNINGS/ADVISORIES
NE...EXTREME HEAT WARNING FROM NOON TODAY TO 8 PM CDT MONDAY FOR
NEZ011-012-015>018-030>034-042>045-050>053-065>068-090-
091-093.
HEAT ADVISORY FROM NOON TODAY TO NOON CDT MONDAY FOR NEZ078-
088-089-092.
EXTREME HEAT WARNING FROM NOON TO 8 PM CDT MONDAY FOR NEZ078-
088-089-092.
IA...EXTREME HEAT WARNING FROM NOON TODAY TO 8 PM CDT MONDAY FOR
IAZ043-055-069-079-080-090-091.
HEAT ADVISORY FROM NOON TODAY TO NOON CDT MONDAY FOR IAZ056.
EXTREME HEAT WARNING FROM NOON TO 8 PM CDT MONDAY FOR IAZ056.
DISCUSSION...NICOLAISEN
AVIATION...NICOLAISEN
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